Nature , IF:49.962 , 2022 Aug doi: 10.1038/s41586-022-05142-w
Structures and mechanisms of the Arabidopsis auxin transporter PIN3.
Department of Biophysics, and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.; Department of Biophysics and Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China.; Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China.; Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, China.; College of agriculture and biotechnology, Zhejiang University, Hangzhou, China.; DP Technology, Beijing, China.; Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, Tianjin, China.; Department of Biophysics and Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. fanyanga@zju.edu.cn.; Alibaba-Zhejiang University Joint Research Center of Future Digital Healthcare, Hangzhou, Zhejiang, China. fanyanga@zju.edu.cn.; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China. fanyanga@zju.edu.cn.; State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China. wushan91@hubu.edu.cn.; Department of Biophysics, and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. jiangtaoguo@zju.edu.cn.; Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, China. jiangtaoguo@zju.edu.cn.; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China. jiangtaoguo@zju.edu.cn.; Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. jiangtaoguo@zju.edu.cn.; Cancer Center, Zhejiang University, Hangzhou, Zhejiang, China. jiangtaoguo@zju.edu.cn.; Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China. jiangtaoguo@zju.edu.cn.
The PIN-FORMED (PIN) protein family of auxin transporters mediates the polar auxin transport and plays crucial roles in plant growth and development(1,2). Here we present cryo-EM structures of PIN3 from Arabidopsis thaliana (AtPIN3) in the apo state and in complex with its substrate indole-3-acetic acid (IAA) and the inhibitor N-1-naphthylphthalamic acid (NPA) at 2.6-3.0 A resolution. AtPIN3 exists as a homodimer, with the transmembrane helices (TMs) 1, 2, and 7 in the scaffold domain involved in dimerization. The dimeric AtPIN3 forms a large, joint extracellular-facing cavity at the dimer interface while each subunit adopts an inward-facing conformation. The structural and functional analyses, along with computational studies, reveal the structural basis for the recognition of IAA and NPA and elucidate the molecular mechanism of NPA inhibition on the PIN-mediated auxin transport. The AtPIN3 structures support an elevator-like model for the transport of auxin, whereby the transport domains undergo up-down rigid-body motions and the dimerized scaffold domains remain static.
PMID: 35917926
Nature , IF:49.962 , 2022 Aug doi: 10.1038/s41586-022-05143-9
Structural insights into auxin recognition and efflux by Arabidopsis PIN1.
The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of CAS, Chinese Academy of Sciences (CAS), Shanghai, China.; MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.; Cryo-EM Center, Core Facility Center for Life Sciences, University of Science and Technology of China, Hefei, China.; Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg, Austria.; The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China. lx023@ustc.edu.cn.; Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, China. lx023@ustc.edu.cn.; The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China. sunlf17@ustc.edu.cn.; Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of China, Hefei, China. sunlf17@ustc.edu.cn.
Polar auxin transport (PAT) is unique to plants and coordinates their growth and development(1,2). The PIN-FORMED (PIN) auxin transporters with remarkable asymmetrical localizations at the plasma membrane drive PAT(3,4), however, their structures and transport mechanisms remain largely unknown. Here, we report three inward-facing conformation structures of the major member of the PIN family, PIN1 in Arabidopsis thaliana (AtPIN1): (i) in the apo state, (ii) in the natural auxin, indole-3-acetic acid (IAA)-bound state, and (iii) in complex with the PAT inhibitor N-1-naphthylphthalamic acid (NPA). The transmembrane domain of AtPIN1 shares a conserved NhaA-fold(5). In the substrate-bound structure, IAA is coordinated through both hydrophobic stacking and hydrogen bonding. The inhibitor NPA competes with IAA for the same site of the intracellular pocket with a much higher affinity. These findings facilitate our understanding of the substrate recognition and transport mechanisms of PINs, and set up a framework for future research on the directional auxin movement, one of the most crucial processes underlying plant development.
PMID: 35917925
Trends Plant Sci , IF:18.313 , 2022 Jul doi: 10.1016/j.tplants.2022.06.002
Towards a hierarchical gene regulatory network underlying somatic embryogenesis.
National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, PR China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), 200032 Shanghai, PR China; ShanghaiTech University, Shanghai 200031, PR China. Electronic address: jwwang@sippe.ac.cn.
Genome-editing technologies have advanced in recent years but designing future crops remains limited by current methods of improving somatic embryogenesis (SE) capacity. In this Opinion, we provide an update on the molecular event by which the phytohormone auxin promotes the acquisition of plant cell totipotency through evoking massive changes in transcriptome and chromatin accessibility. We propose that the chromatin states and individual totipotency-related transcription factors (TFs) from disparate gene families organize into a hierarchical gene regulatory network underlying SE. We conclude with a discussion of the practical paths to probe the cellular origin of the somatic embryo and the epigenetic landscape of the totipotent cell state in the era of single-cell genomics.
PMID: 35810071
Nat Plants , IF:15.793 , 2022 Aug doi: 10.1038/s41477-022-01213-y
PIF4 enhances DNA binding of CDF2 to co-regulate target gene expression and promote Arabidopsis hypocotyl cell elongation.
Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany.; Institute of Biochemistry, University of Cologne, Cologne, Germany.; Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany. coupland@mpipz.mpg.de.
How specificity is conferred within gene regulatory networks is an important problem in biology. The basic helix-loop-helix PHYTOCHROME-INTERACTING FACTORs (PIFs) and single zinc-finger CYCLING DOF FACTORs (CDFs) mediate growth responses of Arabidopsis to light and temperature. We show that these two classes of transcription factor (TF) act cooperatively. CDF2 and PIF4 are temporally and spatially co-expressed, they interact to form a protein complex and act in the same genetic pathway to promote hypocotyl cell elongation. Furthermore, PIF4 substantially strengthens genome-wide occupancy of CDF2 at a subset of its target genes. One of these, YUCCA8, encodes an auxin biosynthesis enzyme whose transcription is increased by PIF4 and CDF2 to contribute to hypocotyl elongation. The binding sites of PIF4 and CDF2 in YUCCA8 are closely spaced, and in vitro PIF4 enhances binding of CDF2. We propose that this occurs by direct protein interaction and because PIF4 binding alters DNA conformation. Thus, we define mechanisms by which PIF and CDF TFs cooperate to achieve regulatory specificity and promote cell elongation in response to light.
PMID: 35970973
Nat Commun , IF:14.919 , 2022 Aug , V13 (1) : P4942 doi: 10.1038/s41467-022-32585-6
PIF7 is a master regulator of thermomorphogenesis in shade.
Institute of Plant Sciences, ARO, Volcani Institute, HaMaccabbim Road 68, Rishon LeZion, 7505101, Israel. yogevb@volcani.agri.gov.il.; Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA. yogevb@volcani.agri.gov.il.; Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA. yogevb@volcani.agri.gov.il.; Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.; Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Slechtitelu 27, CZ-78371, Olomouc, Czech Republic.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umea, Sweden.; Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA. chory@salk.edu.; Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA. chory@salk.edu.
The size of plant organs is highly responsive to environmental conditions. The plant's embryonic stem, or hypocotyl, displays phenotypic plasticity, in response to light and temperature. The hypocotyl of shade avoiding species elongates to outcompete neighboring plants and secure access to sunlight. Similar elongation occurs in high temperature. However, it is poorly understood how environmental light and temperature cues interact to effect plant growth. We found that shade combined with warm temperature produces a synergistic hypocotyl growth response that dependent on PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) and auxin. This unique but agriculturally relevant scenario was almost totally independent on PIF4 activity. We show that warm temperature is sufficient to promote PIF7 DNA binding but not transcriptional activation and we demonstrate that additional, unknown factor/s must be working downstream of the phyB-PIF-auxin module. Our findings will improve the predictions of how plants will respond to increased ambient temperatures when grown at high density.
PMID: 36038577
Nat Commun , IF:14.919 , 2022 Aug , V13 (1) : P4653 doi: 10.1038/s41467-022-32314-z
Strigolactones are chemoattractants for host tropism in Orobanchaceae parasitic plants.
RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan.; Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.; Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.; PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan.; RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045, Japan. ken.shirasu@riken.jp.; Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan. ken.shirasu@riken.jp.
Parasitic plants are worldwide threats that damage major agricultural crops. To initiate infection, parasitic plants have developed the ability to locate hosts and grow towards them. This ability, called host tropism, is critical for parasite survival, but its underlying mechanism remains mostly unresolved. To characterise host tropism, we used the model facultative root parasite Phtheirospermum japonicum, a member of the Orobanchaceae. Here, we show that strigolactones (SLs) function as host-derived chemoattractants. Chemotropism to SLs is also found in Striga hermonthica, a parasitic member of the Orobanchaceae, but not in non-parasites. Intriguingly, chemotropism to SLs in P. japonicum is attenuated in ammonium ion-rich conditions, where SLs are perceived, but the resulting asymmetrical accumulation of the auxin transporter PIN2 is diminished. P. japonicum encodes putative receptors that sense exogenous SLs, whereas expression of a dominant-negative form reduces its chemotropic ability. We propose a function for SLs as navigators for parasite roots.
PMID: 35970835
Nat Commun , IF:14.919 , 2022 Jul , V13 (1) : P4015 doi: 10.1038/s41467-022-31628-2
Regulation of AUXIN RESPONSE FACTOR condensation and nucleo-cytoplasmic partitioning.
Department of Biology, Duke University, Durham, NC, 27008, USA.; Center for Engineering MechanoBiology, Washington University, St. Louis, MO, 63130, USA.; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO, 63130, USA.; Department of Biology, Washington University, St. Louis, MO, 63130, USA.; Department of Biology, Duke University, Durham, NC, 27008, USA. lucia.strader@duke.edu.; Center for Engineering MechanoBiology, Washington University, St. Louis, MO, 63130, USA. lucia.strader@duke.edu.; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO, 63130, USA. lucia.strader@duke.edu.
Auxin critically regulates plant growth and development. Auxin-driven transcriptional responses are mediated through the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARF protein condensation attenuates ARF activity, resulting in dramatic shifts in the auxin transcriptional landscape. Here, we perform a forward genetics screen for ARF hypercondensation, identifying an F-box protein, which we named AUXIN RESPONSE FACTOR F-BOX1 (AFF1). Functional characterization of SCF(AFF1) revealed that this E3 ubiquitin ligase directly interacts with ARF19 and ARF7 to regulate their accumulation, condensation, and nucleo-cytoplasmic partitioning. Mutants defective in AFF1 display attenuated auxin responsiveness, and developmental defects, suggesting that SCF(AFF1) -mediated regulation of ARF protein drives aspects of auxin response and plant development.
PMID: 35817767
Nat Commun , IF:14.919 , 2022 Jul , V13 (1) : P3985 doi: 10.1038/s41467-022-31656-y
Mechanism of fertilization-induced auxin synthesis in the endosperm for seed and fruit development.
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA.; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA. zliu@umd.edu.
The dominance of flowering plants on earth is owed largely to the evolution of maternal tissues such as fruit and seedcoat that protect and disseminate the seeds. The mechanism of how fertilization triggers the development of these specialized maternal tissues is not well understood. A key event is the induction of auxin synthesis in the endosperm, and the mobile auxin subsequently stimulates seedcoat and fruit development. However, the regulatory mechanism of auxin synthesis in the endosperm remains unknown. Here, we show that a type I MADS box gene AGL62 is required for the activation of auxin synthesis in the endosperm in both Fragaria vesca, a diploid strawberry, and in Arabidopsis. Several strawberry FveATHB genes were identified as downstream targets of FveAGL62 and act to repress auxin biosynthesis. In this work, we identify a key mechanism for auxin induction to mediate fertilization success, a finding broadly relevant to flowering plants.
PMID: 35810202
Trends Biochem Sci , IF:13.807 , 2022 Jul doi: 10.1016/j.tibs.2022.06.004
Intrinsic and extrinsic regulators of Aux/IAA protein degradation dynamics.
Department of Biology, Duke University, Durham, NC, USA.; Department of Biology, Duke University, Durham, NC, USA. Electronic address: lucia.strader@duke.edu.
The plant hormone auxin acts through regulated degradation of Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) proteins to regulate transcriptional events. In this review, we examine the composition and function of each Aux/IAA structural motif. We then focus on recent characterization of Aux/IAA N-terminal disordered regions, formation of secondary structure within these disordered regions, and post-translational modifications (PTMs) that affect Aux/IAA function and stability. We propose how structural variations between Aux/IAA family members may be tuned for differential transcriptional repression and degradation dynamics.
PMID: 35817652
Genome Biol , IF:13.583 , 2022 Aug , V23 (1) : P181 doi: 10.1186/s13059-022-02750-7
The Arabidopsis APOLO and human UPAT sequence-unrelated long noncoding RNAs can modulate DNA and histone methylation machineries in plants.
Instituto de Agrobiotecnologia del Litoral, CONICET, Universidad Nacional del Litoral, Colectora Ruta Nacional 168 km 0, 3000, Santa Fe, Argentina.; Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Universite Evry, Universite Paris-Saclay, Batiment 630, 91405, Orsay, France.; Institute of Plant Sciences Paris-Saclay IPS2, Universite de Paris, Batiment 630, 91405, Orsay, France.; Institut de Biologie de l'Ecole Normale Superieure (IBENS), Centre National de la Recherche Scientifique (CNRS), Institut National de la Sante et de la Recherche Medicale (INSERM), Ecole Normale Superieure, PSL Research University, 75005, Paris, France.; Instituto de Agrobiotecnologia del Litoral, CONICET, Universidad Nacional del Litoral, Colectora Ruta Nacional 168 km 0, 3000, Santa Fe, Argentina. fariel@santafe-conicet.gov.ar.
BACKGROUND: RNA-DNA hybrid (R-loop)-associated long noncoding RNAs (lncRNAs), including the Arabidopsis lncRNA AUXIN-REGULATED PROMOTER LOOP (APOLO), are emerging as important regulators of three-dimensional chromatin conformation and gene transcriptional activity. RESULTS: Here, we show that in addition to the PRC1-component LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), APOLO interacts with the methylcytosine-binding protein VARIANT IN METHYLATION 1 (VIM1), a conserved homolog of the mammalian DNA methylation regulator UBIQUITIN-LIKE CONTAINING PHD AND RING FINGER DOMAINS 1 (UHRF1). The APOLO-VIM1-LHP1 complex directly regulates the transcription of the auxin biosynthesis gene YUCCA2 by dynamically determining DNA methylation and H3K27me3 deposition over its promoter during the plant thermomorphogenic response. Strikingly, we demonstrate that the lncRNA UHRF1 Protein Associated Transcript (UPAT), a direct interactor of UHRF1 in humans, can be recognized by VIM1 and LHP1 in plant cells, despite the lack of sequence homology between UPAT and APOLO. In addition, we show that increased levels of APOLO or UPAT hamper VIM1 and LHP1 binding to YUCCA2 promoter and globally alter the Arabidopsis transcriptome in a similar manner. CONCLUSIONS: Collectively, our results uncover a new mechanism in which a plant lncRNA coordinates Polycomb action and DNA methylation through the interaction with VIM1, and indicates that evolutionary unrelated lncRNAs with potentially conserved structures may exert similar functions by interacting with homolog partners.
PMID: 36038910
Mol Plant , IF:13.164 , 2022 Aug doi: 10.1016/j.molp.2022.08.008
The regeneration factors ERF114 and ERF115 regulate auxin-mediated lateral root development in response to mechanical cues.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent, B-9052, Belgium.; Department of Plant Biology, Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Almas alle 5, 756 51, Uppsala, Sweden.; Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), University of Tubingen, 72076 Tubingen, Germany.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, B-9052, Belgium; VIB Center for Plant Systems Biology, Ghent, B-9052, Belgium. Electronic address: lieven.deveylder@psb.vib-ugent.be.
Plants show an unparalleled regenerative capacity, allowing them to survive severe stress conditions, such as injury, herbivory attack and harsh weather conditions. This potential not only replenishes tissues and restores damaged organs, but can also give rise to whole plant bodies. Despite the intertwined nature of development and regeneration, upstream cues and signaling mechanisms that commonly activate organogenesis are largely unknown. Here, we demonstrate that next to being activators of regeneration, ETHYLENE RESPONSE FACTOR 114 (ERF114) and ERF115 govern developmental growth in the absence of wounding or injury. Increased ERF114 and ERF115 activity enhances auxin sensitivity, which is correlated with enhanced xylem maturation and lateral root formation, whereas their knockout results in a decrease in lateral roots. Moreover, we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions. Antagonistically, cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions. Our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114 and ERF115 mediated auxin signaling.
PMID: 36030378
Dev Cell , IF:12.27 , 2022 Aug doi: 10.1016/j.devcel.2022.07.017
Mechanical conflict caused by a cell-wall-loosening enzyme activates de novo shoot regeneration.
Indian Institute of Science Education and Research (IISER)-Pune, Pune 411008, India; IISER-Thiruvananthapuram, Thiruvananthapuram, India.; Indian Institute of Science Education and Research (IISER)-Pune, Pune 411008, India; IISER-Thiruvananthapuram, Thiruvananthapuram, India. Electronic address: mabel.m.mathew@gmail.com.; IISER-Thiruvananthapuram, Thiruvananthapuram, India.; Indian Institute of Science Education and Research (IISER)-Pune, Pune 411008, India.; Laboratory of Biochemistry, Wageningen University, Wageningen, the Netherlands.; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland; Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.; School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.; Indian Institute of Science Education and Research (IISER)-Pune, Pune 411008, India; IISER-Thiruvananthapuram, Thiruvananthapuram, India. Electronic address: kalika.prasad@iiserpune.ac.in.
Cellular heterogeneity is a hallmark of multicellular organisms. During shoot regeneration from undifferentiated callus, only a select few cells, called progenitors, develop into shoot. How these cells are selected and what governs their subsequent progression to a patterned organ system is unknown. Using Arabidopsis thaliana, we show that it is not just the abundance of stem cell regulators but rather the localization pattern of polarity proteins that predicts the progenitor's fate. A shoot-promoting factor, CUC2, activated the expression of the cell-wall-loosening enzyme, XTH9, solely in a shell of cells surrounding the progenitor, causing different mechanical stresses in these cells. This mechanical conflict then activates cell polarity in progenitors to promote meristem formation. Interestingly, genetic or physical perturbations to cells surrounding the progenitor impaired the progenitor and vice versa. These suggest a feedback loop between progenitors and their neighbors for shoot regeneration in the absence of tissue-patterning cues.
PMID: 36002002
EMBO J , IF:11.598 , 2022 Aug : Pe110988 doi: 10.15252/embj.2022110988
ARF2-PIF5 interaction controls transcriptional reprogramming in the ABS3-mediated plant senescence pathway.
State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China.; Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA.; Department of Genetics, Harvard Medical School, Boston, MA, USA.; Institute of Future Agriculture, Northwest A&F University, Yangling, China.
One of the hallmarks of plant senescence is the global transcriptional reprogramming coordinated by a plethora of transcription factors (TFs). However, mechanisms underlying the interactions between different TFs in modulating senescence remain obscure. Previously, we discovered that plant ABS3 subfamily MATE transporter genes regulate senescence and senescence-associated transcriptional changes. In a genetic screen for mutants suppressing the accelerated senescence phenotype of the gain-of-function mutant abs3-1D, AUXIN RESPONSE FACTOR 2 (ARF2) and PHYTOCHROME-INTERACTING FACTOR 5 (PIF5) were identified as key TFs responsible for transcriptional regulation in the ABS3-mediated senescence pathway. ARF2 and PIF5 (as well as PIF4) interact directly and function interdependently to promote senescence, and they share common target genes such as key senescence promoting genes ORESARA 1 (ORE1) and STAY-GREEN 1 (SGR1) in the ABS3-mediated senescence pathway. In addition, we discovered reciprocal regulation between ABS3-subfamily MATEs and the ARF2 and PIF5/4 TFs. Taken together, our findings reveal a regulatory paradigm in which the ARF2-PIF5/4 functional module facilitates the transcriptional reprogramming in the ABS3-mediated senescence pathway.
PMID: 35942625
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac266
Localization of PHRAGMOPLAST ORIENTING KINESIN1 at the division site depends on the microtubule binding proteins TANGLED1 and AUXIN-INDUCED IN ROOT CULTURES9 in Arabidopsis.
Graduate Group in Biochemistry and Molecular Biology.; Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside.
Proper plant growth and development requires spatial coordination of cell divisions. Two unrelated microtubule-binding proteins, TANGLED1 (TAN1) and AUXIN-INDUCED IN ROOT CULTURES9 (AIR9), are together required for normal growth and division-plane orientation in Arabidopsis (Arabidopsis thaliana). The tan1 air9 double mutant has synthetic growth and division-plane orientation defects while single mutants lack obvious defects. Here we show that the division site-localized protein, PHRAGMOPLAST ORIENTING KINESIN1 (POK1), was aberrantly lost from the division site during metaphase and telophase in the tan1 air9 mutant. Since TAN1 and POK1 interact via the first 132 amino acids of TAN1 (TAN11-132), we assessed the localization and function of TAN11-132 in the tan1 air9 double mutant. TAN11-132 rescued tan1 air9 mutant phenotypes and localized to the division site during telophase. However, replacing six amino-acid residues within TAN11-132, which disrupted the POK1-TAN1 interaction in the yeast-two-hybrid system, caused loss of both rescue and division-site localization of TAN11-132 in the tan1 air9 mutant. Full-length TAN1 with the same alanine substitutions had defects in phragmoplast guidance and reduced TAN1 and POK1 localization at the division site but rescued most tan1 air9 mutant phenotypes. Together, these data suggest that TAN1 and AIR9 are required for POK1 localization, and yet unknown proteins may stabilize TAN1-POK1 interactions.
PMID: 36005863
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac262
Auxin and abscisic acid antagonistically regulate ascorbic acid production via the SlMAPK8-SlARF4-SlMYB11 module in tomato.
Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 400044, China.; College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
Ascorbic acid (AsA) is a multifunctional phytonutrient that is essential for the human diet as well as plant development. While much is known about AsA biosynthesis in plants, how this process is regulated in tomato (Solanum lycopersicum) fruits remains unclear. Here we found that auxin treatment inhibited AsA accumulation in the leaves and pericarps of tomato. The auxin response factor gene SlARF4 is induced by auxin to mediate auxin-induced inhibition of AsA accumulation. Specifically, SlARF4 transcriptionally inhibits the transcription factor gene SlMYB11, thereby modulating AsA accumulation by regulating the transcription of the AsA biosynthesis genes L-galactose-1-phosphate phosphatase (GPP), L-galactono-1,4-lactone dehydrogenase (GLDH), and dehydroascorbate (DHAR). By contrast, abscisic acid (ABA) treatment increased AsA accumulation in tomato under drought stress. ABA induced the expression of the mitogen-activated protein kinase gene SlMAPK8. We demonstrate that SlMAPK8 phosphorylates SlARF4 and inhibits its transcriptional activity, whereas SlMAPK8 phosphorylates SlMYB11 and activates its transcriptional activity. SlMAPK8 functions in ABA-induced AsA accumulation and drought stress tolerance. Moreover, ABA antagonizes the effects of auxin on AsA biosynthesis. Therefore, auxin- and ABA-induced regulation of AsA accumulation is mediated by the SlMAPK8-SlARF4-SlMYB11 module in tomato during fruit development and drought stress responses, shedding light on the roles of phytohormones in regulating AsA accumulation to mediate stress tolerance.
PMID: 36000899
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac258
A case of identity: Activation of auxin biosynthesis drives cell reprogramming.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
PMID: 35977390
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac254
A SlCLV3-SlWUS module regulates auxin and ethylene homeostasis in low light-induced tomato flower abscission.
College of Horticulture, Shenyang Agricultural University, Shenyang, Liaoning 110866, China.; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang, Liaoning Province, China.; Crops Pathology and Genetic Research Unit, United States Department of Agriculture Agricultural Research Service, California 95616, USA.; Department of Plant Sciences, University of California, California 95616, USA.
Premature abscission of flowers and fruits triggered by low light stress can severely reduce crop yields. However, the underlying molecular mechanism of this organ abscission is not fully understood. Here, we show that a gene (SlCLV3) encoding CLAVATA3 (CLV3), a peptide hormone that regulates stem cell fate in meristems, is highly expressed in the pedicel abscission zone (AZ) in response to low light in tomato (Solanum lycopersicum). SlCLV3 knockdown and knockout lines exhibit delayed low light-induced flower drop. The receptor kinases SlCLV1 and BARELY ANY MERISTEM1 (SlBAM1) function in the SlCLV3 peptide-induced low light response in the AZ to decrease expression of the transcription factor gene WUSCHEL (SlWUS). DNA affinity purification sequencing identified the transcription factor genes KNOX-LIKE HOMEDOMAIN PROTEIN1 (SlKD1) and FRUITFULL2 (SlFUL2) as SlWUS target genes. Our data reveal that low light reduces SlWUS expression, resulting in higher SlKD1 and SlFUL2 expression in the AZ, thereby perturbing the auxin response gradient and causing increased ethylene production, eventually leading to the initiation of abscission. These results demonstrate that the SlCLV3-SlWUS signaling pathway plays a central role in low light-induced abscission by affecting auxin and ethylene homeostasis.
PMID: 35972422
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac250
Rice EIL1 interacts with OsIAAs to regulate auxin biosynthesis mediated by the tryptophan aminotransferase MHZ10/OsTAR2 during root ethylene responses.
State Key Lab of Plant Genomics, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.; College of Agriculture, South China Agricultural University, Guangzhou 510642, China.; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.
Ethylene plays essential roles in adaptive growth of rice (Oryza sativa). Understanding of the crosstalk between ethylene and auxin is limited in rice. Here, from an analysis of the root-specific ethylene-insensitive rice mutant mao hu zi 10 (mhz10), we identified the tryptophan aminotransferase (TAR) MHZ10/OsTAR2, which catalyzes the key step in indole-3-pyruvic acid-dependent auxin biosynthesis. Genetically, OsTAR2 acts downstream of ethylene signaling in root ethylene responses. OsEIL1 directly activated OsTAR2 expression. Surprisingly, ethylene induction of OsTAR2 expression still required the auxin pathway. We also show that OsIAA1/9 and OsIAA21/31 physically interact with OsEIL1 and show promotive and repressive effects on OsEIL1-activated OsTAR2 promoter activity, respectively. These effects likely depend on their EAR motif-mediated histone acetylation/deacetylation modification. The special promoting activity of OsIAA1/9 on OsEIL1 may require both the EAR motifs and the flanking sequences for recruitment of histone acetyltransferase. The repressors OsIAA21/31 exhibit earlier degradation upon ethylene treatment than the activators OsIAA1/9 in a TIR1/AFB-dependent manner, allowing OsEIL1 activation by activators OsIAA1/9 for OsTAR2 expression and signal amplification. This study reveals a positive feedback regulation of ethylene signaling by auxin biosynthesis and highlights the crosstalk between ethylene and auxin pathways at a previously underappreciated level for root growth regulation in rice.
PMID: 35972379
Plant Cell , IF:11.277 , 2022 Aug doi: 10.1093/plcell/koac218
Transcriptional activation of auxin biosynthesis drives developmental reprogramming of differentiated cells.
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.; Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.; Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan.; Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan.; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8585, Japan.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium.; VIB Center for Plant Systems Biology, Ghent B-9052, Belgium.
Plant cells exhibit remarkable plasticity of their differentiation states, enabling regeneration of whole plants from differentiated somatic cells. How they revert cell fate and express pluripotency, however, remains unclear. In this study we demonstrate that transcriptional activation of auxin biosynthesis is crucial for reprogramming differentiated Arabidopsis (Arabidopsis thaliana) leaf cells. Our data show that interfering with the activity of histone acetyltransferases dramatically reduces callus formation from leaf mesophyll protoplasts. Histone acetylation permits transcriptional activation of PLETHORAs (PLTs), leading to the induction of their downstream YUCCA1 (YUC1) gene encoding an enzyme for auxin biosynthesis. Auxin biosynthesis is in turn required to accomplish initial cell division through the activation of G2/M phase genes mediated by MYB DOMAIN PROTEIN 3-RELATED (MYB3Rs). We further show that the AUXIN RESPONSE FACTOR 7 (ARF7)/ARF19 and INDOLE-3-ACETIC ACID INDUCIBLE 3 (IAA3)/IAA18-mediated auxin signaling pathway is responsible for cell cycle reactivation by transcriptionally upregulating MYB3R4. These findings provide a mechanistic model of how differentiated plant cells revert their fate and reinitiate the cell cycle to become pluripotent.
PMID: 35922895
Plant Cell , IF:11.277 , 2022 Aug , V34 (9) : P3151-3153 doi: 10.1093/plcell/koac175
From the archives: Polar auxin transport in nodule development, DNA replication timing, and developmentally light-regulated genes.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Belgium.; Center for Plant Systems Biology, VIB, Belgium.
PMID: 35770820
Plant Cell , IF:11.277 , 2022 Aug , V34 (9) : P3200-3213 doi: 10.1093/plcell/koac179
On the trail of auxin: Reporters and sensors.
CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.; Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic.
The phytohormone auxin is a master regulator of plant growth and development in response to many endogenous and environmental signals. The underlying coordination of growth is mediated by the formation of auxin maxima and concentration gradients. The visualization of auxin dynamics and distribution can therefore provide essential information to increase our understanding of the mechanisms by which auxin orchestrates these growth and developmental processes. Several auxin reporters have been developed to better perceive the auxin distribution and signaling machinery in vivo. This review focuses on different types of auxin reporters and biosensors used to monitor auxin distribution and its dynamics, as well as auxin signaling, at the cellular and tissue levels in different plant species. We provide a brief history of each reporter and biosensor group and explain their principles and utilities.
PMID: 35708654
Plant Cell , IF:11.277 , 2022 Aug , V34 (9) : P3460-3481 doi: 10.1093/plcell/koac177
The retrograde signaling regulator ANAC017 recruits the MKK9-MPK3/6, ethylene, and auxin signaling pathways to balance mitochondrial dysfunction with growth.
Department of Animal, Plant and Soil Science, La Trobe University, Bundoora, Victoria 3086, Australia.; ARC Centre of Excellence in Plant Energy Biology, La Trobe University, Bundoora, Victoria 3086, Australia.
In plant cells, mitochondria are ideally positioned to sense and balance changes in energy metabolism in response to changing environmental conditions. Retrograde signaling from mitochondria to the nucleus is crucial for adjusting the required transcriptional responses. We show that ANAC017, the master regulator of mitochondrial stress, directly recruits a signaling cascade involving the plant hormones ethylene and auxin as well as the MAP KINASE KINASE (MKK) 9-MAP KINASE (MPK) 3/6 pathway in Arabidopsis thaliana. Chromatin immunoprecipitation followed by sequencing and overexpression demonstrated that ANAC017 directly regulates several genes of the ethylene and auxin pathways, including MKK9, 1-AMINO-CYCLOPROPANE-1-CARBOXYLATE SYNTHASE 2, and YUCCA 5, in addition to genes encoding transcription factors regulating plant growth and stress responses such as BASIC REGION/LEUCINE ZIPPER MOTIF (bZIP) 60, bZIP53, ANAC081/ATAF2, and RADICAL-INDUCED CELL DEATH1. A time-resolved RNA-seq experiment established that ethylene signaling precedes the stimulation of auxin signaling in the mitochondrial stress response, with a large part of the transcriptional regulation dependent on ETHYLENE-INSENSITIVE 3. These results were confirmed by mutant analyses. Our findings identify the molecular components controlled by ANAC017, which integrates the primary stress responses to mitochondrial dysfunction with whole plant growth via the activation of regulatory and partly antagonistic feedback loops.
PMID: 35708648
Plant Cell , IF:11.277 , 2022 Aug , V34 (9) : P3280-3300 doi: 10.1093/plcell/koac146
A molecular framework of ethylene-mediated fruit growth and ripening processes in tomato.
Department of Biology,Institute of Plant and Food Science, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.; Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China.; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.
Although the role of ethylene in tomato (Solanum lycopersicum) fruit ripening has been intensively studied, its role in tomato fruit growth remains poorly understood. In addition, the relationship between ethylene and the developmental factors NON-RIPENING (NOR) and RIPENING INHIBITOR (RIN) during ripening is under debate. Here, we carried out comprehensive genetic analyses of genome-edited mutants of tomato ETHYLENE INSENSITIVE 2 (SlEIN2), four EIN3-like genes (SlEIL1-4), and three EIN3 BINDING F-box protein genes (SlEBF1-3). Both slein2-1 and the high-order sleil mutant (sleil1 sleil2 sleil3/SlEIL3 sleil4) showed reduced fruit size, mainly due to decreased auxin biosynthesis. During fruit maturation, slein2 mutants displayed the complete cessation of ripening, which was partially rescued by slebf1 but not slebf2 or slebf3. We also discovered that ethylene directly activates the expression of the developmental genes NOR, RIN, and FRUITFULL1 (FUL1) via SlEIL proteins. Indeed, overexpressing these genes partially rescued the ripening defects of slein2-1. Finally, the signal intensity of the ethylene burst during fruit maturation was intimately connected with the progression of full ripeness. Collectively, our work uncovers a critical role of ethylene in fruit growth and supports a molecular framework of ripening control in which the developmental factors NOR, RIN, and FUL1 act downstream of ethylene signaling.
PMID: 35604102
Plant Cell , IF:11.277 , 2022 Jul , V34 (7) : P2688-2707 doi: 10.1093/plcell/koac107
AUXIN RESPONSE FACTOR7 integrates gibberellin and auxin signaling via interactions between DELLA and AUX/IAA proteins to regulate cambial activity in poplar.
Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, School of Life Sciences, Southwest University, Chongqing 400715, China.; School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia.; Department of Land, Air and Water Resources, University of California at Davis, Davis, California 95616, USA.; Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.
Cambial development in the stems of perennial woody species is rigorously regulated by phytohormones. Auxin and gibberellin (GA) play crucial roles in stimulating cambial activity in poplar (Populus spp.). In this study, we show that the DELLA protein REPRESSOR of ga1-3 Like 1 (RGL1), AUXIN RESPONSE FACTOR 7 (ARF7), and Aux/INDOLE-3-ACETIC ACID 9 (IAA9) form a ternary complex that mediates crosstalk between the auxin and GA signaling pathways in poplar stems during cambial development. Biochemical analysis revealed that ARF7 physically interacts with RGL1 and IAA9 through distinct domains. The arf7 loss-of-function mutant showed markedly attenuated responses to auxin and GA, whereas transgenic poplar plants overexpressing ARF7 displayed strongly improved cambial activity. ARF7 directly binds to the promoter region of the cambial stem cell regulator WOX4 to modulate its expression, thus integrating auxin and GA signaling to regulate cambial activity. Furthermore, the direct activation of PIN-FORMED 1 expression by ARF7 in the RGL1-ARF7-IAA9 module increased GA-dependent cambial activity via polar auxin transport. Collectively, these findings reveal that the crosstalk between auxin and GA signaling mediated by the RGL1-ARF7-IAA9 module is crucial for the precise regulation of cambial development in poplar.
PMID: 35435234
Plant Cell , IF:11.277 , 2022 Jul , V34 (7) : P2518-2533 doi: 10.1093/plcell/koac080
Genetic control of branching patterns in grass inflorescences.
Donald Danforth Plant Science Center, St Louis, Missouri 63132, USA.
Inflorescence branching in the grasses controls the number of florets and hence the number of seeds. Recent data on the underlying genetics come primarily from rice and maize, although new data are accumulating in other systems as well. This review focuses on a window in developmental time from the production of primary branches by the inflorescence meristem through to the production of glumes, which indicate the transition to producing a spikelet. Several major developmental regulatory modules appear to be conserved among most or all grasses. Placement and development of primary branches are controlled by conserved auxin regulatory genes. Subtending bracts are repressed by a network including TASSELSHEATH4, and axillary branch meristems are regulated largely by signaling centers that are adjacent to but not within the meristems themselves. Gradients of SQUAMOSA-PROMOTER BINDING-like and APETALA2-like proteins and their microRNA regulators extend along the inflorescence axis and the branches, governing the transition from production of branches to production of spikelets. The relative speed of this transition determines the extent of secondary and higher order branching. This inflorescence regulatory network is modified within individual species, particularly as regards formation of secondary branches. Differences between species are caused both by modifications of gene expression and regulators and by presence or absence of critical genes. The unified networks described here may provide tools for investigating orphan crops and grasses other than the well-studied maize and rice.
PMID: 35258600
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Sep , V119 (36) : Pe2121671119 doi: 10.1073/pnas.2121671119
Auxin regulates source-sink carbohydrate partitioning and reproductive organ development in rice.
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Carbohydrate partitioning between the source and sink tissues plays an important role in regulating plant growth and development. However, the molecular mechanisms regulating this process remain poorly understood. In this study, we show that elevated auxin levels in the rice dao mutant cause increased accumulation of sucrose in the photosynthetic leaves but reduced sucrose content in the reproductive organs (particularly in the lodicules, anthers, and ovaries), leading to closed spikelets, indehiscent anthers, and parthenocarpic seeds. RNA sequencing analysis revealed that the expression of AUXIN RESPONSE FACTOR 18 (OsARF18) and OsARF2 is significantly up- and down-regulated, respectively, in the lodicule of dao mutant. Overexpression of OsARF18 or knocking out of OsARF2 phenocopies the dao mutant. We demonstrate that OsARF2 regulates the expression of OsSUT1 through direct binding to the sugar-responsive elements (SuREs) in the OsSUT1 promoter and that OsARF18 represses the expression of OsARF2 and OsSUT1 via direct binding to the auxin-responsive element (AuxRE) or SuRE in their promoters, respectively. Furthermore, overexpression of OsSUT1 in the dao and Osarf2 mutant backgrounds could largely rescue the spikelets' opening and seed-setting defects. Collectively, our results reveal an auxin signaling cascade regulating source-sink carbohydrate partitioning and reproductive organ development in rice.
PMID: 36037381
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Aug , V119 (35) : Pe2208795119 doi: 10.1073/pnas.2208795119
Regulators of early maize leaf development inferred from transcriptomes of laser capture microdissection (LCM)-isolated embryonic leaf cells.
Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan.; Department of Plant Biology, Michigan State University, East Lansing, MI 48824.; Department of Computational Mathematics, Science, and Engineering, Michigan State University, East Lansing, MI 48824.; Department of Bioagricultural Science, National Chiayi University, Chiayi 600, Taiwan.; School of Biological Sciences, Washington State University, Pullman, WA 99164.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan.; Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637.
The superior photosynthetic efficiency of C4 leaves over C3 leaves is owing to their unique Kranz anatomy, in which the vein is surrounded by one layer of bundle sheath (BS) cells and one layer of mesophyll (M) cells. Kranz anatomy development starts from three contiguous ground meristem (GM) cells, but its regulators and underlying molecular mechanism are largely unknown. To identify the regulators, we obtained the transcriptomes of 11 maize embryonic leaf cell types from five stages of pre-Kranz cells starting from median GM cells and six stages of pre-M cells starting from undifferentiated cells. Principal component and clustering analyses of transcriptomic data revealed rapid pre-Kranz cell differentiation in the first two stages but slow differentiation in the last three stages, suggesting early Kranz cell fate determination. In contrast, pre-M cells exhibit a more prolonged transcriptional differentiation process. Differential gene expression and coexpression analyses identified gene coexpression modules, one of which included 3 auxin transporter and 18 transcription factor (TF) genes, including known regulators of Kranz anatomy and/or vascular development. In situ hybridization of 11 TF genes validated their expression in early Kranz development. We determined the binding motifs of 15 TFs, predicted TF target gene relationships among the 18 TF and 3 auxin transporter genes, and validated 67 predictions by electrophoresis mobility shift assay. From these data, we constructed a gene regulatory network for Kranz development. Our study sheds light on the regulation of early maize leaf development and provides candidate leaf development regulators for future study.
PMID: 36001691
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Aug , V119 (32) : Pe2206869119 doi: 10.1073/pnas.2206869119
Chemical inhibition of the auxin inactivation pathway uncovers the roles of metabolic turnover in auxin homeostasis.
Department of Bioscience, Okayama University of Science, Okayama 700-0005, Japan.; Department of Biochemistry, Okayama University of Science, Okayama 700-0005, Japan.; Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu 183-8509, Japan.; Department of Biology, Washington University in St. Louis, St. Louis, MO 63130.; School of Life Sciences, University of Warwick, Coventry CV4 7AS, United Kingdom.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093.; Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu 183-8509, Japan.; RIKEN Center for Sustainable Resource Science, Kanagawa 230-0045, Japan.
The phytohormone auxin, indole-3-acetic acid (IAA), plays a prominent role in plant development. Auxin homeostasis is coordinately regulated by auxin synthesis, transport, and inactivation; however, the physiological contribution of auxin inactivation to auxin homeostasis has not been determined. The GH3 IAA-amino acid conjugating enzymes play a central role in auxin inactivation. Chemical inhibition of GH3 proteins in planta is challenging because the inhibition of these enzymes leads to IAA overaccumulation that rapidly induces GH3 expression. Here, we report the characterization of a potent GH3 inhibitor, kakeimide, that selectively targets IAA-conjugating GH3 proteins. Chemical knockdown of the auxin inactivation pathway demonstrates that auxin turnover is very rapid (about 10 min) and indicates that both auxin biosynthesis and inactivation dynamically regulate auxin homeostasis.
PMID: 35914172
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Aug , V119 (31) : Pe2122460119 doi: 10.1073/pnas.2122460119
Molecular framework integrating nitrate sensing in root and auxin-guided shoot adaptive responses.
Institute of Science and Technology Austria, Klosterneuburg, 3400 Austria.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Olomouc, 78371,Czech Republic.; Institute for Plant Sciences of Montpellier (IPSiM), CNRS, National Research Institute for Agriculture, Food and the Environment (INRAE), Institut Agro, Universite Montpellier, Montpellier, 34060, France.; Institut Jean-Pierre Bourgin, National Research Institute for Agriculture, Food and the Environment (INRAE), AgroParisTech, Universite Paris-Saclay, Versailles, 78000, France.
Mineral nutrition is one of the key environmental factors determining plant development and growth. Nitrate is the major form of macronutrient nitrogen that plants take up from the soil. Fluctuating availability or deficiency of this element severely limits plant growth and negatively affects crop production in the agricultural system. To cope with the heterogeneity of nitrate distribution in soil, plants evolved a complex regulatory mechanism that allows rapid adjustment of physiological and developmental processes to the status of this nutrient. The root, as a major exploitation organ that controls the uptake of nitrate to the plant body, acts as a regulatory hub that, according to nitrate availability, coordinates the growth and development of other plant organs. Here, we identified a regulatory framework, where cytokinin response factors (CRFs) play a central role as a molecular readout of the nitrate status in roots to guide shoot adaptive developmental response. We show that nitrate-driven activation of NLP7, a master regulator of nitrate response in plants, fine tunes biosynthesis of cytokinin in roots and its translocation to shoots where it enhances expression of CRFs. CRFs, through direct transcriptional regulation of PIN auxin transporters, promote the flow of auxin and thereby stimulate the development of shoot organs.
PMID: 35878040
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Aug , V119 (31) : Pe2121058119 doi: 10.1073/pnas.2121058119
RALF1 peptide triggers biphasic root growth inhibition upstream of auxin biosynthesis.
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, 100193 Beijing, China.; Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria.; Department of Biotechnology, College of Science, Taif University, 21944 Taif, Saudi Arabia.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, 78371 Olomouc, Czech Republic.
Plant cell growth responds rapidly to various stimuli, adapting architecture to environmental changes. Two major endogenous signals regulating growth are the phytohormone auxin and the secreted peptides rapid alkalinization factors (RALFs). Both trigger very rapid cellular responses and also exert long-term effects [Du et al., Annu. Rev. Plant Biol. 71, 379-402 (2020); Blackburn et al., Plant Physiol. 182, 1657-1666 (2020)]. However, the way, in which these distinct signaling pathways converge to regulate growth, remains unknown. Here, using vertical confocal microscopy combined with a microfluidic chip, we addressed the mechanism of RALF action on growth. We observed correlation between RALF1-induced rapid Arabidopsis thaliana root growth inhibition and apoplast alkalinization during the initial phase of the response, and revealed that RALF1 reversibly inhibits primary root growth through apoplast alkalinization faster than within 1 min. This rapid apoplast alkalinization was the result of RALF1-induced net H(+) influx and was mediated by the receptor FERONIA (FER). Furthermore, we investigated the cross-talk between RALF1 and the auxin signaling pathways during root growth regulation. The results showed that RALF-FER signaling triggered auxin signaling with a delay of approximately 1 h by up-regulating auxin biosynthesis, thus contributing to sustained RALF1-induced growth inhibition. This biphasic RALF1 action on growth allows plants to respond rapidly to environmental stimuli and also reprogram growth and development in the long term.
PMID: 35878023
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Jul , V119 (30) : Pe2201072119 doi: 10.1073/pnas.2201072119
Ethylene inhibits rice root elongation in compacted soil via ABA- and auxin-mediated mechanisms.
Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.; Future Food Beacon and School of Biosciences, University of Nottingham, LE12 5RD, United Kingdom.; Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences and Faculty of Science of Palacky University, CZ-78371 Olomouc, Czech Republic.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Plant Environmental Signalling and Development, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.; CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.; Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, The Netherlands.; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom.; Division of Plant Science and Technology and Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211.; School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, SA, Australia.
Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8. Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil.
PMID: 35858424
Proc Natl Acad Sci U S A , IF:11.205 , 2022 Jul , V119 (27) : Pe2202669119 doi: 10.1073/pnas.2202669119
The calcium signaling module CaM-IQM destabilizes IAA-ARF interaction to regulate callus and lateral root formation.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; National Center for Plant Gene Research, Beijing 100093, China.
Induction of a pluripotent cell mass, called callus, from detached organs is an initial step in in vitro plant regeneration, during which phytohormone auxin-induced ectopic activation of a root developmental program has been shown to be required for subsequent de novo regeneration of shoots and roots. However, whether other signals are involved in governing callus formation, and thus plant regeneration capability, remains largely unclear. Here, we report that the Arabidopsis calcium (Ca(2+)) signaling module CALMODULIN IQ-MOTIF CONTAINING PROTEIN (CaM-IQM) interacts with auxin signaling to regulate callus and lateral root formation. We show that disruption of IQMs or CaMs retards auxin-induced callus and lateral root formation by dampening auxin responsiveness, and that CaM-IQM complexes physically interact with the auxin signaling repressors INDOLE-3-ACETIC ACID INDUCIBLE (IAA) proteins in a Ca(2+)-dependent manner. We further provide evidence that the physical interaction of CaM6 with IAA19 destabilizes the repressive interaction of IAA19 with AUXIN RESPONSE FACTOR 7 (ARF7), and thus regulates auxin-induced callus formation. These findings not only define a critical role of CaM-IQM-mediated Ca(2+) signaling in callus and lateral root formation, but also provide insight into the interplay of Ca(2+) signaling and auxin actions during plant regeneration and development.
PMID: 35763576
Curr Biol , IF:10.834 , 2022 Jul doi: 10.1016/j.cub.2022.06.064
Apical dominance control by TAR-YUC-mediated auxin biosynthesis is a deep homology of land plants.
Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre for Plant Biology in Uppsala, 750 07 Uppsala, Sweden.; Laboratoire Reproduction et Developpement des Plantes, Universite de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon 69007, France; Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchatel, 2000 Neuchatel, Switzerland.; Laboratoire Reproduction et Developpement des Plantes, Universite de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon 69007, France; Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Universite Paris-Saclay, 78000 Versailles, France.; Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.; Universite Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405 Orsay, France; Universite de Paris, CNRS, INRAE, Institute of Plant Sciences Paris-Saclay (IPS2), 91405 Orsay, France.; Laboratoire Reproduction et Developpement des Plantes, Universite de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, INRIA, Lyon 69007, France. Electronic address: yoan.coudert@cnrs.fr.
A key aim in biology is to identify which genetic changes contributed to the evolution of form through time. Apical dominance, the inhibitory effect exerted by shoot apices on the initiation or outgrowth of distant lateral buds, is a major regulatory mechanism of plant form.(1) Nearly a century of studies in the sporophyte of flowering plants have established the phytohormone auxin as a front-runner in the search for key factors controlling apical dominance,(2)(,)(3) identifying critical roles for long-range polar auxin transport and local auxin biosynthesis in modulating shoot branching.(4-10) A capacity for lateral branching evolved by convergence in the gametophytic shoot of mosses and primed its diversification;(11) however, polar auxin transport is relatively unimportant in this developmental process,(12) the contribution of auxin biosynthesis genes has not been assessed, and more generally, the extent of conservation in apical dominance regulation within the land plants remains largely unknown. To fill this knowledge gap, we sought to identify genetic determinants of apical dominance in the moss Physcomitrium patens. Here, we show that leafy shoot apex decapitation releases apical dominance through massive and rapid transcriptional reprogramming of auxin-responsive genes and altering auxin biosynthesis gene activity. We pinpoint a subset of P. patens TRYPTOPHAN AMINO-TRANSFERASE (TAR) and YUCCA FLAVIN MONOOXYGENASE-LIKE (YUC) auxin biosynthesis genes expressed in the main and lateral shoot apices and show that they are essential for coordinating branch initiation and outgrowth. Our results demonstrate that local auxin biosynthesis acts as a pivotal regulator of apical dominance in moss and constitutes a shared mechanism underpinning shoot architecture control in land plants.
PMID: 35841890
J Hazard Mater , IF:10.588 , 2022 Aug , V435 : P129020 doi: 10.1016/j.jhazmat.2022.129020
Thiourea mediated ROS-metabolites reprogramming restores root system architecture under arsenic stress in rice.
Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India; School of Biological sciencesUM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Vidyanagari 400098, Mumbai.; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India; Division of crop production, ICAR- Indian Institute of Soybean Research, Khandwa Road, Indore 452001, (M.P), India.; Department of Botany, Savitribai Phule Pune University, Pune 411007, India.; Centre for Cellular and Molecular Platforms, GKVK Post, Bengaluru 560065, India.; Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India; Homi Bhabha National Institute, Mumbai 400094, India.; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085, India; Homi Bhabha National Institute, Mumbai 400094, India. Electronic address: ashish@barc.gov.in.
Arsenic (As) is a ubiquitous carcinogenic metalloid that enters into human food chain, through rice consumption. To unravel the conundrum of oxidative vs. reductive stress, the differential root-system architecture (RSA) was studied under As (a ROS producer) and thiourea (TU; a ROS scavenger) alone treatments, which indicated 0.80- and 0.74-fold reduction in the number of lateral roots (NLR), respectively compared with those of control. In case of As+TU treatment, NLR was increased by 4.35-fold compared with those of As-stress, which coincided with partial restoration of redox-status and auxin transport towards the root-tip. The expression levels of 16 ROS related genes, including RBOHC, UPB-1 C, SHR1, PUCHI, were quantified which provided the molecular fingerprint, in accordance with endogenous ROS signature. LC-MS based untargeted and targeted metabolomics data revealed that As-induced oxidative stress was metabolically more challenging than TU alone-induced reductive stress. Cis/trans-ferruloyl putrescine and gamma-glutamyl leucine were identified as novel As-responsive metabolites whose levels were decreased and increased, respectively under As+TU than As-treated roots. In addition, the overall amino acid accumulation was increased in As+TU than As-treated roots, indicating the improved nutritional availability. Thus, the study revealed dynamic interplay between "ROS-metabolites-RSA", to the broader context of TU-mediated amelioration of As-stress in rice.
PMID: 35650738
J Hazard Mater , IF:10.588 , 2022 Jul , V433 : P128769 doi: 10.1016/j.jhazmat.2022.128769
LncRNA PMAT-PtoMYB46 module represses PtoMATE and PtoARF2 promoting Pb(2+) uptake and plant growth in poplar.
National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; School of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, PR China.; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China.; Linnean Center for Plant Biology, Department of Plant Biology, Swedish University of Agricultural Sciences, Box 7080, SE-750 07 Uppsala, Sweden.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Science, Umea, Sweden.; Department of Forest and Conservation Sciences, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, Beijing 100083, PR China; School of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, PR China. Electronic address: DeqiangZhang@bjfu.edu.cn.
Lead (Pb(2+)) is one of the most toxic heavy-metal contaminants. Fast-growing woody plants with substantial biomass are ideal for bioremediation. However, the transcriptional regulation of Pb(2+) uptake in woody plants remains unclear. Here, we identified 226 Pb(2+)-induced, differentially expressed long non-coding RNAs (DELs) in Populus tomentosa. Functional annotation revealed that these DELs mainly regulate carbon metabolism, biosynthesis of secondary metabolites, energy metabolism, and signal transduction through their potential target genes. Association and epistasis analysis showed that the lncRNA PMAT (Pb(2+)-induced multidrug and toxic compound extrusion (MATE) antisense lncRNA) interacts epistatically with PtoMYB46 to regulate leaf dry weight, photosynthesis rate, and transketolase activity. Genetic transformation and molecular assays showed that PtoMYB46 reduces the expression of PtoMATE directly or indirectly through PMAT, thereby reducing the secretion of citric acid (CA) and ultimately promoting Pb(2+) uptake. Meanwhile, PtoMYB46 targets auxin response factor 2 (ARF2) and reduces its expression, thus positively regulating plant growth. We concluded that the PMAT-PtoMYB46-PtoMATE-PtoARF2 regulatory module control Pb(2+) tolerance, uptake, and plant growth. This study demonstrates the involvement of lncRNAs in response to Pb(2+) in poplar, yielding new insight into the potential for developing genetically improved woody plant varieties for phytoremediating lead-contaminated soils.
PMID: 35364535
New Phytol , IF:10.151 , 2022 Aug doi: 10.1111/nph.18448
Bipartite phosphoinositide-dependent modulation of auxin signaling during xylem differentiation in Arabidopsis thaliana roots.
Department of Biology, Swiss Federal Institute of Technology (ETH) Zurich, CH-8092, Zurich, Switzerland.
Efficient root-to-shoot delivery of water and nutrients in plants relies on the correct differentiation of xylem cells into hollow elements. While auxin is integral to the formation of xylem cells, it remains poorly characterized how each subcellular pool of this hormone regulates this process. Combining genetic and cell biological approaches, we investigated the bipartite activity of nucleoplasmic vs plasma membrane-associated phosphatidylinositol 4-phosphate kinases PIP5K1 and its homologue PIP5K2 in Arabidopsis thaliana roots and uncovered a novel mechanism by which phosphoinositides integrate distinct aspects of the auxin signaling cascade and, in turn, regulate the onset of xylem differentiation. The appearance of undifferentiated cells in protoxylem strands of pip5k1 pip5k2 is phenomimicked in auxin transport and perception mutants and can be partially restored by the nuclear residence of PIP5K1. Instead, exclusion of PIP5K1 from the nucleus hinders the auxin-mediated induction of the xylem master regulator VASCULAR RELATED NAC DOMAIN (VND) 7. A xylem-specific increase of auxin levels abolishes pip5k1 pip5k2 vascular defects, indicating that the establishment of auxin maxima is required to activate VND7-mediated xylem differentiation. Our results describe a new mechanism by which distinct subcellular pools of phosphoinositides integrate auxin transport and perception to initiate xylem differentiation in a spatio-temporal manner.
PMID: 36039703
New Phytol , IF:10.151 , 2022 Aug doi: 10.1111/nph.18440
Feedback regulation of auxin signaling through the transcription of H2A.Z and deposition of H2A.Z to SMALL AUXIN UP RNAs in Arabidopsis.
Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.; National key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200032, China.
Auxin is a critical phytohormone that is involved in the regulation of most plant growth and developmental responses. In particular, epigenetic mechanisms like histone modifications and DNA methylation were reported to affect auxin biosynthesis and transport. However, the involvement of other epigenetic factors such as histone variant H2A.Z in the auxin-related developmental regulation remains unclear. We report that the histone variant H2A.Z knockdown mutant in Arabidopsis Col-0 ecotype, h2a.z-kd, has more lateral roots and weak gravitational responses related to auxin-regulated growth performances. Further study revealed that auxin promotes the eviction of H2A.Z from auxin responsive genes SAURs to activate their transcriptions. We found that IAA promotes the transcription of H2A.Z genes through HOMEOBOX PROTEIN 22/25 (AtHB22/25) transcription factors which work as downstream targets of ARF7/19 in auxin signaling. Double mutant of hb22 hb25 showed similar lateral root and gravitropism phenotypes to h2a.z-kd. Our results shed light on a reciprocal regulation hub through INO80-mediated H2A.Z eviction and ARF7/19-HB25/22-mediated H2A.Z transcription to modulate the activation of SAURs and plant growth in Arabidopsis.
PMID: 36017638
New Phytol , IF:10.151 , 2022 Aug doi: 10.1111/nph.18315
Many ways to TOPLESS - manipulation of plant auxin signalling by a cluster of fungal effectors.
Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Vienna Bio Center (VBC), Dr. Bohr-Gasse 3, 1030, Vienna, Austria.; Department of Plant Pathology, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Nussallee 9, 53115, Bonn, Germany.; CEPLAS, Institute for Plant Sciences, University of Cologne, 50674, Cologne, Germany.; Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany.
Plant biotrophic pathogens employ secreted molecules, called effectors, to suppress the host immune system and redirect the host's metabolism and development in their favour. Putative effectors of the gall-inducing maize pathogenic fungus Ustilago maydis were analysed for their ability to induce auxin signalling in plants. Using genetic, biochemical, cell-biological, and bioinformatic approaches we functionally elucidate a set of five, genetically linked effectors, called Topless (TPL) interacting protein (Tips) effectors that induce auxin signalling. We show that Tips induce auxin signalling by interfering with central corepressors of the TPL family. CRISPR-Cas9 mutants and deletion strain analysis indicate that the auxin signalling inducing subcluster effectors plays a redundant role in virulence. Although none of the Tips seem to have a conserved interaction motif, four of them bind solely to the N-terminal TPL domain and, for Tip1 and Tip4, we demonstrate direct competition with auxin/indole-3-acetic acid transcriptional repressors for their binding to TPL class of corepressors. Our findings reveal that TPL proteins, key regulators of growth-defence antagonism, are a major target of the U. maydis effectome.
PMID: 35944559
New Phytol , IF:10.151 , 2022 Jul doi: 10.1111/nph.18381
The Arabidopsis IDD14 transcription factor interacts with bZIP-type ABFs/AREBs and cooperatively regulates ABA-mediated drought tolerance.
School of Life Sciences, Qilu Normal University, Jinan, 250200, China.; School of Life Sciences, Shandong Normal University, Jinan, 250014, China.; State Key Laboratory of Genetic Engineering and Fudan Center for Genetic Diversity and Designing Agriculture, School of Life Sciences, Fudan University, Shanghai, 200438, China.; Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
The INDETERMINATE DOMAIN (IDD) transcription factors mediate various aspects of plant growth and development. We previously reported that an Arabidopsis IDD subfamily regulates spatial auxin accumulation, and thus organ morphogenesis and gravitropic responses. However, its functions in stress responses are not well defined. Here, we use a combination of physiological, biochemical, molecular, and genetic approaches to provide evidence that the IDD14 cooperates with basic leucine zipper-type binding factors/ABA-responsive element (ABRE)-binding proteins (ABRE-binding factors (ABFs)/AREBs) in ABA-mediated drought tolerance. idd14-1D, a gain-of-function mutant of IDD14, exhibits decreased leaf water loss and improved drought tolerance, whereas inactivation of IDD14 in idd14-1 results in increased transpiration and reduced drought tolerance. Altered IDD14 expression affects ABA sensitivity and ABA-mediated stomatal closure. IDD14 can physically interact with ABF1-4 and subsequently promote their transcriptional activities. Moreover, ectopic expression and mutation of ABFs could, respectively, suppress and enhance plant sensitivity to drought stress in the idd14-1 mutant. Our results demonstrate that IDD14 forms a functional complex with ABFs and positively regulates drought-stress responses, thus revealing a previously unidentified role of IDD14 in ABA signaling and drought responses.
PMID: 35842794
New Phytol , IF:10.151 , 2022 Sep , V235 (6) : P2270-2284 doi: 10.1111/nph.18317
miR169o and ZmNF-YA13 act in concert to coordinate the expression of ZmYUC1 that determines seed size and weight in maize kernels.
Biotechnology Research Institute, CAAS/Key Laboratory of Agricultural Genomics (Beijing), Ministry of Agriculture, 100081, Beijing, China.; National Nanfan Research Institute (Sanya), 572022, Sanya, Hainan, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, 100039, Beijing, China.
MicroRNAs (miRNAs) play key regulatory roles in seed development and emerge as new key targets for engineering grain size and yield. The Zma-miRNA169 family is highly expressed during maize seed development, but its functional roles in seed development remain elusive. Here, we generated zma-miR169o and ZmNF-YA13 transgenic plants. Phenotypic and genetic analyses were performed on these lines. Seed development and auxins contents were investigated. Overexpression of maize miRNA zma-miR169o increases seed size and weight, whereas the opposite is true when its expression is suppressed. Further studies revealed that zma-miR169 acts by negatively regulating its target gene, a transcription factor ZmNF-YA13 that also plays a key role in determining seed size. We demonstrate that ZmNF-YA13 regulates the expression of the auxin biosynthetic gene ZmYUC1, which modulates auxin levels in the early developing seeds and determines the number of endosperm cells, thereby governing maize seed size and ultimately yield. Overall, our present study has identified zma-miR169o and ZmNF-YA13 that form a functional module regulating auxin accumulation in maize seeds and playing an important role in determining maize seed size and yield, providing a set of novel molecular tools for yield improvement in molecular breeding and genetic engineering.
PMID: 35713356
New Phytol , IF:10.151 , 2022 Aug , V235 (3) : P1287-1301 doi: 10.1111/nph.18200
Broad-range metalloprotease profiling in plants uncovers immunity provided by defence-related metalloenzyme.
The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK.; Department of Chemistry and the Ineos Oxford Institute for Antimcrobial Research, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.; The Plant Chemetics Laboratory, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany.; Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.; Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
Plants encode > 100 metalloproteases representing > 19 different protein families. Tools to study this large and diverse class of proteases have not yet been introduced into plant research. We describe the use of hydroxamate-based photoaffinity probes to explore plant proteomes for metalloproteases. We detected labelling of 23 metalloproteases in leaf extracts of the model plant Arabidopsis thaliana that belong to nine different metalloprotease families and localize to different subcellular compartments. The probes identified several chloroplastic FtsH proteases, vacuolar aspartyl aminopeptidase DAP1, peroxisomal metalloprotease PMX16, extracellular matrix metalloproteases and many cytosolic metalloproteases. We also identified nonproteolytic metallohydrolases involved in the release of auxin and in the urea cycle. Studies on tobacco plants (Nicotiana benthamiana) infected with the bacterial plant pathogen Pseudomonas syringae uncovered the induced labelling of PRp27, a secreted protein with implicated metalloprotease activity. PRp27 overexpression increases resistance, and PRp27 mutants lacking metal binding site are no longer labelled, but still show increased immunity. Collectively, these studies reveal the power of broad-range metalloprotease profiling in plants using hydroxamate-based probes.
PMID: 35510806
New Phytol , IF:10.151 , 2022 Aug , V235 (3) : P1111-1128 doi: 10.1111/nph.18196
A novel chemical inhibitor of polar auxin transport promotes shoot regeneration by local enhancement of HD-ZIP III transcription.
Research Unit Plant Growth Regulation, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.; Plant Systems Biology, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.; Biotechnology of Horticultural Crops, TUM School of Life Sciences, Technical University of Munich, 85354, Freising, Germany.
De novo shoot organogenesis is a prerequisite for numerous applications in plant research and breeding but is often a limiting factor, for example, in genome editing approaches. Class III homeodomain-leucine zipper (HD-ZIP III) transcription factors have been characterized as crucial regulators of shoot specification, however up-stream components controlling their activity during shoot regeneration are only partially identified. In a chemical genetic screen, we isolated ZIC2, a novel activator of HD-ZIP III activity. Using molecular, physiological and hormone transport analyses in Arabidopsis and sunflower (Helianthus annuus), we examined the molecular mechanism by which the drug promotes HD-ZIP III expression. ZIC2-dependent upregulation of HD-ZIP III transcription promotes shoot regeneration in Arabidopsis and is accompanied by the induction of shoot specifying factors WUS and RAP2.6L and a subset of cytokinin biosynthesis enzymes. ZIC2's effect on HD-ZIP III expression and regeneration is based on its ability to limit polar auxin transport. We further provide evidence that chemical modulation of auxin efflux can enhance de novo shoot formation in the regeneration recalcitrant species sunflower. Activation of HD-ZIP III transcription during shoot regeneration depends on the local distribution of auxin and chemical modulation of auxin transport can be used to overcome poor shoot organogenesis in tissue culture.
PMID: 35491431
Plant Physiol , IF:8.34 , 2022 Aug doi: 10.1093/plphys/kiac374
Identification of growth regulators using cross-species network analysis in plants.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.; VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; Institute of Biosciences and Bioresources, National Research Council (CNR), Via Amendola 165/A, 70126 Bari, Italy.; Umea Plant Science Centre (UPSC), Department of Plant Physiology, Umea University, 90187 Umea, Sweden.; SweTree Technologies AB, Skogsmarksgrand 7, SE-907 36 Umea, Sweden.; Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432 As, Norway.; Umea Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umea, Sweden.; Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052 Ghent, Belgium.
With the need to increase plant productivity, one of the challenges plant scientists are facing is to identify genes that play a role in beneficial plant traits. Moreover, even when such genes are found, it is generally not trivial to transfer this knowledge about gene function across species to identify functional orthologs. Here, we focused on the leaf to study plant growth. First, we built leaf growth transcriptional networks in Arabidopsis (Arabidopsis thaliana), maize (Zea mays), and aspen (Populus tremula). Next, known growth regulators, here defined as genes that when mutated or ectopically expressed alter plant growth, together with cross-species conserved networks, were used as guides to predict novel Arabidopsis growth regulators. Using an in-depth literature screening, 34 out of 100 top predicted growth regulators were confirmed to affect leaf phenotype when mutated or overexpressed and thus represent novel potential growth regulators. Globally, these growth regulators were involved in cell cycle, plant defense responses, gibberellin, auxin, and brassinosteroid signaling. Phenotypic characterization of loss-of-function lines confirmed two predicted growth regulators to be involved in leaf growth (NPF6.4 and LATE MERISTEM IDENTITY2). In conclusion, the presented network approach offers an integrative cross-species strategy to identify genes involved in plant growth and development.
PMID: 35984294
Plant Physiol , IF:8.34 , 2022 Aug doi: 10.1093/plphys/kiac370
Cell- and non-cell-autonomous AUXIN RESPONSE FACTOR3 controls meristem proliferation and phyllotactic patterns.
State Key Laboratory of North China Crop Improvement and Regulation, College of Agronomy, Hebei Agricultural University; Key Laboratory of Crop Growth Regulation of Hebei Province, Baoding, Hebei, 071001, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China; Hebei Collaboration Innovation Center for Cell Signaling, Shijiazhuang, China.; State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, College of Life Sciences, Hebei Agricultural University, Baoding, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Shijiazhuang, China.
In cell-cell communication, non-cell-autonomous transcription factors play vital roles in controlling plant stem cell fate. We previously reported that AUXIN RESPONSE FACTOR3 (ARF3), a member of the ARF family with critical roles in floral meristem maintenance and determinacy, has a distinct accumulation pattern that differs from the expression domain of its encoding gene in the shoot apical meristem (SAM). However, the biological meaning of this difference is obscure. Here, we demonstrate that ARF3 expression in Arabidopsis (Arabidopsis thaliana) is mainly activated at the periphery of the SAM by auxin where ARF3 cell-autonomously regulates the expression of meristem-organ boundary-specific genes, such as CUP-SHAPED COTYLEDON1-3 (CUC1-3), BLADE ON PETIOLE1-2 (BOP1-2) and TARGETS UNDER ETTIN CONTROL3 (TEC3) to regulate the arrangement of organs in regular pattern, a phenomenon referred to as phyllotaxis. We also show that ARF3 is translocated into the organizing center where it represses cytokinin activity and WUSCHEL expression to regulate meristem activity non-cell-autonomously. Therefore, ARF3 acts as a molecular link that mediates the interaction of auxin and cytokinin signaling in the SAM while coordinating the balance between meristem maintenance and organogenesis. Our findings reveal an ARF3-mediated coordination mechanism through cell-cell communication in dynamic SAM maintenance.
PMID: 35972411
Plant Physiol , IF:8.34 , 2022 Jul doi: 10.1093/plphys/kiac332
Class I TCP transcription factor AtTCP8 modulates key brassinosteroid-responsive genes.
Department of Biological Sciences, Butler University, Indianapolis, Indiana, United States of America.; Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.; Christopher S. Bond Life Sciences Center and Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri, United States of America.; Department of Biology, Marian University, Indianapolis, Indiana, United States of America.
The plant-specific TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor family is most closely associated with regulating plant developmental programs. Recently, TCPs were also shown to mediate host immune signaling, both as targets of pathogen virulence factors and as regulators of plant defense genes. However, comprehensive characterization of TCP gene targets is still lacking. Loss of function of the class I TCP gene AtTCP8 attenuates early immune signaling and, when combined with mutations in AtTCP14 and AtTCP15, additional layers of defense signaling in Arabidopsis (Arabidopsis thaliana). Here, we focus on TCP8, the most poorly characterized of the three to date. We used chromatin immunoprecipitation and RNA-sequencing to identify TCP8-bound gene promoters and differentially regulated genes in the tcp8 mutant; these data sets were heavily enriched in signaling components for multiple phytohormone pathways, including brassinosteroids (BRs), auxin, and jasmonic acid. Using BR signaling as a representative example, we showed that TCP8 directly binds and activates the promoters of the key BR transcriptional regulatory genes BRASSINAZOLE-RESISTANT1 (BZR1) and BRASSINAZOLE-RESISTANT2 (BZR2/BES1). Furthermore, tcp8 mutant seedlings exhibited altered BR-responsive growth patterns and complementary reductions in BZR2 transcript levels, while TCP8 protein demonstrated BR-responsive changes in subnuclear localization and transcriptional activity. We conclude that one explanation for the substantial targeting of TCP8 alongside other TCP family members by pathogen effectors may lie in its role as a modulator of BR and other plant hormone signaling pathways.
PMID: 35866682
Plant Physiol , IF:8.34 , 2022 Aug , V189 (4) : P2259-2280 doi: 10.1093/plphys/kiac220
MEDIATOR SUBUNIT17 integrates jasmonate and auxin signaling pathways to regulate thermomorphogenesis.
Plant Mediator Lab, National Institute of Plant Genome Research, New Delhi 110067, India.; Signalling Lab, National Institute of Plant Genome Research, New Delhi 110067, India.; Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czech Republic.; Plant Transcription Regulation Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India.
Plant adjustment to environmental changes involves complex crosstalk between extrinsic and intrinsic cues. In the past two decades, extensive research has elucidated the key roles of PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and the phytohormone auxin in thermomorphogenesis. In this study, we identified a previously unexplored role of jasmonate (JA) signaling components, the Mediator complex, and their integration with auxin signaling during thermomorphogenesis in Arabidopsis (Arabidopsis thaliana). Warm temperature induces expression of JA signaling genes including MYC2, but, surprisingly, this transcriptional activation is not JA dependent. Warm temperature also promotes accumulation of the JA signaling receptor CORONATINE INSENSITIVE1 (COI1) and degradation of the JA signaling repressor JASMONATE-ZIM-DOMAIN PROTEIN9, which probably leads to de-repression of MYC2, enabling it to contribute to the expression of MEDIATOR SUBUNIT17 (MED17). In response to warm temperature, MED17 occupies the promoters of thermosensory genes including PIF4, YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE19 (IAA19), and IAA29. Moreover, MED17 facilitates enrichment of H3K4me3 on the promoters of PIF4, YUC8, IAA19, and IAA29 genes. Interestingly, both occupancy of MED17 and enrichment of H3K4me3 on these thermomorphogenesis-related promoters are dependent on PIF4 (or PIFs). Altered accumulation of COI1 under warm temperature in the med17 mutant suggests the possibility of a feedback mechanism. Overall, this study reveals the role of the Mediator complex as an integrator of JA and auxin signaling pathways during thermomorphogenesis.
PMID: 35567489
Plant Physiol , IF:8.34 , 2022 Aug , V189 (4) : P2281-2297 doi: 10.1093/plphys/kiac215
A PLETHORA/PIN-FORMED/auxin network mediates prehaustorium formation in the parasitic plant Striga hermonthica.
BESE Division, Plant Cell and Developmental Biology, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.; BESE Division, The BioActives Lab, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.; Institute of Cytology and Genetics, Novosibirsk 630090, Russian Federation, Russia.; Novosibirsk State University, Novosibirsk 630090, Russian Federation, Russia.; Plant Systems Physiology, Radboud University, 6500 AJ Nijmegen, the Netherlands.
The parasitic plant Striga (Striga hermonthica) invades the host root through the formation of a haustorium and has detrimental impacts on cereal crops. The haustorium results from the prehaustorium, which is derived directly from the differentiation of the Striga radicle. The molecular mechanisms leading to radicle differentiation shortly after germination remain unclear. In this study, we determined the developmental programs that regulate terminal prehaustorium formation in S. hermonthica at cellular resolution. We showed that shortly after germination, cells in the root meristem undergo multiplanar divisions. During growth, the meristematic activity declines and associates with reduced expression of the stem cell regulator PLETHORA1 and the cell cycle genes CYCLINB1 and HISTONE H4. We also observed a basal localization of the PIN-FORMED (PIN) proteins and a decrease in auxin levels in the meristem. Using the structural layout of the root meristem and the polarity of outer-membrane PIN proteins, we constructed a mathematical model of auxin transport that explains the auxin distribution patterns observed during S. hermonthica root growth. Our results reveal a fundamental molecular and cellular framework governing the switch of S. hermonthica roots to form the invasive prehaustoria.
PMID: 35543497
Plant Physiol , IF:8.34 , 2022 Aug , V189 (4) : P2396-2412 doi: 10.1093/plphys/kiac212
The HD-Zip transcription factor SlHB15A regulates abscission by modulating jasmonoyl-isoleucine biosynthesis.
College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China.; Key Laboratory of Protected Horticulture of Ministry of Education, Shenyang 110866, China.; Department of Plant Sciences, University of California at Davis, Davis, California 95616, USA.; Crops Pathology and Genetic Research Unit, USDA-ARS, Davis, California 95616, USA.
Plant organ abscission, a process that is important for development and reproductive success, is inhibited by the phytohormone auxin and promoted by another phytohormone, jasmonic acid (JA). However, the molecular mechanisms underlying the antagonistic effects of auxin and JA in organ abscission are unknown. We identified a tomato (Solanum lycopersicum) class III homeodomain-leucine zipper transcription factor, HOMEOBOX15A (SlHB15A), which was highly expressed in the flower pedicel abscission zone and induced by auxin. Knocking out SlHB15A using clustered regularly interspaced short palindromic repeats-associated protein 9 technology significantly accelerated abscission. In contrast, overexpression of microRNA166-resistant SlHB15A (mSlHB15A) delayed abscission. RNA sequencing and reverse transcription-quantitative PCR analyses showed that knocking out SlHB15A altered the expression of genes related to JA biosynthesis and signaling. Furthermore, functional analysis indicated that SlHB15A regulates abscission by depressing JA-isoleucine (JA-Ile) levels through inhabiting the expression of JASMONATE-RESISTANT1 (SlJAR1), a gene involved in JA-Ile biosynthesis, which could induce abscission-dependent and abscission-independent ethylene signaling. SlHB15A bound directly to the SlJAR1 promoter to silence SlJAR1, thus delaying abscission. We also found that flower removal enhanced JA-Ile content and that application of JA-Ile severely impaired the inhibitory effects of auxin on abscission. These results indicated that SlHB15A mediates the antagonistic effect of auxin and JA-Ile during tomato pedicel abscission, while auxin inhibits abscission through the SlHB15A-SlJAR1 module.
PMID: 35522030
Plant Physiol , IF:8.34 , 2022 Aug , V189 (4) : P2091-2109 doi: 10.1093/plphys/kiac213
High temperature induces male sterility via MYB66-MYB4-Casein kinase I signaling in cotton.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, Hubei, China.; College of Life Sciences, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, Guangdong, China.
High temperature (HT) causes male sterility and decreases crop yields. Our previous works have demonstrated that sugar and auxin signaling pathways, Gossypium hirsutum Casein kinase I (GhCKI), and DNA methylation are all involved in HT-induced male sterility in cotton. However, the signaling mechanisms leading to distinct GhCKI expression patterns induced by HT between HT-tolerant and HT-sensitive cotton anthers remain largely unknown. Here, we identified a GhCKI promoter (ProGhCKI) region that functions in response to HT in anthers and found the transcription factor GhMYB4 binds to this region to act as an upstream positive regulator of GhCKI. In the tapetum of early-stage cotton anthers, upregulated expression of GhMYB4 under HT and overexpressed GhMYB4 under normal temperature both led to severe male sterility phenotypes, coupled with enhanced expression of GhCKI. We also found that GhMYB4 interacts with GhMYB66 to form a heterodimer to enhance its binding to ProGhCKI. However, GhMYB66 showed an expression pattern similar to GhMYB4 under HT but did not directly bind to ProGhCKI. Furthermore, HT reduced siRNA-mediated CHH DNA methylations in the GhMYB4 promoter, which enhanced the expression of GhMYB4 in tetrad stage anthers and promoted the formation of the GhMYB4/GhMYB66 heterodimer, which in turn elevated the transcription of GhCKI in the tapetum, leading to male sterility. Overall, we shed light on the GhMYB66-GhMYB4-GhCKI regulatory pathway in response to HT in cotton anthers.
PMID: 35522025
Plant Physiol , IF:8.34 , 2022 Aug , V189 (4) : P2454-2466 doi: 10.1093/plphys/kiac194
SAUR15 interaction with BRI1 activates plasma membrane H+-ATPase to promote organ development of Arabidopsis.
State Key Laboratory of Grassland Agro-ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, People's Republic of China.; Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, Ontario K1S 5B6, Canada.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China.; School of Life Sciences, Guangzhou University, Guangzhou 510006, People's Republic of China.
Brassinosteroids (BRs) are an important group of plant steroid hormones that regulate growth and development. Several members of the SMALL AUXIN UP RNA (SAUR) family have roles in BR-regulated hypocotyl elongation and root growth. However, the mechanisms are unclear. Here, we show in Arabidopsis (Arabidopsis thaliana) that SAUR15 interacts with cell surface receptor-like kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) in BR-treated plants, resulting in enhanced BRI1 phosphorylation status and recruitment of the co-receptor BRI1-ASSOCIATED RECEPTOR KINASE 1. Genetic and phenotypic assays indicated that the SAUR15 effect on BRI1 can be uncoupled from BRASSINOSTEROID INSENSITIVE 2 activity. Instead, we show that SAUR15 promotes BRI1 direct activation of plasma membrane H+-ATPase (PM H+-ATPase) via phosphorylation. Consequently, SAUR15-BRI1-PM H+-ATPase acts as a direct, PM-based mode of BR signaling that drives cell expansion to promote the growth and development of various organs. These data define an alternate mode of BR signaling in plants.
PMID: 35511168
Environ Pollut , IF:8.071 , 2022 Aug , V306 : P119375 doi: 10.1016/j.envpol.2022.119375
Physiological and Transcriptomic Analysis provide Molecular Insight into 24-Epibrassinolide mediated Cr(VI)-Toxicity Tolerance in Pepper Plants.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China; Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China.; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China.; College of Ecology and Environment, Hainan University, Haikou, 570100, China.; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, 570100, China; Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China. Electronic address: wangzhiwei@hainanu.edu.cn.
The ever-increasing industrial activities over the decades have generated high toxic metals such as chromium (Cr) that hampers plant growth and development. To counter Cr-toxicity, plants have evolved complex defensive systems including hormonal crosstalk with various signaling pathways. 24-epibrassinolide (24-EBR) lowers oxidative stress and alleviates Cr(VI)-toxicity in plants. In this study, the concealed BR-mediated influences on Cr(VI)-stress tolerance were explored by transcriptome analysis in the Capsicum annuum. Results revealed a linkage between plant development under Cr(VI)-stress and the mitigating effect of 24-epibrassinolide and brassinazole. Growth inhibition, chlorophyll degradation, and a significant rise of malondialdehyde (MDA) were observed after 40 mg/L Cr(VI) treatment in Brz supplemented seedlings, whereas 24-EBR supplemented seedlings exhibited commendatory effect. Comparative transcriptome analysis showed that the expression levels of 6687 genes changed (3846 up-regulated and 2841 downregulated) under Cr(VI)-stress with Brz supplementation. Whereas the expression levels of only 1872 genes changed under Cr(VI)-stress with 24-EBR supplementation (1223 up-regulated and 649 downregulated). The functional categories of the differentially expressed genes (DEGs) by gene ontology (GO) revealed that drug transport, defense responses, and drug catabolic process were the considerable enrichments between 24-EBR and Brz supplemented seedlings under Cr(VI)-stress. Furthermore, auxin signaling, glutathione metabolism, ABC transporters, MAPK pathway, and 36 heavy metal-related genes were significantly differentially expressed components between Cr(VI)-stress, 24-EBR, and Brz supplemented seedlings. Overall, our data demonstrate that employing 24-EBR can commendably act as a growth stimulant in plants subjected to Cr(VI)-stress by modulating the physiological and defense regulatory system.
PMID: 35500717
Sci Total Environ , IF:7.963 , 2022 Aug : P158287 doi: 10.1016/j.scitotenv.2022.158287
Perfluorooctanoic acid and perfluorooctane sulfonic acid inhibit plant growth through the modulation of phytohormone signalling pathways: Evidence from molecular and genetic analysis in Arabidopsis.
College of Horticulture, Shanxi Agricultural University, Taigu 030801, China.; College of Horticulture, Shanxi Agricultural University, Taigu 030801, China. Electronic address: xujin@sxau.edu.cn.
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most representative perfluoroalkyl substances that accumulate in the food chain and are harmful to the environment. The uptake, translocation and physiological effects of PFOA and PFOS in plants have been reported in recent years; however, the regulatory mechanisms underlying PFOA- and PFOS-mediated plant growth and development remain largely unclear. Here, using Arabidopsis thaliana as the study material, we showed that both PFOA and PFOS inhibited plant growth; PFOS showed a stronger inhibitory effect on primary root (PR) growth, whereas PFOA exerted a stronger inhibitory effect on photosynthesis. Transcriptome analysis revealed that PFOA- and PFOS-modulated plant growth and development were correlated with the phytohormones auxin and abscisic acid (ABA). Further genetic analyses using mutants related to auxin biosynthesis, receptors and transport and mutants related to ABA biosynthesis and signalling transduction revealed that both PFOA and PFOS inhibited PR growth by modulating auxin biosynthesis and signalling pathways, and the ABA signalling pathway was also involved in PFOS-mediated PR growth inhibition. Collectively, these results shed new light on the molecular mechanisms of PFOA- and PFOS-mediated root system growth and their effects on phytohormone signalling pathways in plants.
PMID: 36030856
Curr Opin Plant Biol , IF:7.834 , 2022 Aug , V68 : P102258 doi: 10.1016/j.pbi.2022.102258
Inter-organismal phytohormone networks in plant-microbe interactions.
State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.; State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Wuhan 430070, China; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China. Electronic address: tsuda@mail.hzau.edu.cn.
Phytohormones are produced by plants and play central roles in interactions with pathogenic and beneficial microbes as well as plant growth and development. Each phytohormone pathway consists of its biosynthesis, transport, perception, and signaling and is intertwined with each other at various levels to form phytohormone networks in plants. Different kinds of microbes also produce phytohormones that exert physiological roles within microbes and manipulate phytohormone networks in plants by using phytohormones, their mimics, and proteinaceous effectors. In turn, plant-derived phytohormones can directly or indirectly through plant signaling networks affect microbial metabolism and community assembly. Therefore, phytohormone networks in plants and microbes are connected through plant and microbial phytohormones and other molecules to form inter-organismal phytohormone networks. In this review, we summarize recent progress on molecular mechanisms of inter-organismal phytohormone networks and discuss future steps necessary for advancing our understanding of phytohormone networks.
PMID: 35820321
Plant Cell Environ , IF:7.228 , 2022 Aug , V45 (8) : P2508-2519 doi: 10.1111/pce.14366
The co-chaperone HOP participates in TIR1 stabilisation and in auxin response in plants.
Centro de Biotecnologia y Genomica de Plantas. Universidad Politecnica de Madrid (UPM) - Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria-CSIC (INIA/CSIC), Campus de Montegancedo UPM, Pozuelo de Alarcon, Madrid, Spain.; Departamento de Botanica, Ecologia y Fisiologia Vegetal, Universidad de Cordoba, Campus de Rabanales, Cordoba, Spain.; Fundacion Instituto Leloir and Instituto de Investigaciones Bioquimicas de Buenos Aires (IIBA, CONICET), Buenos Aires, Argentina.
HOP (HSP70-HSP90 organising protein) is a conserved family of co-chaperones well known in mammals for its role in the folding of signalling proteins associated with development. In plants, HOP proteins have been involved in the response to multiple stresses, but their role in plant development remains elusive. Herein, we describe that the members of the HOP family participate in different aspects of plant development as well as in the response to warm temperatures through the regulation of auxin signalling. Arabidopsis hop1 hop2 hop3 triple mutant shows different auxin-related phenotypes and a reduced auxin sensitivity. HOP interacts with TIR1 auxin coreceptor in vivo. Furthermore, TIR1 accumulation and auxin transcriptional response are reduced in the hop1 hop2 hop3 triple mutant, suggesting that HOP's function in auxin signalling is related, at least, to TIR1 interaction and stabilisation. Interestingly, HOP proteins form part of the same complexes as SGT1b (a different HSP90 co-chaperone) and these co-chaperones synergistically cooperate in auxin signalling. This study provides relevant data about the role of HOP in auxin regulation in plants and uncovers that both co-chaperones, SGT1b and HOP, cooperate in the stabilisation of common targets involved in plant development.
PMID: 35610185
Microbiol Spectr , IF:7.171 , 2022 Jul : Pe0081022 doi: 10.1128/spectrum.00810-22
Impact of Phyllosphere Methylobacterium on Host Rice Landraces.
National Center for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
The genus Methylobacterium includes widespread plant-associated bacteria that are abundant in the plant phyllosphere (leaf surfaces), consume plant-secreted methanol, and can produce plant growth-promoting metabolites. However, despite the potential to increase agricultural productivity, their impact on host fitness in the natural environment is relatively poorly understood. Here, we conducted field experiments with three traditionally cultivated rice landraces from northeastern India. We inoculated seedlings with native versus nonnative phyllosphere Methylobacterium strains and found significant impacts on plant growth and grain yield. However, these effects were variable. Whereas some Methylobacterium isolates were beneficial for their host, others had no impact or were no more beneficial than the bacterial growth medium on its own. Host plant benefits were not consistently associated with Methylobacterium colonization and did not have altered phyllosphere microbiome composition, changes in the early expression of plant stress response pathways, or bacterial auxin production. We provide the first demonstration of the benefits of phyllosphere Methylobacterium for rice yield under field conditions and highlight the need for further analysis to understand the mechanisms underlying these benefits. Given that the host landrace-Methylobacterium relationship was not generalizable, future agricultural applications will require careful testing to identify coevolved host-bacterium pairs that may enhance the productivity of high-value rice varieties. IMPORTANCE Plants are associated with diverse microbes in nature. Do the microbes increase host plant health, and can they be used for agricultural applications? This is an important question that must be answered in the field rather than in the laboratory or greenhouse. We tested the effects of native, leaf-inhabiting bacteria (genus Methylobacterium) on traditionally cultivated rice varieties in a crop field. We found that inoculation with some bacteria increased rice grain production substantially while a nonnative bacterium reduced plant health. Overall, the effect of bacterial inoculation varied across pairs of rice varieties and their native bacteria. Thus, knowledge of evolved associations between specific bacteria hosted by specific rice varieties is necessary to develop ways to increase the yield of traditional rice landraces and preserve these important sources of cultural and genetic diversity.
PMID: 35856668
Cell Biosci , IF:7.133 , 2022 Jul , V12 (1) : P107 doi: 10.1186/s13578-022-00840-4
Transcriptomic analysis reveals the key role of histone deacetylation via mediating different phytohormone signalings in fiber initiation of cotton.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 450001, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, 572024, Hainan, China.; Sanya Institute, Zhengzhou University, Sanya, 572024, Hainan, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 450001, China. xingyadi@zzu.edu.cn.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 450001, China. aylifug@caas.cn.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China. aylifug@caas.cn.
BACKGROUND: Histone deacetylation is one of the most important epigenetic modifications and plays diverse roles in plant development. However, the detailed functions and mechanisms of histone deacetylation in fiber development of cotton are still unclear. HDAC inhibitors (HDACi) have been commonly used to study the molecular mechanism underlying histone deacetylation or to facilitate disease therapy in humans through hindering the histone deacetylase catalytic activity. Trichostatin A (TSA)-the most widely used HDACi has been extensively employed to determine the role of histone deacetylation on different developmental stages of plants. RESULTS: Through in vitro culture of ovules, we observed that exogenous application of TSA was able to inhibit the fiber initiation development. Subsequently, we performed a transcriptomic analysis to reveal the underlying mechanisms. The data showed that TSA treatment resulted in 4209 differentially expressed genes, which were mostly enriched in plant hormone signal transduction, phenylpropanoid biosynthesis, photosynthesis, and carbon metabolism pathways. The phytohormone signal transduction pathways harbor the most differentially expressed genes. Deeper studies showed that some genes promoting auxin, Gibberellic Acid (GA) signaling were down-regulated, while some genes facilitating Abscisic Acid (ABA) and inhibiting Jasmonic Acid (JA) signaling were up-regulated after the TSA treatments. Further analysis of plant hormone contents proved that TSA significantly promoted the accumulation of ABA, JA and GA3. CONCLUSIONS: Collectively, histone deacetylation can regulate some key genes involved in different phytohormone pathways, and consequently promoting the auxin, GA, and JA signaling, whereas repressing the ABA synthesis and signaling to improve the fiber cell initiation. Moreover, the genes associated with energy metabolism, phenylpropanoid, and glutathione metabolism were also regulated by histone deacetylation. The above results provided novel clues to illuminate the underlying mechanisms of epigenetic modifications as well as related different phytohormones in fiber cell differentiation, which is also very valuable for the molecular breeding of higher quality cotton.
PMID: 35831870
J Integr Plant Biol , IF:7.061 , 2022 Aug doi: 10.1111/jipb.13347
The SlTPL3-SlWUS module regulates multi-locule formation in tomato by modulating auxin and gibberellin levels in the shoot apical meristem.
Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.; Laboratory of Genomics and Biotechnology of Fruits, INRA, Toulouse INP, University of Toulouse, Castanet Tolosan, France.
Malformed fruits depreciate a plant's market value. In tomato (Solanum lycopersicum), fruit malformation is associated with the multi-locule trait, which involves genes regulating shoot apical meristem (SAM) development. The expression pattern of TOPLESS3 (SlTPL3) throughout SAM development prompted us to investigate its functional significance via RNA interference (RNAi) and CRISPR/Cas9-mediated gene editing. Lower SlTPL3 transcript levels resulted in larger fruits with more locules and larger SAMs at the DAG5 stage. Differentially expressed genes in the SAM of wild-type (WT) and SlTPL3-RNAi plants, identified by transcriptome deep sequencing (RNA-seq), were enriched in the gibberellin (GA) biosynthesis and plant hormone signaling pathways. Moreover, exogenous auxin and paclobutrazol treatments rescued the multi-locule phenotype, indicating that SlTPL3 affects SAM size by mediating auxin and GA levels in the SAM. Furthermore, SlTPL3 interacted with WUSCHEL (SlWUS), which plays an important role in SAM size maintenance. We conducted RNA-seq and DNA affinity purification followed by sequencing (DAP-seq) analyses to identify the genes regulated by SlTPL3 and SlWUS in the SAM and to determine how they regulate SAM size. We detected 24 overlapping genes regulated by SlTPL3 and SlWUS and harboring an SlWUS-binding motif in their promoters. Furthermore, functional annotation revealed a notable enrichment for functions in auxin transport, auxin signal transduction, and GA biosynthesis. Dual-luciferase assays also revealed that SlTPL3 enhances SlWUS-mediated regulation (repression and activation) of SlPIN3 and SlGA2ox4 transcription, indicating that the SlTPL3-SlWUS module regulates SAM size by mediating auxin distribution and GA levels, and perturbations of this module result in enlarged SAM. These results provide novel insights into the molecular mechanism of SAM maintenance and locule formation in tomato and highlight the SlTPL3-SlWUS module as a key regulator. This article is protected by copyright. All rights reserved.
PMID: 35980297
J Integr Plant Biol , IF:7.061 , 2022 Aug doi: 10.1111/jipb.13341
The unconventional prefoldin RPB5 interactor mediates the gravitropic response by modulating cytoskeleton organization and auxin transport in Arabidopsis.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, 253023, China.; Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schanzlestrasse 1, D-79104, Freiburg, Germany.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai, China.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.
Gravity-induced root curvature involves the asymmetric distribution of the phytohormone auxin. This response depends on the concerted activities of the auxin transporters such as PIN-FORMED (PIN) proteins for auxin efflux and AUXIN RESISTANT 1 (AUX1) for auxin influx. However, how the auxin gradient is established remains elusive. Here we identified a new mutant with a short root, strong auxin distribution in the lateral root cap and an impaired gravitropic response. The causal gene encoded an Arabidopsis homolog of the human unconventional prefoldinRPB5 interactor (URI). AtURI interacted with prefoldin 2 (PFD2) and PFD6, two beta-type PFD members that modulate actin and tubulin patterning in roots. The auxin reporter DR5 rev :GFP showed that asymmetric auxin redistribution after gravistimulation is disordered in aturi-1 root tips. Treatment with the endomembrane protein trafficking inhibitor brefeldin A indicated that recycling of the auxin transporter PIN2 is disrupted in aturi-1 roots as well as in pfd mutants. We propose that AtURI cooperates with PFDs to recycle PIN2 and modulate auxin distribution. This article is protected by copyright. All rights reserved.
PMID: 35943836
J Integr Plant Biol , IF:7.061 , 2022 Aug doi: 10.1111/jipb.13336
FERONIA is involved in the phototropin 1-mediated blue light phototropic growth in Arabidopsis.
School of Life Sciences, Central South University, Changsha, 410078, China.; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, and Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.; Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.; State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, China.
Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates (PKSs), the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants. This article is protected by copyright. All rights reserved.
PMID: 35924740
J Integr Plant Biol , IF:7.061 , 2022 Jul doi: 10.1111/jipb.13326
Abscisic acid-dependent PMT1 expression regulates salt tolerance by alleviating abscisic acid-mediated reactive oxygen species production in Arabidopsis.
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.; State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, 311300, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
Phosphocholine (PCho) is an intermediate metabolite of nonplastid plant membranes that is essential for salt tolerance. However, how PCho metabolism modulates response to salt stress remains unknown. Here, we characterize the role of phosphoethanolamine N-methyltransferase 1 (PMT1) in salt stress tolerance in Arabidopsis thaliana using a T-DNA insertional mutant, gene-editing alleles, and complemented lines. The pmt1 mutants showed a severe inhibition of root elongation when exposed to salt stress, but exogenous ChoCl or lecithin rescued this defect. pmt1 also displayed altered glycerolipid metabolism under salt stress, suggesting that glycerolipids contribute to salt tolerance. Moreover, pmt1 mutants exhibited altered reactive oxygen species (ROS) accumulation and distribution, reduced cell division activity, and disturbed auxin distribution in the primary root compared with wild-type seedlings. We show that PMT1 expression is induced by salt stress and relies on the abscisic acid (ABA) signaling pathway, as this induction was abolished in the aba2-1 and pyl112458 mutants. However, ABA aggravated the salt sensitivity of the pmt1 mutants by perturbing ROS distribution in the root tip. Taken together, we propose that PMT1 is an important phosphoethanolamine N-methyltransferase participating in root development of primary root elongation under salt stress conditions by balancing ROS production and distribution through ABA signaling.
PMID: 35789105
J Exp Bot , IF:6.992 , 2022 Aug doi: 10.1093/jxb/erac336
Genetic modification of PIN genes induces causal mechanisms of stay-green drought adaptation phenotype.
University of Queensland, Queensland Alliance for Agriculture and Food Innovation (QAAFI), Warwick, QLD 4370, Australia.; University of Queensland, QAAFI, Brisbane, QLD 4072, Australia.; Agri-Science Queensland, Department of Agriculture & Fisheries, Warwick, QLD 4370, Australia.; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.; Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA.
The stay-green trait is recognised as a key drought adaptation mechanism in cereals worldwide. Stay-green sorghum plants exhibit delayed senescence of leaves and stems, leading to prolonged growth, a reduced risk of lodging and higher grain yield under end-of-season drought stress. More than 45 quantitative trait loci (QTL) associated with stay-green have been identified, including two major QTL (Stg1 and Stg2). However, none of the contributing genes that regulate functional stay-green are known. Here we show that the PIN FORMED family of auxin efflux carriers induce some of the causal mechanisms driving the stay-green phenotype in sorghum, with SbPIN4 and SbPIN2 located in Stg1 and Stg2, respectively. We found that 9 of 11 sorghum PIN genes aligned with known stay-green QTL. In transgenic studies, we demonstrated that PIN genes located within the Stg1 (SbPIN4), Stg2 (SbPIN2) and Stg3b (SbPIN1) QTL regions acted pleiotropically to modulate canopy development, root architecture and panicle growth in sorghum, with SbPIN1, SbPIN2 and SbPIN4 differentially expressed in various organs relative to the non stay-green control. The emergent consequence of such modifications in canopy and root architecture is a stay-green phenotype. Crop simulation modelling shows that the SbPIN2 phenotype can increase grain yield under drought.
PMID: 35961690
J Exp Bot , IF:6.992 , 2022 Aug , V73 (14) : P4612-4614 doi: 10.1093/jxb/erac238
How do plant roots overcome physical barriers?
Triticeae Research Institute, Sichuan Agricultural University, 611130 Chengdu, China.; Key Laboratory of Plant-Soil Interactions, MOE, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, 100193 Beijing, China.; Molecular Plant Nutrition, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Gatersleben, Germany.
PMID: 35950462
J Exp Bot , IF:6.992 , 2022 Aug doi: 10.1093/jxb/erac318
GmHY2a encodes a phytochromobilin synthase that regulates internode length and flowering time in soybean.
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Changchun 130012, China.; University of Chinese Academy of Sciences, Beijing 100049, China.
Plant height and flowering time are important agronomic traits that directly affect soybean [Glycine max (L.) Merr.] adaptability and yield. Here, the Glycine max long internode 1 (Gmlin1) mutant was selected from an ethyl methyl sulfonate (EMS)-mutated Williams 82 population due to its long internodes and early flowering. Using bulked segregant analysis (BSA), the Gmlin1 locus was mapped to Glyma.02G304700, a homologue of the Arabidopsis HY2 gene, which encodes a phytochromobilin (PPhiB) synthase involved in phytochrome chromophore synthesis. Mutation of GmHY2a resulted in failure of the de-etiolation response under both red and far-red light. The Gmlin1 mutant exhibits a constitutive shade avoidance response under normal light, and the mutations influence the auxin and gibberellin pathways to promote internode elongation. The Gmlin1 mutant also exhibits decreased photoperiod sensitivity. In addition, the soybean photoperiod repressor gene E1 is downregulated in the Gmlin1 mutant, resulting in accelerated flowering. The nuclear import of phytochrome A (GmphyA) and GmphyB following light treatment was decreased in Gmlin1 protoplasts, indicating that the weak light response of the Gmlin1 mutant is caused by a decrease in functional phytochrome. Together, these results indicate that GmHY2a plays an important role in soybean phytochrome biosynthesis and provide insights into the adaptability of the soybean plant.
PMID: 35946571
J Exp Bot , IF:6.992 , 2022 Aug doi: 10.1093/jxb/erac326
The protein phosphatase 2A catalytic subunit StPP2Ac2b is involved in the control of potato tuber sprouting and source-sink balance in tubers and sprouts.
Instituto de Investigaciones en Ingenieria Genetica y Biologia Molecular "Dr. Hector Torres", Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET). Vuelta de Obligado 2490, C1428ADN Buenos Aires, Argentina.
Sprouting negatively affects the quality of stored potato tubers. Understanding the molecular mechanisms that control this process is important for the development of potato varieties with desired sprouting characteristics. The serine/threonine protein phosphatase type 2A (PP2A) has been implicated in several developmental programs and stress responses in plants. PP2A comprises a catalytic (PP2Ac), a scaffolding (A) and a regulatory (B) subunit. In cultivated potato, six PP2Ac isoforms were identified, named StPP2Ac1, 2a, 2b, 3, 4 and 5. In this study we evaluated the sprouting behavior of potato tubers overexpressing the catalytic subunit 2b (StPP2Ac2b-OE). The onset of sprouting and initial sprout elongation is significantly delayed in StPP2Ac2b-OE tubers; however, sprout growth is accelerated during the late stages of development, due to a high degree of branching. StPP2Ac2b-OE tubers also exhibit a pronounced loss of apical dominance. These developmental characteristics are accompanied by changes in carbohydrate metabolism and response to gibberellic acid, and a differential balance between abscisic acid, gibberellic acid, cytokinins and auxin. Overexpression of StPP2Ac2b alters the source-sink balance, increasing the source capacity of the tuber, and the sink strength of the sprout to support its accelerated growth.
PMID: 35925650
J Exp Bot , IF:6.992 , 2022 Jul doi: 10.1093/jxb/erac319
bZIP88 transcription factor upregulation is involved in resistance to three different herbicides in both Echinochloa crus-galli and Echinochloa glabrescens.
College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.; Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education.
The resistance of weeds to herbicides poses a huge threat to agricultural production. Non target-site resistance (NTSR) is often more detrimental as NTSR mechanisms can in some cases confer resistance to herbicides from multiple modes of action, termed here as multiple-herbicide resistance (MHR). We hypothesized that bZIP transcription factors (TFs), which regulate abiotic stress responses in many plants, play a regulatory role in NTSR. The results of whole-plant assays revealed that Echinochloa crus-galli and E. glabrescens are resistant to the herbicides penoxsulam, cyhalofop-butyl, and quintrione. The results of transcriptome sequencing identified 101 and 49 bZIP TFs with altered expression with differential expression following penoxsulam treatment in E. crus-galli and E. glabrescens, respectively. Twelve of these genes (bZIP36/37/39/4/44/45/50/52/53/79/87/88) had >60% homology with rice genes. bZIP88 expression was considerably upregulated 6 h after treatment with three different herbicides. The relative expression levels before and 12 h after herbicide treatment were not different, and the upregulation was similar between resistant and susceptible populations. We used rice (Oryza sativa L. japonica. cv. Nipponbare) as a model system for functional validation. CRISPR/Cas9 bZIP88 ortholog in rice knockouts increased sensitivity, whereas overexpression reduced. The OsbZIP88 proteins localized to the nucleus. OsbZIP88 was found, with chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-Seq), to form a network regulatory center with other TFs such as bZIP20/52/59, that regulate genes (OsKS1, OsCOE1, OsIM1) related to auxin, abscisic acid (ABA), brassinosteroids (BR), gibberellic acid (GA). Based on these results, weestablished a database of bZIP TFs corresponding to herbicide stress, and resolved the mechanisms of the positive regulation of herbicide resistance by bZIP88, creating a new perspective for NTSR.
PMID: 35867472
J Exp Bot , IF:6.992 , 2022 Jul doi: 10.1093/jxb/erac282
TOR kinase, a GPS in the complex nutrient and hormonal signaling networks to guide plant growth and development.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Haixia Institute of Science and Technology, Plant Synthetic Biology Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA.
To survive and sustain growth, sessile plants have developed sophisticated internal signalling networks that respond to various external and internal cues. Despite the central roles of nutrient and hormone signaling in plant growth and development, how hormone-driven processes coordinate with metabolic status remains largely enigmatic. Target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates energy, nutrients, growth factors, hormones and stress signals to promote growth in all eukaryotes. Inspired by recent comprehensive systems, chemical, genetic and genomic studies on plant TOR, this review discusses a potential role of TOR as the global positioning system to both temporally and spatially direct plant growth and developmental programs by integrating dynamic information in the complex nutrient and hormonal signaling networks. We further evaluate and depict the possible functional and mechanistic models for how a single protein kinase TOR is able to recognize, integrate and even distinguish a plethora of positive and negative input signals to execute appropriate and distinct downstream biological processes via multiple partners and effectors.
PMID: 35781569
J Exp Bot , IF:6.992 , 2022 Aug , V73 (14) : P4832-4849 doi: 10.1093/jxb/erac187
From fruit growth to ripening in plantain: a careful balance between carbohydrate synthesis and breakdown.
Biosystems Department, KULeuven, 3001 Leuven, Belgium.; INRAE, Fruit Biology and Pathology, Universite De Bordeaux, UMR 1332, 33140 Villenave d'Ornon, France.; IITA, Crop Breeding, Ibadan 200001, Oyo State, Nigeria.; IITA, Crop Breeding, PO Box 7878, Kampala, Uganda.; Bioversity International, Biodiversity for Food and Agriculture, 3001 Leuven, Belgium.; SYBIOMA, KULeuven, 3001 Leuven, Belgium.
In this study, we aimed to investigate for the first time different fruit development stages in plantain banana in order gain insights into the order of appearance and dominance of specific enzymes and fluxes. We examined fruit development in two plantain banana cultivars during the period between 2-12 weeks after bunch emergence using high-throughput proteomics, quantification of major metabolites, and analyses of metabolic fluxes. Starch synthesis and breakdown are processes that take place simultaneously. During the first 10 weeks fruits accumulated up to 48% of their dry weight as starch, and glucose 6-phosphate and fructose were important precursors. We found a unique amyloplast transporter and hypothesize that it facilitates the import of fructose. We identified an invertase originating from the Musa balbisiana genome that would enable carbon flow back to growth and starch synthesis and maintain a high starch content even during ripening. Enzymes associated with the initiation of ripening were involved in ethylene and auxin metabolism, starch breakdown, pulp softening, and ascorbate biosynthesis. The initiation of ripening was cultivar specific, with faster initiation being particularly linked to the 1-aminocyclopropane-1-carboxylate oxidase and 4-alpha glucanotransferase disproportionating enzymes. Information of this kind is fundamental to determining the optimal time for picking the fruit in order to reduce post-harvest losses, and has potential applications for breeding to improve fruit quality.
PMID: 35512676
J Exp Bot , IF:6.992 , 2022 Aug , V73 (14) : P4716-4732 doi: 10.1093/jxb/erac188
ROOT PENETRATION INDEX 3, a major quantitative trait locus associated with root system penetrability in Arabidopsis.
Unidad de Genomica Avanzada/LANGEBIO, Centro de Investigacion y de Estudios Avanzados, Irapuato, Mexico.; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, USA.; Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
Soil mechanical impedance precludes root penetration, confining root system development to shallow soil horizons where mobile nutrients are scarce. Using a two-phase-agar system, we characterized Arabidopsis responses to low and high mechanical impedance at three root penetration stages. We found that seedlings whose roots fail to penetrate agar barriers show a significant reduction in leaf area, root length, and elongation zone and an increment in root diameter, while those capable of penetrating show only minor morphological effects. Analyses using different auxin-responsive reporter lines, exogenous auxins, and inhibitor treatments suggest that auxin responsiveness and PIN-mediated auxin distribution play an important role in regulating root responses to mechanical impedance. The assessment of 21 Arabidopsis accessions revealed that primary root penetrability varies widely among accessions. To search for quantitative trait loci (QTLs) associated to root system penetrability, we evaluated a recombinant inbred population derived from Landsberg erecta (Ler-0, with a high primary root penetrability) and Shahdara (Sha, with a low primary root penetrability) accessions. QTL analysis revealed a major-effect QTL localized in chromosome 3, ROOT PENETRATION INDEX 3 (q-RPI3), which accounted for 29.98% (logarithm of odds=8.82) of the total phenotypic variation. Employing an introgression line (IL-321) with a homozygous q-RPI3 region from Sha in the Ler-0 genetic background, we demonstrated that q-RPI3 plays a crucial role in root penetrability. This multiscale study reveals new insights into root plasticity during the penetration process in hard agar layers, natural variation, and genetic architecture behind primary root penetrability in Arabidopsis.
PMID: 35512438
J Exp Bot , IF:6.992 , 2022 Aug , V73 (14) : P4818-4831 doi: 10.1093/jxb/erac185
Arabidopsis TWISTED DWARF1 regulates stamen elongation by differential activation of ABCB1,19-mediated auxin transport.
University of Fribourg, Department of Biology, CH-1700 Fribourg, Switzerland.; IBPM-CNR, Dipartimento di Biologia e Biotecnologie, Sapienza Universita di Roma, P. le A. Moro 5, 00185 Roma, Italy.
Despite clear evidence that a local accumulation of auxin is likewise critical for male fertility, much less is known about the components that regulate auxin-controlled stamen development. In this study, we analyzed physiological and morphological parameters in mutants of key players of ABCB-mediated auxin transport, and spatially and temporally dissected their expression on the protein level as well as auxin fluxes in the Arabidopsis stamens. Our analyses revealed that the FKBP42, TWISTED DWARF1 (TWD1), promotes stamen elongation and, to a lesser extent, anther dehiscence, as well as pollen maturation, and thus is required for seed development. Most of the described developmental defects in twd1 are shared with the abcb1 abcb19 mutant, which can be attributed to the fact that TWD1-as a described ABCB chaperone-is a positive regulator of ABCB1- and ABCB19-mediated auxin transport. However, reduced stamen number was dependent on TWD1 but not on investigated ABCBs, suggesting additional players downstream of TWD1. We predict an overall housekeeping function for ABCB1 during earlier stages, while ABCB19 seems to be responsible for the key event of rapid elongation at later stages of stamen development. Our data indicate that TWD1 controls stamen development by differential activation of ABCB1,19-mediated auxin transport in the stamen.
PMID: 35512423
Int J Biol Macromol , IF:6.953 , 2022 Aug , V220 : P67-78 doi: 10.1016/j.ijbiomac.2022.08.065
PIN and PILS family genes analyses in Chrysanthemum seticuspe reveal their potential functions in flower bud development and drought stress.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Flower Biology and Germplasm Innovation, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, Nanjing Agricultural University, Nanjing 210095, China; College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Flower Biology and Germplasm Innovation, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Biology of Ornamental Plants in East China, National Forestry and Grassland Administration, Nanjing Agricultural University, Nanjing 210095, China; College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: chensm@njau.edu.cn.
Auxin affects almost all plant growth and developmental processes. The PIN-FORMED (PIN) and PIN-LIKES (PILS) family genes determine the direction and distribution gradient of auxin flow by polar localization on the cell membrane. However, there are no systematic studies on PIN and PILS family genes in chrysanthemum. Here, 18 PIN and 13 PILS genes were identified in Chrysanthemum seticuspe. The evolutionary relationships, physicochemical properties, conserved motifs, cis-acting elements, chromosome localization, collinearity, and expression characteristics of these genes were analyzed. CsPIN10a, CsPIN10b, and CsPIN10c are unique PIN genes in C. seticuspe. Expression pattern analysis showed that these genes had different tissue specificities, and the expression levels of CsPIN8, CsPINS1, CsPILS6, and CsPILS10 were linearly related to the developmental period of the flower buds. In situ hybridization assay showed that CsPIN1a, CsPIN1b, and CsPILS8 were expressed in floret primordia and petal tips, and CsPIN1a was specifically expressed in the middle of the bract primordia, which might regulate lateral expansion of the bracts. CsPIN and CsPILS family genes are also involved in drought stress responses. This study provides theoretical support for the cultivation of new varieties with attractive flower forms and high drought tolerance.
PMID: 35970365
Development , IF:6.868 , 2022 Aug doi: 10.1242/dev.200715
The dynamic proteome in Arabidopsis thaliana early embryogenesis.
State Key Laboratory of Agrobiotechnology and School of Life Science, The Chinese University of Hong Kong, 999077, Hong Kong, China.; Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China.
The morphology of the flowering plant is established during early embryogenesis. In recent years, many studies have focused on transcriptional profiling in plant embryogenesis, while the dynamic landscape of Arabidopsis thaliana proteome remains elusive. In this study, Arabidopsis embryos at 2/4-cell, 8-cell, 16-cell, 32-cell, globular, and heart stages were collected for nanoproteomic analysis. In total, 5,386 proteins were identified. Among them, 1051 proteins were universally identified in all developmental stages and a range of 27 to 2154 proteins was found to be stage-specific. These proteins could be clustered into eight clusters according to their expression levels. Gene Ontology enrichment analysis showed that proteins involved in ribosome biogenesis and auxin-activated signalling were enriched during early embryogenesis, indicating active translation and auxin signalling were important events in Arabidopsis embryo development. Combining RNA-Seq data, the correlation between mRNA and protein was evaluated. An overall positive correlation was found between mRNA and protein (mean p-value=0.75). This work provided a comprehensive landscape of proteome in Arabidopsis early embryogenesis. Some important proteins/transcription factors identified through network analysis may serve as potential targets for future investigation.
PMID: 35950926
Development , IF:6.868 , 2022 Jul , V149 (13) doi: 10.1242/dev.200929
PILS proteins provide a homeostatic feedback on auxin signaling output.
Institute of Molecular Plant Biology (IMPB), Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria.; Faculty of Biology, Department of Molecular Plant Physiology (MoPP), University of Freiburg, 79104 Freiburg, Germany.; Center for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
Multiple internal and external signals modulate the metabolism, intercellular transport and signaling of the phytohormone auxin. Considering this complexity, it remains largely unknown how plant cells monitor and ensure the homeostasis of auxin responses. PIN-LIKES (PILS) intracellular auxin transport facilitators at the endoplasmic reticulum are suitable candidates to buffer cellular auxin responses because they limit nuclear abundance and signaling of auxin. We used forward genetics to identify gloomy and shiny pils (gasp) mutants that define the PILS6 protein abundance in a post-translational manner. Here, we show that GASP1 encodes an uncharacterized RING/U-box superfamily protein that impacts on auxin signaling output. The low auxin signaling in gasp1 mutants correlates with reduced abundance of PILS5 and PILS6 proteins. Mechanistically, we show that high and low auxin conditions increase and reduce PILS6 protein levels, respectively. Accordingly, non-optimum auxin concentrations are buffered by alterations in PILS6 abundance, consequently leading to homeostatic auxin output regulation. We envision that this feedback mechanism provides robustness to auxin-dependent plant development.
PMID: 35819066
Cells , IF:6.6 , 2022 Aug , V11 (16) doi: 10.3390/cells11162484
Contrasting Roles of Ethylene Response Factors in Pathogen Response and Ripening in Fleshy Fruit.
Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.; College of Agriculture and Biotechnology, Zhejiang University, Zijinggang Campus, Hangzhou 310058, China.; College of Food Science and Engineering, Hainan University, Haikou 570228, China.; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijinggang Campus, Hangzhou 310058, China.; Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
Fleshy fruits are generally hard and unpalatable when unripe; however, as they mature, their quality is transformed by the complex and dynamic genetic and biochemical process of ripening, which affects all cell compartments. Ripening fruits are enriched with nutrients such as acids, sugars, vitamins, attractive volatiles and pigments and develop a pleasant taste and texture and become attractive to eat. Ripening also increases sensitivity to pathogens, and this presents a crucial problem for fruit postharvest transport and storage: how to enhance pathogen resistance while maintaining ripening quality. Fruit development and ripening involve many changes in gene expression regulated by transcription factors (TFs), some of which respond to hormones such as auxin, abscisic acid (ABA) and ethylene. Ethylene response factor (ERF) TFs regulate both fruit ripening and resistance to pathogen stresses. Different ERFs regulate fruit ripening and/or pathogen responses in both fleshy climacteric and non-climacteric fruits and function cooperatively or independently of other TFs. In this review, we summarize the current status of studies on ERFs that regulate fruit ripening and responses to infection by several fungal pathogens, including a systematic ERF transcriptome analysis of fungal grey mould infection of tomato caused by Botrytis cinerea. This deepening understanding of the function of ERFs in fruit ripening and pathogen responses may identify novel approaches for engineering transcriptional regulation to improve fruit quality and pathogen resistance.
PMID: 36010560
Cells , IF:6.6 , 2022 Jul , V11 (14) doi: 10.3390/cells11142174
Magnetopriming Actuates Nitric Oxide Synthesis to Regulate Phytohormones for Improving Germination of Soybean Seeds under Salt Stress.
School of Biochemistry, Devi Ahilya Vishwavidyalaya, Khandwa Road, Indore 452001, India.; Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India.; Division of Seed Science and Technology, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.; Institute of Plant and Environmental Sciences, Slovak University of Agriculture, A. Hlinku 2, 94976 Nitra, Slovakia.; Department of Botany and Plant Physiology, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, 16500 Prague, Czech Republic.
In this study, the role of the signalling molecule nitric oxide (NO) in magnetopriming-mediated induction of salinity tolerance in soybean seeds is established. The cross-talk of NO with germination-related hormones gibberellic acid (GA), abscisic acid (ABA) and auxin (IAA) for their ability to reduce the Na(+)/K(+) ratio in the seeds germinating under salinity is highlighted. Salt tolerance index was significantly high for seedlings emerging from magnetoprimed seeds and sodium nitroprusside (SNP, NO-donor) treatment. The NO and superoxide (O2(*-)) levels were also increased in both of these treatments under non-saline and saline conditions. NO generation through nitrate reductase (NR) and nitric oxide synthase-like (NOS-like) pathways indicated the major contribution of NO from the NR-catalysed reaction. The relative expression of genes involved in the NO biosynthetic pathways reiterated the indulgence of NR in NO in magnetoprimed seeds, as a 3.86-fold increase in expression was observed over unprimed seeds under salinity. A 23.26-fold increase in relative expression of NR genes by the NO donor (SNP) was observed under salinity, while the NR inhibitor (sodium tungstate, ST) caused maximum reduction in expression of NR genes as compared to other inhibitors [L-NAME (N(G)-nitro-L-arginine methyl ester; inhibitor of nitric oxide synthase-like enzyme) and DPI (diphenylene iodonium; NADPH oxidase inhibitor)]. The ratio of ABA/GA and IAA/GA decreased in magnetoprimed and NO donor-treated seeds, suggesting homeostasis amongst hormones during germination under salinity. The magnetoprimed seeds showed low Na(+)/K(+) ratio in all treatments irrespective of NO inhibitors. Altogether, our results indicate that a balance of ABA, GA and IAA is maintained by the signalling molecule NO in magnetoprimed seeds which lowers the Na(+)/K(+) ratio to offset the adverse effects of salinity in soybean seeds.
PMID: 35883617
Plant J , IF:6.417 , 2022 Aug doi: 10.1111/tpj.15960
Bioenergy sorghum stem growth regulation: Intercalary meristem localization, development and gene regulatory network analysis.
Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, USA.; ABQMR, Inc. 2301 Yale Blvd. SE, Suite C2, Albuquerque, NM, 87106, USA.; Department of Plant Biology, University of Illinois, Champaign-, Urbana, Illinois, 61801, USA.
Bioenergy sorghum is a highly productive drought tolerant C4 grass that accumulates 80% of its harvestable biomass in ~4 m length stems. Stem internode growth is regulated by development, shading, and hormones that modulate cell proliferation in intercalary meristems (IMs). In this study, sorghum stem IMs were localized above the pulvinus at the base of elongating internodes using MRI, microscopy, and transcriptome analysis. A change in cell morphology/organization occurred at the junction between the pulvinus and internode where LATERAL ORGAN BOUNDARIES (SbLOB), a boundary layer gene, was expressed. Inactivation of an AGCVIII kinase in DDYM (dw2) resulted in decreased SbLOB expression, disrupted IM localization and reduced internode cell proliferation. Transcriptome analysis identified ~1,000 genes involved in cell proliferation, hormone signaling and other functions selectively up-regulated in the IM compared to a non-meristematic stem tissue. This cohort of genes is expressed in apical dome stem tissues prior to localization of the IM at the base of elongating internodes. Gene regulatory network analysis identified connections between genes involved in hormone-signaling and cell proliferation. The results indicate that gibberellic acid induces accumulation of growth regulatory factors (GRFs) known to interact with ANGUSTIFOLIA (SbAN3), a master regulator of cell proliferation. GRF:AN3 was predicted to induce SbARF3/ETT expression and regulate SbAN3 expression in an auxin dependent manner. GRFs and ARFs regulate genes involved in cytokinin- and brassinosteroid signaling and cell proliferation. The results provide a molecular framework for understanding how hormone signaling regulates the expression of genes involved in cell proliferation in the stem IM.
PMID: 36038985
Plant J , IF:6.417 , 2022 Aug , V111 (4) : P1167-1182 doi: 10.1111/tpj.15884
OsSPL14 acts upstream of OsPIN1b and PILS6b to modulate axillary bud outgrowth by fine-tuning auxin transport in rice.
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, 430062, China.; Huazhong Agricultural University, Wuhan, 430070, China.; Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.; State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou, 311400, China.
As a multigenic trait, rice tillering can optimize plant architecture for the maximum agronomic yield. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14 (OsSPL14) has been demonstrated to be necessary and sufficient to inhibit rice branching, but the underlying mechanism remains largely unclear. Here, we demonstrated that OsSPL14, which is cleaved by miR529 and miR156, inhibits tillering by fine-tuning auxin transport in rice. RNA interference of OsSPL14 or miR529 and miR156 overexpression significantly increased the tiller number, whereas OsSPL14 overexpression decreased the tiller number. Histological analysis revealed that the OsSPL14-overexpressing line had normal initiation of axillary buds but inhibited outgrowth of tillers. Moreover, OsSPL14 was found to be responsive to indole-acetic acid and 1-naphthylphthalamic acid, and RNA interference of OsSPL14 reduced polar auxin transport and increased 1-naphthylphthalamic acid sensitivity of rice plants. Further analysis revealed that OsSPL14 directly binds to the promoter of PIN-FORMED 1b (OsPIN1b) and PIN-LIKE6b (PILS6b) to regulate their expression positively. OsPIN1b and PILS6b were highly expressed in axillary buds and proved involved in bud outgrowth. Loss of function of OsPIN1b or PILS6b increased the tiller number of rice. Taken together, our findings suggested that OsSPL14 could control axillary bud outgrowth and tiller number by activating the expression of OsPIN1b and PILS6b to fine-tune auxin transport in rice.
PMID: 35765202
Plant J , IF:6.417 , 2022 Aug , V111 (4) : P1015-1031 doi: 10.1111/tpj.15868
H3K4me3 plays a key role in establishing permissive chromatin states during bud dormancy and bud break in apple.
Graduate School of Agriculture, Kyoto University, Kyoto, Japan.; Key Laboratory of Horticultural Plant Biology, Huazhong Agricultural University, Wuhan, China.; School of Engineering, Utsunomiya University, Utsunomiya, Japan.; National Institute for Basic Biology, Okazaki, Japan.; The Graduate University for Advanced Studies, SOKENDAI, Miura-gun, Japan.; Faculty of Agriculture, Shinshu University, Kamiina-gun, Japan.; Agricultural Experimental Station, Ishikawa Prefectural University, Nonoichi, Japan.
Bud dormancy helps woody perennials survive winter and activate robust plant development in the spring. For apple (Malus x domestica), short-term chilling induces bud dormancy in autumn, then prolonged chilling leads to dormancy release and a shift to a quiescent state in winter, with subsequent warm periods promoting bud break in spring. Epigenetic regulation contributes to seasonal responses such as vernalization. However, how histone modifications integrate seasonal cues and internal signals during bud dormancy in woody perennials remains largely unknown. Here, we show that H3K4me3 plays a key role in establishing permissive chromatin states during bud dormancy and bud break in apple. The global changes in gene expression strongly correlated with changes in H3K4me3, but not H3K27me3. High expression of DORMANCY-ASSOCIATED MADS-box (DAM) genes, key regulators of dormancy, in autumn was associated with high H3K4me3 levels. In addition, known DAM/SHORT VEGETATIVE PHASE (SVP) target genes significantly overlapped with H3K4me3-modified genes as bud dormancy progressed. These data suggest that H3K4me3 contributes to the central dormancy circuit, consisting of DAM/SVP and abscisic acid (ABA), in autumn. In winter, the lower expression and H3K4me3 levels at DAMs and gibberellin metabolism genes control chilling-induced release of dormancy. Warming conditions in spring facilitate the expression of genes related to phytohormones, the cell cycle, and cell wall modification by increasing H3K4me3 toward bud break. Our study also revealed that activation of auxin and repression of ABA sensitivity in spring are conditioned at least partly through temperature-mediated epigenetic regulation in winter.
PMID: 35699670
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169477
The miR393-Target Module Regulates Plant Development and Responses to Biotic and Abiotic Stresses.
Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou 225009, China.; School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia.; Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
MicroRNAs (miRNAs), a class of endogenous small RNAs, are broadly involved in plant development, morphogenesis and responses to various environmental stresses, through manipulating the cleavage, translational expression, or DNA methylation of target mRNAs. miR393 is a conserved miRNA family present in many plants, which mainly targets genes encoding the transport inhibitor response1 (TIR1)/auxin signaling F-box (AFB) auxin receptors, and thus greatly affects the auxin signal perception, Aux/IAA degradation, and related gene expression. This review introduces the advances made on the miR393/target module regulating plant development and the plant's responses to biotic and abiotic stresses. This module is valuable for genetic manipulation of optimized conditions for crop growth and development and would also be helpful in improving crop yield through molecular breeding.
PMID: 36012740
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169472
A Long Noncoding RNA Derived from lncRNA-mRNA Networks Modulates Seed Vigor.
National Engineering Research Center of Plant Space Breeding, South China Agricultural University, Guangzhou 510642, China.
The discovery of long noncoding RNAs (lncRNAs) has filled a great gap in our understanding of posttranscriptional gene regulation in a variety of biological processes related to plant stress responses. However, systematic analyses of the lncRNAs expressed in rice seeds that germinate under cold stress have been elusive. In this study, we performed strand-specific whole transcriptome sequencing in germinated rice seeds under cold stress and normal temperature. A total of 6258 putative lncRNAs were identified and expressed in a stage-specific manner compared to mRNA. By investigating the targets of differentially expressed (DE) lncRNAs of LT-I (phase I of low temperature)/NT-I (phase I of normal temperature), it was shown that the auxin-activated signaling pathway was significantly enriched, and twenty-three protein-coding genes with most of the members of the SAUR family located in chromosome 9 were identified as the candidate target genes that may interact with five lncRNAs. A seed vigor-related lncRNA, SVR, which interplays with the members of the SAUR gene family in cis was eventually identified. The CRISPR/Cas 9 engineered mutations in SVR cause delay of germination. The findings provided new insights into the connection between lncRNAs and the auxin-activated signaling pathway in the regulation of rice seed vigor.
PMID: 36012737
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169456
Effects of Exogenous Melatonin on Root Physiology, Transcriptome and Metabolome of Cotton Seedlings under Salt Stress.
State Key Laboratory of North China Crop Improvement and Regulation, College of Life Science, Hebei Agricultural University, Baoding 071000, China.; State Key Laboratory of North China Crop Improvement and Regulation, Key Laboratory of Crop Growth Regulation of Hebei Province, College of Agronomy, Hebei Agricultural University, Baoding 071000, China.; College of Landscape and Tourism, Hebei Agricultural University, Baoding 071000, China.; Cotton Research Center, Key Laboratory of Cotton Breeding and Cultivation in Huang-Huai-Hai Plain, Ministry of Agriculture, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Root systems are the key organs through which plants absorb water and nutrients and perceive the soil environment and thus are easily damaged by salt stress. Melatonin can alleviate stress-induced damage to roots. The present study investigated the effects of exogenous melatonin on the root physiology, transcriptome and metabolome of cotton seedlings under salt stress. Salt stress was observed to damage the cell structure and disorder the physiological system of cotton seedling roots. After subjecting melatonin-soaked seeds to salt stress, the activities of SOD, CAT and POD in cotton seedling roots increased by 10-25%, 50-60% and 50-60%, respectively. The accumulation of H2O2 and MDA were significantly decreased by 30-60% and 30-50%, respectively. The contents of soluble sugar, soluble protein and K(+) increased by 15-30%, 15-30% and 20-50%, respectively, while the Na(+) content was significantly reduced. Melatonin also increased auxin (by 20-40%), brassinosteroids (by 5-40%) and gibberellin (by 5-35%) and promoted melatonin content and root activity. Exogenous melatonin maintained the integrity of root cells and increased the number of organelles. Transcriptomic and metabolomic results showed that exogenous melatonin could mitigate the salt-stress-induced inhibition of plant root development by regulating the reactive oxygen species scavenging system; ABC transporter synthesis; plant hormone signal transduction, endogenous melatonin gene expression; and the expression of the transcription factors MYB, TGA and WRKY33. These results provide a new direction and empirical basis for improving crop salt tolerance with melatonin.
PMID: 36012720
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169454
The MdAux/IAA2 Transcription Repressor Regulates Cell and Fruit Size in Apple Fruit.
Mudanjiang Branch, Heilongjiang Academy of Agricultural Sciences, Mudanjiang 157000, China.; Key Laboratory of Fruit Postharvest Biology (Liaoning Province), Key Laboratory of Protected Horticulture (Ministry of Education), National & Local Joint Engineering Research Center of Northern Horticultural Facilities Design & Application Technology (Liaoning), College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China.
Auxin plays an important role in regulating plant development, and Auxin/indole acetic acid (Aux/IAA) is a type of auxin-responsive gene and plays an important role in auxin signaling; to date, although 29 Aux/IAA proteins have been reported in Abrabidopsis thaliana, only parts of the Aux/IAA family gene functions have been identified. We previously reported that a bud sport of 'Longfeng' (LF) apple (Malus domestica), named 'Grand longfeng' (GLF), which showed a larger fruit size than LF, has lower expression of MdAux/IAA2. In this study, we identified the function of the MdAux/IAA2 gene in apple fruit size difference using Agrobacterium-mediated genetic transformation. Overexpression of MdAux/IAA2 decreased the apple flesh callus increment and caused a smaller globular cell size. In addition, overexpression of MdAux/IAA2 in GLF fruit resulted in the reduction of apple fruit size, weight, and cell size, while silencing MdAux/IAA2 in LF apple fruit resulted in an increase in apple fruit weight and cell size. We suggest that the high auxin content depressed the expression of MdAux/IAA2, and that the downregulated expression of MdAux/IAA2 led to the formation of GLF. Our study suggests a mechanism for fruit size regulation in plants and we will explore the transcription factors functioning in this process in the future.
PMID: 36012719
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169379
Salicylic Acid Regulates Root Gravitropic Growth via Clathrin-Independent Endocytic Trafficking of PIN2 Auxin Transporter in Arabidopsis thaliana.
The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai 264025, China.; College of Life Sciences, Nanjing University, Nanjing 210093, China.; CAS Center for Excellence in Molecular Plant Sciences, Shanghai 201602, China.
The phytohormone salicylic acid (SA) plays a crucial role in plant growth and development. However, the mechanism of high-concentration SA-affected gravitropic response in plant root growth and root hair development is still largely unclear. In this study, wild-type, pin2 mutant and various transgenic fluorescence marker lines of Arabidopsis thaliana were investigated to understand how root growth is affected by high SA treatment under gravitropic stress conditions. We found that exogenous SA application inhibited gravitropic root growth and root hair development in a dose-dependent manner. Further analyses using DIRECT REPEAT5 (DR5)-GFP, auxin sensor DII-VENUS, auxin efflux transporter PIN2-GFP, trans-Golgi network/early endosome (TGN/EE) clathrin-light-chain 2 (CLC2)-mCherry and prevacuolar compartment (PVC) (Rha1)-mCherry transgenic marker lines demonstrated that high SA treatment severely affected auxin accumulation, root-specific PIN2 distribution and PIN2 gene transcription and promoted the vacuolar degradation of PIN2, possibly independent of clathrin-mediated endocytic protein trafficking. Our findings proposed a new underlying mechanism of SA-affected gravitropic root growth and root hair development via the regulation of PIN2 gene transcription and PIN2 protein endocytosis in plants.
PMID: 36012641
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169270
Regulation of Heat Stress in Physcomitrium (Physcomitrella) patens Provides Novel Insight into the Functions of Plant RNase H1s.
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China.; School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China.; Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China.; Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou 225009, China.
RNase H1s are associated with growth and development in both plants and animals, while the roles of RNase H1s in bryophytes have been rarely reported. Our previous data found that PpRNH1A, a member of the RNase H1 family, could regulate the development of Physcomitrium (Physcomitrella) patens by regulating the auxin. In this study, we further investigated the biological functions of PpRNH1A and found PpRNH1A may participate in response to heat stress by affecting the numbers and the mobilization of lipid droplets and regulating the expression of heat-related genes. The expression level of PpRNH1A was induced by heat stress (HS), and we found that the PpRNH1A overexpression plants (A-OE) were more sensitive to HS. At the same time, A-OE plants have a higher number of lipid droplets but with less mobility in cells. Consistent with the HS sensitivity phenotype in A-OE plants, transcriptomic analysis results indicated that PpRNH1A is involved in the regulation of expression of heat-related genes such as DNAJ and DNAJC. Taken together, these results provide novel insight into the functions of RNase H1s.
PMID: 36012542
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23169043
Genome-Wide Identification and Analysis of the Growth-Regulating Factor Family in Zanthoxylum armatum DC and Functional Analysis of ZaGRF6 in Leaf Size and Longevity Regulation.
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang 550025, China.
Growth-regulating factors (GRFs) are plant-specific transcription factors that play an important role in plant growth and development. In this study, fifteen GRF gene members containing QLQ and WRC domains were identified in Zanthoxylum armatum. Phylogenetic and collinearity analysis showed that ZaGRFs were closely related to CsGRFs and AtGRFs, and distantly related to OsGRFs. There are a large number of cis-acting elements related to hormone response and stress induction in the GRF gene promoter region of Z. armatum. Tissue-specific expression analysis showed that except for ZaGRF7, all the ZaGRFs were highly expressed in young parts with active growth and development, including terminal buds, seeds, and young flowers, suggesting their key roles in Z. armatum growth and development. Eight ZaGRFs were selected to investigate the transcriptional response to auxin, gibberellin and drought treatments. A total of six ZaGRFs in the NAA treatment, four ZaGRFs in the GA3 treatment, and six ZaGRFs in the PEG treatment were induced and significantly up-regulated. Overexpression of ZaGRF6 increased branching and chlorophyll content and delayed senescence of transgenic Nicotiana benthamiana. ZaGRF6 increased the expression of CRF2 and suppressed the expression of ARR4 and CKX1, indicating that ZaGRF6 is involved in cytokinin metabolism and signal transduction. These research results lay a foundation for further analysis of the GRF gene function of Z. armatum and provide candidate genes for growth, development, and stress resistance breeding of Z. armatum.
PMID: 36012309
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (16) doi: 10.3390/ijms23168965
Mutation of OsPIN1b by CRISPR/Cas9 Reveals a Role for Auxin Transport in Modulating Rice Architecture and Root Gravitropism.
College of Agriculture, Henan University of Science and Technology, Luoyang 471000, China.
The distribution and content of auxin within plant tissues affect a variety of important growth and developmental processes. Polar auxin transport (PAT), mainly mediated by auxin influx and efflux transporters, plays a vital role in determining auxin maxima and gradients in plants. The auxin efflux carrier PIN-FORMED (PIN) family is one of the major protein families involved in PAT. Rice (Oryza sativa L.) genome possesses 12 OsPIN genes. However, the detailed functions of OsPIN genes involved in regulating the rice architecture and gravity response are less well understood. In the present study, OsPIN1b was disrupted by CRISPR/Cas9 technology, and its roles in modulating rice architecture and root gravitropism were investigated. Tissue-specific analysis showed that OsPIN1b was mainly expressed in roots, stems and sheaths at the seedling stage, and the transcript abundance was progressively decreased during the seedling stages. Expression of OsPIN1b could be quickly and greatly induced by NAA, indicating that OsPIN1b played a vital role in PAT. IAA homeostasis was disturbed in ospin1b mutants, as evidenced by the changed sensitivity of shoot and root to NAA and NPA treatment, respectively. Mutation of OsPIN1b resulted in pleiotropic phenotypes, including decreased growth of shoots and primary roots, reduced adventitious root number in rice seedlings, as well as shorter and narrower leaves, increased leaf angle, more tiller number and decreased plant height and panicle length at the late developmental stage. Moreover, ospin1b mutants displayed a curly root phenotype cultured with tap water regardless of lighting conditions, while nutrient solution culture could partially rescue the curly root phenotype in light and almost completely abolish this phenotype in darkness, indicating the involvement of the integration of light and nutrient signals in root gravitropism regulation. Additionally, amyloplast sedimentation was impaired in the peripheral tiers of the ospin1b root cap columella cell, while it was not the main contributor to the abnormal root gravitropism. These data suggest that OsPIN1b not only plays a vital role in regulating rice architecture but also functions in regulating root gravitropism by the integration of light and nutrient signals.
PMID: 36012245
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (15) doi: 10.3390/ijms23158643
GmIAA27 Encodes an AUX/IAA Protein Involved in Dwarfing and Multi-Branching in Soybean.
College of Agriculture, Northeast Agricultural University, Harbin 150030, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Institute of Plant Virology, Ningbo University, Ningbo 315211, China.
Soybean plant height and branching affect plant architecture and yield potential in soybean. In this study, the mutant dmbn was obtained by treating the cultivar Zhongpin 661 with ethylmethane sulfonate. The dmbn mutant plants were shorter and more branched than the wild type. The genetic analysis showed that the mutant trait was controlled by a semi-dominant gene. The candidate gene was fine-mapped to a 91 kb interval on Chromosome 9 by combining BSA-seq and linkage analysis. Sequence analysis revealed that Glyma.09g193000 encoding an Aux/IAA protein (GmIAA27) was mutated from C to T in the second exon of the coding region, resulting to amino acid substitution of proline to leucine. Overexpression of the mutant type of this gene in Arabidopsis thaliana inhibited apical dominance and promoted lateral branch development. Expression analysis of GmIAA27 and auxin response genes revealed that some GH3 genes were induced. GmIAA27 relies on auxin to interact with TIR1, whereas Gmiaa27 cannot interact with TIR1 owing to the mutation in the degron motif. Identification of this unique gene that controls soybean plant height and branch development provides a basis for investigating the mechanisms regulating soybean plant architecture development.
PMID: 35955771
Int J Mol Sci , IF:5.923 , 2022 Aug , V23 (15) doi: 10.3390/ijms23158593
Fluorescent Auxin Analogs Report Two Auxin Binding Sites with Different Subcellular Distribution and Affinities: A Cue for Non-Transcriptional Auxin Signaling.
Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76133 Karlsruhe, Germany.; Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510301, China.; Department of Biochemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan.
The complexity of auxin signaling is partially due to multiple auxin receptors that trigger differential signaling. To obtain insight into the subcellular localization of auxin-binding sites, we used fluorescent auxin analogs that can undergo transport but do not deploy auxin signaling. Using fluorescent probes for different subcellular compartments, we can show that the fluorescent analog of 1-naphthaleneacetic acid (NAA) associates with the endoplasmic reticulum (ER) and tonoplast, while the fluorescent analog of indole acetic acid (IAA) binds to the ER. The binding of the fluorescent NAA analog to the ER can be outcompeted by unlabeled NAA, which allows us to estimate the affinity of NAA for this binding site to be around 1 muM. The non-transportable auxin 2,4-dichlorophenoxyacetic acid (2,4-D) interferes with the binding site for the fluorescent NAA analog at the tonoplast but not with the binding site for the fluorescent IAA analog at the ER. We integrate these data into a working model, where the tonoplast hosts a binding site with a high affinity for 2,4-D, while the ER hosts a binding site with high affinity for NAA. Thus, the differential subcellular localization of binding sites reflects the differential signaling in response to these artificial auxins.
PMID: 35955725
Int J Mol Sci , IF:5.923 , 2022 Jul , V23 (15) doi: 10.3390/ijms23158480
Involvement of Auxin-Mediated CqEXPA50 Contributes to Salt Tolerance in Quinoa (Chenopodium quinoa) by Interaction with Auxin Pathway Genes.
College of Life Science, Sichuan Agricultural University, Ya'an 625014, China.; College of Life Science, Nanjing Agricultural University, Nanjing 210032, China.; Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China.
Soil salinization is a global problem that limits crop yields and threatens agricultural development. Auxin-induced expansins contribute to plant salt tolerance through cell wall loosening. However, how auxins and expansins contribute to the adaptation of the halophyte quinoa (Chenopodium quinoa) to salt stress has not yet been reported. Here, auxin was found to contribute to the salt tolerance of quinoa by promoting the accumulation of photosynthetic pigments under salt stress, maintaining enzymatic and nonenzymatic antioxidant systems and scavenging excess reactive oxygen species (ROS). The Chenopodium quinoa expansin (Cqexpansin) family and the auxin pathway gene family (Chenopodium quinoa auxin response factor (CqARF), Chenopodium quinoa auxin/indoleacetic acid (CqAux/IAA), Chenopodium quinoa Gretchen Hagen 3 (CqGH3) and Chenopodium quinoa small auxin upregulated RNA (CqSAUR)) were identified from the quinoa genome. Combined expression profiling identified Chenopodium quinoa alpha-expansin 50 (CqEXPA50) as being involved in auxin-mediated salt tolerance. CqEXPA50 enhanced salt tolerance in quinoa seedlings was revealed by transient overexpression and physiological and biochemical analyses. Furthermore, the auxin pathway and salt stress-related genes regulated by CqEXPA50 were identified. The interaction of CqEXPA50 with these proteins was demonstrated by bimolecular fluorescence complementation (BIFC). The proteins that interact with CqEXPA50 were also found to improve salt tolerance. In conclusion, this study identified some genes potentially involved in the salt tolerance regulatory network of quinoa, providing new insights into salt tolerance.
PMID: 35955612
Int J Mol Sci , IF:5.923 , 2022 Jul , V23 (15) doi: 10.3390/ijms23158208
The L-Type Lectin-like Receptor Kinase Gene TaLecRK-IV.1 Regulates the Plant Height in Wheat.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Department of Biological Sciences, Faculty of Science, University of Ngaoundere, Ngaoundere P.O. Box 454, Cameroon.
Dwarfing is important for the production of wheat (Triticumaestivum L.). In model plants, receptor-like kinases have been implicated in signal transduction, immunity, and development. However, functional roles of lectin receptor-like kinases in wheat are poorly understood. In this study, we identified an L-type lectin receptor-like kinase gene in wheat, designated as TaLecRK-IV.1, and revealed its role in plant height. Real time quantitative PCR analyses indicated that TaLecRK-IV.1 transcript level was lower in a dwarf wheat line harboring the Rht-D1b gene compared to its transcript level detected in a taller wheat line CI12633. Importantly, the virus-induced gene silencing results showed that silencing of TaLecRK-IV.1 in the wheat line CI12633 led to dwarf plants. The results of the disease resistance test performed after the gene silencing experiment suggest no significant role of TaLecRK-IV.1 in the resistance reaction of wheat line CI12633 to sharp eyespot. Gene expression analysis revealed that the transcript abundance of TaLecRK-IV.1 was more up-regulated after the exogenous application of gibberellic acid and auxin, two development-related phytohormones, compared to the gene transcript levels detected in the control plants (mock treatment). These findings support the potential implication of TaLecRK-IV.1 in the pathway controlling plant height rather than the disease resistance role, and suggest that TaLecRK-IV.1 may be a positive regulator of plant height through the gibberellic acid and auxin-signaling pathways.
PMID: 35897784
Int J Mol Sci , IF:5.923 , 2022 Jul , V23 (15) doi: 10.3390/ijms23158057
Integrated Analysis of Microarray, Small RNA, and Degradome Datasets Uncovers the Role of MicroRNAs in Temperature-Sensitive Genic Male Sterility in Wheat.
Institute of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.; Molecular Genetic Beijing Key Laboratory of Hybrid Wheat, Beijing 100097, China.; College of Horticulture, China Agricultural University, Beijing 100193, China.
Temperature-sensitive genic male sterile (TGMS) line Beijing Sterility 366 (BS366) has been utilized in hybrid breeding for a long time, but the molecular mechanism underlying male sterility remains unclear. Expression arrays, small RNA, and degradome sequencing were used in this study to explore the potential role of miRNA in the cold-induced male sterility of BS366. Microspore observation showed defective cell plates in dyads and tetrads and shrunken microspores at the vacuolated stage. Differential regulation of Golgi vesicle transport, phragmoplast formation, sporopollenin biosynthesis, pollen exine formation, and lipid metabolism were observed between cold and control conditions. Pollen development was significantly represented in the 352 antagonistic miRNA-target pairs in the integrated analysis of miRNA and mRNA profiles. The specific cleavage of ARF17 and TIR1 by miR160 and miR393 were found in the cold-treated BS366 degradome, respectively. Thus, the cold-mediated miRNAs impaired cell plate formation through repression of Golgi vesicle transport and phragmoplast formation. The repressed expression of ARF17 and TIR1 impaired pollen exine formation. The results of this study will contribute to our understanding of the roles of miRNAs in male sterility in wheat.
PMID: 35897633
Int J Mol Sci , IF:5.923 , 2022 Jul , V23 (14) doi: 10.3390/ijms23147574
Genome-Wide Identification of TaSAUR Gene Family Members in Hexaploid Wheat and Functional Characterization of TaSAUR66-5B in Improving Nitrogen Use Efficiency.
State Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
Excessive input of nitrogen fertilizer not only causes a great waste of resources but brings about a series of ecological and environmental problems. Although Small Auxin Up-regulated RNAs (SAURs) participate in diverse biological processes, the function of SAURs in the nitrogen starvation response has not been well-studied. Here, we identified 308 TaSAURs in wheat and divided them into 10 subfamilies. The promoter regions of most TaSAURs contain hormone responsive elements, and their expression levels change under the treatment of different hormones, such as IAA, MeJA, and ABA. Interestingly, overexpression of one of the TaSAUR family members, a nitrogen starvation responsive gene, TaSAUR66-5B, can promote the growth of Arabidopsis and wheat roots. In addition, overexpression of TaSAUR66-5B in Arabidopsis up-regulates the expression levels of auxin biosynthesis related genes, suggesting that overexpression TaSAUR66-5B may promote root growth by increasing the biosynthesis of auxin. Furthermore, overexpression of TaSAUR66-5B in wheat can increase the biomass and grain yields of transgenic plants, as well as the nitrogen concentration and accumulation of both shoots and grains, especially under low nitrogen conditions. This study provides important genomic information of the TaSAUR gene family and lays a foundation for elucidating the functions of TaSAURs in improving nitrogen utilization efficiency in wheat.
PMID: 35886923
Int J Mol Sci , IF:5.923 , 2022 Jul , V23 (13) doi: 10.3390/ijms23137415
Morphological and Proteomic Analyses of Soybean Seedling Interaction Mechanism Affected by Fiber Crosslinked with Zinc-Oxide Nanoparticles.
Faculty of Environment and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan.; R&D Laboratory for Applied Product, Asahi Kasei Corporation, Moriyama 524-0002, Japan.; Department of Medical Technology, Yokkaichi Nursing and Medical Care University, Yokkaichi 512-8045, Japan.; Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan.; Business Promotion Section Business Strategy Department, Bemberg Division, Asahi Kasei Corporation, Osaka 530-8205, Japan.
Nanoparticles (NPs) enhance soybean growth; however, their precise mechanism is not clearly understood. To develop a more effective method using NPs for the enhancement of soybean growth, fiber crosslinked with zinc oxide (ZnO) NPs was prepared. The solution of ZnO NPs with 200 nm promoted soybean growth at the concentration of 10 ppm, while fibers crosslinked with ZnO NPs promoted growth at a 1 ppm concentration. Soybeans grown on fiber cross-linked with ZnO NPs had higher Zn content in their roots than those grown in ZnO NPs solution. To study the positive mechanism of fiber crosslinked with ZnO NPs on soybean growth, a proteomic technique was used. Proteins categorized in photosynthesis and secondary metabolism accumulated more in soybeans grown on fiber crosslinked with ZnO NPs than in those grown in ZnO NPs solution. Furthermore, significantly accumulated proteins, which were NADPH oxidoreductase and tubulins, were confirmed using immunoblot analysis. The abundance of NADPH oxidoreductase increased in soybean by ZnO NPs application. These results suggest that fiber crosslinked with ZnO NPs enhances soybean growth through the increase of photosynthesis and secondary metabolism. Additionally, the accumulation of NADPH oxidoreductase might relate to the effect of auxin with fiber crosslinked with ZnO NPs on soybean growth.
PMID: 35806419
PLoS Genet , IF:5.917 , 2022 Jul , V18 (7) : Pe1010320 doi: 10.1371/journal.pgen.1010320
Cytidinediphosphate diacylglycerol synthase-Mediated phosphatidic acid metabolism is crucial for early embryonic development of Arabidopsis.
Shanghai Collaborative Innovation Center of Agri-Seeds, Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.; State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life and Science, Hubei University, Wuhan, China.
Embryonic development is a key developmental event in plant sexual reproduction; however, regulatory networks of plant early embryonic development, particularly the effects and functional mechanisms of phospholipid molecules are still unknown due to the limitation of sample collection and analysis. We innovatively applied the microspore-derived in vitro embryogenesis of Brassica napus and revealed the dynamics of phospholipid molecules, especially phosphatidic acid (PA, an important second messenger that plays an important role in plant growth, development, and stress responses), at different embryonic developmental stages by using a lipidomics approach. Further analysis of Arabidopsis mutants deficiency of CDS1 and CDS2 (cytidinediphosphate diacylglycerol synthase, key protein in PA metabolism) revealed the delayed embryonic development from the proembryo stage, indicating the crucial effect of CDS and PA metabolism in early embryonic development. Decreased auxin level and disturbed polar localization of auxin efflux carrier PIN1 implicate that CDS-mediated PA metabolism may regulate early embryogenesis through modulating auxin transport and distribution. These results demonstrate the dynamics and importance of phospholipid molecules during embryo development, and provide informative clues to elucidate the regulatory network of embryogenesis.
PMID: 35877676
Front Plant Sci , IF:5.753 , 2022 , V13 : P948901 doi: 10.3389/fpls.2022.948901
Distinct GmASMTs are involved in regulating transcription factors and signalling cross-talk across embryo development, biotic, and abiotic stress in soybean.
Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute, Mysore, Karnataka, India.; Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh, India.
N-Acetylserotonin O-methyltransferase (ASMT) is the final enzyme involved in melatonin biosynthesis. Identifying the expression of ASMT will reveal the regulatory role in the development and stress conditions in soybean. To identify and characterize ASMT in soybean (GmASMT), we employed genome-wide analysis, gene structure, cis-acting elements, gene expression, co-expression network analysis, and enzyme assay. We found seven pairs of segmental and tandem duplication pairs among the 44 identified GmASMTs by genome-wide analysis. Notably, co-expression network analysis reported that distinct GmASMTs are involved in various stress response. For example, GmASMT3, GmASMT44, GmASMT17, and GmASMT7 are involved in embryo development, heat, drought, aphid, and soybean cyst nematode infections, respectively. These distinct networks of GmASMTs were associated with transcription factors (NAC, MYB, WRKY, and ERF), stress signalling, isoflavone and secondary metabolites, calcium, and calmodulin proteins involved in stress regulation. Further, GmASMTs demonstrated auxin-like activities by regulating the genes involved in auxin transporter (WAT1 and NRT1/PTR) and auxin-responsive protein during developmental and biotic stress. The current study identified the key regulatory role of GmASMTs during development and stress. Hence GmASMT could be the primary target in genetic engineering for crop improvement under changing environmental conditions.
PMID: 36035712
Front Plant Sci , IF:5.753 , 2022 , V13 : P944515 doi: 10.3389/fpls.2022.944515
Regulation of plant biotic interactions and abiotic stress responses by inositol polyphosphates.
Departmentof Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-Universitat Bonn, Bonn, Germany.; Department of Biochemistry, Indian Institute of Science, Bengaluru, India.; Department of Chemistry and Pharmacy & CIBSS - The Center of Biological Signaling Studies, Albert-Ludwigs University Freiburg, Freiburg, Germany.
Inositol pyrophosphates (PP-InsPs), derivatives of inositol hexakisphosphate (phytic acid, InsP6) or lower inositol polyphosphates, are energy-rich signaling molecules that have critical regulatory functions in eukaryotes. In plants, the biosynthesis and the cellular targets of these messengers are not fully understood. This is because, in part, plants do not possess canonical InsP6 kinases and are able to synthesize PP-InsP isomers that appear to be absent in yeast or mammalian cells. This review will shed light on recent discoveries in the biosynthesis of these enigmatic messengers and on how they regulate important physiological processes in response to abiotic and biotic stresses in plants.
PMID: 36035672
Front Plant Sci , IF:5.753 , 2022 , V13 : P959053 doi: 10.3389/fpls.2022.959053
The roles of epigenetic modifications in the regulation of auxin biosynthesis.
Ministry of Education (MOE) Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.; Gansu Province Key Laboratory of Gene Editing for Breeding, School of Life Sciences, Lanzhou University, Lanzhou, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.; College of Life Science and Technology, Gansu Agricultural University, Lanzhou, China.; Basic Forestry and Proteomics Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.
Auxin is one of the most important plant growth regulators of plant morphogenesis and response to environmental stimuli. Although the biosynthesis pathway of auxin has been elucidated, the mechanisms regulating auxin biosynthesis remain poorly understood. The transcription of auxin biosynthetic genes is precisely regulated by complex signaling pathways. When the genes are expressed, epigenetic modifications guide mRNA synthesis and therefore determine protein production. Recent studies have shown that different epigenetic factors affect the transcription of auxin biosynthetic genes. In this review, we focus our attention on the molecular mechanisms through which epigenetic modifications regulate auxin biosynthesis.
PMID: 36017262
Front Plant Sci , IF:5.753 , 2022 , V13 : P890613 doi: 10.3389/fpls.2022.890613
Melatonin confers fenugreek tolerance to salinity stress by stimulating the biosynthesis processes of enzymatic, non-enzymatic antioxidants, and diosgenin content.
Department of Agronomy and Plant Breeding, Faculty of Agriculture, Shahrood University of Technology, Semnan, Iran.; Department of Plant Production and Genetics, Faculty of Agriculture, Urmia University, Urmia, Iran.
Salinity-induced stress is widely considered a main plant-growth-limiting factor. The positive effects of melatonin in modulating abiotic stresses have led this hormone to be referred to as a growth regulator in plants. This study aims to show how melatonin protects fenugreek against the negative effects of salt stress. Different amounts of melatonin (30, 60, and 90 ppm), salinity stress (150 mM and 300 mM), and the use of both salinity and melatonin were used as treatments. The results showed that applying different melatonin levels to salinity-treated fenugreek plants effectively prevented the degradation of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid contents compared with salinity treatment without melatonin application. Besides, melatonin increases the biosynthesis of enzymatic and non-enzymatic antioxidants, thereby adjusting the content of reactive oxygen species, free radicals, electrolyte leakage, and malondialdehyde content. It was observed that applying melatonin increased the activity of potassium-carrying channels leading to the maintenance of ionic homeostasis and increased intracellular water content under salinity stress. The results revealed that melatonin activates the defense signaling pathways in fenugreek through the nitric oxide, auxin, and abscisic acid-dependent pathways. Melatonin, in a similar vein, increased the expression of genes involved in the biosynthesis pathway of diosgenin, a highly important steroidal sapogenin in medical and food industries, and hence the diosgenin content. When 150 mM salinity stress and 60 ppm melatonin were coupled, the diosgenin concentration rose by more than 5.5 times compared to the control condition. In conclusion, our findings demonstrate the potential of melatonin to enhance the plant tolerance to salinity stress by stimulating biochemical and physiological changes.
PMID: 36003823
Front Plant Sci , IF:5.753 , 2022 , V13 : P961651 doi: 10.3389/fpls.2022.961651
Halophyte Nitraria billardieri CIPK25 mitigates salinity-induced cell damage by alleviating H2O2 accumulation.
Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education of China, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.; Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou, China.; College of Biology and the Environment, Nanjing Forestry University, Nanjing, China.
The plant-specific module of calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs) play a crucial role in plant adaptation to different biotic and abiotic stresses in various plant species. Despite the importance of the CBL-CIPK module in regulating plant salt tolerance, few halophyte CIPK orthologs have been studied. We identified NbCIPK25 in the halophyte Nitraria billardieri as a salt-responsive gene that may improve salt tolerance in glycophytes. Sequence analyses indicated that NbCIPK25 is a typical CIPK family member with a conserved NAF motif, which contains the amino acids: asparagine, alanine, and phenylalanine. NbCIPK25 overexpression in salt-stressed transgenic Arabidopsis seedlings resulted in enhanced tolerance to salinity, a higher survival rate, longer newly grown roots, more root meristem cells, and less damaged root cells in comparison to wild-type (WT) plants. H2O2 accumulation and malondialdehyde (MDA) content were both deceased in NbCIPK25-transgenic plants under salt treatment. Furthermore, their proline content, an important factor for scavenging reactive oxygen species, accumulated at a significantly higher level. In concordance, the transcription of genes related to proline accumulation was positively regulated in transgenic plants under salt condition. Finally, we observed a stronger auxin response in salt-treated transgenic roots. These results provide evidence for NbCIPK25 improving salt tolerance by mediating scavenging of reactive oxygen species, thereby protecting cells from oxidation and maintaining plant development under salt stress. These findings suggest the potential application of salt-responsive NbCIPK25 for cultivating glycophytes with a higher salt tolerance through genetic engineering.
PMID: 36003812
Front Plant Sci , IF:5.753 , 2022 , V13 : P958964 doi: 10.3389/fpls.2022.958964
Molecular evolutionary analysis of the SHI/STY gene family in land plants: A focus on the Brassica species.
School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China.
The plant-specific SHORT INTERNODES/STYLISH (SHI/STY) proteins belong to a family of transcription factors that are involved in the formation and development of early lateral roots. However, the molecular evolution of this family is rarely reported. Here, a total of 195 SHI/STY genes were identified in 21 terrestrial plants, and the Brassica species is the focus of our research. Their physicochemical properties, chromosome location and duplication, motif distribution, exon-intron structures, genetic evolution, and expression patterns were systematically analyzed. These genes are divided into four clades (Clade 1/2/3/4) based on phylogenetic analysis. Motif distribution and gene structure are similar in each clade. SHI/STY proteins are localized in the nucleus by the prediction of subcellular localization. Collinearity analysis indicates that the SHI/STYs are relatively conserved in evolution. Whole-genome duplication is the main factor for their expansion. SHI/STYs have undergone intense purifying selection, but several positive selection sites are also identified. Most promoters of SHI/STY genes contain different types of cis-elements, such as light, stress, and hormone-responsive elements, suggesting that they may be involved in many biological processes. Protein-protein interaction predicted some important SHI/STY interacting proteins, such as LPAT4, MBOATs, PPR, and UBQ3. In addition, the RNA-seq and qRT-PCR analysis were studied in detail in rape. As a result, SHI/STYs are highly expressed in root and bud, and can be affected by Sclerotinia sclerotiorum, drought, cold, and heat stresses. Moreover, quantitative real-time PCR (qRT-PCR) analyses indicates that expression levels of BnSHI/STYs are significantly altered in different treatments (cold, salt, drought, IAA, auxin; ABA, abscisic acid; 6-BA, cytokinin). It provides a new understanding of the evolution and expansion of the SHI/STY family in land plants and lays a foundation for further research on their functions.
PMID: 35991428
Front Plant Sci , IF:5.753 , 2022 , V13 : P919290 doi: 10.3389/fpls.2022.919290
Hairy root transformation system as a tool for CRISPR/Cas9-directed genome editing in oilseed rape (Brassica napus).
CEITEC MU - Central European Institute of Technology, Masaryk University, Brno, Czechia.; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia.; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia.
Our study examined the mutation efficiency of the CRISPR/Cas9 method for tryptophan aminotransferase BnaTAA1 genes involved in the auxin biosynthesis pathway. We made nine CRISPR/Cas9 constructs with various promoters driving the expression of a Cas9 from Staphylococcus aureus (SaCas9) or a plant-codon-optimized Streptococcus pyogenes Cas9 (pcoCas9). We developed a fast and efficient system for evaluating the variety and frequency of mutations caused by each construct using Brassica napus hairy roots. We showed that pcoCas9 is more efficient in mutating the targeted loci than SaCas9 and the presence of the NLS signal enhanced the chance of mutagenesis by 25%. The mutations were studied further in regenerated lines, and we determined the BnaTAA1 gene expression and heritability of the gene modifications in transgenic plants. Hairy root transformation combined with CRISPR/Cas9-mediated gene editing represents a fast and straightforward system for studying target gene function in the important oilseed crop B. napus.
PMID: 35991410
Front Plant Sci , IF:5.753 , 2022 , V13 : P967031 doi: 10.3389/fpls.2022.967031
CRISPR/Cas9-mediated mutation in auxin efflux carrier OsPIN9 confers chilling tolerance by modulating reactive oxygen species homeostasis in rice.
College of Agriculture, Henan University of Science and Technology, Luoyang, China.; College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, China.; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
Phytohormone auxin plays a vital role in plant development and responses to environmental stresses. The spatial and temporal distribution of auxin mainly relies on the polar distribution of the PIN-FORMED (PIN) auxin efflux carriers. In this study, we dissected the functions of OsPIN9, a monocot-specific auxin efflux carrier gene, in modulating chilling tolerance in rice. The results showed that OsPIN9 expression was dramatically and rapidly suppressed by chilling stress (4 degrees C) in rice seedlings. The homozygous ospin9 mutants were generated by CRISPR/Cas9 technology and employed for further research. ospin9 mutant roots and shoots were less sensitive to 1-naphthaleneacetic acid (NAA) and N-1-naphthylphthalamic acid (NPA), indicating the disturbance of auxin homeostasis in the ospin9 mutants. The chilling tolerance assay showed that ospin9 mutants were more tolerant to chilling stress than wild-type (WT) plants, as evidenced by increased survival rate, decreased membrane permeability, and reduced lipid peroxidation. However, the expression of well-known C-REPEAT BINDING FACTOR (CBF)/DEHYDRATION-RESPONSIVE ELEMENT-BINDING PROTEIN 1 (DREB)-dependent transcriptional regulatory pathway and Ca(2+) signaling genes was significantly induced only under normal conditions, implying that defense responses in ospin9 mutants have probably been triggered in advance under normal conditions. Histochemical staining of reactive oxygen species (ROS) by 3'3-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) showed that ospin9 mutants accumulated more ROS than WT at the early stage of chilling stress, while less ROS was observed at the later stage of chilling treatment in ospin9 mutants. Consistently, antioxidant enzyme activity, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), improved significantly during the early chilling treatments, while was kept similar to WT at the later stage of chilling treatment, implying that the enhanced chilling tolerance of ospin9 mutants is mainly attributed to the earlier induction of ROS and the improved ROS scavenging ability at the subsequent stages of chilling treatment. In summary, our results strongly suggest that the OsPIN9 gene regulates chilling tolerance by modulating ROS homeostasis in rice.
PMID: 35979077
Front Plant Sci , IF:5.753 , 2022 , V13 : P894985 doi: 10.3389/fpls.2022.894985
Agronomic efficiency and genome mining analysis of the wheat-biostimulant rhizospheric bacterium Pseudomonas pergaminensis sp. nov. strain 1008(T).
Rizobacter Argentina S.A., Buenos Aires, Argentina.; Escuela de Ciencias Agrarias, Exactas y Naturales, Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA), Buenos Aires, Argentina.; Departamento de Ciencias Naturales y Exactas, Universidad Nacional de San Antonio de Areco (UNSAdA), Buenos Aires, Argentina.; Indrasa Biotecnologia S.A., Cordoba, Argentina.; Laboratorio de Fisiologia y Genetica de Bacterias Beneficiosas para Plantas, Centro de Bioquimica y Microbiologia del Suelo, Universidad Nacional de Quilmes-CONICET, Buenos Aires, Argentina.; Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
Pseudomonas sp. strain 1008 was isolated from the rhizosphere of field grown wheat plants at the tillering stage in an agricultural plot near Pergamino city, Argentina. Based on its in vitro phosphate solubilizing capacity and the production of IAA, strain 1008 was formulated as an inoculant for bacterization of wheat seeds and subjected to multiple field assays within the period 2010-2017. Pseudomonas sp. strain 1008 showed a robust positive impact on the grain yield (+8% on average) across a number of campaigns, soil properties, seed genotypes, and with no significant influence of the simultaneous seed treatment with a fungicide, strongly supporting the use of this biostimulant bacterium as an agricultural input for promoting the yield of wheat. Full genome sequencing revealed that strain 1008 has the capacity to access a number of sources of inorganic and organic phosphorus, to compete for iron scavenging, to produce auxin, 2,3-butanediol and acetoin, and to metabolize GABA. Additionally, the genome of strain 1008 harbors several loci related to rhizosphere competitiveness, but it is devoid of biosynthetic gene clusters for production of typical secondary metabolites of biocontrol representatives of the Pseudomonas genus. Finally, the phylogenomic, phenotypic, and chemotaxonomic comparative analysis of strain 1008 with related taxa strongly suggests that this wheat rhizospheric biostimulant isolate is a representative of a novel species within the genus Pseudomonas, for which the name Pseudomonas pergaminensis sp. nov. (type strain 1008(T) = DSM 113453(T) = ATCC TSD-287(T)) is proposed.
PMID: 35968096
Front Plant Sci , IF:5.753 , 2022 , V13 : P923293 doi: 10.3389/fpls.2022.923293
Subcellular trafficking and post-translational modification regulate PIN polarity in plants.
Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.; Hainan Yazhou Bay Seed Laboratory, Sanya, China.; Zhejiang Provincial Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, China.
Auxin regulates plant growth and tropism responses. As a phytohormone, auxin is transported between its synthesis sites and action sites. Most natural auxin moves between cells via a polar transport system that is mediated by PIN-FORMED (PIN) auxin exporters. The asymmetrically localized PINs usually determine the directionality of intercellular auxin flow. Different internal cues and external stimuli modulate PIN polar distribution and activity at multiple levels, including transcription, protein stability, subcellular trafficking, and post-translational modification, and thereby regulate auxin-distribution-dependent development. Thus, the different regulation levels of PIN polarity constitute a complex network. For example, the post-translational modification of PINs can affect the subcellular trafficking of PINs. In this review, we focus on subcellular trafficking and post-translational modification of PINs to summarize recent progress in understanding PIN polarity.
PMID: 35968084
Front Plant Sci , IF:5.753 , 2022 , V13 : P961899 doi: 10.3389/fpls.2022.961899
Transcriptomics and metabolomics changes triggered by exogenous 6-benzylaminopurine in relieving epicotyl dormancy of Polygonatum cyrtonema Hua seeds.
School of Life Sciences, Anhui Agricultural University, Hefei, China.
Polygonatum cyrtonema Hua is one of the most useful herbs in traditional Chinese medicine and widely used in medicinal and edible perennial plant. However, the seeds have the characteristics of epicotyl dormancy. In this study, the molecular basis for relieving epicotyl dormancy of P. cyrtonema seeds under exogenous 6-benzylaminopurine (6-BA) treatment was revealed for the first time through transcriptome and metabolomics analysis. We determined the elongation of epicotyl buds as a critical period for dormancy release and found that the content of trans-zeatin, proline, auxin and gibberellin was higher, while flavonoids and arginine were lower in the treatment group. Transcriptome analysis showed that there were significant differences in gene expression in related pathways, and the expression patterns were highly consistent with the change of metabolites in corresponding pathways. Co-expression analysis showed that cytokinin dehydrogenase of P. cyrtonema (PcCKXs) and pelargonidin in flavonoid biosynthesis, as well as L-proline, L-ornithine, and L-citrulline in arginine and proline metabolism form network modules, indicating that they have related regulatory roles. Above all, our findings provide new insight into the exogenous 6-BA relieving epicotyl dormancy of P. cyrtonema seeds.
PMID: 35958203
Front Plant Sci , IF:5.753 , 2022 , V13 : P953450 doi: 10.3389/fpls.2022.953450
Comparative transcriptome analysis unveiling reactive oxygen species scavenging system of Sonneratia caseolaris under salinity stress.
Mangrove Institute, Lingnan Normal University, Zhanjiang, China.
Many mangrove forests have undergone major changes as a result of human activity and global climate change. Sonneratia caseolaris is a common tree located in inner mangroves, and its range extends inland along tidal creeks, as far as the influence of salinity extends. This study investigated the physiological and molecular response mechanisms of S. caseolaris by analyzing its antioxidant defense capacity, including its differentially expressed genes (DEGs) under similar salt stress conditions. Salt treatment significantly affected the osmoprotectants and lipid peroxidation in S. caseolaris seedlings, which increased proline (Pro) content by 31.01-54.90% during all sample periods and decreased malonaldehyde (MDA) content by 12.81 and 18.17% at 25 and 40 days under 3.0% NaCl treatment. Antioxidant enzyme activities increased significantly following 3.0% NaCl treatment. Transcriptome analysis following De novo assembly showed 26,498 matched unigenes. The results showed that 1,263 DEGs responded to transcription factors (TFs) and plant phytohormones and mediated oxidoreductase activity to scavenge reactive oxygen species (ROS) in the control vs. 3.0% NaCl comparison. In addition, the transcription levels of genes associated with auxin and ethylene signal transduction also changed. Under salt stress, ROS scavenging genes (POD, CAT, and APX) and part of AP2, MYB, NAC, C2C2, bHLH, and WRKY TFs were upregulated. This study identified important pathways and candidate genes involved in S. caseolaris salinity tolerance and provided suggestions for further research into the mechanisms of salt tolerance in S. caseolaris.
PMID: 35958196
Front Plant Sci , IF:5.753 , 2022 , V13 : P945379 doi: 10.3389/fpls.2022.945379
Integrative analysis of transcriptome and miRNAome reveals molecular mechanisms regulating pericarp thickness in sweet corn during kernel development.
Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, China.
Pericarp thickness affects the edible quality of sweet corn (Zea mays L. saccharata Sturt.). Therefore, breeding varieties with a thin pericarp is important for the quality breeding of sweet corn. However, the molecular mechanisms underlying the pericarp development remain largely unclear. We performed an integrative analysis of mRNA and miRNA sequencing to elucidate the genetic mechanism regulating pericarp thickness during kernel development (at 15 days, 19 days, and 23 days after pollination) of two sweet corn inbred lines with different pericarp thicknesses (M03, with a thinner pericarp and M08, with a thicker pericarp). A total of 2,443 and 1,409 differentially expressed genes (DEGs) were identified in M03 and M08, respectively. Our results indicate that phytohormone-mediated programmed cell death (PCD) may play a critical role in determining pericarp thickness in sweet corn. Auxin (AUX), gibberellin (GA), and brassinosteroid (BR) signal transduction may indirectly mediate PCD to regulate pericarp thickness in M03 (the thin pericarp variety). In contrast, abscisic acid (ABA), cytokinin (CK), and ethylene (ETH) signaling may be the key regulators of pericarp PCD in M08 (the thick pericarp variety). Furthermore, 110 differentially expressed microRNAs (DEMIs) and 478 differentially expressed target genes were identified. miRNA164-, miRNA167-, and miRNA156-mediated miRNA-mRNA pairs may participate in regulating pericarp thickness. The expression results of DEGs were validated by quantitative real-time PCR. These findings provide insights into the molecular mechanisms regulating pericarp thickness and propose the objective of breeding sweet corn varieties with a thin pericarp.
PMID: 35958194
Front Plant Sci , IF:5.753 , 2022 , V13 : P946213 doi: 10.3389/fpls.2022.946213
The Central Circadian Clock Protein TaCCA1 Regulates Seedling Growth and Spike Development in Wheat (Triticum aestivum L.).
The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.; Institute of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.; National Key Facility of Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China.
The biological functions of the circadian clock on growth and development have been well elucidated in model plants, while its regulatory roles in crop species, especially the roles on yield-related traits, are poorly understood. In this study, we characterized the core clock gene CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1) homoeologs in wheat and studied their biological functions in seedling growth and spike development. TaCCA1 homoeologs exhibit typical diurnal expression patterns, which are positively regulated by rhythmic histone modifications including histone H3 lysine 4 trimethylation (H3K4me3), histone H3 lysine 9 acetylation (H3K9Ac), and histone H3 lysine 36 trimethylation (H3K36me3). TaCCA1s are preferentially located in the nucleus and tend to form both homo- and heterodimers. TaCCA1 overexpression (TaCCA1-OE) transgenic wheat plants show disrupted circadian rhythmicity coupling with reduced chlorophyll and starch content, as well as biomass at seedling stage, also decreased spike length, grain number per spike, and grain size at the ripening stage. Further studies using DNA affinity purification followed by deep sequencing [DNA affinity purification and sequencing (DAP-seq)] indicated that TaCCA1 preferentially binds to sequences similarly to "evening elements" (EE) motif in the wheat genome, particularly genes associated with photosynthesis, carbon utilization, and auxin homeostasis, and decreased transcriptional levels of these target genes are observed in TaCCA1-OE transgenic wheat plants. Collectively, our study provides novel insights into a circadian-mediated mechanism of gene regulation to coordinate photosynthetic and metabolic activities in wheat, which is important for optimal plant growth and crop yield formation.
PMID: 35923880
Front Plant Sci , IF:5.753 , 2022 , V13 : P959859 doi: 10.3389/fpls.2022.959859
Fine mapping and target gene identification of qSE4, a QTL for stigma exsertion rate in rice (Oryza sativa L.).
State Key Laboratory of Rice Biology, Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture, China National Rice Improvement Centre, China National Rice Research Institute, Hangzhou, China.; Rice Research Institute, Shengyang Agricultural University, Shenyang, China.
The stigma exsertion rate (SER) is a complex agronomy phenotype controlled by multiple genes and climate and a key trait affecting the efficiency of hybrid rice seed production. Using a japonica two-line male sterile line (DaS) with a high SER as the donor and a tropical japonica rice (D50) with a low SER as the acceptor to construct a near-isogenic line [NIL (qSE4 (DaS))]. Populations were segregated into 2,143 individuals of BC3F2 and BC4F2, and the stigma exsertion quantitative trait locus (QTL) qSE4 was determined to be located within 410.4 Kb between markers RM17157 and RM17227 on chromosome 4. Bioinformatic analysis revealed 13 candidate genes in this region. Sequencing and haplotype analysis indicated that the promoter region of LOC_Os04g43910 (ARF10) had a one-base substitution between the two parents. Further Reverse Transcription-Polymerase Chain Reaction (RT-PCR) analysis showed that the expression level of ARF10 in DaS was significantly higher than in D50. After knocking out ARF10 in the DaS background, it was found that the SER of arf10 (the total SER of the arf10-1 and the arf10-2 were 62.54 and 66.68%, respectively) was significantly lower than that of the wild type (the total SER was 80.97%). Transcriptome and hormone assay analysis showed that arf10 had significantly higher auxin synthesis genes and contents than the wild type and the expression of auxin signaling-related genes was significantly different, Similar results were observed for abscisic acid and jasmonic acid. These results indicate that LOC_Os04g43910 is mostly likely the target gene of qSE4, and the study of its gene function is of great significance for understanding the molecular mechanisms of SER and improving the efficiency of hybrid seed production.
PMID: 35923872
Front Plant Sci , IF:5.753 , 2022 , V13 : P919177 doi: 10.3389/fpls.2022.919177
Comparative Physiological and Transcriptome Analysis Reveal the Molecular Mechanism of Melatonin in Regulating Salt Tolerance in Alfalfa (Medicago sativa L.).
School of Agriculture, Ningxia University, Yinchuan, China.; Ningxia Grassland and Animal Husbandry Engineering Technology Research Center, Yinchuan, China.
As a high-quality legume forage, alfalfa is restricted by various abiotic stresses during its growth and development. Melatonin is a multifunctional signaling molecule that involves in plant defense against multiple stresses. However, little is known about its downstream signaling pathway and regulatory mechanisms in salt stress of alfalfa. In this study, we investigated the protective effects and key regulatory pathways of melatonin on alfalfa under salt tolerance. The results showed that melatonin promoted the growth of alfalfa seedlings under salt stress, as demonstrated by higher plant height, leaf area, and fresh weight. Melatonin treatment resulted in an increase in the photosynthetic capacity and starch content of alfalfa. Moreover, melatonin decreased cell membrane damage and reactive oxygen species (ROS) accumulation by enhancing antioxidant defense activity under salt stress conditions. Transcriptome sequencing (RNA-seq) analysis revealed that melatonin mainly induced the transcription of genes involved in Ca(2+) signaling (cyclic nucleotide gated channel, CNGCs; cam modulin/calmodulin-like protein, CAM/CMLs and calcium-dependent protein kinase, CDPKs), starch and sucrose metabolism (alpha-amylase, AMYs; beta-amylase, BAMs; starch synthase, SSs and sucrose synthase, SUSs), plant hormone signal transduction (auxin/indole acetic acid protein, AUX/IAAs; ABA receptor, PYL4; protein phosphatase 2C, PP2Cs; scarecrow-like protein, SCLs and ethylene-responsive transcription factor 1B, ERF1B), and key transcription factors (C3Hs, MYBs, ERFs, and WRKYs). Specifically, we focused on starch and sucrose metabolism and plant hormone signal transduction pathways. The interactions between melatonin and other phytohormones occurred via regulation of the expression of genes involved in hormone signaling pathways. In addition, melatonin increased the contents of endogenous melatonin, auxin, gibberellic acid (GA3), salicylic acid, brassinosteroids, and ethylene, while decreasing the abscisic acid content under salt stress. In summary, this study established a regulatory network for melatonin-induced key signaling pathways and functional genes under salt stress and provided a theoretical basis for salt tolerance breeding in alfalfa.
PMID: 35909721
Front Plant Sci , IF:5.753 , 2022 , V13 : P889045 doi: 10.3389/fpls.2022.889045
How Strigolactone Shapes Shoot Architecture.
Department of Biology, University of Fribourg, Fribourg, Switzerland.
Despite its central role in the control of plant architecture, strigolactone has been recognized as a phytohormone only 15 years ago. Together with auxin, it regulates shoot branching in response to genetically encoded programs, as well as environmental cues. A central determinant of shoot architecture is apical dominance, i.e., the tendency of the main shoot apex to inhibit the outgrowth of axillary buds. Hence, the execution of apical dominance requires long-distance communication between the shoot apex and all axillary meristems. While the role of strigolactone and auxin in apical dominance appears to be conserved among flowering plants, the mechanisms involved in bud activation may be more divergent, and include not only hormonal pathways but also sugar signaling. Here, we discuss how spatial aspects of SL biosynthesis, transport, and sensing may relate to apical dominance, and we consider the mechanisms acting locally in axillary buds during dormancy and bud activation.
PMID: 35903239
Front Plant Sci , IF:5.753 , 2022 , V13 : P875528 doi: 10.3389/fpls.2022.875528
New Insights Into the Activity of Apple Dihydrochalcone Phloretin: Disturbance of Auxin Homeostasis as Physiological Basis of Phloretin Phytotoxic Action.
Institute for Biological Research "Sinisa Stankovic" - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Olomouc, Czechia.
Apple species are the unique naturally rich source of dihydrochalcones, phenolic compounds with an elusive role in planta, but suggested auto-allelochemical features related to "apple replant disease" (ARD). Our aim was to elucidate the physiological basis of the phytotoxic action of dihydrochalcone phloretin in the model plant Arabidopsis and to promote phloretin as a new prospective eco-friendly phytotoxic compound. Phloretin treatment induced a significant dose-dependent growth retardation and severe morphological abnormalities and agravitropic behavior in Arabidopsis seedlings. Histological examination revealed a reduced starch content in the columella cells and a serious disturbance in root architecture, which resulted in the reduction in length of meristematic and elongation zones. Significantly disturbed auxin metabolome profile in roots with a particularly increased content of IAA accumulated in the lateral parts of the root apex, accompanied by changes in the expression of auxin biosynthetic and transport genes, especially PIN1, PIN3, PIN7, and ABCB1, indicates the role of auxin in physiological basis of phloretin-induced growth retardation. The results reveal a disturbance of auxin homeostasis as the main mechanism of phytotoxic action of phloretin. This mechanism makes phloretin a prospective candidate for an eco-friendly bioherbicide and paves the way for further research of phloretin role in ARD.
PMID: 35873993
Front Plant Sci , IF:5.753 , 2022 , V13 : P929831 doi: 10.3389/fpls.2022.929831
Auxin Coordinates Achene and Receptacle Development During Fruit Initiation in Fragaria vesca.
College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, China.; Plant Synthetic Biology Center, Horticulture Biology and Metabolic Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, China.; College of Ecology and Resources Engineering, Wuyi University, Wuyishan, China.
In strawberries, fruit set is considered as the transition from the quiescent ovary to a rapidly growing fruit. Auxin, which is produced from the fertilized ovule in the achenes, plays a key role in promoting the enlargement of receptacles. However, detailed regulatory mechanisms for fruit set and the mutual regulation between achenes and receptacles are largely unknown. In this study, we found that pollination promoted fruit development (both achene and receptacle), which could be stimulated by exogenous auxin treatment. Interestingly, auxin was highly accumulated in achenes, but not in receptacles, after pollination. Further transcriptome analysis showed that only a small portion of the differentially expressed genes induced by pollination overlapped with those by exogenous auxin treatment. Auxin, but not pollination, was able to activate the expression of growth-related genes, especially in receptacles, which resulted in fast growth. Meanwhile, those genes involved in the pathways of other hormones, such as GA and cytokinin, were also regulated by exogenous auxin treatment, but not pollination. This suggested that pollination was not able to activate auxin responses in receptacles but produced auxin in fertilized achenes, and then auxin might be able to transport or transduce from achenes to receptacles and promote fast fruit growth at the early stage of fruit initiation. Our work revealed a potential coordination between achenes and receptacles during fruit set, and auxin might be a key coordinator.
PMID: 35873981
Front Plant Sci , IF:5.753 , 2022 , V13 : P943662 doi: 10.3389/fpls.2022.943662
Red and Blue Light Affect the Formation of Adventitious Roots of Tea Cuttings (Camellia sinensis) by Regulating Hormone Synthesis and Signal Transduction Pathways of Mature Leaves.
Tea Research Institute, Qingdao Agricultural University, Qingdao, China.; Rizhao Tea Research Institute, Rizhao, China.; Tea Research Institute, Shandong Academy of Agricultural Sciences, Rizhao, China.; College of Agronomy, Liaocheng University, Liaocheng, China.
Light is an important environmental factor which affects plant growth, through changes of intensity and quality. In this study, monochromatic white (control), red (660 nm), and blue (430 nm) light-emitting diodes (LEDs) were used to treat tea short cuttings. The results showed the most adventitious roots in blue light treated tea cuttings, but the lowest roots in that treated by red light. In order to explore the molecular mechanism of light quality affecting adventitious root formation, we performed full-length transcriptome and metabolome analyses of mature leaves under three light qualities, and then conducted weighted gene co-expression network analysis (WGCNA). Phytohormone analysis showed that Indole-3-carboxylic acid (ICA), Abscisic acid (ABA), ABA-glucosyl ester (ABA-GE), trans-Zeatin (tZ), and Jasmonic acid (JA) contents in mature leaves under blue light were significantly higher than those under white and red light. A crosstalk regulatory network comprising 23 co-expression modules was successfully constructed. Among them, the "MEblue" module which had a highly positive correlation with ICA (R = 0.92, P = 4e-04). KEGG analysis showed that related genes were significantly enriched in the "Plant hormone signal transduction (ko04075)" pathway. YUC (a flavin-containing monooxygenase), AUX1, AUX/IAA, and ARF were identified as hub genes, and gene expression analysis showed that the expression levels of these hub genes under blue light were higher than those under white and red light. In addition, we also identified 6 auxin transport-related genes, including PIN1, PIN3, PIN4, PILS5, PILS6, and PILS7. Except PILS5, all of these genes showed the highest expression level under blue light. In conclusion, this study elucidated the molecular mechanism of light quality regulating adventitious root formation of tea short cutting through WGCNA analysis, which provided an innovation for "rapid seedling" of tea plants.
PMID: 35873958
Genomics , IF:5.736 , 2022 Aug : P110465 doi: 10.1016/j.ygeno.2022.110465
Series-temporal transcriptome profiling of cotton reveals the response mechanism of phosphatidylinositol signaling system in the early stage of drought stress.
Institute of Industrial Crops, Shandong Academy of Agricultural Sciences, Key Laboratory of Cotton Breeding and Cultivation in Huang-Huai-Hai Plain, Ministry of Agriculture, Jinan, Shandong 250100, PR China.; Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Sciences, Hebei Key Laboratory of Crops Drought Resistance, Hengshui, Hebei 053000, PR China. Electronic address: daimaohua@sina.com.; Institute of Industrial Crops, Shandong Academy of Agricultural Sciences, Key Laboratory of Cotton Breeding and Cultivation in Huang-Huai-Hai Plain, Ministry of Agriculture, Jinan, Shandong 250100, PR China. Electronic address: zongfuhan@126.com.
Plants are sessile organisms suffering severe environmental conditions. Drought stress is one of the major environmental issues that affect plant growth and productivity. Although complex regulatory gene networks of plants under drought stress have been analyzed extensively, the response mechanism in the early stage of drought stress is still rarely mentioned. Here, we performed transcriptome analyses on cotton samples treated for a short time (10min, 30min, 60min, 180min) using 10% PEG, which is used to simulate drought stress. The analysis of differently expressed genes (DEGs) showed that the number of DEGs in roots was obviously more than that in stems and leaves at the four time points and maintained >2000 FDEGs (DEGs appearing for the first time) from 10min, indicating that root tissues of plants respond to drought stress quickly and continuously strongly. Gene ontology (GO) analysis showed that DEGs in roots were mainly enriched in protein modification and microtubule-based process. DEGs were found significantly enriched in phosphatidylinositol signaling system at 10min through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, implying the great importance of phosphatidylinositol signal in the early stage of drought stress. What was more, two co-expression modules, which were significantly positively correlated with drought stress, were found by Weighted Gene Co-expression Network Analysis (WGCNA). From one of the co-expression modules, we identified a hub-gene Gohir.A07G058200, which is annotated as "phosphatidylinositol 3- and 4-kinase" in phosphatidylinositol signaling system, and found this gene may interact with auxin-responsive protein. This result suggested that Gohir.A07G058200 may be involved in the crosstalk of phosphatidylinositol signal and auxin signal in the early stage of drought stress. In summary, through transcriptome sequencing, we found that phosphatidylinositol signaling system is an important signal transduction pathway in early stage in response to drought stress, and it may interact with auxin signal transduction through phosphatidylinositol 3- and 4-kinase.
PMID: 36038061
Theor Appl Genet , IF:5.699 , 2022 Aug doi: 10.1007/s00122-022-04196-8
Integrated genetic mapping and transcriptome analysis reveal the BnaA03.IAA7 protein regulates plant architecture and gibberellin signaling in Brassica napus L.
College of Agronomy and Biotechnology, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing, 400715, China.; Biotechnology Research Center, Southwest University, Chongqing, 400715, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, School of Life Sciences, Hubei University, Wuhan, 430070, China.; College of Agronomy and Biotechnology, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing, 400715, China. liezhao@swu.edu.cn.
KEY MESSAGE: A novel mutation in the BnaA03.IAA7 protein reduces plant height and enhances gibberellin signaling in Brassica napus L. Rapeseed (Brassica napus) is an excellent and important source for vegetable oil production, but its production is severely affected by lodging. Lodging hinders mechanization and decreases yield, and an ideal solution is semidwarf breeding. Limited by germplasm resources, semidwarf breeding developed slowly in rapeseed. In the current study, a mutant called sdA03 was isolated from EMS-mutagenized lines of Zhongshuang 11 (ZS11). The inheritance analysis showed that phenotypes of sdA03 were controlled by a single semidominant gene. Genetic mapping, RNA-seq and candidate gene analysis identified BnaA03.IAA7 as a candidate gene, and a function test confirmed that the mutated BnaA03.iaa7 regulates plant architecture in a dose-dependent manner. Yeast two-hybrid and transient expression experiments illustrated the P87L substitution in the GWPPV/I degron motif of BnaA03.iaa7 impaired the interaction between BnaA03.IAA7 and TIR1 proteins, and BnaA03.iaa7 prevented ARF from activating the auxin signaling pathway.The gibberellin (GA) content was higher in sdA03 hypocotyls than in those of ZS11. Further expression analysis showed more active gibberellin signaling in hypocotyl and richer expression of GA synthetic genes in root and cotyledon of sdA03 seedlings. Finally, a marker was developed based on the SNP found in BnaA03.iaa7 and used in molecular breeding. The study enriched our understanding of the architectural regulation of rapeseed and provided germplasm resources for breeding.
PMID: 35962210
Environ Microbiol , IF:5.491 , 2022 Aug , V24 (8) : P3580-3597 doi: 10.1111/1462-2920.15920
A bacterial chemoreceptor that mediates chemotaxis to two different plant hormones.
Department of Environmental Protection, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas, Granada, Spain.; Department of Microbiology, Facultad de Farmacia, Campus Universitario de Cartuja, Universidad de Granada, Granada, 18071, Spain.
Indole-3-acetic acid (IAA) is the main naturally occurring auxin and is produced by organisms of all kingdoms of life. In addition to the regulation of plant growth and development, IAA plays an important role in the interaction between plants and growth-promoting and phytopathogenic bacteria by regulating bacterial gene expression and physiology. We show here that an IAA metabolizing plant-associated Pseudomonas putida isolate exhibits chemotaxis to IAA that is independent of auxin metabolism. We found that IAA chemotaxis is based on the activity of the PcpI chemoreceptor and heterologous expression of pcpI conferred IAA taxis to different environmental and human pathogenic isolates of the Pseudomonas genus. Using ligand screening, microcalorimetry and quantitative chemotaxis assays, we found that PcpI failed to bind IAA directly, but recognized and mediated chemoattractions to various aromatic compounds, including the phytohormone salicylic acid. The expression of pcpI and its role in the interactions with plants was also investigated. PcpI extends the range of central signal molecules recognized by chemoreceptors. To our knowledge, this is the first report on a bacterial receptor that responds to two different phytohormones. Our study reinforces the multifunctional role of IAA and salicylic acid as intra- and inter-kingdom signal molecules.
PMID: 35088505
iScience , IF:5.458 , 2022 Jul , V25 (7) : P104683 doi: 10.1016/j.isci.2022.104683
Transcriptional reprogramming during floral fate acquisition.
Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, 69342 Lyon, France.; Univ. Grenoble Alpes, CNRS, CEA, INRAE, BIG-LPCV, 38000 Grenoble, France.; Institute of Biotechnology, HiLIFE/Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, 00014 Helsinki, Finland.; Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE, Universite Paris-Sud, Universite d'Evry, Universite Paris-Saclay, Batiment 630, Plateau de Moulon, 91192 Gif sur Yvette, France.; Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRAE Universite Paris-Diderot, Sorbonne Paris-Cite, Batiment 630, Plateau de Moulon, 91192 Gif sur Yvette, France.; IRHS-UMR1345, Universite d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, 49071 Beaucouze, France.; Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT, UK.; Department of Biological Sciences, University of Alberta, CW-405 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada.; The Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.
Coordinating growth and patterning is essential for eukaryote morphogenesis. In plants, auxin is a key regulator of morphogenesis implicated throughout development. Despite this central role, our understanding of how auxin coordinates cell fate and growth changes is still limited. Here, we addressed this question using a combination of genomic screens to delve into the transcriptional network induced by auxin at the earliest stage of flower development, prior to morphological changes. We identify a shoot-specific network suggesting that auxin initiates growth through an antagonistic regulation of growth-promoting and growth-repressive hormones, quasi-synchronously to floral fate specification. We further identify two DNA-binding One Zinc Finger (DOF) transcription factors acting in an auxin-dependent network that could interface growth and cell fate from the early stages of flower development onward.
PMID: 35856019
Front Chem , IF:5.221 , 2022 , V10 : P975267 doi: 10.3389/fchem.2022.975267
Design, synthesis, and herbicidal activity of indole-3-carboxylic acid derivatives as potential transport inhibitor response 1 antagonists.
Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, College of Chemistry and Materials Engineering, Zhejiang A & F University, Hangzhou, China.; Key Laboratory of Organic Chemistry of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang, China.; Key Laboratory of Pesticide & Chemical Biology of the Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, China.
Auxins as an important class of phytohormones play essential roles in plant life cycle; therefore, developing compounds with auxin-like properties for plant growth regulation and weed control applications is of great significance. Herein, we reported the design, synthesis, and herbicidal activity evaluation of a series of novel indole-3-carboxylic acid derivatives as auxin receptor protein TIR1 antagonists. Petri dish herbicidal activity assay demonstrated that most of the as-synthesized target compounds exhibited good-to-excellent inhibition effects (60-97% inhibitory rates) on roots and shoots of both dicotyledonous rape (B. napus) and monocotyledonous barnyard grass (E. crus-galli). The inhibition rates of compounds 10d and 10h reached up to 96% and 95% for the root of rape (B. napus) at 100 mg/L, and they also maintained 92% and 93% inhibition rates even if at 10 mg/L, respectively. Molecular docking revealed that the interactions between these synthesized target compounds and TIR1 protein include tight pi-pi stacking, hydrogen bond, and hydrophobic interactions. This work expands the range of auxin chemistry for the development of new auxin mimic herbicides.
PMID: 35958241
Biology (Basel) , IF:5.079 , 2022 Aug , V11 (8) doi: 10.3390/biology11081192
Application of 2,4-Epibrassinolide Improves Drought Tolerance in Tobacco through Physiological and Biochemical Mechanisms.
Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture and Rural Affairs, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China.; College of Life Science and Technology, Guangxi University, Nanning 530004, China.; Department of Agronomy, The University of Agriculture Peshawar, Peshawar 25130, Pakistan.
Drought stress is a major abiotic stress that hinders plant growth and development. Brassinosteroids (BR), including 2,4-epibrassinolide (EBR), play important roles in plant growth, development, and responses to abiotic stresses, including drought stress. This work investigates exogenous EBR application roles in improving drought tolerance in tobacco. Tobacco plants were divided into three groups: WW (well-watered), DS (drought stress), and DSB (drought stress + 0.05 mM EBR). The results revealed that DS decreased the leaf thickness (LT), whereas EBR application upregulated genes related to cell expansion, which were induced by the BR (DWF4, HERK2, and BZR1) and IAA (ARF9, ARF6, PIN1, SAUR19, and ABP1) signaling pathway. This promoted LT by 28%, increasing plant adaptation. Furthermore, EBR application improved SOD (22%), POD (11%), and CAT (5%) enzyme activities and their related genes expression (FeSOD, POD, and CAT) along with a higher accumulation of osmoregulatory substances such as proline (29%) and soluble sugars (14%) under DS and conferred drought tolerance. Finally, EBR application augmented the auxin (IAA) (21%) and brassinolide (131%) contents and upregulated genes related to drought tolerance induced by the BR (BRL3 and BZR2) and IAA (YUCCA6, SAUR32, and IAA26) signaling pathways. These results suggest that it could play an important role in improving mechanisms of drought tolerance in tobacco.
PMID: 36009819
Plant Methods , IF:4.993 , 2022 Jul , V18 (1) : P94 doi: 10.1186/s13007-022-00929-4
Deep learning for detecting herbicide weed control spectrum in turfgrass.
College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.; Peking University Institute of Advanced Agricultural Sciences, Weifang, 261325, Shandong, China.; Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, 77843, USA.; College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China. chenyongjsnj@163.com.; Peking University Institute of Advanced Agricultural Sciences, Weifang, 261325, Shandong, China. jialin.yu@pku-iaas.edu.cn.
BACKGROUND: Precision spraying of postemergence herbicides according to the herbicide weed control spectrum can substantially reduce herbicide input. The objective of this research was to evaluate the effectiveness of using deep convolutional neural networks (DCNNs) for detecting and discriminating weeds growing in turfgrass based on their susceptibility to ACCase-inhibiting and synthetic auxin herbicides. RESULTS: GoogLeNet, MobileNet-v3, ShuffleNet-v2, and VGGNet were trained to discriminate the vegetation into three categories based on the herbicide weed control spectrum: weeds susceptible to ACCase-inhibiting herbicides, weeds susceptible to synthetic auxin herbicides, and turfgrass without weed infestation (no herbicide). ShuffleNet-v2 and VGGNet showed high overall accuracy (>/= 0.999) and F1 scores (>/= 0.998) in the validation and testing datasets to detect and discriminate weeds susceptible to ACCase-inhibiting and synthetic auxin herbicides. The inference time of ShuffleNet-v2 was similar to MobileNet-v3, but noticeably faster than GoogLeNet and VGGNet. ShuffleNet-v2 was the most efficient and reliable model among the neural networks evaluated. CONCLUSION: These results demonstrated that the DCNNs trained based on the herbicide weed control spectrum could detect and discriminate weeds based on their susceptibility to selective herbicides, allowing the precision spraying of particular herbicides to susceptible weeds and thereby saving more herbicides. The proposed method can be used in a machine vision-based autonomous spot-spraying system of smart sprayers.
PMID: 35879797
Plant Cell Physiol , IF:4.927 , 2022 Jul doi: 10.1093/pcp/pcac104
OsAMT1;1 and OsAMT1;2 Coordinate Root Morphological and Physiological Responses to Ammonium for Efficient Nitrogen Foraging in Rice.
Key Laboratory of Plant-Soil Interactions, MOE, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, 100193 Beijing, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Optimal plant growth and development rely on morphological and physiological adaptions of root system to forage heterogeneously distributed nitrogen (N) in soils. Rice grows mainly in the paddy soil where ammonium (NH4+) is present as the major N source. Although root NH4+ foraging behaviors are expected to be agronomically relevant, the underlying mechanism remains largely unknown. Here, we showed that NH4+ supply transiently enhanced the high-affinity NH4+ uptake and stimulated lateral root (LR) branching and elongation. These synergistic physiological and morphological responses were closely related to NH4+-induced expression of ammonium transporters OsAMT1;1 and OsAMT1;2 in roots. The two independent double mutants (dko) defective in OsAMT1;1 and OsAMT1;2 failed to induce NH4+ uptake and stimulate LR formation, suggesting that OsAMT1s conferred the substrate-dependent root NH4+ foraging. In dko plants, NH4+ was unable to activate expression of OsPIN2, and OsPIN2 mutant (lra1) exhibited strong reduction in NH4+-triggered LR branching, suggesting that auxin pathway was likely involved in OsAMT1s-dependent LR branching. Importantly, OsAMT1s-dependent root NH4+ foraging behaviors facilitated rice growth and N acquisition under fluctuating NH4+ supply. These results revealed an essential role of OsAMT1s in synergizing root morphological and physiological processes, allowing for efficient root NH4+ foraging to optimize N capture under fluctuating N availabilities.
PMID: 35861152
Plant Cell Physiol , IF:4.927 , 2022 Aug , V63 (8) : P1038-1051 doi: 10.1093/pcp/pcac078
Root Cap to Soil Interface: A Driving Force Toward Plant Adaptation and Development.
Indian Institute of Science Education and Research (IISER) Tirupati, Biology Division, Tirupati, Andhra Pradesh 517507, India.
Land plants have developed robust roots to grow in diverse soil ecosystems. The distal end of the root tip has a specialized organ called the 'root cap'. The root cap assists the roots in penetrating the ground, absorbing water and minerals, avoiding heavy metals and regulating the rhizosphere microbiota. Furthermore, root-cap-derived auxin governs the lateral root patterning and directs root growth under varying soil conditions. The root cap formation is hypothesized as one of the key innovations during root evolution. Morphologically diversified root caps in early land plant lineage and later in angiosperms aid in improving the adaptation of roots and, thereby, plants in diverse soil environments. This review article presents a retrospective view of the root cap's important morphological and physiological characteristics for the root-soil interaction and their response toward various abiotic and biotic stimuli. Recent single-cell RNAseq data shed light on root cap cell-type-enriched genes. We compiled root cap cell-type-enriched genes from Arabidopsis, rice, maize and tomato and analyzed their transcription factor (TF) binding site enrichment. Further, the putative gene regulatory networks derived from root-cap-enriched genes and their TF regulators highlight the species-specific biological functions of root cap genes across the four plant species.
PMID: 35662353
Plant Cell Physiol , IF:4.927 , 2022 Aug , V63 (8) : P1029-1037 doi: 10.1093/pcp/pcac069
Seed Dormancy and Longevity: A Mutual Dependence or a Trade-Off?
School of Environment and Ecology, Northwestern Polytechnical University, No. 1, Dongxiang Road, Xi'an 710129, China.; Research and Development Institute of Northwestern Polytechnical University in Shenzhen, No. 45, Gaoxin South 9 Road, Shenzhen 518057, China.
Seed dormancy is an important agronomic trait in cereals and leguminous crops as low levels of seed dormancy during harvest season, coupled with high humidity, can cause preharvest sprouting. Seed longevity is another critical trait for commercial crop propagation and production, directly influencing seed germination and early seedling establishment. Both traits are precisely regulated by the integration of genetic and environmental cues. Despite the significance of these two traits in crop production, the relationship between them at the molecular level is still elusive, even with contradictory conclusions being reported. Some studies have proposed a positive correlation between seed dormancy and longevity in association with differences in seed coat permeability or seed reserve accumulation, whereas an increasing number of studies have highlighted a negative relationship, largely with respect to phytohormone-dependent pathways. In this review paper, we try to provide some insights into the interactions between regulatory mechanisms of genetic and environmental cues, which result in positive or negative relationships between seed dormancy and longevity. Finally, we conclude that further dissection of the molecular mechanism responsible for this apparently contradictory relationship between them is needed.
PMID: 35594901
Plant Cell Physiol , IF:4.927 , 2022 Jul , V63 (7) : P932-943 doi: 10.1093/pcp/pcac055
SMAX1 Integrates Karrikin and Light Signals into GA-Mediated Hypocotyl Growth during Seedling Establishment.
Department of Chemistry, Seoul National University, Seoul 08826, South Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, South Korea.
Morphogenic adaptation of young seedlings to light environments is a critical developmental process that ensures plant survival and propagation, as they emerge from the soil. Photomorphogenic responses are facilitated by a network of light and growth hormonal signals, such as auxin and gibberellic acid (GA). Karrikins (KARs), a group of butenolide compounds produced from burning plant materials in wildfires, are known to stimulate seed germination in fire-prone plant species. Notably, recent studies support that they also regulate seedling growth, while underlying molecular mechanisms have been unexplored yet. Here, we demonstrate that SUPPRESSOR OF MAX2 1 (SMAX1), a negative regulator of KAR signaling, integrates light and KAR signals into GA-DELLA pathways that regulate hypocotyl growth during seedling establishment. We found that SMAX1 facilitates degradation of DELLA proteins in the hypocotyls. Interestingly, light induces the accumulation of SMAX1 proteins, and SMAX1-mediated degradation of DELLA is elevated in seedling establishment during the dark-to-light transition. Our observations indicate that SMAX1-mediated integration of light and KAR signals into GA pathways elaborately modulates seedling establishment.
PMID: 35477800
Appl Environ Microbiol , IF:4.792 , 2022 Aug : Pe0088222 doi: 10.1128/aem.00882-22
Elucidating the Effect of Endophytic Entomopathogenic Fungi on Bread Wheat Growth through Signaling of Immune Response-Related Hormones.
Department of Agronomy, ETSIAM, University of Cordoba, Cordoba, Spain.; Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Cordoba, UCO-CeiA3, Cordoba, Spain.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; Center of Plant Systems Biology, VIB, Ghent, Belgium.
Entomopathogenic fungi (EF) provide a potent biocontrol tool; also, their endophytic behavior has broadened their contribution to integrated pest management (IPM) and crop production. In this work, Beauveria bassiana and Metarhizium brunneum were applied to bread wheat (Triticum aestivum) seedlings to elucidate how fungal colonization influences plant growth and the relative expression of 24 genes involved in hormonal syntheses and plant immune mechanisms. A preliminary assay was used to determine the time needed for fungal colonization and assess its effect on wheat growth. Then, plant material collected at various times after inoculation (viz., 2, 8, 20, and 36 h and 9 and 15 days) was used to investigate gene expression by quantitative reverse transcription PCR (RT-qPCR). During the colonization time, B. bassiana and M. brunneum caused strong downregulation of most genes associated with plant immunity and the synthesis of hormones like auxin, cytokinin, and gibberellin. This effect was concomitant with a slowdown of endophytic-colonization-related plant growth until 19 days postinoculation (dpi). However, the wheat started to recover at 15 dpi, simultaneously with upregulation of auxin- and gibberellin-related genes. The results suggest that the EF trigger induced systemic resistance rather than acquired systemic resistance during early plant-microbe cross talk in wheat. Also, they confirm that the hormone and immune responses of wheat triggered by EF inoculation influenced plant growth, which can be useful with a view to optimizing management of these microorganisms for sustainable agriculture. IMPORTANCE Microbial control of insect and mite pests is a key tool to develop integrated pest management (IPM) and sustainable agriculture. Entomopathogenic fungi (EF) may have associations with the plants, playing additional ecological roles in the rhizosphere, in the phylloplane, and as plant endophytes. Beauveria bassiana 04/01TIP and Metarhizium brunneum 01/58Su are two strains that showed very good results either in pest control or plant growth promotion and would be good candidates to develop mycoinsecticides as an alternative to pesticides. However, deep knowledge about their interaction with the plant would let farmers optimize their use and understand the plant response, enhancing and promoting their broader contribution to IPM and crop production.
PMID: 36036583
Rice (N Y) , IF:4.783 , 2022 Aug , V15 (1) : P42 doi: 10.1186/s12284-022-00588-y
Salicylic Acid Acts Upstream of Auxin and Nitric Oxide (NO) in Cell Wall Phosphorus Remobilization in Phosphorus Deficient Rice.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing, 210008, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 1138657, Japan.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing, 210008, China. xiaofangzhu@issas.ac.cn.; University of Chinese Academy of Sciences, Beijing, 100049, China. xiaofangzhu@issas.ac.cn.
Salicylic acid (SA) is thought to be involved in phosphorus (P) stress response in plants, but the underlying molecular mechanisms are poorly understood. Here, we showed that P deficiency significantly increased the endogenous SA content by inducing the SA synthesis pathway, especially for up-regulating the expression of PAL3. Furthermore, rice SA synthetic mutants pal3 exhibited the decreased root and shoot soluble P content, indicating that SA is involved in P homeostasis in plants. Subsequently, application of exogenous SA could increase the root and shoot soluble P content through regulating the root and shoot cell wall P reutilization. In addition, - P + SA treatment highly upregulated the expression of P transporters such as OsPT2 and OsPT6, together with the increased xylem P content, suggesting that SA also participates in the translocation of the P from the root to the shoot. Moreover, both signal molecular nitric oxide (NO) and auxin (IAA) production were enhanced when SA is applied while the addition of respective inhibitor c-PTIO (NO scavenger) and NPA (IAA transport inhibitor) significantly decreased the root and shoot cell wall P remobilization in response to P starvation. Taken together, here SA-IAA-NO-cell wall P reutilization pathway has been discovered in P-starved rice.
PMID: 35920901
Rice (N Y) , IF:4.783 , 2022 Jul , V15 (1) : P40 doi: 10.1186/s12284-022-00587-z
miR167d-ARFs Module Regulates Flower Opening and Stigma Size in Rice.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China.; State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China. j316wenmingwang@163.com.
Flower opening and stigma exertion are two critical traits for cross-pollination during seed production of hybrid rice (Oryza sativa L.). In this study, we demonstrate that the miR167d-ARFs module regulates stigma size and flower opening that is associated with the elongation of stamen filaments and the cell arrangement of lodicules. The overexpression of miR167d (OX167d) resulted in failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule, resulting in cleistogamy. Blocking miR167d by target mimicry also led to a morphological alteration of the individual floral organs, including a reduction in stigma size and alteration of lodicule cell morphology, but did not show the cleistogamous phenotype. In addition, the four target genes of miR167d, namely ARF6, ARF12, ARF17, and ARF25, have overlapping functions in flower opening and stigma size. The loss-of-function of a single ARF gene did not influence the flower opening and stigma size, but arf12 single mutant showed a reduced plant height and aborted apical spikelets. However, mutation in ARF12 together with mutation in either ARF6, ARF17, or ARF25 led to the same defective phenotypes that were observed in OX167d, including the failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule. These findings indicate that the appropriate expression of miR167d is crucial and the miR167d-ARFs module plays important roles in the regulation of flower opening and stigma size in rice.
PMID: 35876915
Plant Sci , IF:4.729 , 2022 Aug , V324 : P111421 doi: 10.1016/j.plantsci.2022.111421
AtHB40 modulates primary root length and gravitropism involving CYCLINB and auxin transporters.
Instituto de Agrobiotecnologia del Litoral (CONICET, Universidad Nacional del Litoral, FBCB), Colectora Ruta Nacional 168, km 0, 3000 Santa Fe, Argentina.; Centro Nacional de Biotecnologia (CNB) - CSIC, Madrid, Spain.; Instituto de Agrobiotecnologia del Litoral (CONICET, Universidad Nacional del Litoral, FBCB), Colectora Ruta Nacional 168, km 0, 3000 Santa Fe, Argentina. Electronic address: rchan@fbcb.unl.edu.ar.
Gravitropism is a finely regulated tropistic response based on the plant perception of directional cues. Such perception allows them to direct shoot growth upwards, above ground, and root growth downwards, into the soil, anchoring the plant to acquire water and nutrients. Gravity sensing occurs in specialized cells and depends on auxin distribution, regulated by influx/efflux carriers. Here we report that AtHB40, encoding a transcription factor of the homeodomain-leucine zipper I family, was expressed in the columella and the root tip. Athb40 mutants exhibited longer primary roots. Enhanced primary root elongation was in agreement with a higher number of cells in the transition zone and the induction of CYCLINB transcript levels. Moreover, athb40 mutants and AtHB40 overexpressors displayed enhanced and delayed gravitropistic responses, respectively. These phenotypes were associated with altered auxin distribution and deregulated expression of the auxin transporters LAX2, LAX3, and PIN2. Accordingly, lax2 and lax3 mutants also showed an altered gravitropistic response, and LAX3 was identified as a direct target of AtHB40. Furthermore, AtHB40 is induced by AtHB53 when the latter is upregulated by auxin. Altogether, these results indicate that AtHB40 modulates cell division and auxin distribution in the root tip thus altering primary root length and gravitropism.
PMID: 35995111
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111415 doi: 10.1016/j.plantsci.2022.111415
IbTLD modulates reactive oxygen species scavenging and DNA protection to confer salinity stress tolerance in tobacco.
Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan. Electronic address: tcch@ucdavis.edu.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: abslwert@gmail.com.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: r98b43022@gmail.com.; Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: jslin@dragon.nchu.edu.tw.
Plants accumulate reactive oxygen species (ROS) that may damage the cells under prolonged stress conditions. Reduction of the excessive ROS production can alleviate oxidative damage and enhance the survival rates under stress. TLDc-containing protein (TLD) was reported to confer tolerance to oxidative stress, but the regulatory mechanism of TLD remains unclear. In this study, we ectopically overexpressed the Ipomoea batatas TLDc gene (IbTLD) in tobacco and characterized its functions. RNA-sequencing analysis and Gene Ontology term enrichment analysis revealed that IbTLD up-regulates auxin-responsive genes in response to oxidative stress. Under salinity stress, the IbTLD transgenic lines showed higher germination rates, chlorophyll contents, and root lengths than wild type (W38). In addition, the IbTLD transgenic lines showed higher expression of ROS scavenging genes, nudix hydrolases, ROS scavenging enzyme activity, and lesser DNA damage compared to W38 under salinity stress. Therefore, our results suggest that IbTLD activates the expression of ROS scavenging genes and confers tolerance to salinity stress in planta.
PMID: 35963494
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111409 doi: 10.1016/j.plantsci.2022.111409
PpPIF8, a DELLA2-interacting protein, regulates peach shoot elongation possibly through auxin signaling.
College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China.; College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China. Electronic address: jcheng2007@163.com.; College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China. Electronic address: jcfeng@henau.edu.cn.
Rapid growth of branches in a peach tree restricts the light penetration and air ventilation within the orchard, which lowers fruit quality and promotes the occurrence of diseases and insects. Our previous works showed that PpDELLA1 and PpDELLA2 repress the rapid growth of annual shoots. Proteins that interact with DELLA are vital for its function. In this study, seven PpPIFs (PpPIF1, -2, -3, -4, -6, -7 and -8) were identified in the peach genome and contain a conserved bHLH domain. Among the seven PpPIFs, PpPIF8 interacted with PpDELLA2 through an unknown motif in the C-terminal and/or the bHLH domain. Overexpression of PpPIF8 in Arabidopsis promotes plant height and branch numbers. Hypocotyl elongation was significantly enhanced by PpPIF8 under weak light intensity. PpPIF8 overexpressed in Arabidopsis and transiently expressed in peach seedlings upregulated the transcription of YUCCA and SAUR19 and downregulated SHY1 and -2. Additionally, PpPIF4 and -8 were significantly induced by weak light. Phylogentic analysis and intron patterns of the bHLH domain strongly suggested that PIFs from six species could be divided into two groups of different evolutionary origins. These results lay a foundation for the further study of the repression of shoot growth by PpDELLA2 through protein interaction with PpPIF8 in peach.
PMID: 35934255
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111408 doi: 10.1016/j.plantsci.2022.111408
Overexpression of a SHORT-ROOT transcriptional factor enhances the auxin mediated formation of adventitious roots and lateral roots in poplar trees.
School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 2441909790@qq.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 1501661988@qq.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: 18700944808@163.com.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: shaohuiyang77@tju.edu.cn.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin 300072, China.. Electronic address: jiehuawang@tju.edu.cn.
SHORT-ROOT (SHR) defines root stem cells and maintains radial patterning, but its involvement in adventitious root (AR) formation has not been reported. In this study, we showed that PtSHR2 was transcriptionally upregulated by excision before the formation of AR and responded dynamically to auxin. PtSHR2 overexpression (SHR2B(OE)) in hybrid poplars resulted in an increased number of ARs with an initial delay. Despite a lower endogenous content in the stems than in wild-type plants, indole-3-acetic acid (IAA) content at the SHR2B(OE) basal stem increased rapidly after cutting and reached a higher maximum than in wild-type plants, which was accompanied by a more sustained and stronger induction of AR formation marker genes. In addition, the higher auxin content in SHR2B(OE) ARs resulted in more and longer lateral roots (LRs). Application of auxin abolished the early delay in the formation of AR and largely other AR phenotypes of SHR2B(OE) plants, whereas the polar auxin transport inhibitor N-1-naphthylphthalamic acid completely inhibited both AR and LR abnormalities. Since the enhanced rooting ability of SHR2B(OE) stem cuttings in hydroponics was clearly confirmed, our results suggest a novel role of poplar SHR2 as a positive regulator during the organogenesis of AR and LR by affecting local auxin homeostasis.
PMID: 35932828
Plant Sci , IF:4.729 , 2022 Oct , V323 : P111401 doi: 10.1016/j.plantsci.2022.111401
The Citrus sinensis TILLER ANGLE CONTROL 1 (CsTAC1) gene regulates tree architecture in sweet oranges by modulating the endogenous hormone content.
Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA. Electronic address: manjul@ufl.edu.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA; Pomology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA; Department of Agricultural Botany, Faculty of Agriculture, Tanta University, Tanta 31512, Egypt.; Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL 33850, USA.
Citrus is a major fruit crop cultivated on a global scale. Citrus trees are long lived perennials with a large canopy. Understanding the genetic control of tree architecture could provide tools for breeding and selection of citrus cultivars suitable for high density planting with improved light exposure. Tree architecture is modulated by the TILLER ANGLE CONTROL 1 (TAC1) gene which plays an important role in the regulation of the shoot angle. Herein, we used CRISPR/Cas9 technology to knockout the CsTAC1 gene for the biochemical and molecular analysis of its function. Nine transgenic lines were obtained, and five edited plants were confirmed based on T7EI mismatch detection assay and Sanger sequencing. The transgenic citrus lines exhibited pleiotropic phenotypes, including differences in branch angle and stem growth. Additionally, silencing CsTAC1 led to enhanced CsLAZY1 transcript levels in the tested lines. Analysis of the phytohormonal profile revealed that TAC1-edited plants exhibited lower auxin contents and increased cytokinin levels in the leaves compared to the wild-type plants. The GA7 gibberellin level was enhanced in most of the edited lines. Collectively, TAC1 affects branch angle in association with hormone signals in citrus.
PMID: 35905898
Plant Sci , IF:4.729 , 2022 Sep , V322 : P111371 doi: 10.1016/j.plantsci.2022.111371
Auxin facilitates cell wall phosphorus reutilization in a nitric oxide-ethylene dependent manner in phosphorus deficient rice (Oryza sativa L.).
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xiaofangzhu@issas.ac.cn.
Auxin is involved in stress responses of plants, such as phosphorus (P) deficiency in rice. Studies on whether auxin participates in cell-wall inorganic phosphorous (Pi) reutilization in Pi-starved rice are scarce. This study explored the mechanisms underlying auxin-facilitated cell-wall Pi-reutilization in rice roots. Pi deficiency rapidly induced auxin accumulation in roots; exogenous auxin [alpha-naphthaleneacetic acid (NAA), a permeable analog of auxin] elevated soluble Pi content in roots and shoots by increasing pectin content by enhancing activity of pectin methylesterase, and upregulating the transcript level of PHOSPHORUS-TRANSPORTER-2, such that more Pi was translocated to the shoot. Irrespective of the Pi status, exogenous auxin induced nitric oxide (NO) and ethylene production, while exogenous sodium nitroprusside (an NO donor) and 1-aminocyclopropane-1-carboxylic acid (a precursor of ethylene) had no effect on auxin content, suggesting that auxin may act upstream of NO and ethylene. The beneficial effect of NAA in increasing soluble Pi content in roots and shoots disappeared when 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (a scavenger of NO) or aminoethoxyvinylglycine (an inhibitor of ethylene) were applied, suggesting that auxin facilitates cell-wall Pi-reutilization in a NO-ethylene-dependent manner in Pi-deficient rice. Our study results suggest auxin application as an effective agronomic practice for improving plant Pi nutrition in P-deficient conditions.
PMID: 35809682
Plant Sci , IF:4.729 , 2022 Aug , V321 : P111340 doi: 10.1016/j.plantsci.2022.111340
Modeling-based age-dependent analysis reveals the net patterns of ethylene-dependent and -independent aerenchyma formation in rice and maize roots.
Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan. Electronic address: atkyama@agr.nagoya-u.ac.jp.; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan; School of Agriculture and Environment, The University of Western Australia, Crawley, WA 6009, Australia.
Plants require oxygen for the functioning of roots, and thus the establishment of a long-distance diffusion path from above-water tissues to the submerged roots is essential to survive flooding. Rice (Oryza sativa) constitutively forms aerenchyma (gas spaces) under aerobic conditions, and induces its formation in response to low-oxygen conditions. Constitutive aerenchyma formation in rice roots is regulated by the phytohormone auxin, whereas ethylene stimulates inducible aerenchyma formation. However, the net patterns of the ethylene-dependent and -independent (auxin-dependent) aerenchyma formation remain unclear. In the present study, we used a modeling approach to determine age-dependent aerenchyma formation in the wild-type rice and reduced culm number 1 mutant, in which ethylene production is reduced, to reveal the net patterns of ethylene-dependent and -independent aerenchyma formation. Subsequent comparison of age-dependent aerenchyma formation between rice and maize roots suggested that more rapid induction of ethylene-dependent aerenchyma formation and more aerenchyma in rice roots are essential to achieve efficient oxygen diffusion under low-oxygen conditions. Moreover, rice roots showed rapid increase in the expression levels of ethylene biosynthesis and responsive genes, suggesting that the local ethylene production at an early time point after root-cell emergence contributes to the rapid induction of the ethylene-dependent aerenchyma formation in rice. DATA AVAILABILITY: All data included in this study are available upon request by contact with the corresponding author.
PMID: 35696932
Plant Sci , IF:4.729 , 2022 Aug , V321 : P111326 doi: 10.1016/j.plantsci.2022.111326
Metabolic changes in cucumber leaves are enhanced by blue light but differentially affected by UV interactions with light signalling pathways in the visible spectrum.
Aarhus University, Plant Food and Climate, Department of Food Science, Agrofoodpark 48, DK-8200 Aarhus, Denmark.; School of Science and Technology, Man-Technology-Environment Research Centre (MTM), Orebro University, SE-70182 Orebro, Sweden.; School of Science and Technology, Orebro Life Science Centre, Orebro University, SE-70182 Orebro, Sweden.; Section of Crop Sciences, Institute of Plant and Environmental Sciences, University of Copenhagen, Hojbakkegard Alle 9, DK-2630 Tastrup, Denmark.; School of Science and Technology, Orebro Life Science Centre, Orebro University, SE-70182 Orebro, Sweden. Electronic address: ake.strid@oru.se.
Ultraviolet radiation (UV, 280-400 nm) as an environmental signal triggers metabolic acclimatory responses. However, how different light qualities affect UV acclimation during growth is poorly understood. Here, cucumber plants (Cucumis sativus) were grown under blue, green, red, or white light in combination with UV. Their effects on leaf metabolites were determined using untargeted metabolomics. Blue and white growth light triggered increased levels of compounds related to primary and secondary metabolism, including amino acids, phenolics, hormones, and compounds related to sugar metabolism and the TCA cycle. In contrast, supplementary UV in a blue or white light background decreased leaf content of amino acids, phenolics, sugars, and TCA-related compounds, without affecting abscisic acid, auxin, zeatin, or jasmonic acid levels. However, in plants grown under green light, UV induced increased levels of phenolics, hormones (auxin, zeatin, dihydrozeatin-7-N-dihydrozeatin, jasmonic acid), amino acids, sugars, and TCA cycle-related compounds. Plants grown under red light with UV mainly showed decreased sugar content. These findings highlight the importance of the blue light component for metabolite accumulation. Also, data on interactions of UV with green light on the one hand, and blue or white light on the other, further contributes to our understanding of light quality regulation of plant metabolism.
PMID: 35696926
Plant Sci , IF:4.729 , 2022 Aug , V321 : P111324 doi: 10.1016/j.plantsci.2022.111324
BSISTER transcription factors directly binds to the promoter of IAA19 and IAA29 genes to up-regulate gene expression and promote the root development.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: tangyujin@nwafu.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: wangling0922@nwafu.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: 444807610@qq.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: 1300904734@qq.com.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: zhaoting@nwafu.edu.cn.; College of Life Sciences, Northwest A&F University, Yangling 712100, Shaanxi, China. Electronic address: liyan@nwsuaf.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Northwest Region), Ministry of Agriculture, Yangling 712100, Shaanxi, China. Electronic address: zhangchaohong@nwsuaf.edu.cn.
Roots play an important role in the growth and development of plants and auxin participates in regulating plant root development. Some studies have shown that BS (BSISTER) gene (the closest gene of class B gene) is involved in plant root development, but whether BS regulates root development via auxin signaling still not clear. To explore VviBS1 and VviBS2 roles in root development, VviBS1 and VviBS2 were overexpressedin Arabidopsis tt16 mutant and we found that they could restore the phenotype of shorter PR (primary roots) and high density of LR (lateral root) of tt16 compared with the wild type Ws Arabidopsis seedlings. However, the addition of exogenous NAA (naphthalene acetic acid) could not significantly promote the PR length of tt16 Arabidopsis, and the auxin signal transduction of tt16 may be blocked. The expression levels of auxin signal transduction pathway genes in Ws, tt16, p35s:VviBS1 in tt16 and p35s:VviBS2 in tt16 seedlings were detected. It was found that the expression of AtARF2, AtARF12, AtARF14, AtARF15, AtARF20, AtGH3, AtGH3-2 and AtSAUR51 genes in tt16 seedlings was higher than that in Ws, while the expression of AtIAA19 and AtIAA29 in Ws seedlings was higher than that of tt16. More importantly, BS may up regulate AtIAA19 and AtIAA29 expression directly by binding to their promoter. In addition, VviBS1 and VviBS2 also affect seed germination and may regulate leaf yellowing by regulating ethylene synthase. Therefore, our findings reveal a molecular mechanism that BS may modulate root system development via Aux/IAA-based auxin signaling, and provide insight into the BS function in regulation of leaf yellowing.
PMID: 35696924
Plant Sci , IF:4.729 , 2022 Aug , V321 : P111307 doi: 10.1016/j.plantsci.2022.111307
Overexpression of HANABA TARANU in cultivated strawberry delays flowering and leads to defective flower and fruit development.
College of Horticulture, China Agricultural University, Beijing 100193, PR China.; College of Horticulture, Nanjing Agricultural University, Nanjing 210095, PR China.; College of Horticulture, China Agricultural University, Beijing 100193, PR China. Electronic address: wanghq@cau.edu.cn.
Cultivated strawberry is one of the most important horticultural crops in the world, and the fruit yields and economic benefits are largely dependent on the quality of floral initiation and floral organ development. However, the underlying regulatory mechanisms controlling these processes in strawberry are largely unknown. In this study, the function of a GATA transcription factor gene, HANABA TARANU (HAN), in floral initiation and floral organ development was characterized in strawberry. FaHAN is expressed in four whorls of the floral organs. Overexpression (OE) of FaHAN in the strawberry cultivar 'Benihoppe' delayed flowering by at least one week by affecting key genes, such as TERMINAL FLOWER 1, APETALA 1...and increased the number of runners. FaHAN-OE plants also showed malformed floral organs, especially the deformed stigmas with disordered arrangement. Several key genes for pistil apical development such as STYLISH, YUCCA 1, and auxin-related genes such as GH3.5, PIN-FORMED 1, which play important roles in pistil primordium development in many plant species, were all down-regulated in FaHAN-OE plants. Further observations showed that the fruit deformity rate was nearly 4-fold higher than in control plants. Together, this study provides a new approach for exploring floral initiation and floral organ development in strawberry.
PMID: 35696907
Front Genet , IF:4.599 , 2022 , V13 : P932207 doi: 10.3389/fgene.2022.932207
Identification and Analysis of Long Non-Coding RNAs Related to UV-B-Induced Anthocyanin Biosynthesis During Blood-Fleshed Peach (Prunus persica) Ripening.
College of Horticulture Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, China.; Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization, Qinhuangdao, China.; The Key Laboratory for Silviculture and Conservation of Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China.; College of Agriculture and Animal Husbandry, Qinghai University, Xining, China.
Blood flesh is a key fruit trait in peaches (Prunus persica) and can be attributed to the accumulation of anthocyanins. The roles of long non-coding RNAs (lncRNAs) have been highlighted by multiple studies in regulating fruit ripening, anthocyanin accumulation, and abiotic stress responses in many flowering plants. Such regulatory functions of lncRNAs in Prunus persica, nonetheless, have not been reported. In this research, we sequenced and analyzed the complete transcriptome of C3-20 (a blood-fleshed peach) fruit at four developmental stages. Analyses of the correlated genes and differentially expressed lncRNA target genes helped to forecast lncRNAs' possible functions. The RNA-seq data were generated using high-throughput sequencing. In total, 17,456 putative lncRNAs, including 4,800 intergenic lncRNAs, 2,199 antisense lncRNAs, and 10,439 intronic lncRNAs were discovered, of which 4,871 differentially expressed lncRNAs (DE-lncRNAs) were annotated in the fruit developmental processes. The target genes of these DE-lncRNAs and their regulatory relationship identifying 21,795 cis-regulated and 18,271 trans-regulated targets of the DE-lncRNAs were in a similar way predicted by us. The enriched GO terms for the target genes included anthocyanin biosynthesis. Flavonoid biosynthesis and plant hormone signal transduction were also included in the enriched KEGG pathways. Co-expression network construction demonstrated that the highly expressed genes might co-regulate multiple other genes associated with auxin signal transduction and take effect in equal pathways. We discovered that lncRNAs, including LNC_000987, LNC_000693, LNC_001323, LNC_003610, LNC_001263, and LNC_003380, correlated with fruit that ripened and could take part in ethylene biosynthesis and metabolism and the ABA signaling pathway. Several essential transcription factors, such as ERFs, WRKY70, NAC56, and NAC72, may in a similar way regulate fruit ripening. Three DE-lncRNAs, XLOC_011933, XLOC_001865, and XLOC_042291, are involved in UV-B-induced anthocyanin biosynthesis and positively regulating UVR8 and COP10, were identified and characterized. Our discovery and characterization of XLOC_011933, XLOC_001865, and XLOC_042291 provide a more precise understanding and preliminarily establishes a theoretical framework for UV-B-induced flesh anthocyanin biosynthesis. This phenomenon might encourage more in-depth investigations to study the molecular mechanisms underlying peach flesh coloring.
PMID: 36017497
Plant Cell Rep , IF:4.57 , 2022 Aug doi: 10.1007/s00299-022-02921-7
Disruption of transcription factor RhMYB123 causes the transformation of stamen to malformed petal in rose (Rosa hybrida).
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, China.; School of Applied Chemistry and Biotechnology, Shenzhen Polytechnic, Shenzhen, China.; Yunnan Yuntianhua Modern Agriculture Development Co., Ltd, Kunming, China.; College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.; Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, China. zhouxiaofeng@cau.edu.cn.
KEY MESSAGE: We find that the R2R3 MYB transcription factor RhMYB123 has a novel function to regulate stamen-petal organ specification in rose. Rose is one of the ornamental plants with economic importance worldwide. Malformed flower seriously affects the ornamental value and fertility of rose. However, the regulatory mechanism is largely unknown. In this work, we identified a R2R3 MYB transcription factor RhMYB123 from rose, the expression of which significantly decreased from flower differentiation stage to floral organ development stage. Phylogenetic analysis indicated that it belongs to the same subgroup as MYB123 of Arabidopsis and located in nucleus. In addition, RhMYB123 was confirmed to have transcriptional activation function by dual luciferase assay. Silencing RhMYB123 using Virus-Induced Gene Silencing (VIGS) in rose could increase the number of malformed petaloid stamen. Furthermore, we identified 549 differential expressed genes (DEGs) in TRV-RhMYB123 lines compared to TRV controls by RNA-seq of floral buds (flower differentiation stage). Among of those genes, expression of 3 MADS box family genes related to floral organ development reduced in TRV-RhMYB123 lines, including AGAMOUS (RhAG), AGAMOUS LIKE 15 (RhAGL15), and SHATTERPROOF 1 (RhSHP1). Given, previous studies have shown that auxin plays a crucial role in floral meristem initiation and stamen-petal organ specification. We also found 6 DEGs were involved in auxin signal transduction, of which five were reduced expression in TRV-RhMYB123. Taken together, our findings suggested that RhMYB123 may govern the development of malformed petaloid stamen by regulating the expressions of some MADS box family members and auxin signaling pathway elements.
PMID: 35999377
Plant Cell Rep , IF:4.57 , 2022 Jul doi: 10.1007/s00299-022-02908-4
The strigolactone receptor SlDWARF14 plays a role in photosynthetic pigment accumulation and photosynthesis in tomato.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China.; Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT, 06269, USA.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. wuhan@njau.edu.cn.
KEY MESSAGE: Tomato DWARF14 regulates the development of roots, shoot branches and leaves, and also plays a role in photosynthetic pigment accumulation and photosynthetic capacity. Strigolactones (SLs) are a novel class of plant hormones. DWARF14 (D14) is the only SL receptor identified to date, but it is not functionally analyzed in tomato (Solanum lycopersicum). In the present study, we identified the potential SL receptor in tomato by bioinformatic analysis, which was designated as SlD14. SlD14 was expressed in roots, stems, flowers and developing fruits, with the highest expression level in leaves. sld14 mutant plants produced by the CRISPR/Cas9 system displayed reduced plant height and root biomass, increased shoot branching and altered leaf shape comparing with WT plants. The cytokinin biosynthetic gene ISOPENTENYLTRANSFERASE 3 (SlIPT3), auxin biosynthetic genes FLOOZY (SlFZY) and TRYPTOPHAN AMINOTRANSFERASE RELATED 1 (SlTAR1) and several auxin transport genes SlPINs, which are involved in branch formation, showed higher expression levels in the sld14 plant stem. In addition, sld14 plants exhibited light-green leaves, reduced chlorophyll and carotenoid contents, abnormal chloroplast structure and reduced photosynthetic capacity. Transcriptomic analysis showed that the transcript levels of six chlorophyll biosynthetic genes, three carotenoid biosynthetic genes and numerous chlorophyll a/b-binding protein genes were decreased in sld14 plants. These results suggest that tomato SL receptor gene SlD14 not only regulates the development of roots, shoot branches and leaves, but also plays a role in regulating photosynthetic pigment accumulation and photosynthetic capacity.
PMID: 35907035
Plant Cell Rep , IF:4.57 , 2022 Sep , V41 (9) : P1895-1906 doi: 10.1007/s00299-022-02899-2
Heterologous expression of a Fraxinus velutina SnRK2 gene in Arabidopsis increases salt tolerance by modifying root development and ion homeostasis.
Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, 250014, China.; Shandong Provincial Key Laboratory of Forest Tree Genetic Improvement, Shandong Academy of Forestry, Jinan, 250014, China. pangcaihong@shandong.cn.; Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, 250014, China. chenminrundong@126.com.; Dongying Institute, Shandong Normal University, No. 2 Kangyang Road, Dongying, 257000, China. chenminrundong@126.com.
KEY MESSAGE: FvSnRK2182 is involved in regulating the growth and stress response. SnRK2 family members are positive regulators of downstream signals in the abscisic acid (ABA) signaling pathway, playing key roles in the plant responses to abiotic stresses. Fraxinus velutina Torr. is a candidate phytoremediator of saline-alkali areas, and is a valuable research subject because of its adaptability in saline soil. We identified a SnRK2 gene in F. velutina (named FvSnRK2182), which was significantly upregulated under salt stress. A bioinformatics analysis showed that FvSnRK2182 has a Ser/Thr kinase domain typical of the SnRK2 subfamily. Compared with wild-type (WT) Arabidopsis, its heterologous expression in Arabidopsis resulted in higher auxin content during seed germination and seedling growth, leading to longer primary roots and more lateral roots. The transgenic lines were better able to tolerate treatments with NaCl (100 mM) and/or ABA (0.2 and 0.5 microM), producing a greater biomass than the WT plants. Under NaCl treatment, the shoots of the transgenic lines had lower Na(+) contents and higher K(+) contents than the WT plants, and the genes encoding the ion transport-related proteins SOS1, HKT1, NHX1, and AKT1 were significantly upregulated. In addition, the expression of the genes functioning downstream of SnRK2 in the ABA signaling pathway (Rboh, AREB4, ABF2, and ABF3) were significantly upregulated in transgenic lines under NaCl stress. These results showed that expressing FvSnRK2182 in Arabidopsis significantly increased their resistance to ABA and salt stress by regulating root development and maintaining ion homeostasis, which suggests that FvSnRK2182 may be involved in regulating the growth and stress response of F. velutina.
PMID: 35794394
Microb Ecol , IF:4.552 , 2022 Jul doi: 10.1007/s00248-022-02080-y
Screening of Phosphate Solubilization Identifies Six Pseudomonas Species with Contrasting Phytostimulation Properties in Arabidopsis Seedlings.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Catedratico CONACYT-Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Catedratico CONACYT-Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico. jbucio@umich.mx.
The interaction of plants with bacteria and the long-term success of their adaptation to challenging environments depend upon critical traits that include nutrient solubilization, remodeling of root architecture, and modulation of host hormonal status. To examine whether bacterial promotion of phosphate solubilization, root branching and the host auxin response may account for plant growth, we isolated and characterized ten bacterial strains based on their high capability to solubilize calcium phosphate. All strains could be grouped into six Pseudomonas species, namely P. brassicae, P. baetica, P. laurylsulfatiphila, P. chlororaphis, P. lurida, and P. extremorientalis via 16S rRNA molecular analyses. A Solibacillus isronensis strain was also identified, which remained neutral when interacting with Arabidopsis roots, and thus could be used as inoculation control. The interaction of Arabidopsis seedlings with bacterial streaks from pure cultures in vitro indicated that their phytostimulation properties largely differ, since P. brassicae and P. laurylsulfatiphila strongly increased shoot and root biomass, whereas the other species did not. Most bacterial isolates, except P. chlororaphis promoted lateral root formation, and P. lurida and P. chlororaphis strongly enhanced expression of the auxin-inducible gene construct DR5:GUS in roots, but the most bioactive probiotic bacterium P. brassicae could not enhance the auxin response. Inoculation with P. brassicae and P. lurida improved shoot and root growth in medium supplemented with calcium phosphate as the sole Pi source. Collectively, our data indicate the differential responses of Arabidopsis seedlings to inoculation with several Pseudomonas species and highlight the potential of P. brassicae to manage phosphate nutrition and plant growth in a more eco-friendly manner.
PMID: 35867140
Molecules , IF:4.411 , 2022 Aug , V27 (16) doi: 10.3390/molecules27165051
Growth Stimulation, Phosphate Resolution, and Resistance to Fungal Pathogens of Some Endogenous Fungal Strains in the Rhizospheres of Medicinal Plants in Vietnam.
University of Economics-Technology for Industries (UNETI), Hanoi 11622, Vietnam.; Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi 11307, Vietnam.; Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi 11307, Vietnam.; School of Materials Science and Energy Engineering, Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi 11307, Vietnam.
Endophytic fungi are recognized for their many potential applications in agriculture, such as supporting cropland expansion and increasing the yield and resistance of plants by creating antibiotics that inhibit the growth of pathogenic microorganisms. In addition, they can produce enzymes that break down hard-to-solubilize substances within soil, dissolve phosphates, fix nitrogen, reduce metals, and produce hormones that promote plant growth (auxin, cytokinin, and gibberellins) to keep crops healthy. In this report, three strains of endophytic fungi, namely, N1, N2, and N3, were isolated from the roots of Stevia rebaudiana (Bert.) Hemsl., Polyscias fruticosa, and Angelica dahurica in some localities in Vietnam. Through a screening process, it was found that they can produce high levels of indole acetic acid (IAA), resolve phosphates, and resist disease, and they were selected to as an alternative to chemical fertilizers to make probiotics in order to increase medicinal plant yields. The results show that the three strains of fungi have the ability to degrade phosphate to 341.90, 1498.46, and 390.79 ppm; the content of IAA produced in the culture medium reached 49.00, 52.35, and 33.34 ppm. Based on some morphological characteristics and an internal transcribed spacer gene sequence analysis of the fungal strains, N1, N2, and N3 were named Penicillium simplicissimum CN7, Talaromyces flavus BC1, and Trichoderma konilangbra DL3, respectively, which have the ability to inhibit the growth of pathogenic fungal strains, such as fungus C. gloeosporioides (CD1), fungus F. oxysporum, fungus L. theobromae N13, and N. dimidiatum. They grow significantly over a period of 5 to 6 days.
PMID: 36014291
Sci Rep , IF:4.379 , 2022 Aug , V12 (1) : P14031 doi: 10.1038/s41598-022-17839-z
Transcriptome analysis of halophyte Nitraria tangutorum reveals multiple mechanisms to enhance salt resistance.
Qinghai Provincial Key Laboratory of High-Value Utilization of Characteristic Economic Plants, Qinghai Minzu University, Xining, 810007, China.; Institute of Ecology and Environment of Qinghai-Tibet Plateau, Qinghai Minzu University, Xining, 810007, China.; College of Forestry, Gansu Agricultural University, Lanzhou, 730000, China.; Lanzhou Institute of Husbandry and Pharmaceutical Science, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China.; College of Eco-Environmental Engineering, Qinghai University, Xining, 810016, China.; Lanzhou Agriculture and Rural Affairs Bureau in Gansu Province, Lanzhou, 730030, China.; College of Forestry, Gansu Agricultural University, Lanzhou, 730000, China. liyi@gsau.edu.cn.; Qinghai Provincial Key Laboratory of High-Value Utilization of Characteristic Economic Plants, Qinghai Minzu University, Xining, 810007, China. wangjiuli12@mails.ucas.ac.cn.; Institute of Ecology and Environment of Qinghai-Tibet Plateau, Qinghai Minzu University, Xining, 810007, China. wangjiuli12@mails.ucas.ac.cn.
As a typical halophyte, Nitraria tangutorum Bobr. has attracted the interest of many researchers with the excellent salt tolerance. Elucidation of the mechanism of N. tangutorum salinity tolerance will facilitate the genetic improvement of productive plants faced with salinity. To reveal the molecular response to gradually accumulated salt stress in N. tangutorum, RNA-sequencing and analysis of gradually accumulated NaCl treated samples and control samples were performed, and a total of 1419 differentially expressed genes were identified, including 949 down-regulated genes and 470 up-regulated genes. Detailed analysis uncovered that the catabolism of organic compounds mainly based on oxidative phosphorylation genes was up-regulated. Additionally, various antioxidant genes, especially anthocyanin-related genes, were found to help N. tangutorum remove reactive oxygen species. Moreover, the Mitogen activated protein kinase signaling pathway and other signaling pathways co-regulated various salt tolerance activities. Additionally, intracellular ion homeostasis was maintained via regulation of osmotic regulator-related genes, cutin-related genes, and cell elongation-related genes to retain cellular water and reduce ion concentration. In particularly, simultaneous up-regulation in cytoskeleton-related genes, cell wall-related genes, and auxin-related genes, provided evidence of important role of cell expansion in plant salt tolerance. In conclusion, complex regulatory mechanisms modulated by multiple genes might contribute to the salt tolerance by N. tangutorum.
PMID: 35982183
Sci Rep , IF:4.379 , 2022 Jul , V12 (1) : P12057 doi: 10.1038/s41598-022-16255-7
Key regulatory pathways, microRNAs, and target genes participate in adventitious root formation of Acer rubrum L.
Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing University of Agriculture, Beijing, 102206, People's Republic of China.; College of Landscape Architecture, Beijing University of Agriculture, Beijing, 102206, People's Republic of China.; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing, 102206, People's Republic of China.; Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing University of Agriculture, Beijing, 102206, People's Republic of China. zhangkezhongbua@163.com.; College of Landscape Architecture, Beijing University of Agriculture, Beijing, 102206, People's Republic of China. zhangkezhongbua@163.com.; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing, 102206, People's Republic of China. zhangkezhongbua@163.com.; Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing University of Agriculture, Beijing, 102206, People's Republic of China. 2562860102@qq.com.; College of Landscape Architecture, Beijing University of Agriculture, Beijing, 102206, People's Republic of China. 2562860102@qq.com.; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing, 102206, People's Republic of China. 2562860102@qq.com.
Red maple (Acer rubrum L.) is a type of colorful ornamental tree with great economic value. Because this tree is difficult to root under natural conditions and the seedling survival rate is low, vegetative propagation methods are often used. Because the formation of adventitious roots (ARs) is essential for the asexual propagation of A. rubrum, it is necessary to investigate the molecular regulatory mechanisms of AR formation in A. rubrum. To address this knowledge gap, we sequenced the transcriptome and small RNAs (sRNAs) of the A. rubrum variety 'Autumn Fantasy' using high-throughput sequencing and explored changes in gene and microRNA (miRNA) expression in response to exogenous auxin treatment. We identified 82,468 differentially expressed genes (DEGs) between the treated and untreated ARs, as well as 48 known and 95 novel miRNAs. We also identified 172 target genes of the known miRNAs using degradome sequencing. Two key regulatory pathways (ubiquitin mediated proteolysis and plant hormone signal transduction), Ar-miR160a and the target gene auxin response factor 10 (ArARF10) were selected based on KEGG pathway and cluster analyses. We further investigated the expression patterns and regulatory roles of ArARF10 through subcellular localization, transcriptional activation, plant transformation, qRT-PCR analysis, and GUS staining. Experiments overexpressing ArARF10 and Ar-miR160a, indicated that ArARF10 promoted AR formation, while Ar-miR160a inhibited AR formation. Transcription factors (TFs) and miRNAs related to auxin regulation that promote AR formation in A. rubrum were identified. Differential expression patterns indicated the Ar-miR160a-ArARF10 interaction might play a significant role in the regulation of AR formation in A. rubrum. Our study provided new insights into mechanisms underlying the regulation of AR formation in A. rubrum.
PMID: 35835811
Sci Rep , IF:4.379 , 2022 Jul , V12 (1) : P11505 doi: 10.1038/s41598-022-15309-0
Phyllanthus amarus shoot cultures as a source of biologically active lignans: the influence of selected plant growth regulators.
Department of Pharmacognosy with Medicinal Plants Garden, Medical University of Gdansk, Gdansk, Poland.; Department of Pharmacognosy with Medicinal Plants Garden, Medical University of Gdansk, Gdansk, Poland. krauze@gumed.edu.pl.
This is the first comprehensive study of the influence of plant growth regulators (PGRs) on the development of shoots and accumulation of biologically active lignans-phyllanthin and hypophyllanthin, in the shoot culture of P. amarus Schum. & Thonn. (Euphorbiaceae) obtained by direct organogenesis. The following PGRs were included in the experiments-cytokinins: kinetin (Kin), 6-benzylaminopurine (BAP), 2-isopentenyladenine (2iP), 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea, thidiazuron (TDZ) and auxin, indole-3-butyric acid (IBA) and used at various concentrations. Depending on PGRs and their concentrations, differences in the culture response and lignan accumulation were observed. The highest content of the investigated compounds was found in the shoot culture grown on Murashige and Skoog's (MS) medium supplemented with Kin 0.25 mg/L. The sum of phyllanthin and hypophyllanthin was ~ 10 mg/g of dry weight (DW), which was similar or even higher than that in the plant material obtained from natural conditions. The results of the research provide new data on the selection of the optimal growth medium for the production of plant material with a significant level of phyllanthin and hypophyllanthin biosynthesis. The obtained data may also be valuable in designing systems for large-scale cultivation of P. amarus shoots with high productivity of hepatoprotective lignans.
PMID: 35798810
Plant Physiol Biochem , IF:4.27 , 2022 Sep , V186 : P182-196 doi: 10.1016/j.plaphy.2022.07.002
Exogenous spermidine regulates the anaerobic enzyme system through hormone concentrations and related-gene expression in Phyllostachys praecox roots under flooding stress.
State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.; College of Forestry, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, China.; State Key Lab of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. Electronic address: syzhuang@issas.ac.cn.
PURPOSE: Acclimation to hypoxia and anoxia is important in various ecological systems, especially flooded soil. Phyllostachys pracecox is sensitive to flooding, and therefore, it is important to explore ways of alleviating hypoxia stress in the roots. In this study, we investigated the regulatory effect of spermidine (Spd) on flooded P. praecox seedlings. METHODS: A batch experiment was carried out in roots treated with Spd under flooding for eight days. The following factors were subsequently measured: growth, survival rate, root respiratory activity, soluble protein and anaerobic respiration enzyme contents (pyruvate decarboxylase, PDC; alcohol dehydrogenase, ADH; lactate dehydrogenase, LDH; alanine aminotransferase, AlaAT), S-adenosylmethionine decarboxylase (SAMDC), nitrate reductase (NR), ACC oxidase (ACO) and ACC synthetase (ACS) activities, free Spd, spermine (Spm) and the diamine precursor putrescine (Put) content, indole-3-acetic acid (IAA) and abscisic acid (ABA) content, ethylene emissions and expression of hormone-related genes. RESULTS: Application of Spd promoted root growth (root length, volume, surface and dry weight) and root respiratory inhibition, improved the soluble protein content, and reduced the O2(.-) production rate, H2O2 and MDA content to alleviate the damage of roots under flooding. A significant increase in SAMDC activity, and ABA and IAA contents were also observed, along with a reduction in ethylene emissions, NR, ACO and ACS activities (p < 0.05). Exogenous Spd increased the free Spd and Spm contents in the P. praecox roots, but decreased the free Put content. Taken together, these findings suggest that hypoxia stress was alleviated. Moreover, exogenous Spd up-regulated the expression of auxin-related genes ARF1, AUX1, AUX2, AUX3 and AUX4, and down-regulated the expression of ethylene-related ACO and ACS genes during flooding. In addition, correlation and RDA analysis showed that ARF1, ACO and ACS significantly promoted the expression of auxin, ACO and ACS enzyme activities, respectively (p < 0.05), while ADH, NR, AlaAT, ethylene emissions, Put, Spd, ACS and ACO were significantly correlated with ACS, ACO, and auxin-related gene expression (p < 0.05). Overall, ethylene emissions, ACS and ACO were identified as the main drivers of ethylene and auxin-related gene structure. CONCLUSIONS: These results suggest that Spd regulated hormone concentrations, the content of Spd, Spm and Put, and related gene expression, in turn regulating physiological changes such as anaerobic enzyme activity, mitigating flooding stress in the roots and improving overall growth. Spd therefore has the potential to improve the adaptability of P. praecox to flooding stress.
PMID: 35868108
Plant Physiol Biochem , IF:4.27 , 2022 Aug , V185 : P260-267 doi: 10.1016/j.plaphy.2022.06.013
Mechanism of pod shattering in the forage legume Medicago ruthenica.
Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, China.; Grassland and Resources Environment Institute, Inner Mongolia Agriculture University, Hohhot, China.; Grassland Supervision Office, Chahar Right Back Banner, Ulanqab, China.; Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, China. Electronic address: zhiyongli1216@126.com.; Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot, China; Key Laboratory of Herbage & Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, China. Electronic address: lijun1538@126.com.
Pod shattering is a seed dispersal strategy and an important agronomical trait in domesticated crops. The relationship between pod shattering and pod morphology in the genus Medicago is well known; however, the detailed mechanism underlying pod dehiscence in Medicago ruthenica, a perennial legume used for forage production, is unknown. Here, the pod ventral sutures of shatter-resistant and shatter-susceptible M. ruthenica genotypes were examined at 8, 12, 16, and 20 d after flowering. The mechanism of pod shattering was analyzed through microscopic observations, polygalacturonase (PG) and cellulase (CE) activity analyses, and RNA-sequencing (RNA-Seq), and the results were verified via reverse transcriptase-quantitative polymerase chain reaction. Pod shattering at the ventral suture in M. ruthenica occurs via a combination of two mechanisms: degradation of the middle lamella at the abscission layers (ALs) and detachment of lignified cells on either side of the ALs triggered by physical forces. Increased PG and CE activities in the pod ventral suture are essential for AL cell-autolysis in the shatter-susceptible genotype. RNA-Seq revealed that 11 genes encoding PG and CE were highly expressed in the ventral sutures of the shatter-susceptible genotype. The expression levels of auxin biosynthesis-related genes decreased in the AL cells and they were negatively associated with pod dehiscence. These results enhance our understanding of the pod shattering mechanism not only in M. ruthenica but also in other leguminous plants.
PMID: 35717734
Plant Physiol Biochem , IF:4.27 , 2022 Aug , V185 : P244-259 doi: 10.1016/j.plaphy.2022.06.006
Auxin regulates growth, photosynthetic efficiency and mitigates copper induced toxicity via modulation of nutrient status, sugar metabolism and antioxidant potential in Brassica juncea.
Department of Botany, Plant Physiology Section, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India.; Department of Biology, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, 11942, Saudi Arabia.; Department of Botany, Plant Physiology Section, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India. Electronic address: hayat_68@yahoo.co.in.
The involvement of auxin (IAA) in growth and development of plants is well known, but its role in the mitigation of metal stress, especially copper (Cu), is not fully understood; therefore, it is time to explore its involvement in minimizing the stress. A pot experiment was conducted to assess the protective function of IAA, applied to the foliage, on photosynthetic machinery, carbohydrate metabolism, and growth of Brassica juncea, grown with Cu (30 or 60 mg kg(-1) of soil). Among the different concentrations (10(-10), 10(-8), or 10(-6) M), 10(-8) M of IAA alone enhanced the photosynthetic characteristics, sugar accumulation and vegetative growth with minimal cellular oxidative stress level. Moreover, the same concentration of auxin was most effective in decreasing the stress levels generated by Cu and maintained it nearly to that of the control in terms of photosynthetic attributes, gas exchange parameters, PSII activity, electron transport rate, and growth attributes. Auxin also maintained the membrane stability and ultrastructure of chloroplast, stomatal morphology with a reduction in malondialdehyde (MDA), electrolyte leakage (EL) and cell death in test plants even under Cu stress. IAA also improved the translocation of Cu from root to the aerial parts, thus enhanced the Cu-reclamation in metal contaminated soils. Our findings suggest that the application of 10(-8) M of IAA maintains the overall growth of plants and may be used as an effective agent to improve growth, photosynthesis and phyto-remediation potential of B. juncea in Cu contaminated soil.
PMID: 35717733
Plant Physiol Biochem , IF:4.27 , 2022 Aug , V184 : P98-111 doi: 10.1016/j.plaphy.2022.05.019
Characterization of 24-epibrassinolide-mediated modulation of the drought stress responses: Morphophysiology, antioxidant metabolism and hormones in grapevine (Vitis vinifera L.).
College of Enology, Northwest A&F University, Yangling, Shaanxi, 712100, China.; College of Enology, Northwest A&F University, Yangling, Shaanxi, 712100, China; Shaanxi Engineering Research Center for Viti-Viniculture, Yangling, Shaanxi, 712100, China. Electronic address: xizhumei@nwafu.edu.cn.
Drought stress is one of the major abiotic stresses that limit grape growth and yield. Brassinosteroids (BRs) are a class of phytohormones essential for plant growth, development, and adaptation to environmental stress. This study aimed to reveal the physiological and biochemical mechanisms of exogenous BRs in alleviating the drought stress in grapevines. Two-year-old grape seedlings (Vitis vinifera L.) were sprayed with 24-epibrassinolide (EBR), a synthetic analog of BRs, and then subjected to drought treatment. The results showed that exogenous EBR significantly mitigated the reduction of photosynthetic pigment contents and photosystem II efficiency and decreased the damage to chloroplasts when grape seedlings were subjected to drought stress. Drought stress resulted in the accumulation of reactive oxidative species (ROS) and an increase in lipid peroxidation. A reduction in oxidative damage was observed in EBR-pretreated plants, which was probably due to the elevated antioxidant system. Exogenous EBR improved the activities of superoxide dismutase (14%), catalase (18%), peroxidase (17%), and ascorbate peroxidase (9%), and promoted the accumulation of ascorbic acid (10%) and glutathione (7%) under drought stress. EBR pretreatment also promoted autophagic activity, which contributed to the degradation of damaged chloroplasts. Moreover, EBR pretreatment increased the concentrations of abscisic acid, jasmonic acid, auxin, and gibberellic acid. Taken together, exogenous EBR could ameliorate the deleterious effects of drought stress by up-regulating photosynthetic capacity, antioxidant system, autophagic activity, and hormone concentrations.
PMID: 35636336
Plant Physiol Biochem , IF:4.27 , 2022 Jul , V183 : P46-55 doi: 10.1016/j.plaphy.2022.05.003
Probing into the unique relationship between a soil bacterium, Pseudomonas putida AKMP7 and Arabidopsis thaliana: A case of "conditional pathogenesis".
Department of Biological Sciences, Birla Institute of Technology and Science (Pilani), Hyderabad Campus, India.; Department of Biological Sciences, Birla Institute of Technology and Science (Pilani), Hyderabad Campus, India. Electronic address: sridev.mohapatra@hyderabad.bits-pilani.ac.in.
Plant growth-promoting rhizobacteria (PGPR) are beneficial soil bacteria that colonise the rhizosphere and help plants in growth, development, and stress tolerance. While there is a significant body of research elucidating their benefits to plants, studies on the "abnormal" or "unexpected" behavior of these bacteria are almost non-existent. One such study from our laboratory has previously reported a unique situation in which a certain strain of drought and thermo-tolerant PGPR, namely, Pseudomonas putida AKMP7, becomes pathogenic towards Arabidopsis thaliana under drought conditions, but not under normal (well-watered) conditions. In this study, we have probed deeper into this phenomenon of "conditional pathogenesis". We found that, AKMP7 imparts an enhancement in plant growth under well-watered conditions, while, causing a deterioration in plant health under drought conditions. In an attempt to understand the underlying reasons for this phenomenon, we analysed the phytohormones released by Pseudomonas putida AKMP7 using LC-ESI-MS/MS technique. We identified that AKMP7 releases zeatin (a cytokinin), the auxin derivative -indole acetamide and amino acid-conjugates of auxin (indole-3-acetyl-L-alanine, indole-3-acetyl-L-phenylalanine and indole-3-acetyl-L-aspartate) in the growth medium. By treating the plants with commercially obtained forms of these phytohormones, individually or in combination with AKMP7, we identified that zeatin and auxin derivative indole acetamide can play a crucial role in the conditional pathogenesis exhibited by this bacterium on A. thaliana under drought conditions. Our work lays a foundation for further understanding the precise molecular mechanisms involved in this unique phenomenon of conditional/opportunistic pathogenesis.
PMID: 35567874
BMC Plant Biol , IF:4.215 , 2022 Aug , V22 (1) : P415 doi: 10.1186/s12870-022-03801-8
Full-length transcriptome-referenced analysis reveals crucial roles of hormone and wounding during induction of aerial bulbils in lily.
Key Laboratory of Plant Resources and China National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, Xiangshan, 100093, China.; Key Laboratory of Plant Resources and China National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, Xiangshan, 100093, China. shilei_67@126.com.
Aerial bulbils are important vegetative reproductive organs in Lilium. They are often perpetually dormant in most Lilium species, and little is known about the induction of these vegetative structures. The world-famous Oriental hybrid lily cultivar 'Sorbonne', which blooms naturally devoid of aerial bulbils, is known for its lovely appearance and sweet fragrance. We found that decapitation stimulated the outgrowth of aerial bulbils at lower stems (LSs) and then application of low and high concentrations of IAA promoted aerial bulbils emergence around the wound at upper stems (USs) of 'Sorbonne'. However, the genetic basis of aerial bulbil induction is still unclear. Herein, 'Sorbonne' transcriptome has been sequenced for the first time using the combination of third-generation long-read and next-generation short-read technology. A total of 46,557 high-quality non-redundant full-length transcripts were generated. Transcriptomic profiling was performed on seven tissues and stems with treatments of decapitation and application of low and high concentrations of IAA, respectively. Functional annotation of 1918 DEGs within stem samples of different treatments showed that hormone signaling, sugar metabolism and wound-induced genes were crucial to bulbils outgrowth. The expression pattern of auxin-, shoot branching hormone-, plant defense hormone- and wound-inducing-related genes indicated their crucial roles in bulbil induction. Then we established five hormone- and wounding-regulated co-expression modules and identified some candidate transcriptional factors, such as MYB, bZIP, and bHLH, that may function in inducing bulbils. High connectivity was observed among hormone signaling genes, wound-induced genes, and some transcriptional factors, suggesting wound- and hormone-invoked signals exhibit extensive cross-talk and regulate bulbil initiation-associated genes via multilayered regulatory cascades. We propose that the induction of aerial bulbils at LSs after decapitation can be explained as the release of apical dominance. In contrast, the induction of aerial bulbils at the cut surface of USs after IAA application occurs via a process similar to callus formation. This study provides abundant candidate genes that will deepen our understanding of the regulation of bulbil outgrowth, paving the way for further molecular breeding of lily.
PMID: 36030206
BMC Plant Biol , IF:4.215 , 2022 Aug , V22 (1) : P389 doi: 10.1186/s12870-022-03778-4
The effect of DC electric field on the elongation growth, proton extrusion and membrane potential of Zea mays L. coleoptile cells; a laboratory study.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, 28 Jagiellonska St, 40-032, Katowice, Poland. waldemar.karcz@us.edu.pl.; Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, 28 Jagiellonska St, 40-032, Katowice, Poland.
BACKGROUND: In this study, we investigated the effect of an electric field, with an intensity similar to that of the Earth's field, on plant cells growth. The molecular mechanism underlying this effect remains unclear. RESULTS: It was found that the electric field, depending on the applied voltage, its duration and the polarization of the maize seedlings, stimulated or inhibited the growth of the seedling organs (root, mesocotyl and coleoptile). Moreover, it was also noticed that the gravitropic response of maize seedlings was inhibited at all voltages studied. Simultaneous measurements of growth and external medium pH show that auxin(IAA, indole-3-acetic acid)- and fusicoccin(FC)-induced elongation growth and proton extrusion of maize coleoptile segments were significantly inhibited at higher voltages. The ionic current flowing through the single coleoptile segment during voltage application was 1.7-fold lower in segments treated with cation channel blocker tetraethylammonium chloride (TEA-Cl) and 1.4-fold higher with IAA compared to the control. The electrophysiological experiments show that the electric field caused the depolarization of the membrane potential of parenchymal coleoptile cells, which was not reversible over 120 min. CONCLUSION: It is suggested that a DC electric field inhibits the plasma membrane H(+) pump activity and K(+) uptake through voltage-dependent, inwardly rectifying ZMK1 channels (Zea mays K(+) channel 1). The data presented here are discussed, taking into account the "acid growth hypothesis" of the auxin action and the mechanism of gravitropic response induction.
PMID: 35922781
BMC Plant Biol , IF:4.215 , 2022 Aug , V22 (1) : P383 doi: 10.1186/s12870-022-03768-6
Eco-biochemical responses, phytoremediation potential and molecular genetic analysis of Alhagi maurorum grown in metal-contaminated soils.
Botany Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt. yasminheikal@mans.edu.eg.; Botany Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt. mohamed.elesawi@science.tanta.edu.eg.; Global Centre for Environmental Remediation (GCER), College of Engineering, Science and Environment, The University of Newcastle, Callaghan, NSW, 2308, Australia.; Botany Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt. mahammy@mans.edu.eg.
BACKGROUND: Alhagi maurorum Medik. (camelthorn) is a dominant desert plant indigenous in various habitats, including the Western Desert of Egypt. The plant is especially prevalent in and around economic iron ore deposits. Nutrient and heavy metal levels in A. maurorum tissues and soil samples were assessed to identify associations between heavy metal levels in plants and soil. The objective was to evaluate this species as an indicator of heavy metal pollution. Photosynthetic pigments, protein, proline, alkaloids, flavonoids, 2,2-diphenyl-1-picrylhydrazylscavenging, reduced glutathione, malondialdehyde, antioxidant enzymes, and stress-related gene expression were assessed to determine their functional roles in metal stress adaptation in ultra- and molecular structure. Additionally, the molecular genetic variation in A. maurorum samples was assessed using co-dominant sequence-related amplified polymorphism (SRAP) and inter simple sequence repeats (ISSR). RESULTS: A substantial difference in enzymatic and non-enzymatic antioxidants of A. maurorum was observed in samples collected from three sites. A. maurorum is suited to the climate in mineralized regions. Morphologically, the stem shows spines, narrow leaves, and a reduced shoot system. Anatomically, modifications included a cuticle coating on leaves and stems, sunken stomata, a compact epidermis, and a thick cortex. Significant anatomical-physiological differences were observed with varying heavy metal soil content, antioxidative enzyme activities increased as a tolerance strategy, and glutathione levels decreased in response to heavy metal toxicity. Heavy metal accumulation also affected the expression of stress-related genes. The highest levels of expression of GST, G6PDH, 6PGD, nitrate reductase 1, and sulfate transporter genes were found in plants collected from site A1. However, auxin-induced protein exhibited its highest expression in plants collected from A2. Six SRAP combinations yielded 25 scoreable markers with a polymorphism rate of 64%, and 5 ISSR markers produced 11 bands with a polymorphism rate of 36.36% for three A. maurorum genotypes. The ME1xEM7 primer combinations provided the most polymorphic information content and resolving power, making it the most useful primer for differentiating A. maurorum genotypes. SRAP markers exhibited a higher diversity index (0.24) than ISSR markers (0.16). CONCLUSIONS: A. maurorum displayed adaptive characteristics for heavy metal sequestration from mining site soils and is proposed as a strong candidate for phytoremediation.
PMID: 35909101
BMC Plant Biol , IF:4.215 , 2022 Jul , V22 (1) : P361 doi: 10.1186/s12870-022-03756-w
Gene expression profiling before and after internode culture for adventitious shoot formation in ipecac.
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma, 374-0193, Japan.; Trans-Scale Biology Center, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.; Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma, 374-0193, Japan. umehara@toyo.jp.; Department of Applied Biosciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma, 374-0193, Japan. umehara@toyo.jp.
BACKGROUND: In ipecac (Carapichea ipecacuanha (Brot.) L. Andersson), adventitious shoots can be induced simply by placing internodal segments on phytohormone-free culture medium. The shoots form locally on the epidermis of the apical region of the segments, but not the basal region. Levels of endogenous auxin and cytokinin transiently increase in the segments after 1 week of culture. RESULTS: Here, we conducted RNA-seq analysis to compare gene expression patterns in apical and basal regions of segments before culture and after 1 week of culture for adventitious shoot formation. The results revealed 8987 differentially expressed genes in a de novo assembly of 76,684 genes. Among them, 276 genes were upregulated in the apical region after 1 week of culture relative to before culture and the basal region after 1 week of culture. These genes include 18 phytohormone-response genes and shoot-formation-related genes. Validation of the gene expression by quantitative real-time PCR assay confirmed that the expression patterns were similar to those of the RNA-seq data. CONCLUSIONS: The transcriptome data show that expression of cytokinin biosynthesis genes is induced along with the acquisition of cellular pluripotency and the initiation of cell division by wounding in the apical region of internodal segments, that trigger adventitious shoot formation without callusing.
PMID: 35869421
BMC Plant Biol , IF:4.215 , 2022 Jul , V22 (1) : P348 doi: 10.1186/s12870-022-03695-6
Comparative transcriptomic analysis of maize ear heterosis during the inflorescence meristem differentiation stage.
National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China.; Henan Institute of Crop Molecular Breeding, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.; National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China. liwh416@163.com.; National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China. tangjihua1@163.com.; The Shennong Laboratory, Zhengzhou, Henan, 450002, China. tangjihua1@163.com.
BACKGROUND: Heterosis is widely used in many crops and is important for global food safety, and maize is one of the most successful crops to take advantage of heterosis. Gene expression patterns control the development of the maize ear, but the mechanisms by which heterosis affects transcriptional-level control are not fully understood. RESULTS: In this study, we sampled ear inflorescence meristems (IMs) from the single-segment substitution maize (Zea mays) line lx9801(hlEW2b), which contains the heterotic locus hlEW2b associated with ear width, as well as the receptor parent lx9801, the test parent Zheng58, and their corresponding hybrids Zheng58 x lx9801(hlEW2b) (HY) and Zheng58 x lx9801 (CK). After RNA sequencing and transcriptomic analysis, 2531 unique differentially expressed genes (DEGs) were identified between the two hybrids (HY vs. CK). Our results showed that approximately 64% and 48% of DEGs exhibited additive expression in HY and CK, whereas the other genes displayed a non-additive expression pattern. The DEGs were significantly enriched in GO functional categories of multiple metabolic processes, plant organ morphogenesis, and hormone regulation. These essential processes are potentially associated with heterosis performance during the maize ear developmental stage. In particular, 125 and 100 DEGs from hybrids with allele-specific expression (ASE) were specifically identified in HY and CK, respectively. Comparison between the two hybrids suggested that ASE genes were involved in different development-related processes that may lead to the hybrid vigor phenotype during maize ear development. In addition, several critical genes involved in auxin metabolism and IM development were differentially expressed between the hybrids and showed various expression patterns (additive, non-additive, and ASE). Changes in the expression levels of these genes may lead to differences in auxin homeostasis in the IM, affecting the transcription of core genes such as WUS that control IM development. CONCLUSIONS: Our research suggests that additive, non-additive, and allele-specific expression patterns may fine-tune the expression of crucial DEGs that modulate carbohydrate and protein metabolic processes, nitrogen assimilation, and auxin metabolism to optimal levels, and these transcriptional changes may play important roles in maize ear heterosis. The results provide new information that increases our understanding of the relationship between transcriptional variation and heterosis during maize ear development, which may be helpful for clarifying the genetic and molecular mechanisms of heterosis.
PMID: 35843937
BMC Plant Biol , IF:4.215 , 2022 Jul , V22 (1) : P330 doi: 10.1186/s12870-022-03730-6
Transporter NRT1.5/NPF7.3 suppresses primary root growth under low K(+) stress by regulating the degradation of PIN-FORMED2.
Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.; Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China. 08321@njnu.edu.cn.
BACKGROUND: The availability of potassium is one of the main environmental factors for modifying the plasticity of root architecture. Many potassium channels and transporters are involved in regulating primary root growth in response to low potassium stress. NRT1.5/NPF7.3 transporter is a NO3(-)/H(+) and K(+)/H(+) cotransporter, and participates in NO3(-) and K(+) translocation from the roots to the shoots. However, the underlying mechanism of NRT1.5-regulated primary root growth under low potassium stress is unclear. RESULTS: We show that NRT1.5/NPF7.3 inhibited primary root growth under low potassium conditions by regulating the accumulation of PIN2 protein and auxin levels. Under low potassium conditions, the mutants nrt1.5 and lks2 exhibited longer primary roots, longer meristem regions and elongation zones of primary roots, and more cell activity in the meristem region compared to WT plants, revealing the involvement of NRT1.5 in LK (low potassium)-inhibition primary root growth. In addition, exogenous auxin (IAA), auxin analogue (NAA, 2.4-D) or auxin precursor (IBA) promoted the primary root growth of WT and the complementation line NRT1.5 COM plants. In addition, the application of NPA inhibited the primary root growth of the nrt1.5 and lks2 mutants. Auxin accumulation was higher in the root tip of nrt1.5 plants than in WT plants, indicating that NRT1.5 regulates root growth inhibition by regulating auxin distribution. Furthermore, PIN2 was degraded more quickly in nrt1.5 plants under LK stress. CONCLUSIONS: Our findings reveal that NRT1.5 inhibits primary root growth by modulating the auxin level in the root tip via the degradation of PIN2.
PMID: 35804293
BMC Plant Biol , IF:4.215 , 2022 Jul , V22 (1) : P319 doi: 10.1186/s12870-022-03701-x
Integrated transcriptome and hormonal analysis of naphthalene acetic acid-induced adventitious root formation of tea cuttings (Camellia sinensis).
Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), Hangzhou, 310008, China.; Tea Research Institute, Yunnan Academy of Agricultural Sciences, Menghai, 666201, China.; Tea Research Institute of Enshi Academy of Agricultural Sciences, Enshi, 445000, China.; Tea Research Institute of Enshi Academy of Agricultural Sciences, Enshi, 445000, China. hbeshsz@yahoo.com.cn.; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), Hangzhou, 310008, China. wangly@tricaas.com.; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, National Center for Tea Improvement, Tea Research Institute Chinese Academy of Agricultural Sciences (TRICAAS), Hangzhou, 310008, China. weikang@tricaas.com.
BACKGROUND: Tea plant breeding or cultivation mainly involves propagation via cuttings, which not only ensures the inheritance of the excellent characteristics of the mother plant but also facilitates mechanized management. The formation of adventitious root (AR) determines the success of cutting-based propagation, and auxin is an essential factor involved in this process. To understand the molecular mechanism underlying AR formation in nodal tea cuttings, transcriptome and endogenous hormone analysis was performed on the stem bases of red (mature)- and green (immature)-stem cuttings of 'Echa 1 hao' tea plant as affected by a pulse treatment with naphthalene acetic acid (NAA). RESULTS: In this study, NAA significantly promoted AR formation in both red- and green-stem cuttings but slightly reduced callus formation. External application of NAA reduced the levels of endogenous indole-3-acetic acid (IAA) and cytokinin (TZR, trans-zeatin riboside). The number of DEGs (NAA vs. CK) identified in the green-stem cuttings was significantly higher than that in the red-stem cuttings, which corresponded to a higher rooting rate of green-stem cuttings under the NAA treatment. A total of 82 common DEGs were identified as being hormone-related and involved in the auxin, cytokinin, abscisic acid, ethylene, salicylic acid, brassinosteroid, and jasmonic acid pathways. The negative regulation of NAA-induced IAA and GH3 genes may explain the decrease of endogenous IAA. NAA reduced endogenous cytokinin levels and further downregulated the expression of cytokinin signalling-related genes. By the use of weighted gene co-expression network analysis (WGCNA), several hub genes, including three [cellulose synthase (CSLD2), SHAVEN3-like 1 (SVL1), SMALL AUXIN UP RNA (SAUR21)] that are highly related to root development in other crops, were identified that might play important roles in AR formation in tea cuttings. CONCLUSIONS: NAA promotes the formation of AR of tea cuttings in coordination with endogenous hormones. The most important endogenous AR inductor, IAA, was reduced in response to NAA. DEGs potentially involved in NAA-mediated AR formation of tea plant stem cuttings were identified via comparative transcriptome analysis. Several hub genes, such as CSLD2, SVL1 and SAUR21, were identified that might play important roles in AR formation in tea cuttings.
PMID: 35787241
Tree Physiol , IF:4.196 , 2022 Aug doi: 10.1093/treephys/tpac073
A genotype-specific architectural and physiological profile is involved in the flowering regularity of apple trees.
AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, 34398 Montpellier Cedex 5, France.; ITK, Clapiers, France.
In polycarpic plants, meristem fate varies within individuals in a given year. In perennials, the proportion of floral induction (FI) in meristems also varies between consecutive years and among genotypes of a given species. Previous studies have suggested that FI of meristems could be determined by the within plant competition for carbohydrates and by hormone signaling as key components of the flowering pathway. At the genotypic level, variability in FI was also associated with variability in architectural traits. However, the part of genotype-depended variability in FI that can be explained by either tree architecture or tree physiology is still not fully understood. This study aimed at deciphering the respective effect of architectural and physiological traits on FI variability within apple trees by comparing six genotypes with contrasted architectures. Shoot type demography as well as the flowering and fruit production patterns were followed over six years and characterized by different indexes. Architectural morphotypes were then defined based on architectural traits using a clustering approach. For two successive years, non-structural starch content in leaf, stem and meristems and hormonal contents (gibberellins, cytokinins, auxin and abscisic acid) in meristems were quantified and correlated to FI within-tree proportions. Based on a multi-step regression analysis, cytokinins and gibberellins content in meristem, starch content in leaves and the proportion of long shoots in tree annual growth were shown to contribute to FI. Although the predictive linear model of FI was common to all genotypes, each of the explicative variables had a different weight in FI determination, depending on the genotype. Our results therefore suggest both a common determination model and a genotype-specific architectural and physiological profile linked to its flowering behavior.
PMID: 35951430
Tree Physiol , IF:4.196 , 2022 Jul doi: 10.1093/treephys/tpac089
The dark septate endophyte Phialocephala sphaeroides suppresses conifer pathogen transcripts and promotes root growth of Norway spruce.
College of Forestry, Fujian Agriculture and Forestry University, 350002, Fuzhou, China.; Department of Forest Sciences, P.O. box 27, University of Helsinki, FIN-00014 Helsinki, Finland.
Plant associated microbes including dark septate endophytes (DSE) of forest trees play diverse functional roles in host fitness including growth promotion and increased defence. However, little is known about the impact on the fungal transcriptome and metabolites during tripartite interaction involving plant host, endophyte and pathogen. To understand the transcriptional regulation of endophyte and pathogen during co-infection, Norway spruce (Picea abies) seedlings were infected with DSE Phialocephala sphaeroides, or conifer root-rot pathogen Heterobasidion parviporum, or both. P. sphaeroides showed low but stable transcripts abundance (a decrease of 40%) during interaction with Norway spruce and conifer pathogen. By contrast, H. parviporum transcripts were significantly reduced (92%) during co-infection. With RNAseq analysis, P. sphaeroides experienced a shift from cell growth to anti-stress and antagonistic responses, while it repressed the ability of H. parviporum to access carbohydrate nutrients by suppressing its carbohydrate/polysaccharide degrading enzyme machinery. The pathogen on the other hand secreted cysteine peptidase to restrict free growth of P. sphaeroides. The expression of both DSE P. sphaeroides and pathogen H. parviporum genes encoding plant growth promotion products were equally detected in both dual and tripartite interaction systems. This was further supported by the presence of tryptophan-dependent indolic compound in liquid culture of P. sphaeroides. Norway spruce and Arabidopsis seedlings treated with P. sphaeroides culture filtrate exhibited auxin-like phenotypes, such as enhanced root hairs, and primary root elongation at low concentration but shortened primary root at high concentration. The results suggested that the presence of the endophyte had strong repressive or suppressive effect on H. parviporum transcripts encoding genes involved in nutrient acquisition.
PMID: 35878416
Tree Physiol , IF:4.196 , 2022 Jul , V42 (7) : P1411-1431 doi: 10.1093/treephys/tpac008
Roles of auxin in the inhibition of shoot branching in 'Dugan' fir.
Department of Forest Genetics & Biotechnology, Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China.; Department of Molecular Biology and Biochemistry, College of Biology and Environment, Nanjing Forestry University, No.159 Longpan Road, Nanjing, Jiangsu 210037, China.
Shoot branching substantially impacts vegetative and reproductive growth as well as wood characteristics in perennial woody species by shaping the shoot system architecture. Although plant hormones have been shown to play a fundamental role in shoot branching in annual species, their corresponding actions in perennial woody plants are largely unknown, in part due to the lack of branching mutants. Here, we demonstrated the role of plant hormones in bud dormancy transition toward activation and outgrowth in woody plants by comparing the physiological and molecular changes in the apical shoot stems of 'Yangkou' 020 fir and 'Dugan' fir, two Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) clones with normal and completely abolished branching phenotypes, respectively. Our studies showed that the defect in bud outgrowth was the cause of failed shoot branching in 'Dugan' fir whereas apically derived signals acted as triggers of this ectopic bud activity. Further studies indicated that auxin played a key role in inhibiting bud outgrowth in 'Dugan' fir. During bud dormancy release, the differential auxin resistant 1/Like AUX1 (AUX1/LAX) and PIN-formed (PIN) activity resulted in an ectopic auxin/indole-3-acetic acid (IAA) accumulation in the apical shoot stem of 'Dugan' fir, which could inhibit the cell cycle in the axillary meristem by decreasing cytokinin (CK) biosynthesis but increasing abscisic acid (ABA) production and response through the signaling pathway. In contrast, during bud activation and outgrowth, the striking increase in auxin biosynthesis and PIN activity in the shoot tip of 'Dugan' fir may trigger the correlative inhibition of axillary buds by modulating the polar auxin transport stream (PATS) and connective auxin transport (CAT) in shoots, and by influencing the biosynthesis of secondary messengers, including CK, gibberellin (GA) and ABA, thereby inducing the paradormancy of axillary buds in 'Dugan' fir by apical dominance under favorable conditions. The findings of this study provide important insights into the roles of plant hormones in bud outgrowth control in perennial woody plants.
PMID: 35088089
Anal Bioanal Chem , IF:4.142 , 2022 Aug , V414 (20) : P6259-6269 doi: 10.1007/s00216-022-04198-x
Effect of ion source polarity and dopants on the detection of auxin plant hormones by ion mobility-mass spectrometry.
Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynska dolina F2, 84248, Bratislava, Slovakia. vahideh.ilbeigi@fmph.uniba.sk.; Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran.; Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynska dolina F2, 84248, Bratislava, Slovakia.; Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynska dolina F2, 84248, Bratislava, Slovakia. stefan.matejcik@fmph.uniba.sk.
Ion mobility spectrometry (IMS) equipped with a corona discharge (CD) ion source was used for measurement of three auxin plant hormones including indole-3-acetic acid (IAA), indole-3-propionic acid (IPA), and indole-3-butyric acid (IBA). The measurements were performed in both positive and negative polarities of the CD ion source. Dopant gases NH3, CCl4, and CHBr3 were used to modify the ionization mechanism. A time-of-flight mass spectrometer (TOFMS) orthogonal to the IMS cell was used for identification of the product ions. Density functional theory was used to rationalize formation of the ions, theoretically. The mixtures of the auxins were analyzed by CD-IMS. The separation performance depended on the ion polarity and the dopants. In the positive polarity without dopants, auxins were ionized via protonation and three distinguished peaks were observed. Application of NH3 dopant resulted in two ionization channels, protonation, and NH4(+) attachment leading to peak overlapping. In the negative polarity, two ionization reactions were operative, via deprotonation and O2(-) attachment. The separation of the monomer peaks was not achieved while the peaks of anionic dimers [2 M-H](-) were separated well. The best LOD (4 ng) was obtained in negative polarity with CCl4 dopant. Methylation (esterification) of IAA improved LODs by about one order.
PMID: 35794348
Planta , IF:4.116 , 2022 Aug , V256 (3) : P53 doi: 10.1007/s00425-022-03962-8
Single-base methylome analysis reveals dynamic changes of genome-wide DNA methylation associated with rapid stem growth of woody bamboos.
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, Yunnan, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, Yunnan, China. guozhenhua@mail.kib.ac.cn.; University of Chinese Academy of Sciences, Beijing, 100049, China. guozhenhua@mail.kib.ac.cn.; Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming, 650201, Yunnan, China. DZL@mail.kib.ac.cn.; University of Chinese Academy of Sciences, Beijing, 100049, China. DZL@mail.kib.ac.cn.
MAIN CONCLUSION: CG and CHG methylation levels in the rapid shoot growth stages (ST2-ST4) of woody bamboos were obviously decreased, which might regulate the internode elongation during rapid shoot growth, while CHH methylation was strongly associated with shoot developmental time or age. DNA methylation plays a critical role in the regulation of plant growth and development. Woody bamboos have a unique trait of rapid stem growth resulted from internode elongation at the shooting period. However, it is still unclear whether DNA methylation significantly controls the bamboo rapid stem growth. Here we present whole-genome DNA methylation profiles of the paleotropical woody bamboo Bonia amplexicaulis at five newly defined stages of shoot growth, named ST1-ST5. We found that CG and CHG methylation levels in the rapid shoot growth stages (ST2-ST4) were significantly lower than in the incubation (ST1) and plateau stages (ST5). The changes in methylation levels mainly occurred in flanking regions of genes and gene body regions, and 23647 differentially methylated regions (DMRs) were identified between ST1 and rapid shoot growth stages (ST2-ST4). Combined with transcriptome analysis, we found that DMR-related genes enriched in the auxin and jasmonic acid (JA) signal transduction, and other pathways closely related to plant growth. Intriguingly, CHH methylation was not involved in the rapid shoot growth, but strongly associated with shoot developmental time by gradually accumulating in transposable elements (TEs) regions. Overall, our results reveal the importance of DNA methylation in regulating the bamboo rapid shoot growth and suggest a role of DNA methylation associated with development time or age in woody bamboos.
PMID: 35913571
Planta , IF:4.116 , 2022 Jul , V256 (2) : P44 doi: 10.1007/s00425-022-03936-w
ARF2 positively regulates flavonols and proanthocyanidins biosynthesis in Arabidopsis thaliana.
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.; Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China. pangyongzhen@caas.cn.
MAIN CONCLUSION: Auxin response factor 2 acts as a positive regulator to fine-tune the spatial and temporal accumulation of flavonoid compounds, mainly flavonols and proanthocyanidins in Arabidopsis. Auxin response factor (ARF) proteins are reported to involve in auxin-mediated regulation of flavonoid biosynthesis. However, the detailed regulation mechanism of ARF remains still unknown. Here, we provide genetic and molecular evidence that one of the twenty-three ARF members-ARF2-positively regulates flavonoid biosynthesis at multi-level in tissue-specific manner in Arabidopsis thaliana. Loss-of-function mutation of ARF2 led to significant reduction in flavonoid content (e.g., flavonols and proanthocyanidins) in the seedlings and seeds of the Arabidopsis arf2 mutants. Over-expression of ARF2 increased flavonols and proanthocyanidins content in Arabidopsis. Additionally, the changes of flavonoid content correlate well with the transcript abundance of several regulatory genes (e.g., MYB11, MYB12, MYB111, TT2, and GL3), and key biosynthetic genes (e.g., CHS, F3'H, FLS, ANS, ANR, TT12, TT19, and TT15), in the arf2 mutant and ARF2 over-expression lines. Transient transactivation assays with site-directed mutagenesis confirmed that ARF2 directly regulates the expression of MYB12 and FLS genes in the flavonol pathway and ANR in the proanthocyanidin pathway, and indirectly regulates MYB11 and MYB111 genes in the flavonol pathway, and ANS, TT12, TT19 and TT15 genes in the proanthocyanidin pathway. Further genetic results indicated that ARF2 acts upstream of MYB12 to regulate flavonol accumulation, and of TT2 to regulate proanthocyanidins accumulation. In particular, yeast two-hybrid assays revealed that ARF2 physically interacts with TT2, a master regulator of proanthocyanidins biosynthesis. Combined together, these results indicated that ARF2 functions as a positive regulator for the fine-tuned spatial and temporal regulation of flavonoids (mainly flavonols and proanthocyanidins) accumulation in Arabidopsis.
PMID: 35857143
Genes (Basel) , IF:4.096 , 2022 Jul , V13 (7) doi: 10.3390/genes13071203
Leaf Development in Medicago truncatula.
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
Forage yield is largely dependent on leaf development, during which the number of leaves, leaflets, leaf size, and shape are determined. In this mini-review, we briefly summarize recent studies of leaf development in Medicago truncatula, a model plant for legumes, with a focus on factors that could affect biomass of leaves. These include: floral development and related genes, lateral organ boundary genes, auxin biosynthesis, transportation and signaling genes, and WOX related genes.
PMID: 35885986
Plant Mol Biol , IF:4.076 , 2022 Aug doi: 10.1007/s11103-022-01304-6
Combined analysis of mRNA and miRNA reveals the banana potassium absorption regulatory network and validation of miRNA160a.
Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China.; Institute of Fruit Tree ResearchKey Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural AffairsGuangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.; School of Agriculture and Environment, The UWA Institute of Agriculture, The University of Western Australia, Perth, 6009 WA, Australia.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. w_mingyuan@163.com.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. 907153549@qq.com.; Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China. yuhailing1989@163.com.
Potassium (K) has an important effect on the growth and development of plants. Banana contains higher K content than many other fruits, and its plant requires more K nutrient in soil. However, the soil in the banana-producing areas in China is generally deficient in K. Therefore, understanding the mechanism of banana K absorption may assist in providing effective strategy to solve this problem. This study used two banana varieties with contrasting K tolerance, 'Guijiao No. 1' (low-K tolerant), and 'Brazilian banana' (low-K sensitive)to investigate K absorption mechanisms in response to low-K stress through miRNA and mRNA sequencing analysis. Under low-K condition, 'Guijiao No.1' showed higher plant height, dry weight, tissue K content and ATPase activity. Analysis of transcription factors showed that they were mainly in the types or classes of MYB, AP-EREBP, bHLH, etc. The sequencing results showed that 'Guijiao No. 1' had 776 differentially expressed genes (DEGs) and 27 differentially expressed miRNAs (DEMs), and 'Brazilian banana' had 71 DEGs and 14 DEMs between normal and low K treatments. RT-qPCR results showed that all miRNAs and mRNAs showed similar expression patterns with RNA-Seq and transcriptome. miRNA regulatory network was constructed by integrated analysis of miRNA-mRNA data. miR160a was screened out as a key miRNA, and preliminary functional validation was performed. Arabidopsis overexpressing miR160a showed reduced tolerance to low K, and inhibited phenotypic traits such as shorter root length, and reduced K accumulation. The overexpressed miR160a had a targeting relationship with ARF10 and ARF16 in Arabidopsis. These results indicate that miR160a may regulate K absorption in bananas through the auxin pathway. This study provides a theoretical basis for further study on the molecular mechanism of banana response to low potassium stress.
PMID: 35962899
Plant Mol Biol , IF:4.076 , 2022 Jul doi: 10.1007/s11103-022-01298-1
SlBBX28 positively regulates plant growth and flower number in an auxin-mediated manner in tomato.
Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Escola Superior de Agricultura 'Luiz de Queiroz', Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.; Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil. mmrossi@usp.br.
KEY MESSAGE: SlBBX28 is a positive regulator of auxin metabolism and signaling, affecting plant growth and flower number in tomato B-box domain-containing proteins (BBXs) comprise a family of transcription factors that regulate several processes, such as photomorphogenesis, flowering, and stress responses. For this reason, attention is being directed toward the functional characterization of these proteins, although knowledge in species other than Arabidopsis thaliana remains scarce. Particularly in the tomato, Solanum lycopersicum, only three out of 31 SlBBX proteins have been functionally characterized to date. To deepen the understanding of the role of these proteins in tomato plant development and yield, SlBBX28, a light-responsive gene, was constitutively silenced, resulting in plants with smaller leaves and fewer flowers per inflorescence. Moreover, SlBBX28 knockdown reduced hypocotyl elongation in darkness-grown tomato. Analyses of auxin content and responsiveness revealed that SlBBX28 promotes auxin-mediated responses. Altogether, the data revealed that SlBBX28 promotes auxin production and signaling, ultimately leading to proper hypocotyl elongation, leaf expansion, and inflorescence development, which are crucial traits determining tomato yield.
PMID: 35798935
Plant Mol Biol , IF:4.076 , 2022 Aug , V109 (6) : P703-715 doi: 10.1007/s11103-022-01268-7
Generalist endophyte Phomopsis liquidambaris colonization of Oryza sativa L. promotes plant growth under nitrogen starvation.
Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, Nanjing, China.; Centre for Novel Agricultural Products, Department of Biology, University of York, YO10 5DD, York, United Kingdom.; Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 210023, Nanjing, China. daichuanchao@njnu.edu.cn.
Fungal endophytes establish symbiotic relationships with host plants, which results in a mutual growth benefit. However, little is known about the plant genetic response underpinning endophyte colonization. Phomopsis liquidambaris usually lives as an endophyte in a wide range of asymptomatic hosts and promotes biotic and abiotic stress resistance. In this study, we show that under low nitrogen conditions P. liquidambaris promotes rice growth in a hydroponic system, which is free of other microorganisms. In order to gain insights into the mechanisms of plant colonization by P. liquidambaris under low nitrogen conditions, we compared root and shoot transcriptome profiles of root-inoculated rice at different colonization stages. We determined that genes related to plant growth promotion, such as gibberellin and auxin related genes, were up-regulated at all developmental stages both locally and systemically. The largest group of up-regulated genes (in both roots and shoots) were related to flavonoid biosynthesis, which is involved in plant growth as well as antimicrobial compounds. Furthermore, genes encoding plant defense-related endopeptidase inhibitors were strongly up-regulated at the early stage of colonization. Together, these results provide new insights into the molecular mechanisms of plant-microbe mutualism and the promotion of plant growth by a fungal endophyte under nitrogen-deficient conditions.
PMID: 35522401
Phytochemistry , IF:4.072 , 2022 Aug , V200 : P113219 doi: 10.1016/j.phytochem.2022.113219
Complexity of the auxin biosynthetic network in Arabidopsis hypocotyls is revealed by multiple stable-labeled precursors.
Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: mkreiser@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: tangx575@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: ggardner@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Alderman Hall, 1970 Folwell Ave, St. Paul, Minnesota, 55108, USA. Electronic address: cohen047@umn.edu.
Auxin is a key regulator of plant development and in Arabidopsis thaliana can be synthesized through multiple pathways; however, the contributions of various biosynthetic pathways to specific developmental processes are largely unknown. To trace the involvement of various biosynthetic routes to indole-3-acetic acid (IAA) under conditions that induce adventitious root formation in Arabidopsis hypocotyls, we treated seedlings with three different stable isotope-labeled precursors ([(13)C6]anthranilate, [(15)N1]indole, and [(13)C3]serine) and monitored label incorporation into a number of proposed biosynthesis intermediates as well as IAA. We also employed inhibitors targeting tryptophan aminotransferases and flavin monooxygenases of the IPyA pathway, and treatment with these inhibitors differentially altered the labeling patterns from all three precursors into intermediate compounds and IAA. [(13)C3]Serine was used to trace utilization of tryptophan (Trp) and downstream intermediates by monitoring (13)C incorporation into Trp, indole-3-pyruvic acid (IPyA), and IAA; most (13)C incorporation into IAA was eliminated with inhibitor treatments, suggesting Trp-dependent IAA biosynthesis through the IPyA pathway is a dominant contributor to the auxin pool in de-etiolating hypocotyls that can be effectively blocked using chemical inhibitors. Labeling treatment with both [(13)C6]anthranilate and [(15)N1]indole simultaneously resulted in higher label incorporation into IAA through [(15)N1]indole than through [(13)C6]anthranilate; however, this trend was reversed in the proposed precursors that were monitored, with the majority of isotope label originating from [(13)C6]anthranilate. An even greater proportion of IAA became [(15)N1]-labeled compared to [(13)C6]-labeled in seedlings treated with IPyA pathway inhibitors, suggesting that, when the IPyA pathway is blocked, IAA biosynthesis from labeled indole may also come from an origin independent of the measured pool of Trp in these tissues.
PMID: 35523282
Pestic Biochem Physiol , IF:3.963 , 2022 Aug , V186 : P105165 doi: 10.1016/j.pestbp.2022.105165
Investigating resistance levels to cyhalofop-butyl and mechanisms involved in Chinese sprangletop (Leptochloa chinensis L.) from Anhui Province, China.
Anhui Province key Laboratory of Crop Integrated Pest Management, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.; Anhui Province key Laboratory of Crop Integrated Pest Management, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China. Electronic address: zhaon@ahau.edu.cn.; Anhui Province key Laboratory of Crop Integrated Pest Management, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China; Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, China. Electronic address: caohq@ahau.edu.cn.
Chinese sprangletop (Leptochloa chinensis (L.) Nees) is a common grass species that severely threatens rice (Oryza sativa L.) cropping systems globally. Cyhalofop-butyl is a highly efficient acetyl-CoA carboxylase (ACCase)-inhibiting herbicide widely used for control of this species in China. However, some L. chinensis populations have gradually evolved resistance to this herbicide in recent years. To better understand the cyhalofop-butyl resistance status of L. chinensis in the major rice planting area of the middle-lower Yangtze River basin, 73 populations collected from the rice fields across Anhui Province were investigated for cyhalofop-butyl susceptibility and potential herbicide resistance-conferring mutations. Single-dose testing indicated that of the 73 populations, 25 had evolved resistance to cyhalofop-butyl and were separately classified as "RRR" and "RR" populations according to their fresh weight reductions, 8 had a high risk of evolving cyhalofop-butyl resistance and were classified as "R?" populations, and 40 were susceptible and classified as "S" populations. Whole-plant dose-response experiments showed that the resistance index (RI) of these R?, RR, and RRR populations to cyhalofop-butyl ranged from 2.47 to 36.94. Target gene sequencing identified seven ACCase resistance mutations (I1781L, W1999C, W2027S, W2027L, W2027C, I2041N, and D2078G), with W1999C and W2027C the two most common detected in about three quarters of all the resistant populations. Seven populations including LASC3, BBHY1, AQQS1, HFFD3, HFFD4, AQWJ1, and HFLJ6 each carrying a specific ACCase mutation were tested for their cross- and multiple-resistance patterns. Compared with a standard susceptible population HFLY1, the seven resistant populations showed distinct cross-resistance. All had low- to high-level cross-resistance to metamifop (RIs ranging from 6.16 to 17.65), fenoxaprop-P-ethyl (RIs ranging from 6.39 to 24.08), and quizalofop-P-ethyl (RIs ranging from 2.20 to 10.25), but responded differently to clodinafop-propargyl and clethodim. Multiple-resistance testing suggested that the seven resistant populations were all susceptible to the 4-hydroxyphenylpyruvate dioxygenase inhibitor tripyrasulfone, the protoporphyrinogen oxidase inhibitor oxyfluorfen, and the auxin mimic herbicide florpyrauxifen. In conclusion, this study has shown that cyhalofop-butyl resistance was prevalent in L. chinensis in Anhui Province, China, and target site mutation was one of the most common resistance mechanisms.
PMID: 35973761
Plants (Basel) , IF:3.935 , 2022 Aug , V11 (16) doi: 10.3390/plants11162163
Transcriptomic Analysis of Radish (Raphanus sativus L.) Roots with CLE41 Overexpression.
Department of Genetics and Biotechnology, Saint Petersburg State University, 199034 Saint Petersburg, Russia.
The CLE41 peptide, like all other TRACHEARY ELEMENT DIFFERENTIATION INHIBITORY FACTOR (TDIF) family CLE peptides, promotes cell division in (pro-)cambium vascular meristem and prevents xylem differentiation. In this work, we analyzed the differential gene expression in the radish primary-growing P35S:RsCLE41-1 roots using the RNA-seq. Our analysis of transcriptomic data revealed a total of 62 differentially expressed genes between transgenic radish roots overexpressing the RsCLE41-1 gene and the glucuronidase (GUS) gene. For genes associated with late embryogenesis, response to abscisic acid and auxin-dependent xylem cell fate determination, an increase in the expression in P35S:RsCLE41-1 roots was found. Among those downregulated, stress-associated genes prevailed. Moreover, several genes involved in xylem specification were also downregulated in the roots with RsCLE41-1 overexpression. Unexpectedly, none of the well-known targets of TDIFs, such as WOX4 and WOX14, were identified as DEGs in our experiment. Herein, we discuss a suggestion that the activation of pathways associated with desiccation resistance, which are more characteristic of late embryogenesis, in roots with RsCLE41-overexpression may be a consequence of water deficiency onset due to impaired vascular specification.
PMID: 36015466
Plants (Basel) , IF:3.935 , 2022 Aug , V11 (16) doi: 10.3390/plants11162092
Systematic Analysis of the Grafting-Related Glucanase-Encoding GH9 Family Genes in Pepper, Tomato and Tobacco.
Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China.; Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen 518120, China.; Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.
Grafting is an important agricultural practice to control soil-borne diseases, alleviate continuous cropping problems and improve stress tolerance in vegetable industry, but it is relatively less applied in pepper production. A recent study has revealed the key roles of beta-1, 4-glucanase in graft survival. We speculated that the GH9 family gene encoding glucanase may be involved in the obstacles of pepper grafting. Therefore, we performed a systematic analysis of the GH9 family in pepper, tomato and tobacco. A total of 25, 24 and 42 GH9 genes were identified from these three species. Compared with the orthologues of other solanaceous crops, the deduced pepper GH9B3 protein lacks a conserved motif (Motif 5). Promoter cis-element analysis revealed that a wound-responsive element exists in the promoter of tobacco NbGH9B3, but it is absent in the GH9B3 promoter of most solanaceous crops. The auxin-responsive related element is absent in CaGH9B3 promoter, but it presents in the promoter of tobacco, tomato, potato and petunia GH9B3. Tissue and induction expression profiles indicated that GH9 family genes are functionally differentiated. Nine GH9 genes, including CaGH9B3, were detected expressing in pepper stem. The expression patterns of NbGH9B3 and CaGH9B3 in grafting were different in our test condition, with obvious induction in tobacco but repression in pepper. Furthermore, weighted correlation network analysis (WGCNA) revealed 58 transcription factor genes highly co-expressed with NbGH9B3. Eight WRKY binding sites were detected in the promoter of NbGH9B3, and several NbWRKYs were highly co-expressed with NbGH9B3. In conclusion, the missing of Motif 5 in CaGH9B3, and lacking of wound- and auxin-responsive elements in the gene promoter are the potential causes of grafting-related problems in pepper. WRKY family transcription factors could be important regulator of NbGH9B3 in tobacco grafting. Our analysis points out the putative regulators of NbGH9B3, which would be helpful to the functional validation and the study of signal pathways related to grafting in the future.
PMID: 36015396
Plants (Basel) , IF:3.935 , 2022 Aug , V11 (15) doi: 10.3390/plants11152013
Auxin-Cytokinin Cross Talk in Somatic Embryogenesis of Coffea canephora.
Unidad de Bioquimica y Biologia Molecular de Plantas, Centro de Investigacion Cientifica de Yucatan, Calle 43, No. 130 x 32 y 34, Merida 97205, Mexico.; Catedratico CONACYT, Unidad de Bioquimica y Biologia Molecular de Plantas, Centro de Investigacion Cientifica de Yucatan, Merida 97205, Mexico.
Cytokinins (CK) are plant growth regulators involved in multiple physiological processes in plants. One less studied aspect is CK homeostasis (HM). The primary genes related to HM are involved in biosynthesis (IPT), degradation (CKX), and signaling (ARR). This paper demonstrates the effect of auxin (Aux) and CK and their cross talk in a Coffea canephora embryogenic system. The transcriptome and RT-qPCR suggest that Aux in pre-treatment represses biosynthesis, degradation, and signal CK genes. However, in the induction, there is an increase of genes implicated in the CK perception/signal, indicating perhaps, as in other species, Aux is repressing CK, and CK are inducing per se genes involved in its HM. This is reflected in the endogenous concentration of CK; pharmacology experiments helped study the effect of each plant growth regulator in our SE system. We conclude that the Aux-CK balance is crucial to directing somatic embryogenesis in C. canephora.
PMID: 35956493
Plants (Basel) , IF:3.935 , 2022 Jul , V11 (15) doi: 10.3390/plants11151992
Distinct Hormone Signalling-Modulation Activities Characterize Two Maize Endosperm-Specific Type-A Response Regulators.
Departamento de Biomedicina y Biotecnologia, Campus Universitario, Universidad de Alcala, Alcala de Henares, 28805 Madrid, Spain.
ZmTCRR1 and 2 are type-A response regulators expressed in the maize endosperm transfer cells (TC). While type-B response regulators transcriptionally control canonical type-A response regulators, as part of the cytokinin signal transduction mechanism, the ZmTCRRs are regulated by ZmMRP1, a master regulator of TC identity. In addition, the corresponding proteins are not detected in the TC, accumulating in the inner endosperm cells instead. These features suggest these molecules are not involved in classical, cell-autonomous, cytokinin signalling pathways. Using transgenic Arabidopsis plants ectopically expressing these genes, we have shown that ZmTCRR1 and 2 can modulate auxin and cytokinin signalling, respectively. In Arabidopsis, the ectopic expression of ZmTCRR2 blocked, almost completely, cytokinin perception. Given the conservation of these signalling pathways at the molecular level, our results suggest that the ZmTCRRs modulate cytokinin and auxin perception in the inner endosperm cells.
PMID: 35956471
Plants (Basel) , IF:3.935 , 2022 Jul , V11 (15) doi: 10.3390/plants11151971
Sugarcane Genotypes with Contrasting Biological Nitrogen Fixation Efficiencies Differentially Modulate Nitrogen Metabolism, Auxin Signaling, and Microorganism Perception Pathways.
Laboratorio de Biologia Molecular de Plantas, Instituto de Bioquimica Medica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, RJ, Brazil.; Laboratorio de Quimica e Funcoes de Proteinas e Peptideos, Centro de Biociencias e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes 28015-622, RJ, Brazil.; Laboratorio de Genetica e Bioquimica, Centro Nacional de Pesquisa de Agrobiologia, Embrapa Agrobiologia, Rio de Janeiro 23897-970, RJ, Brazil.
Sugarcane is an economically important crop that is used for the production of fuel ethanol. Diazotrophic bacteria have been isolated from sugarcane tissues, without causing visible plant anatomical changes or disease symptoms. These bacteria can be beneficial to the plant by promoting root growth and an increase in plant yield. Different rates of Biological Nitrogen Fixation (BNF) were observed in different genotypes. The aim of this work was to conduct a comprehensive molecular and physiological analysis of two model genotypes for contrasting BNF efficiency in order to unravel plant genes that are differentially regulated during a natural association with diazotrophic bacteria. A next-generation sequencing of RNA samples from the genotypes SP70-1143 (high-BNF) and Chunee (low-BNF) was performed. A differential transcriptome analysis showed that several pathways were differentially regulated among the two BNF-contrasting genotypes, including nitrogen metabolism, hormone regulation and bacteria recognition. Physiological analyses, such as nitrogenase and GS activity quantification, bacterial colonization, auxin response and root architecture evaluation, supported the transcriptome expression analyses. The differences observed between the genotypes may explain, at least in part, the differences in BNF contributions. Some of the identified genes might be involved in key regulatory processes for a beneficial association and could be further used as tools for obtaining more efficient BNF genotypes.
PMID: 35956449
Plants (Basel) , IF:3.935 , 2022 Jul , V11 (15) doi: 10.3390/plants11151898
Bioinformatics Study of Aux/IAA Family Genes and Their Expression in Response to Different Hormones Treatments during Japanese Apricot Fruit Development and Ripening.
College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.; College of Horticulture, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.; Department of Horticultural Sciences, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan.; College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.; Department of Animal Sciences, Ghazi University, Dera Ghazi Khan 32200, Pakistan.; Ayub Agricultural Research Institute, Faisalabad 38850, Pakistan.
Auxin/indole-3-acetic acid (Aux/IAA) is a transcriptional repressor in the auxin signaling pathway that plays a role in several plant growth and development as well as fruit and embryo development. However, it is unclear what role they play in Japanese apricot (Prunus mume) fruit development and maturity. To investigate the role of Aux/IAA genes in fruit texture, development, and maturity, we comprehensively identified and expressed 19 PmIAA genes, and demonstrated their conserved domains and homology across species. The majority of PmIAA genes are highly responsive and expressed in different hormone treatments. PmIAA2, PmIAA5, PmIAA7, PmIAA10, PmIAA13, PmIAA18, and PmIAA19 showed a substantial increase in expression, suggesting that these genes are involved in fruit growth and maturity. During fruit maturation, alteration in the expression of PmIAA genes in response to 1-Methylcyclopropene (1-MCP) treatment revealed an interaction between auxin and ethylene. The current study investigated the response of Aux/IAA development regulators to auxin during fruit ripening, with the goal of better understanding their potential application in functional genomics.
PMID: 35893602
Plants (Basel) , IF:3.935 , 2022 Jul , V11 (14) doi: 10.3390/plants11141867
Morphological and Physiological Indicators for Screening Cell Lines with High Potential for Somatic Embryo Maturation at an Early Stage of Somatic Embryogenesis in Pinus Koraiensis.
State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 150040, China.; State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin 150040, China.; Laboratory of Forest Genetics and Breeding, Institution of the Russian Academy of Sciences, V.N. Sukachev Institute of Forest Siberian Branch of RAS, 660036 Krasnoyarsk, Russia.; Department of Cell Biology, Institute of Plant Physiology, K.A. Timiryazev Russian Academy of Sciences, 127276 Moscow, Russia.; Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia.
Many cell lines in the embryogenic callus cannot produce somatic embryos (SEs) even if they meet the optimal SE maturation culture conditions during conifer somatic embryogenesis. This phenomenon hinders the progress of the industrial-scale reproduction of conifers. Therefore, there is an urgent need to obtain morphological and physiological markers to screen embryogenic calli in response to SE maturation conditions. To detect cell lines with high somatic embryogenesis potential during the proliferation process, we counted the number of pro-embryos and early SEs (ESEs) in different cell lines and storage substances, endogenous hormones, and polyamine contents. The results showed that the yield of P. koraiensis SEs was heavily dependent on genotype (p = 0.001). There were high levels of PE III (pro-embryo III) number, ESE number, and soluble protein content, in the response cell lines (R cell lines), which were 1.6-, 3-, and 1.1-fold those of the obstructive cell lines (B cell lines), respectively. The B cell line had high levels of starch, auxin (IAA), Put, Spd, and putrescine: spermine (Put: Spm) compared to the R cell line. In addition, the numbers of PE III, ESEs, and soluble protein content were significantly positively correlated with SE yield. In contrast, the contents of starch, abscisic acid (ABA), Put, Spm, and Spd were significantly negatively correlated with SE yield. To ensure the accuracy of the results, we used nine cell lines to test the results. The PE III and ESE numbers and the Spm and Spd contents were positively correlated with SE yield, while the levels of starch, ABA, IAA, Put: Spd, and Put: Spm were negatively correlated with SE yield. Thus, we recommend using high PE III and ESEs as morphological indicators and low levels of starch, IAA, ABA, and Put: Spm as physiological markers to screen cell lines with a high somatic embryogenesis potential. In addition, we also found that the relationship between Spd, Spm, and SE yield was opposite in the two experimental results. Therefore, we speculate that the differences in Spd and Spm content are mainly affected by genotype. In conclusion, this study obtained the morphological and physiological markers of some high-somatic embryogenic cell lines by comparing the differences between nine somatic embryogenic cell lines. Our results can guide the improvement of conifer somatic embryogenesis technology and can provide a theoretical basis for accelerating the application of biotechnology in large-scale artificial breeding.
PMID: 35890500
Plants (Basel) , IF:3.935 , 2022 Jul , V11 (14) doi: 10.3390/plants11141817
Plant Development of Early-Maturing Spring Wheat (Triticum aestivum L.) under Inoculation with Bacillus sp. V2026.
Agrophysical Scientific Research Institute, Grazhdansky Pr. 14, 195220 St. Petersburg, Russia.; All-Russia Research Institute for Agricultural Microbiology, Podbelskogohwy 3, Pushkin, 196608 St. Petersburg, Russia.
The effect of a plant growth-promoting bacterium (PGPB) Bacillus sp. V2026, a producer of indolyl-3-acetic acid (IAA) and gibberellic acid (GA), on the ontogenesis and productivity of four genotypes of early-maturing spring wheat was studied under controlled conditions. The inoculation of wheat plants with Bacillus sp. V2026 increased the levels of endogenous IAA and GA in wheat of all genotypes and the level of trans-Zeatin in Sonora 64 and Leningradskaya rannyaya cvs but decreased it in AFI177 and AFI91 ultra-early lines. Interactions between the factors "genotype" and "inoculation" were significant for IAA, GA, and trans-Zeatin concentrations in wheat shoots and roots. The inoculation increased the levels of chlorophylls and carotenoids and reduced lipid peroxidation in leaves of all genotypes. The inoculation resulted in a significant increase in grain yield (by 33-62%), a reduction in the time for passing the stages of ontogenesis (by 2-3 days), and an increase in the content of macro- and microelements and protein in the grain. Early-maturing wheat genotypes showed a different response to inoculation with the bacterium Bacillus sp. V2026. Cv. Leningradskaya rannyaya was most responsive to inoculation with Bacillus sp. V2026.
PMID: 35890450
Life (Basel) , IF:3.817 , 2022 Aug , V12 (8) doi: 10.3390/life12081285
New Wine in an Old Bottle: Utilizing Chemical Genetics to Dissect Apical Hook Development.
Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.; Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen 518055, China.
The apical hook is formed by dicot seedlings to protect the tender shoot apical meristem during soil emergence. Regulated by many phytohormones, the apical hook has been taken as a model to study the crosstalk between individual signaling pathways. Over recent decades, the roles of different phytohormones and environmental signals in apical hook development have been illustrated. However, key regulators downstream of canonical hormone signaling have rarely been identified via classical genetics screening, possibly due to genetic redundancy and/or lethal mutation. Chemical genetics that utilize small molecules to perturb and elucidate biological processes could provide a complementary strategy to overcome the limitations in classical genetics. In this review, we summarize current progress in hormonal regulation of the apical hook, and previously reported chemical tools that could assist the understanding of this complex developmental process. We also provide insight into novel strategies for chemical screening and target identification, which could possibly lead to discoveries of new regulatory components in apical hook development, or unidentified signaling crosstalk that is overlooked by classical genetics screening.
PMID: 36013464
Life (Basel) , IF:3.817 , 2022 Aug , V12 (8) doi: 10.3390/life12081283
The Application of Auxin-like Compounds Promotes Cold Acclimation in the Oilseed Rape Plant.
Laboratory of Plant Physiology, Nature Research Centre, Akademijos Str. 2, 08412 Vilnius, Lithuania.
Cold is a major environmental key factor influencing plant growth, development, and productivity. Responses and adaption processes depend on plant physiological and biochemical modifications, first of all via the hormonal system. Indole-3-acetic acid (IAA) plays a critical role in the processes of plant functioning. To assess the influence of the auxin-like compounds 1-[2-chloroethoxycarbonylmethyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxycarbonylmethyl]naphthalene chloromethylate (TA-14) in the process of cold acclimation, long-term field trials over four years were performed with two rapeseed (Brassica napus L.) plant cultivars with different wintering resistance in temperate-zone countries. In these two rapeseed cultivars, namely 'Casino' (less resistant) and 'Valesca' (more resistant), investigations were conducted in the terminal buds and root collars. The application of auxin-like compounds revealed a close interlinkage between the composition of dehydrins and the participation of the phytohormone IAA in the adaptation processes. By applying TA-12 and TA-14, the importance of the proteins, especially the composition of the dehydrins, the IAA amount, and the status of the oilseed rape cultivars at the end of the cold acclimation period were confirmed. Following on from this, when introducing oilseed rape cultivars from foreign countries, it may also be of value to assess their suitability for cultivation in temperate-zone countries.
PMID: 36013462
Life (Basel) , IF:3.817 , 2022 Aug , V12 (8) doi: 10.3390/life12081260
Analysis of Floral Organ Development and Sex Determination in Schisandra chinensis by Scanning Electron Microscopy and RNA-Sequencing.
College of Chinese Medicine Materials, Jilin Agricultural University, Changchun 130118, China.; School of Life Sciences, Tonghua Normal University, Tonghua 134000, China.
S. chinensis is a typical monoecious plant, and the number and development of female flowers determines the yield of S. chinensis. Due to a lack of genetic information, the molecular mechanism of sex differentiation in S. chinensis remains unclear. In this study, the combination of scanning electron microscopy (SEM) and RNA sequencing (RNA-seq) was used to understand the way of sex differentiation of S. chinensis and to mine the related genes of sex determination. The result shows the development of male and female S. chinensis flowers was completed at the same time, the unisexual S. chinensis flowers did not undergo a transition stage between sexes, and sex may have been determined at an early stage in flower development. The results of the gene function analysis of the plant hormone signaling pathway and sucrose metabolism pathway suggest that auxin and JA could be the key hormones for sex differentiation in S. chinensis, and sucrose may promote pollen maturation at the later stage of male flower development. Two AGAMOUS (GAG) genes, 10 AGAMOUS-like MADS-box (AGLs) genes, and the MYB, NAC, WRKY, bHLH, and Trihelix transcription factor families may play important roles in sex determination in S. chinensis. Taken together, the present findings provide valuable genetic information on flower development and sex determination in S. chinensis.
PMID: 36013439
Life (Basel) , IF:3.817 , 2022 Aug , V12 (8) doi: 10.3390/life12081231
Effects of Different Growth Regulators on the Rooting of Catalpa bignonioides Softwood Cuttings.
College of Forest, Henan Agricultural University, Zhengzhou 450002, China.
(1) Background: To further improve the rapid reproduction and large-scale application of Catalpa bignonioides. (2) Methods: With young softwood cuttings from a 3-year-old C. bignonioides mother plant used as materials, the effects of indole-3-acetic acid(IAA), indolebutyric acid(IBA) and rhizogenic powder-1(ABT-1) growth regulators at different concentrations on cutting indexes and the dynamic changes in endogenous hormone contents during the rooting of the C. bignonioides cuttings were studied. (3) Results: The rooting of C. bignonioides cuttings could be divided into five stages. There were three types of rooting of adventitious roots. IBA treatment resulted in a high rooting rate and beneficial root morphology. The morphological indexes of the cutting roots after treatment with 1000 mg.L(-1) IBA had the best overall quality, which was significantly higher than that of the roots in the control (CK) group (p < 0.05). Although the average longest root length (20.51 cm) under ABT-1 was the longest, its overall average rooting rate was slightly lower than that under IBA. The rooting effect under IAA was generally lower than that under IBA and ABT-1. The endogenous hormone content of the cuttings was found to be closely related to rooting; the IAA and zeatin nucleoside (ZR) content was high, and the ratios of IAA/ABA and IAA/ZR were high. The contents of gibberellin3 (GA3) and abscisic acid (ABA) were low, which had a promoting effect on the rooting of the cuttings. (5) Conclusions: All three kinds of auxin can promote rooting and, of the three treatment groups, the rooting effect of cuttings in the IBA treatment group was the strongest, with 1000 mg.L(-1) being the optimum concentration.
PMID: 36013410
Gene , IF:3.688 , 2022 Aug , V837 : P146692 doi: 10.1016/j.gene.2022.146692
SAUR8, a small auxin-up RNA gene in poplar, confers drought tolerance to transgenic Arabidopsis plants.
Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China.; Laboratory of Modern Biotechnology, School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China. Electronic address: xiangyanahau@sina.com.
SAUR (small auxin-up RNA) is an early auxin-responsive gene. In this study, a novel SAUR gene PtSAUR8 was cloned from poplar (Populus trichocarpa), and subcellular location analysis showed that it is targeted to the nuclear membrane. In addition, PtSAUR8 overexpression in Arabidopsis improved the plant resistance to drought stress. Meanwhile, the loss of function mutant saur53 showed more drought sensitivity compared to the WT. PtSAUR8 conferred drought tolerance in transgenic Arabidopsis, as determined through phenotypic and stress-associated physiological indicator analyses, namely, root length, germination rate, relative water content, proline content, CAT content, POD content, malondialdehyde content, hydrogen peroxide content, and relative conductivity. In addition, after the 1 muM abscisic acid (ABA) treatment, the PtSAUR8-OE lines promoted stomata closure. Quantitative fluorescence analysis of related genes induced by drought mutant stress further confirmed that overexpression of PtSAUR8 can improve drought resistance in transgenic Arabidopsis lines. Therefore, PtSAUR8 may play a role in plant drought resistance through ABA-mediated pathways; thus, providing new research materials for molecular breeding of poplar resistance.
PMID: 35760288
Gene , IF:3.688 , 2022 Jul , V833 : P146592 doi: 10.1016/j.gene.2022.146592
Comparative transcriptome profiling of sweetpotato storage roots during curing-mediated wound healing.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; R&D Center, Genolution Inc., 63, Magokjungang 8-ro 3-gil, Gangseo-gu, Seoul 07793, Republic of Korea.; Department of Biology Education, IALS, Gyeongsang National University, Jinju 52828, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea.; Bioenergy Crop Research Institute, National Institute of Crop Science, Rural Development Administration, 199 Muan-ro, Muan-gun 58545, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea. Electronic address: sskwak@kribb.re.kr.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea. Electronic address: hskim@kribb.re.kr.
Sweetpotato (Ipomoea batatas L. Lam) is an economically important crop that is cultivated for its storage roots. Storage roots provide a source of valuable nutrients, processed foods, animal feeds, and pigments. Sweetpotato storage roots spoil during post-harvest handling because of wounding, which makes them more susceptible to disease-causing microorganisms. Curing to promote wound healing is a common method to control microbial spoilage during post-harvest storage. However, molecular mechanisms underlying the process of curing in sweetpotato storage roots are unknown. To better understand the biology behind curing, the transcriptome of the sweetpotato cultivar, Pungwonmi, was studied using RNA-seq. Storage roots of sweetpotato were treated at 33 degrees C (Curing) and 13 degrees C (Control) for 3 days. RNA-seq data identified 78,781 unigenes and 3,366 differentially expressed genes by over log2 fold change (FC) > 2 and <-2. During curing, DEGs encoded genes related to drought/salt stress responses, phyto-hormones (e.g., auxin, ethylene and jasmonic acid), and proteolysis, were up-regulated, whereas those related to redox state, phyto-hormones (e.g., salicylic acid and brassinosteroids), and lignin and flavonoid biosynthesis were down-regulated. Additionally, among the candidate genes, DEGs encoded genes related to proteolysis and pathogen defense, such as protease inhibitors and lipid transfer proteins, were highly up-regulated during curing and storage. This study provides a valuable resource to further understand the molecular basis of curing-mediated wound healing in sweetpotato storage roots. Moreover, genes revealed in this work could present targets for the development of sweetpotato varieties with improved post-harvest storage characteristics.
PMID: 35605748
J Plant Physiol , IF:3.549 , 2022 Aug , V277 : P153792 doi: 10.1016/j.jplph.2022.153792
Regulation of pollen tube growth by cellular pH and ions.
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China. Electronic address: zhouzhg18@lzu.edu.cn.; College of Life Sciences, Northwest Normal University, Lanzhou, Gansu, 730070, China; Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, Qinghai, 810016, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China.; College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China; Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, Qinghai, 810016, China; College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, 524088, China. Electronic address: qiuqsh@lzu.edu.cn.
Tip growth of the pollen tube is a model system for the study of cell polarity establishment in flowering plants. The tip growth of the pollen tube displays an oscillating pattern corresponding to cellular ion and pH dynamics. Therefore, cellular pH and ions play an important role in pollen growth and development. In this review, we summarized the current advances in understanding the function of cellular pH and ions in regulating pollen tube growth. We analyzed the physiological roles and underlying mechanisms of cellular pH and ions, including Ca(2+), K(+), and Cl(-), in regulating pollen tube growth. We further examined the function of Ca(2+) in regulating cytoskeletons, small G proteins, and cell wall development in relation to pollen tube growth. We also examined the regulatory roles of cellular pH in pollen tube growth as well as pH regulation of ion flow, cell wall development, auxin signaling, and cytoskeleton function in pollen. In addition, we assessed the regulation of pollen tube growth by proton pumps and the maintenance of pH homeostasis in the trans-Golgi network by ion transporters. The interplay of ion homeostasis and pH dynamics was also assessed. We discussed the unanswered questions regarding pollen tube growth that need to be addressed in the future.
PMID: 35973258
J Plant Physiol , IF:3.549 , 2022 Aug , V275 : P153738 doi: 10.1016/j.jplph.2022.153738
Bacterial cyclodipeptides elicit Arabidopsis thaliana immune responses reducing the pathogenic effects of Pseudomonas aeruginosa PAO1 strains on plant development.
Laboratorio de Biotecnologia Molecular de Plantas, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico.; Laboratorio de Biologia del Desarrollo Vegetal, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico.; Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, 62250, Cuernavaca, Morelos, Mexico.; Laboratorio de Bioquimica y Biologia Molecular de Plantas, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico.; Laboratorio de Interaccion Suelo Planta Microorganismo, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico.; Laboratorio de Biotecnologia Microbiana, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico. Electronic address: jesus.campos@umich.mx.; Laboratorio de Biotecnologia Molecular de Plantas, Instituto de Investigaciones Quimico Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, 58030, Morelia, Michoacan, Mexico. Electronic address: homero.reyes@umich.mx.
Plants being sessile organisms are exposed to various biotic and abiotic factors, thus causing stress. The Pseudomonas aeruginosa bacterium is an opportunistic pathogen for animals, insects, and plants. Direct exposure of Arabidopsis thaliana to the P. aeruginosa PAO1 strain induces plant death by producing a wide variety of virulence factors, which are regulated mainly by quorum sensing systems. Besides virulence factors, P. aeruginosa PAO1 also produces cyclodipeptides (CDPs), which possess auxin-like activity and promote plant growth through activation of the target of the rapamycin (AtTOR) pathway. On the other hand, plant defense mechanisms are regulated through the production of phytohormones, such as salicylic acid (SA) and jasmonic acid (JA), which are induced in response to pathogen-associated molecular patterns (PAMPs), activating defense genes associated with SA and JA such as PATHOGENESIS-RELATED-1 (PR-1) and LIPOXYGENASE2 (LOX2), respectively. PR proteins are suggested to play critical roles in coordinating the Systemic Acquired Resistance (SAR). In contrast, LOX proteins (LOX2, LOX3, and LOX4) have been associated with the production of JA by producing its precursors, oxylipins. The activation of defense mechanisms involves signaling cascades such as Mitogen-Activated Protein Kinases (MAPKs) or the TOR pathway as a switch for re-directing energy towards defense or growth. In this work, we challenged A. thaliana (wild type, mpk6 or mpk3 mutants, and overexpressing TOR) seedlings with P. aeruginosa PAO1 strains to identify the role of bacterial CDPs in the plant immune response. Results showed that the pre-exposure of these Arabidopsis seedlings to CDPs significantly reduced plant infection of the pathogenic P. aeruginosa PAO1 strains, indicating that plants that over-express AtTOR or lack MPK3/MPK6 protein-kinases are more susceptible to the pathogenic effects. In addition, CDPs induced the GUS activity only in the LOX2::GUS plants, indicative of JA-signaling activation. Our findings indicate that the CDPs are molecules that trigger SA-independent and JA-dependent defense responses in A. thaliana; hence, bacterial CDPs may be considered elicitors of the Arabidopsis immune response to pathogens.
PMID: 35690030
ACS Omega , IF:3.512 , 2022 Jul , V7 (27) : P23566-23575 doi: 10.1021/acsomega.2c02102
Effect of Coated Diammonium Phosphate Combined with Paecilomyces variotii Extracts on Soil Available Nutrients, Photosynthesis-Related Enzyme Activities, Endogenous Hormones, and Maize Yield.
National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian 271018, Shandong, China.; Shandong Pengbo Biotechnology Co., Ltd., Taian 271018, Shandong, China.; Kingenta Ecological Engineering Group Co., Ltd., Linshu 276700, Shandong, China.
Coated diammonium phosphate (CDAP) is intended to release nutrients steadily in response to the demand of crop growth. A novel biostimulant extracted from Paecilomyces variotii has been shown to regulate gene expression in nutrient transport, enhance nitrogen (N) and phosphorus (P) uptake, and improve nutrient use efficiency. The application of CDAP combined with the Paecilomyces variotii extracts (ZNC) in maize is an efficient approach for reducing waste of resources, improving nutrient supply, and maintaining production stability. The effects of CDAP combined with ZNC on photosynthesis, enzyme activities, endogenous hormone content, maize yield, and P use efficiency (PUE) were investigated in this study. In a pot experiment, CDAP and diammonium phosphate (DAP) were tested together with P levels (1.80, 1.44 g pot(-1), P2O5) and two ZNC application rates (0, 4.4 mug pot(-1)), which included the control treatment that had no P fertilizer added. Results showed that the key influencing elements of maize growth and yield were the soil available-P content, endogenous hormone content, and plant photosynthesis in this study. The combination of DAP and ZNC increased the soil available-P content and the auxin content in leaves at the key stage and hence increased the yield and PUE of maize, compared with DAP. The net photosynthetic rate of CDAP combined with ZNC was higher by 23.1% than that of CDAP alone, as well as by 32.0% than that of DAP combined with ZNC. Moreover, the combination of CDAP and ZNC increased the yield and PUE by 8.2% and 15.6 percentage points compared with DAP combined with ZNC while increasing the yield and PUE compared with CDAP. In conclusion, combining CDAP with ZNC as an environmentally friendly fertilizer could improve photosynthesis-related enzyme activity and enhance the net photosynthetic rate, resulting in an increase in maize yield and PUE significantly.
PMID: 35847329
Phytochem Anal , IF:3.373 , 2022 Aug , V33 (6) : P869-878 doi: 10.1002/pca.3135
Development of approach for flavonoid profiling of biotechnological raw materials Iris sibirica L. by HPLC with high-resolution tandem mass spectrometry.
Institute of Chemistry, Saint Petersburg State University, Saint Petersburg, Russia.; Saint Petersburg Scientific Research Institute of Vaccines and Serums and the Enterprise for the Production of Bacterial Preparations, Saint Petersburg, Russia.
INTRODUCTION: Iris L. are promising in medicine due to the biological activity of extracts. Iris sibirica L. is spread in Russia but its phytochemical composition has not been studied in detail though it is included in the Red Book. For this reason, I. sibirica L. biotechnology is in high demand. One of the key points in biotechnology is the regulation of plant metabolism using phytohormones. Obtaining of chromatographic metabolite profiles allows to control this process. OBJECTIVE: The aim of this study was to develop an approach for effective control of biotechnological raw materials of I. sibirica L. by flavonoid profiles using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and to investigate the influence of phytohormones in nutrient media on content of flavonoids. METHODOLOGY: Iris sibirica L. regenerated plants were grown on Murashige-Skoog media with 6-benzylaminopurine (6-BAP) and alpha-naphtylacetic acid (NAA) additives. To optimise extraction conditions, the design of the experiment was used. Profiles of polyphenols were obtained by HPLC-MS/MS in the positive and negative ionisation modes. RESULTS: The process for efficient extraction from leaves of I. sibirica L. were developed. The factors influencing the extraction efficiency of flavonoids have been determined. A total of 36 compounds were identified by HPLC-MS/MS. Among them isoflavones and their glycosides are the main classes. Addition of an auxin-like hormone increased the non-polar flavonoid levels, but decreased the polar ones. The variation in concentration of cytokinin (6-BAP) affected almost all of the analytes. CONCLUSION: The methodology for effective control of I. sibirica L. raw plant material biotechnology was developed by analysing obtained chromatographic polyphenol profiles.
PMID: 35680077
Pathog Dis , IF:3.166 , 2022 Aug , V80 (1) doi: 10.1093/femspd/ftac029
3-indoleacetonitrile attenuates biofilm formation and enhances sensitivity to imipenem in Acinetobacter baumannii.
Department of Biotechnology, South Campus, Basic Medical Science (Block I), Panjab University, Sector 25, 160014, Chandigarh, India.; Department of Microbiology, South Campus, Basic Medical Science (Block I), Panjab University, Sector 25, 160014, Chandigarh, India.
Acinetobacter baumannii poses a global danger due to its ability to resist most of the currently available antimicrobial agents. Furthermore, the rise of carbapenem-resistant A. baumannii isolates has limited the treatment options available. In the present study, plant auxin 3-indoleacetonitrile (3IAN) was found to inhibit biofilm formation and motility of A. baumannii at sublethal concentration. Mechanistically, 3IAN inhibited the synthesis of the quorum sensing signal 3-OH-C12-HSL by downregulating the expression of the abaI autoinducer synthase gene. 3IAN was found to reduce the minimum inhibitory concentration of A. baumannii ATCC 17978 against imipenem, ofloxacin, ciprofloxacin, tobramycin, and levofloxacin, and significantly decreased persistence against imipenem. Inhibition of efflux pumps by downregulating genes expression may be responsible for enhanced sensitivity and low persistence. 3IAN reduced the resistance to imipenem in carbapenem-resistant A. baumannii isolates by downregulating the expression of OXA beta-lactamases (blaoxa-51 and blaoxa-23), outer membrane protein carO, and transporter protein adeB. These findings demonstrate the therapeutic potential of 3IAN, which could be explored as an adjuvant with antibiotics for controlling A. baumannii infections.
PMID: 35867872
PeerJ , IF:2.984 , 2022 , V10 : Pe13798 doi: 10.7717/peerj.13798
Identification and characterization of auxin response factor (ARF) family members involved in fig (Ficus carica L.) fruit development.
College of Horticulture, China Agricultural University, Beijing, Beijing, China.; State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, Beijing, China.
The auxin response factor (ARF) combines with AuxREs cis-acting elements in response to auxin to regulate plant development. To date, no comprehensive analysis of ARF genes expressed during fruit development has been conducted for common fig (Ficus carica L.). In this study, members of the FcARF gene family were screened, identified in the fig genome database and their features characterized using bioinformatics. Twenty FcARF genes were clustered into three classes, with almost similar highly conserved DBD (B3-like DNA binding domain), AUX/IAA (auxin/indole-3-acetic acid gene family) and MR domain structure among class members. Analysis of amino acid species in MR domain revealed 10 potential transcription activators and 10 transcription inhibitors, and 17 FcARF members were predicted to be located in the nucleus. DNA sequence analysis showed that the ARF gene family consisted of 4-25 exons, and the promoter region contained 16 cis-acting elements involved in stress response, hormone response and flavonoid biosynthesis. ARF genes were expressed in most tissues of fig, especially flower and peel. Transcriptomics analysis results showed that FcARF2, FcARF11 and FcARF12, belonging to class-Ia, were stably and highly expressed in the early development stage of flower and peel of 'Purple peel' fig. However, their expression levels decreased after maturity. Expression of class-Ic member FcARF3 conformed to the regularity of fig fruit development. These four potential transcription inhibitors may regulate fruit growth and development of 'Purple Peel' fig. This study provides comprehensive information on the fig ARF gene family, including gene structure, chromosome position, phylogenetic relationship and expression pattern. Our work provides a foundation for further research on auxin-mediated fig fruit development.
PMID: 35898939
PeerJ , IF:2.984 , 2022 , V10 : Pe13710 doi: 10.7717/peerj.13710
ZmIAA5 regulates maize root growth and development by interacting with ZmARF5 under the specific binding of ZmTCP15/16/17.
College of Agronomy, Anhui Agricultural University, Hefei, Anhui, China.; School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, China.
Background: The auxin indole-3-acetic acid (IAA) is a type of endogenous plant hormone with a low concentration in plants, but it plays an important role in their growth and development. The AUX/IAA gene family was found to be an early sensitive auxin gene with a complicated way of regulating growth and development in plants. The regulation of root growth and development by AUX/IAA family genes has been reported in Arabidopsis, rice and maize. Results: In this study, subcellular localization indicated that ZmIAA1-ZmIAA6 primarily played a role in the nucleus. A thermogram analysis showed that AUX/IAA genes were highly expressed in the roots, which was also confirmed by the maize tissue expression patterns. In maize overexpressing ZmIAA5, the length of the main root, the number of lateral roots, and the stalk height at the seedling stage were significantly increased compared with those of the wild type, while the EMS mutant zmiaa5 was significantly reduced. The total number of roots and the dry weight of maize overexpressing ZmIAA5 at the mature stage were also significantly increased compared with those of the wild type, while those of the mutant zmiaa5 was significantly reduced. Yeast one-hybrid experiments showed that ZmTCP15/16/17 could specifically bind to the ZmIAA5 promoter region. Bimolecular fluorescence complementation and yeast two-hybridization indicated an interaction between ZmIAA5 and ZmARF5. Conclusions: Taken together, the results of this study indicate that ZmIAA5 regulates maize root growth and development by interacting with ZmARF5 under the specific binding of ZmTCP15/16/17.
PMID: 35855434
J Theor Biol , IF:2.691 , 2022 Aug : P111261 doi: 10.1016/j.jtbi.2022.111261
Modeling phyllotaxis: From the Inhibition Potential to the Real Plant.
Laboratoire de Thermodynamique des Milieux Ioniques et Biologiques, Universite Paris Cite, France, retired: 45 cours Lassus 66000 Perpignan, France. Electronic address: jpwalch511@gmail.com.
We developed a new parametrization of the classic Douady and Couder model of phyllotaxis based on the inhibition potential: it allowed us to accurately reproduce the vegetative meristem of Linum usitatissimum displaying Fibonacci phyllotaxis, and the reproductive meristem of Ranunculus repens. We calculated the inhibition potential within the meristem and the auxin concentration at the front. We show that phyllotaxis modes and the convergence of the divergence angles towards "noble" angles are the consequence of minimizing the inhibitory potential under the constraint of decreasing plastochron ratios. Our approach, which gives a physicochemical basis to the van Iterson diagram, produces the same results as approaches based on mechanical constraints, suggesting these are two facets of the same botanical reality.
PMID: 36037857
Dose Response , IF:2.658 , 2022 Jul-Sep , V20 (3) : P15593258221121202 doi: 10.1177/15593258221121202
Wool Wax Extraction From Washing Effluent and Effect on Olea europea Germination and Growth.
Laboratory of Functional Physiology and Valorization of Bio Resources, High Institute of Biotechnology of Beja, University of Jendouba, Beja, Tunisia.; G-TEX B CORPORATION SARL, Bradaa, Tunisia.
Effluents from textile industry using wool pose serious environmental nuisances in Tunisia that are mainly due to their pollutant load and the release of unpleasant odors. In order to minimize these hazards and to take advantage of these wastes for the sake of our environment, the present work consists on valuating wool wax from washing effluent on olive (Olea europea), germination and growth. Extraction was made in water at 70 degrees C or hexane using sonication followed by concentration of the extracts in soxhlet apparatus. Results showed that this waste is characterized by its richness in total lipid content with extraction yields of 60.7 and 95.6%, respectively. GC-MS analysis of wax showed its richness on fatty acids. Six saturated fatty acids ranking from 15 to 27 carbon atoms were characterized. Furthermore, diluted wax at a dose of 1.25 mg/g significantly improves germination of olive seeds by germination index calculation, to reach a maximum of 150 +/- 17%. In fertigation experiment, the use of the same dose of diluted wax promotes plant length to reach 45.7 +/- 2.52 cm. GC-MS analysis after derivatization showed significant enhancement of auxin production in plants treated with 1.25 mg of wax/g of soil compared to control with a concentration of 1.1 +/- .1 and .7 +/- .2 ng/mg, respectively. This leads us to valuate wool wax as environmental friendly natural product in agricultural and fertigation practice of olive plant.
PMID: 36003318
J Microbiol Biotechnol , IF:2.351 , 2022 Jul , V32 (7) : P862-868 doi: 10.4014/jmb.2205.05016
Effect of Scenedesmus sp. CHK0059 on Strawberry Microbiota Community.
Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea.; Division of Applied Life Science (BK21 Plus), Gyeongsang National University, Jinju 52828, Republic of Korea.; Department of Plant Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea.
Microalgae are photosynthetic cyanobacteria and eukaryotic microorganisms, mainly living in the water. In agriculture, numerous studies have been conducted to utilize microalgae as a biostimulant resource. Scenedesmus has been known to be one such microalga that can promote plant growth by secretion of auxin or cytokinin hormone analogs. However, no research has been performed on the effect of microalgae treatment on plant microbiota communities. This study was conducted to investigate the mode of action of microalgae as biostimulants in a plant microbiota perspective by using Scenedesmus sp. CHK0059 (also known as species Chlorella fusca), which has been well documented as a biostimulant for strawberries. The strawberry cultivar Keumsil was bred with Seolhyang and Maehyang as the parent cultivars. Using these three cultivars, microbiota communities were evaluated for changes in structural composition according to the CHK0059 treatment. CHK0059-treated Seolhyang, and CHK0059-untreated Maehyang were similar in microbial diversity in the endosphere. From a microbiota community perspective, the diversity change showed that CHK0059 was affected by the characteristics of the host. Conversely, when CHK0059 treatment was applied, populations of Streptomyces and Actinospica were observed in the crown endosphere.
PMID: 35880478
Mol Biol Rep , IF:2.316 , 2022 Jul doi: 10.1007/s11033-022-07731-4
PheGRF4e initiated auxin signaling during moso bamboo shoot development.
Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo and Rattan Science and Technology, International Center for Bamboo and Rattan, Beijing, 100102, China.; Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo and Rattan Science and Technology, International Center for Bamboo and Rattan, Beijing, 100102, China. gaojian@icbr.ac.cn.
BACKGROUND: As a ubiquitous acid-regulating protein family in eukaryotes, general regulatory factors (GRFs) are active in various life activities of plants. However, detailed investigations of the GRFs gene family in moso bamboo are scarce. METHODS AND RESULTS: Genome-wide characteristics of the GRF gene family in moso bamboo were analyzed using the moso bamboo genome. GRF phylogeny, gene structure, conserved domains, cis-element promoters, and gene expression were systematically analyzed. A total of 20 GRF gene family members were identified in the moso bamboo genome. These genes were divided into epsilon and non-epsilon groups. qRT-PCR (real-time quantitative reverse transcription polymerase chain reaction) showed that PheGRF genes responded to auxin and gibberellin treatment. To further study PheGRF gene functions, a yeast two-hybrid experiment was performed and verified by a bimolecular fluorescence complementation experiment. The results showed that PheGRF4e could interact with PheIAA30 (auxin/indole-3-acetic acid, an Aux/IAA family gene), and both were found to act mainly on the root tip meristem and vascular bundle cells of developing shoots by in situ hybridization assay. CONCLUSIONS: This study revealed that PheGRF genes were involved in hormone response during moso bamboo shoot development, and the possible regulatory functions of PheGRF genes were enriched by the fact that PheGRF4e initiated auxin signaling by binding to PheIAA30.
PMID: 35867290
Mol Biol Rep , IF:2.316 , 2022 Jul doi: 10.1007/s11033-022-07712-7
Determination of genotoxic damages of picloram and dicamba with comet assay in Allium cepa rooted in tissue culture and distilled water.
Faculty of Gazi Education, Department of Biology Education, Gazi University, Ankara, Turkey. cigdemozel@gazi.edu.tr.; Science Faculty, Department of Biology, Gazi University, Ankara, Turkey.; Vocational School of Technical Sciences, Amasya University, Amasya, Turkey.; Faculty of Gazi Education, Department of Biology Education, Gazi University, Ankara, Turkey.
BACKGROUND: Many genotoxicity tests allow us to understand the mechanism of damages on genetic material occurring in living organisms against various physical and chemical agents. One of them is the Comet test. The current study aimed to evaluate genotoxic caused by picloram and dicamba to root meristems of Allium cepa utilizing comet assay. METHODS: Two different protocols were used for rooting and auxin/pesticide application. (i) A. cepa bulbs were rooted in MS medium and then treated with Murashige and Skoog (MS) medium (control) and 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba using aseptic tissue culture techniques. (ii) A. cepa bulbs were then rooted in bidistilled water and treated with 0 (control), 0.67, 1.34, 2.01, 2.68, 3.35, 4.02, and 8.04 mg/L of picloram and dicamba in distilled water. The A. cepa root tip cells in both treatment groups were examined using comet test to find the possible DNA damaging effects of picloram and dicamba. RESULTS: The results obtained at all the concentrations were statistically compared with their control groups. Almost at all the concentrations of Picloram and dicamba increased comet tail intensity (%) and tail moment in roots treated in MS medium. Two highest concentrations revealed toxic effect. On the other hand, DNA damaging effect of both auxins was only noted on the highest (> 4.02 mg/L) in roots treated in distilled water. CONCLUSIONS: This study approve and confirm genotoxic effects of how growth regulators on plants. These findings give an evidence of DNA damage in A. cepa. Therefore, both picloram and dicamba should only be used in appropriate and recommended concentrations in agriculture to conserve ecosystem and to pose minimum threat to life.
PMID: 35804213
Mol Biol Rep , IF:2.316 , 2022 Aug , V49 (8) : P7455-7464 doi: 10.1007/s11033-022-07548-1
Overexpression of TaLAX3-1B alters the stomatal aperture and improves the salt stress resistance of tobacco.
College of Agriculture, Guizhou University, Guiyang, 550025, China.; Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China.; College of Agriculture, Guizhou University, Guiyang, 550025, China. xrhgz@163.com.; Guizhou Sub-Center of National Wheat Improvement Center, Guiyang, 550025, China. xrhgz@163.com.
BACKGROUND: Stomata, which play important roles in both optimizing photosynthesis efficiency and adapting to stress, are closely related to IAA and ABA. In plants, the auxin influx carrier LAX3 has been found to play roles in development and stress tolerance. However, the function of LAX3 in stomata and in response to salt stress remains largely unknown. METHODS AND RESULTS: Here, we show that overexpression of wheat TaLAX3-1B in tobacco results in a decrease in stomatal aperture and a relatively closed state of the stomata. In addition, the stomatal movement of the OxTaLAX3-1B lines was less sensitive to ABA than that of the WT. Consistently, compared with the WT, the OxTaLAX3-1B lines showed significantly higher expression of stomate-, IAA- and ABA-related genes and endogenous IAA and ABA contents. Furthermore, compared with the WT, the OxTaLAX3-1B lines exhibited higher proline content, salt stress-related gene expression and ROS antioxidant enzyme activity but lower MDA content and ROS accumulation after salt treatment. CONCLUSIONS: The present results suggest that TaLAX3-1B plays a positive role in regulating stomatal closure and enhancing salt stress tolerance.
PMID: 35624389
Mol Biol Rep , IF:2.316 , 2022 Aug , V49 (8) : P8071-8086 doi: 10.1007/s11033-022-07354-9
Phosphorus homeostasis: acquisition, sensing, and long-distance signaling in plants.
Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India.; ICAR- Indian Agricultural Statistical Research Institute, New Delhi, India.; Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, India. arunatyagi19@yahoo.com.
Phosphorus (P), an essential nutrient required by plants often becomes the limiting factor for plant growth and development. Plants employ various mechanisms to sense the continuously changing P content in the soil. Transcription factors, such as SHORT ROOT (SHR), AUXIN RESPONSE FACTOR19 (ARF19), and ETHYLENE-INSENSITIVE3 (EIN3) regulate the growth of primary roots, root hairs, and lateral roots under low P. Crop improvement strategies under low P depend either on improving P acquisition efficiency or increasing P utilization. The various phosphate transporters (PTs) are involved in the uptake and transport of P from the soil to various plant cellular organelles. A plethora of regulatory elements including transcription factors, microRNAs and several proteins play a critical role in the regulation of coordinated cellular P homeostasis. Among these, the well-established P starvation signaling pathway comprising of central transcriptional factor phosphate starvation response (PHR), microRNA399 (miR399) as a long-distance signal molecule, and PHOSPHATE 2 (PHO2), an E2 ubiquitin conjugase is crucial in the regulation of phosphorus starvation responsive genes. Under PHR control, several classes of PHTs, microRNAs, and proteins modulate root architecture, and metabolic processes to enable plants to adapt to low P. Even though sucrose and inositol phosphates are known to influence the phosphorus starvation response genes, the exact mechanism of regulation is still unclear. In this review, a basic understanding of P homeostasis under low P in plants and all the above aspects are discussed.
PMID: 35318578
Biochem Genet , IF:1.89 , 2022 Aug , V60 (4) : P1205-1221 doi: 10.1007/s10528-021-10158-4
Expression Analysis of AUX/IAA Family Genes in Apple Under Salt Stress.
Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China.; Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China. zhuyd@cau.edu.cn.
Members of the auxin/indoleacetic acid (Aux/IAA) gene family in plants are primary auxin-responsive genes that play important roles in many aspects of plant development and in responses to abiotic stress. Recently, 33 Aux/IAA have been identified in the apple genome. The biological responses of MdIAAs to salt stress are still unknown. In this study, Malus zumi, Malus baccata, and Malus x domestica 'Fuji' plantlets were subjected to salt stress by supplementing hydroponic media with NaCl at various concentrations. M. zumi showed the strongest salt resistance, followed by 'Fuji', and M. baccata was the most sensitive to salt stress. Tissue-specific expression profiles of MdIAAs were determined by quantitative real-time polymerase chain reaction. When apple plantlets were subjected to salt stress, most of salt-responsive MdIAAs were up-regulated by 1 h, 3 h, and 6 h in roots, shoot tips, and leaves, respectively. Highly expressed MdIAAs in roots, especially for M. zumi, consisted with the salt tolerance of apple rootstocks. Transgenic apple calli were tolerant to salt stress when over-expressed salt-responsive genes, MdIAA8, -9, and -25. These results provide clues about salt resistance in these three Malus species, which helps apple breeding of salt tolerance by genetic transformation.
PMID: 34802110
Microbiol Resour Announc , 2022 Aug : Pe0042522 doi: 10.1128/mra.00425-22
Draft Genome Sequence of Bacillus paralicheniformis Strain GSFE7, a Halotolerant Plant Growth-Promoting Bacterial Endophyte Isolated from Cultivated Saline Areas of the Dead Sea Region.
Department of Land, Water, and Environment, School of Agriculture, The University of Jordan, Amman, Jordan.; Department of Biological Sciences, School of Science, The University of Jordan, Amman, Jordan.; Hamdi Mango Center for Scientific Research, The University of Jordan, Amman, Jordan.
Here, we report the draft genome sequence of Bacillus paralicheniformis strain GSFE7, which was isolated from saline fields near the Dead Sea region. The genome was 4,452,800 bp in size and contained 4,382 coding sequences. Several genes were predicted to be involved in auxin production, nitrogen fixation, phosphate mobilization, and putative production of siderophores and antibiotics such as bacitracin, butirosin, and fengycin.
PMID: 35950866