Nat Rev Mol Cell Biol , IF:94.444 , 2023 Dec doi: 10.1038/s41580-023-00691-y
Structure and growth of plant cell walls.
Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA. dcosgrove@psu.edu.
Plant cells build nanofibrillar walls that are central to plant growth, morphogenesis and mechanics. Starting from simple sugars, three groups of polysaccharides, namely, cellulose, hemicelluloses and pectins, with very different physical properties are assembled by the cell to make a strong yet extensible wall. This Review describes the physics of wall growth and its regulation by cellular processes such as cellulose production by cellulose synthase, modulation of wall pH by plasma membrane H(+)-ATPase, wall loosening by expansin and signalling by plant hormones such as auxin and brassinosteroid. In addition, this Review discusses the nuanced roles, properties and interactions of cellulose, matrix polysaccharides and cell wall proteins and describes how wall stress and wall loosening cooperatively result in cell wall growth.
PMID: 38102449
Cell , IF:41.582 , 2023 Dec doi: 10.1016/j.cell.2023.11.021
RAF-like protein kinases mediate a deeply conserved, rapid auxin response.
Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands.; Department of Experimental Plant Biology, Charles University, Prague, Czech Republic.; Institute of Science and Technology Austria, Klosterneuburg, Austria.; Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands.; Graduate School of Biostudies, Kyoto University, Kyoto, Japan.; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.; Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, the Netherlands. Electronic address: dolf.weijers@wur.nl.
The plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism. We recently identified a fast, proteome-wide phosphorylation response to auxin. Here, we show that this response occurs across 5 land plant and algal species and converges on a core group of shared targets. We found conserved rapid physiological responses to auxin in the same species and identified rapidly accelerated fibrosarcoma (RAF)-like protein kinases as central mediators of auxin-triggered phosphorylation across species. Genetic analysis connects this kinase to both auxin-triggered protein phosphorylation and rapid cellular response, thus identifying an ancient mechanism for fast auxin responses in the green lineage.
PMID: 38128538
Cell , IF:41.582 , 2023 Dec , V186 (25) : P5438-5439 doi: 10.1016/j.cell.2023.10.021
Found: The missing discriminators of cell-surface auxin receptors.
Department of Plant Science and Landscape Architecture at the University of Maryland, College Park, MD 20742, USA. Electronic address: asmurphy@umd.edu.; Departments of Biology and Pharmacology at The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
An Arabidopsis cell-surface auxin receptor that mediates rapid elongation consists of transmembrane kinases (TMKs) and an auxin-binding co-receptor. Auxin-binding protein 1 (ABP1) is one identified TMK co-receptor, but abp1 mutants have no elongation phenotypes. Yu et al. use structural analysis of the ABP1-binding pocket to identify functional ABP1-like (ABL) TMK co-receptors that regulate rapid growth.
PMID: 38065077
Cell , IF:41.582 , 2023 Dec , V186 (25) : P5457-5471.e17 doi: 10.1016/j.cell.2023.10.017
ABLs and TMKs are co-receptors for extracellular auxin.
Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China; Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, P.R. China.; Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China.; Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China; College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China.; Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China; Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, Guangdong 518055, P.R. China; Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, P.R. China.; Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, P.R. China.; Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, P.R. China; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, Shandong 261000, P.R. China.; School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, P.R. China.; Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California-Riverside, Riverside, CA 92507, USA.; College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China.; Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China; Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, P.R. China. Electronic address: tdxu@sibs.ac.cn.; Haixia Institute of Science and Technology, School of Future Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, P.R. China; Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, Guangdong 518055, P.R. China; Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, P.R. China; Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California-Riverside, Riverside, CA 92507, USA. Electronic address: yang@ucr.edu.
Extracellular perception of auxin, an essential phytohormone in plants, has been debated for decades. Auxin-binding protein 1 (ABP1) physically interacts with quintessential transmembrane kinases (TMKs) and was proposed to act as an extracellular auxin receptor, but its role was disputed because abp1 knockout mutants lack obvious morphological phenotypes. Here, we identified two new auxin-binding proteins, ABL1 and ABL2, that are localized to the apoplast and directly interact with the extracellular domain of TMKs in an auxin-dependent manner. Furthermore, functionally redundant ABL1 and ABL2 genetically interact with TMKs and exhibit functions that overlap with those of ABP1 as well as being independent of ABP1. Importantly, the extracellular domain of TMK1 itself binds auxin and synergizes with either ABP1 or ABL1 in auxin binding. Thus, our findings discovered auxin receptors ABL1 and ABL2 having functions overlapping with but distinct from ABP1 and acting together with TMKs as co-receptors for extracellular auxin.
PMID: 37979582
Trends Plant Sci , IF:18.313 , 2023 Dec doi: 10.1016/j.tplants.2023.12.004
CLV3-CLV1 signaling governs flower primordia outgrowth across environmental temperatures.
College of Bioscience and Bioengineering, Jiangxi Agricultural University, Jiangxi, Nanchang, 330045, China.; Jiangxi Key Laboratory for Postharvest Technology and Nondestructive Testing of Fruits and Vegetables, Collaborative Innovation Center of Post-Harvest Key Technology and Quality Safety of Fruits and Vegetables, Jiangxi Agricultural University, Nanchang, 330045, China.; Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, China.; College of Bioscience and Bioengineering, Jiangxi Agricultural University, Jiangxi, Nanchang, 330045, China. Electronic address: huibinhan@jxau.edu.cn.
The initiation and outgrowth of floral primordia are critical for flower formation and reproductive success; however, the underlying mechanisms are still unclear. Two reports (Jones et al.; John et al.) shed light on how CLV3-CLV1 signaling promoted flower primordia formation and outgrowth by regulating auxin biosynthesis under distinct environmental temperatures.
PMID: 38102046
Nat Commun , IF:14.919 , 2023 Dec , V14 (1) : P8088 doi: 10.1038/s41467-023-43975-9
Control of compound leaf patterning by MULTI-PINNATE LEAF1 (MPL1) in chickpea.
Division of Life Sciences and Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China.; CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China.; School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, 650500, China.; University of Chinese Academy of Sciences, Beijing, China.; College of Life Science, Southwest Forestry University, Kunming, China.; CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.; Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.; Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA. million.tadege@okstate.edu.; Division of Life Sciences and Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. jhchen@xtbg.ac.cn.; CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China. jhchen@xtbg.ac.cn.; University of Chinese Academy of Sciences, Beijing, China. jhchen@xtbg.ac.cn.; College of Life Science, Southwest Forestry University, Kunming, China. jhchen@xtbg.ac.cn.; CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China. heliangliang@xtbg.ac.cn.; University of Chinese Academy of Sciences, Beijing, China. heliangliang@xtbg.ac.cn.
Plant lateral organs are often elaborated through repetitive formation of developmental units, which progress robustly in predetermined patterns along their axes. Leaflets in compound leaves provide an example of such units that are generated sequentially along the longitudinal axis, in species-specific patterns. In this context, we explored the molecular mechanisms underlying an acropetal mode of leaflet initiation in chickpea pinnate compound leaf patterning. By analyzing naturally occurring mutants multi-pinnate leaf1 (mpl1) that develop higher-ordered pinnate leaves with more than forty leaflets, we show that MPL1 encoding a C2H2-zinc finger protein sculpts a morphogenetic gradient along the proximodistal axis of the early leaf primordium, thereby conferring the acropetal leaflet formation. This is achieved by defining the spatiotemporal expression pattern of CaLEAFY, a key regulator of leaflet initiation, and also perhaps by modulating the auxin signaling pathway. Our work provides novel molecular insights into the sequential progression of leaflet formation.
PMID: 38062032
Small , IF:13.281 , 2023 Dec : Pe2304862 doi: 10.1002/smll.202304862
Biofunctional Inorganic Layered Double Hydroxide Nanohybrid Enhances Immunotherapeutic Effect on Atopic Dermatitis Treatment.
Department of Biomedical Engineering, SKKU Institute for Convergence, Sungkyunkwan University (SKKU), Suwon, Gyeonggi, 16419, Republic of Korea.; Department of Intelligent Precision Healthcare Convergence, SKKU Institute for Convergence, Sungkyunkwan University (SKKU), Suwon, Gyeonggi, 16419, Republic of Korea.; Department of Engineering Chemistry, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.; Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.; Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), Suwon, Gyeonggi, 16419, Republic of Korea.; Department of Tropical Medicine, Medical Microbiology, and Pharmacology, John A. Burns School Medicine, University of Hawai'i at Manoa, Honolulu, Hawaii, 96813, USA.; School of Integrative Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea.; Department of Bioengineering, Hanyang University, Seoul, 04763, Republic of Korea.; Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.; Biomaterials Research Center, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea.; Research and Development Center, MediArk Inc., Cheongju, Chungbuk, 28644, Republic of Korea.; Department of Industrial Cosmetic Science, College of Bio-Health University System, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.; Department of Synchrotron Radiation Science and Technology, College of Bio-Health University System, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.; LANG SCIENCE Inc, Cheongju, Chungbuk, 28644, Republic of Korea.; Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU), Suwon, Gyeonggi, 16419, Republic of Korea.
Atopic dermatitis (AD) is a widespread, recurrent, and chronic inflammatory skin condition that imposes a major burden on patients. Conventional treatments, such as corticosteroids, are associated with various side effects, underscoring the need for innovative therapeutic approaches. In this study, the possibility of using indole-3-acetic acid-loaded layered double hydroxides (IAA-LDHs) is evaluated as a novel treatment for AD. IAA is an auxin-class plant hormone with antioxidant and anti-inflammatory effects. Following the synthesis of IAA-LDH nanohybrids, their ability to induce M2-like macrophage polarization in macrophages obtained from mouse bone marrow is assessed. The antioxidant activity of IAA-LDH is quantified by assessing the decrease in intracellular reactive oxygen species levels. The anti-inflammatory and anti-atopic characteristics of IAA-LDH are evaluated in a mouse model of AD by examining the cutaneous tissues, immunological organs, and cells. The findings suggest that IAA-LDH has great therapeutic potential as a candidate for AD treatment based on its in vitro and in vivo modulation of AD immunology, enhancement of macrophage polarization, and antioxidant activity. This inorganic drug delivery technology represents a promising new avenue for the development of safe and effective AD treatments.
PMID: 38050931
Mol Plant , IF:13.164 , 2023 Dec doi: 10.1016/j.molp.2023.12.021
Unveiling a new regulator: vacuolar V-ATPase mediates brassinosteroid signaling in Arabidopsis.
Department of Plant Pathology, Entomology, and Microbiology. Iowa State University, Ames, IA, USA.; Department of Plant Pathology, Entomology, and Microbiology. Iowa State University, Ames, IA, USA.. Electronic address: jwalley@iastate.edu.
Plant growth and development are intricately regulated by hormones such as auxin, gibberellins, jamonates, cytokinins, and brassinosteroids (BR). BRs are a group of plant steroid hormones that play a vital role in plant growth and response to the environment. BRs regulate many biological processes including cell elongation, cell division, and male fertility as well as abiotic and biotic stress responses. To facilitate modulation of these biological processes, induction of BR signaling results in massive alterations in the transcriptome, proteome, and phosphoproteome (Clark et al., 2021). BRs are perceived by the plasma membrane-bound leucine-rich repeat receptor BRASSINOSTEROID INSENSITIVE1 (BRI1), causing a conformational change in the receptor and promoting interaction with the co-receptor BRI1-ASSOCIATED KINASE1 (BAK1). BR perception initiates a downstream kinase signaling cascade inactivating the GSK3-like kinase BRASSINOSTEROID INSENSITIVE 2 (BIN2), which is a negative regulator of BR signaling, ultimately resulting in dephosphorylation and activation of BRASSINAZOLE RESISTANT 1 (BZR1) and BRI1-EMS-SUPPRESSOR1 (BES1) (Wang et al., 2016; Nolan et al., 2020; Wang et al., 2021).
PMID: 38155571
Mol Plant , IF:13.164 , 2023 Dec doi: 10.1016/j.molp.2023.12.009
A new oxidative pathway of nitric oxide production from oximes in plants.
Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA); Avda. de Pamplona 123, E-31192 Mutilva, Spain.; Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA); Campus de Arrosadia; E-31006 Pamplona, Spain.; Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU); Sarriena s/n; Apdo. 644; E-48080 Bilbao, Spain.; Center for Plant Molecular Biology (ZMBP), University of Tubingen, Geschwister-Scholl-Platz, 72074 Tubingen, Germany.; Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA); Campus de Arrosadia; E-31006 Pamplona, Spain. Electronic address: merino@unavarra.es.; Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA); Avda. de Pamplona 123, E-31192 Mutilva, Spain. Electronic address: jose.moran@unavarra.es.
Nitric Oxide (NO) is an essential reactive oxygen species and a signal molecule in plants. Although several works have proposed the occurrence of oxidative NO production, only reductive routes for NO production, such as the nitrate reductase pathway, have been evidenced up to date in land plants. However, plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite (NO(2)(-)) and nitrate (NO(3)(-)), evidencing the existence of a metabolic pathway for oxidative production of NO. We hypothesised that oximes, such as the indole-3-acetaldoxime (IAOx), a precursor to indole-3-acetic acid, are intermediate oxidation products in the NO synthesis. We have detected the production of NO from IAOx and other oximes catalysed by peroxidase enzyme (POD) using both DAF-FM fluorescence and chemiluminescence. Flavins stimulated the reaction, while superoxide dismutase inhibited it. Interestingly, mouse NO synthase can also use IAOx to produce NO, at a lower rate than POD. We provide here a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by Density-Functional Theory (DFT) calculations. We show that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO, while in vivo supplementation of IAOx and other oximes increased the number of lateral roots, as shown for NO donors, and a >10-fold increase in IAOx dehydratase expression. Also, in vivo supplementation of IAOx increased the NO production in Arabidopsis thaliana wild-type plants, while prx33-34 mutant plants, defective for POD33-34, had reduced production. Our data show that the release of NO by IAOx, together with its auxinic effect, explains the superroot phenotype. Altogether, we demonstrate that plants produce NO utilising diverse molecules such as oximes, POD, and flavins, which are widely distributed in the plant kingdom, thus introducing a long-awaited oxidative pathway to NO production in plants. This knowledge has essential implications to understand signalling in biological systems.
PMID: 38102832
EMBO J , IF:11.598 , 2023 Dec , V42 (24) : Pe113941 doi: 10.15252/embj.2023113941
Long noncoding RNA-mediated epigenetic regulation of auxin-related genes controls shade avoidance syndrome in Arabidopsis.
Instituto de Agrobiotecnologia del Litoral, CONICET, Universidad Nacional del Litoral, Santa Fe, Argentina.; School of Life Sciences, University of Warwick, Coventry, UK.; Plant Molecular Genetics Department, Centro Nacional de Biotecnologia-CSIC, Campus Universidad Autonoma de Madrid, Madrid, Spain.; Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Universite Evry, Universite Paris-Saclay, Orsay, France.; Institute of Plant Sciences Paris-Saclay IPS2, Universite de Paris, Orsay, France.; Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura (IFEVA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina.; Instituto de Investigaciones Biotecnologicas (IIBIO), CONICET, Universidad Nacional de San Martin, Buenos Aires, Argentina.
The long noncoding RNA (lncRNA) AUXIN-REGULATED PROMOTER LOOP (APOLO) recognizes a subset of target loci across the Arabidopsis thaliana genome by forming RNA-DNA hybrids (R-loops) and modulating local three-dimensional chromatin conformation. Here, we show that APOLO regulates shade avoidance syndrome by dynamically modulating expression of key factors. In response to far-red (FR) light, expression of APOLO anti-correlates with that of its target BRANCHED1 (BRC1), a master regulator of shoot branching in Arabidopsis thaliana. APOLO deregulation results in BRC1 transcriptional repression and an increase in the number of branches. Accumulation of APOLO transcription fine-tunes the formation of a repressive chromatin loop encompassing the BRC1 promoter, which normally occurs only in leaves and in a late response to far-red light treatment in axillary buds. In addition, our data reveal that APOLO participates in leaf hyponasty, in agreement with its previously reported role in the control of auxin homeostasis through direct modulation of auxin synthesis gene YUCCA2, and auxin efflux genes PID and WAG2. We show that direct application of APOLO RNA to leaves results in a rapid increase in auxin signaling that is associated with changes in the plant response to far-red light. Collectively, our data support the view that lncRNAs coordinate shade avoidance syndrome in A. thaliana, and reveal their potential as exogenous bioactive molecules. Deploying exogenous RNAs that modulate plant-environment interactions may therefore become a new tool for sustainable agriculture.
PMID: 38054357
Plant Cell , IF:11.277 , 2023 Dec doi: 10.1093/plcell/koad317
Root branching under high salinity requires auxin-independent modulation of LATERAL ORGAN BOUNDARY DOMAIN 16 function.
Laboratory of Plant Physiology, Wageningen University & Research, The Netherlands.; Plant Cell Biology, Faculty of Science, Swammerdam Institute for Life Sciences, University of Amsterdam, The Netherlands.; College of Agriculture, South China Agricultural University, China.; Molecular Plant Physiology, Philipps-Universitat Marburg, Germany.; Bioinformatics Group, Wageningen University & Research, The Netherlands.
Salinity stress constrains lateral root (LR) growth and severely affects plant growth. Auxin signaling regulates LR formation, but the molecular mechanism by which salinity affects root auxin signaling and whether salt induces other pathways that regulate LR development remains unknown. In Arabidopsis thaliana, the auxin-regulated transcription factor LATERAL ORGAN BOUNDARY DOMAIN 16 (LBD16) is an essential player in LR development under control conditions. Here we show that under high-salt conditions, an alternative pathway regulates LBD16 expression. Salt represses auxin signaling but in parallel activates ZINC FINGER OF ARABIDOPSIS THALIANA 6 (ZAT6), a transcriptional activator of LBD16. ZAT6 activates LBD16 expression, thus contributing to downstream cell wall remodeling and promoting LR development under high-salt conditions. Our study thus shows that the integration of auxin-dependent repressive and salt-activated auxin-independent pathways converging on LBD16 modulates root branching under high-salt conditions.
PMID: 38142228
Plant Cell , IF:11.277 , 2023 Dec doi: 10.1093/plcell/koad309
An apple a day: MdBPC2 transcription factor keeps the auxin away and causes dwarfing in Malus domestica.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists, USA.; Natural Resources and the Environment Department, University of New Hampshire, Durham, NH, 03824, USA.
PMID: 38084887
Plant Cell , IF:11.277 , 2023 Dec , V36 (1) : P158-173 doi: 10.1093/plcell/koad255
Transcriptional activation by WRKY23 and derepression by removal of bHLH041 coordinately establish callus pluripotency in Arabidopsis regeneration.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, China National Botanical Garden, Beijing 100093, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; National Center for Plant Gene Research, Beijing 100093, China.
Induction of the pluripotent cell mass termed callus from detached organs or tissues is an initial step in typical in vitro plant regeneration, during which auxin-induced ectopic activation of root stem cell factors is required for subsequent de novo shoot regeneration. While Arabidopsis (Arabidopsis thaliana) AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 and their downstream transcription factors LATERAL ORGAN BOUNDARIES DOMAIN (LBD) are known to play key roles in directing callus formation, the molecules responsible for activation of root stem cell factors and thus establishment of callus pluripotency are unclear. Here, we identified Arabidopsis WRKY23 and BASIC HELIX-LOOP-HELIX 041 (bHLH041) as a transcriptional activator and repressor, respectively, of root stem cell factors during establishment of auxin-induced callus pluripotency. We show that auxin-induced WRKY23 downstream of ARF7 and ARF19 directly activates the transcription of PLETHORA 3 (PLT3) and PLT7 and thus that of the downstream genes PLT1, PLT2, and WUSCHEL-RELATED HOMEOBOX 5 (WOX5), while LBD-induced removal of bHLH041 derepresses the transcription of PLT1, PLT2, and WOX5. We provide evidence that transcriptional activation by WRKY23 and loss of bHLH041-imposed repression act synergistically in conferring shoot-regenerating capability on callus cells. Our findings thus disclose a transcriptional mechanism underlying auxin-induced cellular reprogramming, which, together with previous studies, outlines the molecular framework of auxin-induced pluripotent callus formation for in vitro plant regeneration programs.
PMID: 37804093
Curr Biol , IF:10.834 , 2023 Dec , V33 (24) : PR1268-R1269 doi: 10.1016/j.cub.2023.11.005
Dolf Weijers.
Wageningen University and Research Laboratory of Biochemistry, Stippeneng 4, 6708 WE Wageningen, The Netherlands. Electronic address: dolf.weijers@wur.nl.
Interview with Dolf Weijers, who studies the mechanisms underlying early plant development and auxin response at Wageningen University.
PMID: 38113831
Curr Biol , IF:10.834 , 2023 Dec , V33 (24) : P5355-5367.e5 doi: 10.1016/j.cub.2023.10.072
Natural variants of molybdate transporters contribute to yield traits of soybean by affecting auxin synthesis.
National Key Laboratory of Plant Molecular Genetics, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, 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.; National Key Laboratory of Plant Molecular Genetics, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.; University of Chinese Academy of Sciences, Beijing 100049, 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. Electronic address: zxtian@genetics.ac.cn.; National Key Laboratory of Plant Molecular Genetics, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: dychao@cemps.ac.cn.
Soybean (Glycine max) is a crop with high demand for molybdenum (Mo) and typically requires Mo fertilization to achieve maximum yield potential. However, the genetic basis underlying the natural variation of Mo concentration in soybean and its impact on soybean agronomic performance is still poorly understood. Here, we performed a genome-wide association study (GWAS) to identify GmMOT1.1 and GmMOT1.2 that drive the natural variation of soybean Mo concentration and confer agronomic traits by affecting auxin synthesis. The soybean population exhibits five haplotypes of the two genes, with the haplotype 5 demonstrating the highest expression of GmMOT1.1 and GmMOT1.2, as well as the highest transport activities of their proteins. Further studies showed that GmMOT1.1 and GmMOT1.2 improve soybean yield, especially when cultivated in acidic or slightly acidic soil. Surprisingly, these two genes contribute to soybean growth by enhancing the activity of indole-3-acetaldehyde (IAAld) aldehyde oxidase (AO), leading to increased indole-3-acetic acid (IAA) synthesis, rather than being involved in symbiotic nitrogen fixation or nitrogen assimilation. Furthermore, the geographical distribution of five haplotypes in China and their correlation with soil pH suggest the potential significance of GmMOT1.1 and GmMOT1.2 in soybean breeding strategies.
PMID: 37995699
J Hazard Mater , IF:10.588 , 2024 Jan , V461 : P132541 doi: 10.1016/j.jhazmat.2023.132541
Genome-wide profiling of genetic variations reveals the molecular basis of aluminum stress adaptation in Tibetan wild barley.
Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China; Plant Biotechnology Laboratory, Center for Viticulture & Small Fruit Research, Florida A&M University, FL 32317, USA.; Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China. Electronic address: wufeibo@zju.edu.cn.
Aluminum (Al) toxicity in acidic soil is a major factor affecting crop productivity. The extensive genetic diversity found in Tibetan wild barley germplasms offers a valuable reservoir of alleles associated with aluminum tolerance. Here, resequencing of two Al-tolerant barley genotypes (Tibetan wild barley accession XZ16 and cultivated barley Dayton) identified a total of 19,826,182 and 16,287,277 single nucleotide polymorphisms (SNPs), 1628,052 and 1386,973 insertions/deletions (InDels), 61,532 and 57,937 structural variations (SVs), 248,768 and 240,723 copy number variations (CNVs) in XZ16 and Dayton, respectively, and uncovered approximately 600 genes highly related to Al tolerance in barley. Comparative genomic analyses unveiled 71 key genes that contain unique genetic variants in XZ16 and are predominantly associated with organic acid exudation, Al sequestration, auxin response, and transcriptional regulation. Manipulation of these key genes at the genetic and transcriptional level is a promising strategy for developing optimal haplotype combinations and new barley cultivars with improved Al tolerance. This study represents the first comprehensive examination of genetic variation in Al-tolerant Tibetan wild barley through genome-wide profiling. The obtained results make the deep insight into the mechanisms underlying barley adaptation to Al toxicity, and identified the candidate genes useful for improvement of Al tolerance in barley.
PMID: 37716271
J Adv Res , IF:10.479 , 2023 Dec doi: 10.1016/j.jare.2023.12.015
Development of a bacterial gene transcription activating strategy based on transcriptional activator positive feedback.
State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China.; State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China. Electronic address: wanghailong@sdu.edu.cn.
INTRODUCTION: Transcription of biological nitrogen fixation (nif) genes is activated by the NifA protein which recognizes specific activating sequences upstream of sigma(54)-dependent nif promoters. The large quantities of nitrogenase which can make up 20% of the total proteins in the cell indicates high transcription activating efficiency of NifA and high transcription level of nifHDK nitrogenase genes. OBJECTIVES: Development of an efficient gene transcription activating strategy in bacteria based on positive transcription regulatory proteins and their regulating DNA sequences. METHODS: We designed a highly efficient gene transcription activating strategy in which the nifA gene was placed directly downstream of its regulating sequences. The NifA protein binds its regulating sequences and stimulates transcription of itself and downstream genes. Overexpressed NifA causes transcription activation by positive reinforcement. RESULTS: When this gene transcription activating strategy was used to overexpress NifA in Pseudomonas stutzeri DSM4166 containing the nif gene cluster, the nitrogenase activity was increased by 368 folds which was 16 times higher than that obtained by nifA driven by the strongest endogenous constitutive promoter. When this strategy was used to activate transcription of exogenous biosynthetic genes for the plant auxin indole-3-acetic acid and the antitumor alkaloid pigment prodigiosin in DSM4166, both of them resulted in better performance than the strongest endogenous constitutive promoter and the highest reported productions in heterologous hosts to date. Finally, we demonstrated the universality of this strategy using the positive transcriptional regulator of the psp operon, PspF, in E. coli and the pathway-specific positive transcription regulator of the polyene antibiotic salinomycin biosynthesis, SlnR, in Streptomyces albus. CONCLUSION: Many positive transcription regulatory proteins and their regulating DNA sequences have been identified in bacteria. The gene transcription activating strategy developed in this study will have broad applications in molecular biology and biotechnology.
PMID: 38123018
New Phytol , IF:10.151 , 2023 Dec doi: 10.1111/nph.19503
A novel miR160a-GmARF16-GmMYC2 module determines soybean salt tolerance and adaptation.
College of Agronomy, Shandong Agricultural University, Tai'an, Shandong, 271018, China.; Crop Research Institute, Shandong Academy of Agricultural Sciences, Ji'nan, Shandong, 250131, China.; Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou, 510006, China.
Salt stress is a major challenge that has a negative impact on soybean growth and productivity. Therefore, it is important to understand the regulatory mechanism of salt response to ensure soybean yield under such conditions. In this study, we identified and characterized a miR160a-GmARF16-GmMYC2 module and its regulation during the salt-stress response in soybean. miR160a promotes salt tolerance by cleaving GmARF16 transcripts, members of the Auxin Response Factor (ARF) family, which negatively regulates salt tolerance. In turn, GmARF16 activates GmMYC2, encoding a bHLH transcription factor that reduces salinity tolerance by down-regulating proline biosynthesis. Genomic analysis among wild and cultivated soybean accessions identified four distinct GmARF16 haplotypes. Among them, the GmARF16(H3) haplotype is preferentially enriched in localities with relatively saline soils, suggesting GmARF16(H3) was artificially selected to improve salt tolerance. Our findings therefore provide insights into the molecular mechanisms underlying salt response in soybean and provide valuable genetic targets for the molecular breeding of salt tolerance.
PMID: 38135657
New Phytol , IF:10.151 , 2024 Jan , V241 (2) : P592-606 doi: 10.1111/nph.19382
The IAA17.1/HSFA5a module enhances salt tolerance in Populus tomentosa by regulating flavonol biosynthesis and ROS levels in lateral roots.
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.; Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, 400715, China.; Key Laboratory of Three Gorges Regional Plant Genetics & Germplasm Enhancement (CTGU), Biotechnology Research Center, China Three Gorges University, Yichang, 443000, China.
Auxin signaling provides a promising approach to controlling root system architecture and improving stress tolerance in plants. However, how the auxin signaling is transducted in this process remains unclear. The Aux indole-3-acetic acid (IAA) repressor IAA17.1 is stabilized by salinity, and primarily expressed in the lateral root (LR) primordia and tips in poplar. Overexpression of the auxin-resistant form of IAA17.1 (IAA17.1m) led to growth inhibition of LRs, markedly reduced salt tolerance, increased reactive oxygen species (ROS) levels, and decreased flavonol content. We further identified that IAA17.1 can interact with the heat shock protein HSFA5a, which was highly expressed in roots and induced by salt stress. Overexpression of HSFA5a significantly increased flavonol content, reduced ROS accumulation, enhanced LR growth and salt tolerance in transgenic poplar. Moreover, HSFA5a could rescue the defective phenotypes caused by IAA17.1m. Expression analysis showed that genes associated with flavonol biosynthesis were altered in IAA17.1m- and HAFA5a-overexpressing plants. Furthermore, we identified that HSFA5a directly activated the expression of key enzyme genes in the flavonol biosynthesis pathway, while IAA17.1 suppressed HSFA5a-mediated activation of these genes. Collectively, the IAA17.1/HSFA5a module regulates flavonol biosynthesis, controls ROS accumulation, thereby modulating the root system of poplar to adapt to salt stress.
PMID: 37974487
New Phytol , IF:10.151 , 2023 Dec , V240 (5) : P1729-1731 doi: 10.1111/nph.19303
FASEB: the mechanism of plant development: Saxtons River, Vermont, 24-29 July 2022.
Centro de Biotecnologia y Genomica de Plantas (CBGP), Universidad Politecnica de Madrid (UPM)-Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (CNINIA, CSIC), Campus de Montegancedo, Pozuelo de Alarcon, 28223, Madrid, Spain.; Departement de Sciences Biologique, Institut de Recherche en Biologie Vegetale, Universite de Montreal, Montreal, QC, H1X 2B2, Canada.; Laboratory of Biochemistry, Wageningen University, Wageningen, 6708 WE, the Netherlands.; Sainsbury Laboratory, University of Cambridge, CB2 1LR, Cambridge, UK.; Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
PMID: 37817389
New Phytol , IF:10.151 , 2023 Dec , V240 (5) : P1883-1899 doi: 10.1111/nph.19292
Chemical induction of hypocotyl rooting reveals extensive conservation of auxin signalling controlling lateral and adventitious root formation.
Horticell, Department Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000, Ghent, Belgium.; Institute of Food and Biotechnology, Can Tho University, 900000, Can Tho City, Vietnam.; Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.; School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.; Department of Biosciences, University of Milan, via Celoria 26, 20133, Milan, Italy.; Institute of Biophysics, National Research Council of Italy (CNR), 20133, Milan, Italy.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052, Ghent, Belgium.; VIB Centre for Plant Systems Biology, Technologiepark 71, 9052, Ghent, Belgium.; Department of Plant Physiology, Umea Plant Science Centre, Umea University, SE-90736, Umea, Sweden.; Universite Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000, Versailles, France.
Upon exposure to light, etiolated Arabidopsis seedlings form adventitious roots (AR) along the hypocotyl. While processes underlying lateral root formation are studied intensively, comparatively little is known about the molecular processes involved in the initiation of hypocotyl AR. AR and LR formation were studied using a small molecule named Hypocotyl Specific Adventitious Root INducer (HYSPARIN) that strongly induces AR but not LR formation. HYSPARIN does not trigger rapid DR5-reporter activation, DII-Venus degradation or Ca(2+) signalling. Transcriptome analysis, auxin signalling reporter lines and mutants show that HYSPARIN AR induction involves nuclear TIR1/AFB and plasma membrane TMK auxin signalling, as well as multiple downstream LR development genes (SHY2/IAA3, PUCHI, MAKR4 and GATA23). Comparison of the AR and LR induction transcriptome identified SAURs, AGC kinases and OFP transcription factors as specifically upregulated by HYSPARIN. Members of the SAUR19 subfamily, OFP4 and AGC2 suppress HYS-induced AR formation. While SAUR19 and OFP subfamily members also mildly modulate LR formation, AGC2 regulates only AR induction. Analysis of HYSPARIN-induced AR formation uncovers an evolutionary conservation of auxin signalling controlling LR and AR induction in Arabidopsis seedlings and identifies SAUR19, OFP4 and AGC2 kinase as novel regulators of AR formation.
PMID: 37787103
New Phytol , IF:10.151 , 2023 Dec , V240 (5) : P1900-1912 doi: 10.1111/nph.19284
GH3-mediated auxin inactivation attenuates multiple stages of lateral root development.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, 9052, Belgium.; Center for Plant Systems Biology, VIB, 9052, Ghent, Belgium.; MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River and State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.; Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium.; Department of Bioscience, Okayama University of Science, Okayama, 700-0005, Japan.; Department of Biology, University of Fribourg, Fribourg, CH-1700, Switzerland.; Computational Developmental Biology Group, Faculty of Science, Utrecht University, Utrecht, 3584 CH, the Netherlands.
Lateral root (LR) positioning and development rely on the dynamic interplay between auxin production, transport but also inactivation. Nonetheless, how the latter affects LR organogenesis remains largely uninvestigated. Here, we systematically analyze the impact of the major auxin inactivation pathway defined by GRETCHEN HAGEN3-type (GH3) auxin conjugating enzymes and DIOXYGENASE FOR AUXIN OXIDATION1 (DAO1) in all stages of LR development using reporters, genetics and inhibitors in Arabidopsis thaliana. Our data demonstrate that the gh3.1/2/3/4/5/6 hextuple (gh3hex) mutants display a higher LR density due to increased LR initiation and faster LR developmental progression, acting epistatically over dao1-1. Grafting and local inhibitor applications reveal that root and shoot GH3 activities control LR formation. The faster LR development in gh3hex is associated with GH3 expression domains in and around developing LRs. The increase in LR initiation is associated with accelerated auxin response oscillations coinciding with increases in apical meristem size and LR cap cell death rates. Our research reveals how GH3-mediated auxin inactivation attenuates LR development. Local GH3 expression in LR primordia attenuates development and emergence, whereas GH3 effects on pre-initiation stages are indirect, by modulating meristem activities that in turn coordinate root growth with LR spacing.
PMID: 37743759
New Phytol , IF:10.151 , 2023 Dec , V240 (5) : P1930-1943 doi: 10.1111/nph.19273
Parallel tuning of semi-dwarfism via differential splicing of Brachytic1 in commercial maize and smallholder sorghum.
Corteva Agriscience, 7300 NW 62nd Ave, Johnston, IA, 50131, USA.; Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.; Department of Agronomy, Kansas State University, Manhattan, KS, 66506, USA.; Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.; Soil & Crop Sciences, Colorado State University, Plant Sciences Building, Fort Collins, CO, 11111, USA.; Napigen Inc., 200 Powder Mill Road, Delaware Innovation Space - E500, Wilmington, DE, 19803, USA.
In the current genomic era, the search and deployment of new semi-dwarf alleles have continued to develop better plant types in all cereals. We characterized an agronomically optimal semi-dwarf mutation in Zea mays L. and a parallel polymorphism in Sorghum bicolor L. We cloned the maize brachytic1 (br1-Mu) allele by a modified PCR-based Sequence Amplified Insertion Flanking Fragment (SAIFF) approach. Histology and RNA-Seq elucidated the mechanism of semi-dwarfism. GWAS linked a sorghum plant height QTL with the Br1 homolog by resequencing a West African sorghum landraces panel. The semi-dwarf br1-Mu allele encodes an MYB transcription factor78 that positively regulates stalk cell elongation by interacting with the polar auxin pathway. Semi-dwarfism is due to differential splicing and low functional Br1 wild-type transcript expression. The sorghum ortholog, SbBr1, co-segregates with the major plant height QTL qHT7.1 and is alternatively spliced. The high frequency of the Sbbr1 allele in African landraces suggests that African smallholder farmers used the semi-dwarf allele to improve plant height in sorghum long before efforts to introduce Green Revolution-style varieties in the 1960s. Surprisingly, variants for differential splicing of Brachytic1 were found in both commercial maize and smallholder sorghum, suggesting parallel tuning of plant architecture across these systems.
PMID: 37737036
Cell Rep , IF:9.423 , 2023 Dec , V43 (1) : P113617 doi: 10.1016/j.celrep.2023.113617
STOP1 attenuates the auxin response to maintain root stem cell niche identity.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, China.; College of Life Sciences, Liaocheng University, Liaocheng, Shandong, China.; The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, China. Electronic address: dingzhaojun@sdu.edu.cn.
In plant roots, the identity of the stem cell niche (SCN) is maintained by an auxin gradient with its maximum in the quiescent center (QC). Optimal levels of auxin signaling are essential for root SCN identity, but the regulatory mechanisms that control this pathway in root are largely unknown. Here, we find that the zinc finger transcription factor sensitive to proton rhizotoxicity 1 (STOP1) regulates root SCN identity by negative feedback of auxin signaling in root tips. Mutation and overexpression of STOP1 both affect QC cell division and distal stem cell differentiation in the root. We find that auxin treatment stabilizes STOP1 via MPK3/6-dependent phosphorylation. Accumulating STOP1 can compete with AUX/IAAs to interact with, and enhance the repressive activity of, auxin-repressive response factor ARF2. Overall, we show that the MPK3/6-STOP1-ARF2 module prevents excessive auxin signaling in the presence of auxin to maintain root SCN identity.
PMID: 38150366
Plant Physiol , IF:8.34 , 2023 Dec doi: 10.1093/plphys/kiad658
A high-resolution gene expression map of the medial and lateral domains of the gynoecium of Arabidopsis.
Unidad de Genomica Avanzada (UGA-LANGEBIO), Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Irapuato CP 36824, Guanajuato, Mexico.; Department of Cell & Systems Biology/Centre for the Analysis of Genome Evolution and Function, University of Toronto. 25 Willcocks St., Toronto, ON. M5S 3B2. Canada.; Polytech Nice Sophia, Universite Cote d'Azur, 930 Rte des Colles, 06410 Biot, France.
Angiosperms are characterized by the formation of flowers, and in their inner floral whorl, one or various gynoecia are produced. These female reproductive structures are responsible for fruit and seed production, thus ensuring the reproductive competence of angiosperms. In Arabidopsis (Arabidopsis thaliana), the gynoecium is composed of two fused carpels with different tissues that need to develop and differentiate to form a mature gynoecium and thus the reproductive competence of Arabidopsis. For these reasons, they have become the object of study for floral and fruit development. However, due to the complexity of the gynoecium, specific spatio-temporal tissue expression patterns are still scarce. In this study, we used precise laser-assisted microdissection and high-throughput RNA sequencing to describe the transcriptional profiles of the medial and lateral domain tissues of the Arabidopsis gynoecium. We provide evidence that the method used is reliable and that, in addition to corroborating gene expression patterns of previously reported regulators of these tissues, we found genes whose expression dynamics point to being involved in cytokinin and auxin homeostasis and in cell cycle progression. Furthermore, based on differential gene expression analyses, we functionally characterized several genes and found that they are involved in gynoecium development. This resource is available via the Arabidopsis eFP browser and will serve the community in future studies on developmental and reproductive biology.
PMID: 38088205
Environ Pollut , IF:8.071 , 2023 Dec , V343 : P123112 doi: 10.1016/j.envpol.2023.123112
Exogenous auxin alters the polycyclic aromatic hydrocarbons apoplastic and symplastic uptake by wheat seedling roots.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China. Electronic address: zhujiahui319@126.com.; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China.; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu Province, 210095, People's Republic of China. Electronic address: xhzhan@njau.edu.cn.
Polycyclic aromatic hydrocarbons (PAHs) are a category of organic pollutants known for their high carcinogenicity. Our previous research has illustrated that plant roots actively absorb PAHs through a co-transport mechanism with H(+) ions. Because auxin can increase the H(+)-ATPase activity, the wheat roots were exposed to PAHs with/without auxins to study whether auxins facilitate the uptake of PAHs by plant roots and to gain insights into the underlying mechanisms of this process. In our study, indole acetic acid (100 muM) and alpha-naphthaleneacetic acid (10 muM) significantly increased the PAHs concentrations in apoplast and symplast, and the treating time and concentrations were positively correlated with PAHs accumulations. The time-dependent kinetics for 36 h followed the Elovich equation, and the concentration-dependent kinetics of apoplastic and symplastic uptake for 4 h could be described with the Freundlich and Michaelis-Menten equations, respectively. The proportion of PAHs accumulated in apoplast could be enhanced by auxins in most treatments. Our findings offer novel insights into the mechanisms of PAH uptake by plant roots under auxin exposure. Additionally, this research aids in refining strategies for ensuring crop safety and improving phytoremediation of PAH-contaminated soil and water.
PMID: 38097155
Sci Total Environ , IF:7.963 , 2024 Feb , V910 : P168522 doi: 10.1016/j.scitotenv.2023.168522
Intergenerational consequences of an auxin-like herbicide on plant sensitivity to a graminicide mediated by a fungal endophyte.
Instituto de Investigacion Interdisciplinaria (I(3)), Universidad de Talca, Talca, Chile; Centro de Ecologia Integrativa, Instituto de Ciencias Biologicas, Universidad de Talca, Talca, Chile. Electronic address: aueno@agro.uba.ar.; IFEVA, CONICET, Facultad de Agronomia, Universidad de Buenos Aires, Buenos Aires, Argentina.; IFEVA, CONICET, Facultad de Agronomia, Universidad de Buenos Aires, Buenos Aires, Argentina; Centro de Ecologia Integrativa, Instituto de Ciencias Biologicas, Universidad de Talca, Talca, Chile.
In agroecosystems, herbicides are the predominant anthropogenic selection pressure for agriculture weed species. While weeds are the primary target, herbicides can have adverse impacts on non-target plant beneficial microorganisms. We aimed to investigate the influence of a foliar endophytic fungus (Epichloe occultans) on the sensitivity of Lolium multiflorum to a graminicide herbicide (diclofop-methyl) during both plant ontogeny and progeny. Susceptible individuals to diclofop-methyl with and without endophyte were pre-exposed to the auxin 2,4-D herbicide. This herbicide is known to stimulate the metabolic detoxification mechanism (CYP-450) of diclofop-methyl. Regardless of the endophyte, 2,4-D pre-treatment increased mother plant survival to nearly 100 % under diclofop treatment but not in the progeny. Furthermore, maternal plant exposure to 2,4-D reduced endophyte transmission to the seeds and from seed-to-seedlings. Our findings suggest that, despite a reduction in diclofop-methyl sensitivity during the ontogeny of mother plants, 2,4-D-mediated induction of likely CYP-450 metabolism is not intergenerationally transmitted and shows detrimental effects on the symbiotic endophyte persistence.
PMID: 37956837
Sci Total Environ , IF:7.963 , 2023 Dec , V904 : P166878 doi: 10.1016/j.scitotenv.2023.166878
Enhancing sustainability through microalgae cultivation in urban wastewater for biostimulant production and nutrient recovery.
GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain.; GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: enrica.uggetti@upc.edu.
Microalgae can produce biostimulants in form of phytohormones, which are compounds that, even if applied in low concentrations, can have stimulant effects on plants growth and can enhance their quality and their resistance to stress. Considering that microalgal biomass can grow recovering nutrients from wastewater, this circular approach allows to use residues for the production of high added value compounds (such as phytohormones) at low cost. The interest on biostimulants production from microalgae have recently raised. Scientists are focused on the direct application of these cellular extracts on plants, while the number of studies on the identification of bioactive molecules, such as phytohormones, is very scarce. Two cyanobacteria strains (Synechocystis sp. (SY) and Phormidium sp. (PH)) and a chlorophyte (Scenedesmus sp. (SC)) were cultured in laboratory-scale PBRs with a working volume of 2.5 L in secondary urban wastewater varying N:P ratio in the cultures to obtain the highest productivity. The variation of N:P ratio affects microalgae growth, and SY and PH presented higher productivities (73 and 48 mg L(-1) d, respectively) under higher N:P ratio (> 22:1). Microalgal biomass was freeze-dried and phytohormones content was measured with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The three microalgae showed similar phytohormones profiles, being the auxin (indole-3-acetic acid, IAA) the most abundant (72 ng g(-1)(DW) in SY). Proteins were major macronutrient for all strains, reaching 48 %(DW) in PH culture. To optimize the biostimulants production, a balance between the production of such compounds, biomass productivity and nutrients removal should be taken into consideration. In this sense, SC was the most promising strain, showing the highest N and P removal rates (73 % and 59 %, respectively) while producing phytohormones.
PMID: 37678521
Sci Total Environ , IF:7.963 , 2023 Dec , V904 : P166644 doi: 10.1016/j.scitotenv.2023.166644
Auxin is involved in cadmium accumulation in rice through controlling nitric oxide production and the ability of cell walls to bind cadmium.
State Key Laboratory 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.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Advanced Agricultural Sciences, Zhejiang A & F University, Hangzhou 311300, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory 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. Electronic address: xiaofangzhu@issas.ac.cn.
Although auxin has been linked to plants' responses to cadmium (Cd) stress, the exact mechanism is yet elusive. The objective of the current investigation was to determine the role and the mechanism of auxin in controlling rice's Cd accumulation. Rice roots with Cd stress have higher endogenous auxin levels, and exogenous auxin combined Cd treatment could reduce root cell wall's hemicellulose content when compared with Cd treatment alone, which in turn reduced its fixation of Cd, as well as decreased the expression of OsCd1 (a major facilitator superfamily gene), OsNRAMP1/5 (Natural Resistance-Associated Macrophage Protein 1/5), OsZIP5/9 (Zinc Transporter 5/9), and OsHMA2 (Heavy Metal ATPase 2) that participated in Cd uptake and root to shoot translocation. Furthermore, less Cd accumulated in the shoots as a result of auxin's impact in increasing the expression of OsCAL1 (Cadmium accumulation in Leaf 1), OsABCG36/OsPDR9 (G-type ATP-binding cassette transporter/Pleiotropic drug resistance 9), and OsHMA3, which were in charge of Cd efflux and sequestering into vacuoles, respectively. Additionally, auxin decreased endogenous nitric oxide (NO) levels and antioxidant enzyme activity, while treatment of a NO scavenger-cPTIO-reduced auxin's alleviatory effects. In conclusion, the rice's ability to tolerate Cd toxicity was likely increased by the auxin-accelerated cell wall Cd exclusion mechanism, a pathway that controlled by the buildup of NO.
PMID: 37659569
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102480 doi: 10.1016/j.pbi.2023.102480
Unlocking nature's (sub)cellular symphony: Phase separation in plant meristems.
Institute for Developmental Genetics, Heinrich-Heine University Duesseldorf, Germany.; Institute for Developmental Genetics, Heinrich-Heine University Duesseldorf, Germany; Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine University Duesseldorf, Germany. Electronic address: Yvonne.Stahl@hhu.de.
Plant development is based on the balance of stem cell maintenance and differentiation in the shoot and root meristems. The necessary cell fate decisions are regulated by intricate networks of proteins and biomolecules within plant cells and require robust and dynamic compartmentalization strategies, including liquid-liquid phase separation (LLPS), which allows the formation of membrane-less compartments. This review summarizes the current knowledge about the emerging field of LLPS in plant development, with a particular focus on the shoot and root meristems. LLPS regulates not only floral transition and flowering time while integrating environmental signals in the shoots but also influences auxin signalling and is putatively involved in maintaining the stem cell niche (SCN) in the roots. Therefore, LLPS has the potential to play a crucial role in the plasticity of plant development, necessitating further research for a comprehensive understanding.
PMID: 37862837
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102479 doi: 10.1016/j.pbi.2023.102479
Tunable recurrent priming of lateral roots in Arabidopsis: More than just a clock?
Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.; Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany. Electronic address: alexis.maizel@cos.uni-heidelberg.de.
Lateral root (LR) formation in Arabidopsis is a continuous, repetitive, post-embryonic process regulated by a series of coordinated events and tuned by the environment. It shapes the root system, enabling plants to efficiently explore soil resources and adapt to changing environmental conditions. Although the auxin-regulated modules responsible for LR morphogenesis and emergence are well documented, less is known about the initial priming. Priming is characterised by recurring peaks of auxin signalling, which, once memorised, earmark cells to form the new LR. We review the recent experimental and modelling approaches to understand the molecular processes underlying the recurring LR formation. We argue that the intermittent priming of LR results from interweaving the pattern of auxin flow and root growth together with an oscillatory auxin-modulated transcriptional mechanism and illustrate its long-range sugar-mediated tuning by light.
PMID: 37857036
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102473 doi: 10.1016/j.pbi.2023.102473
Developing for nutrient uptake: Induced organogenesis in parasitic plants and root nodule symbiosis.
Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.; Nara Institute of Science and Technology, Graduate School of Science and Technology, Ikoma, Nara, Japan.; Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan; Tsukuba Plant-Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan. Electronic address: suzaki.takuya.fn@u.tsukuba.ac.jp.; Nara Institute of Science and Technology, Graduate School of Science and Technology, Ikoma, Nara, Japan. Electronic address: satokoy@bs.naist.jp.
Plants have evolved diverse strategies to meet their nutritional needs. Parasitic plants employ haustoria, specialized structures that facilitate invasion of host plants and nutrient acquisition. Legumes have adapted to nitrogen-limited conditions by developing nodules that accommodate nitrogen-fixing rhizobia. The formation of both haustoria and nodules is induced by signals originating from the interacting organisms, namely host plants and rhizobial bacteria, respectively. Emerging studies showed that both organogenesis crucially involves plant hormones such as auxin, cytokinins, and ethylene and also integrate nutrient availability, particularly nitrogen. In this review, we discuss recent advances on hormonal and environmental control of haustoria and nodules development with side-by-side comparison. These underscore the remarkable plasticity of plant organogenesis.
PMID: 37826989
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102460 doi: 10.1016/j.pbi.2023.102460
Pick a side: Integrating gene expression and mechanical forces to polarize aerial organs.
Department of Biology, University of Pennsylvania, Philadelphia PA 19104, USA.; Department of Biology, University of Pennsylvania, Philadelphia PA 19104, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia PA 19104, USA. Electronic address: ayh@sas.upenn.edu.
How organs acquire their shapes is a central question in developmental biology. In plants, aerial lateral organs such as leaves initiate at the flanks of the growing meristem as dome-shaped primordia. These simple structures then grow out along multiple polarity axes to achieve a dizzying array of final shapes. Many of the hormone signaling pathways and genetic interactions that influence growth along these axes have been identified in the past few decades. Open questions include how and when initial gene expression patterns are set in organ primordia, and how these patterns are translated into the physical outcomes observed at the cellular and tissue levels. In this review, we highlight recent studies into the auxin signaling and gene expression dynamics that govern adaxial-abaxial patterning, and the contributions of mechanical forces to the development of flattened structures.
PMID: 37775406
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102461 doi: 10.1016/j.pbi.2023.102461
Connecting emerging with existing vasculature above and below ground.
Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland. Electronic address: noel.blancotourinan@unil.ch.; Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland. Electronic address: christian.hardtke@unil.ch.
The vascular system was essential for plants to colonize land by facilitating the transport of water, nutrients, and minerals throughout the body. Our current knowledge on the molecular-genetic control of vascular tissue specification and differentiation is mostly based on studies in the Arabidopsis primary root. To what degree these regulatory mechanisms in the root meristem can be extrapolated to vascular tissue development in other organs is a question of great interest. In this review, we discuss the most recent progress on cotyledon vein formation, with a focus on polar auxin transport-dependent and -independent mechanisms. We also provide an overview of vasculature formation in postembryonic organs, namely lateral roots, which is more complex than anticipated as several tissues of the parent root must act in a spatio-temporally coordinated manner.
PMID: 37774454
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102451 doi: 10.1016/j.pbi.2023.102451
Hormonal regulation of inflorescence and intercalary meristems in grasses.
Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.; Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA. Electronic address: mcsteenp@missouri.edu.
Hormones played a fundamental role in improvement of yield in cereal grasses. Natural variants affecting gibberellic acid (GA) and auxin pathways were used to breed semi-dwarf varieties of rice, wheat, and sorghum, during the "Green Revolution" in the 20th century. Since then, variants with altered GA and cytokinin homeostasis have been used to breed cereals with increased grain number. These yield improvements were enabled by hormonal regulation of intercalary and inflorescence meristems. Recent advances have highlighted additional pathways, beyond the traditional CLAVATA-WUSCHEL pathway, in the regulation of auxin and cytokinin in inflorescence meristems, and have expanded our understanding of the role of GA in intercalary meristems.
PMID: 37739867
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102445 doi: 10.1016/j.pbi.2023.102445
Regulation of PIN polarity in response to abiotic stress.
Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden. Electronic address: petra.marhava@slu.se.
Plants have evolved robust adaptive mechanisms to withstand the ever-changing environment. Tightly regulated distribution of the hormone auxin throughout the plant body controls an impressive variety of developmental processes that tailor plant growth and morphology to environmental conditions. The proper flow and directionality of auxin between cells is mainly governed by asymmetrically localized efflux carriers - PINs - ensuring proper coordination of developmental processes in plants. Discerning the molecular players and cellular dynamics involved in the establishment and maintenance of PINs in specific membrane domains, as well as their ability to readjust in response to abiotic stressors is essential for understanding how plants balance adaptability and stability. While much is known about how PINs get polarized, there is still limited knowledge about how abiotic stresses alter PIN polarity by acting on these systems. In this review, we focus on the current understanding of mechanisms involved in (re)establishing and maintaining PIN polarity under abiotic stresses.
PMID: 37714753
Curr Opin Plant Biol , IF:7.834 , 2023 Dec , V76 : P102452 doi: 10.1016/j.pbi.2023.102452
Illuminating the path to shoot meristem regeneration: Molecular insights into reprogramming cells into stem cells.
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan. Electronic address: yetkincaka.ince@riken.jp.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045 Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033 Japan. Electronic address: keiko.sugimoto@riken.jp.
Plant cells possess the ability to dedifferentiate and reprogram into stem cell-like populations, enabling the regeneration of new organs. However, the maintenance of stem cells relies on specialized microenvironments composed of distinct cell populations with specific functions. Consequently, the regeneration process necessitates the orchestrated regulation of multiple pathways across diverse cellular populations. One crucial pathway involves the transcription factor WUSCHEL HOMEOBOX 5 (WOX5), which plays a pivotal role in reprogramming cells into stem cells and promoting their conversion into shoot meristems through WUSCHEL (WUS). Additionally, cell and tissue mechanics, including cell wall modifications and mechanical stress, critically contribute to de novo shoot organogenesis by regulating polar auxin transport. Furthermore, light signaling emerges as a key regulator of plant regeneration, directly influencing expression of meristem genes and potentially influencing aforementioned pathways as well.
PMID: 37709567
Plant Cell Environ , IF:7.228 , 2024 Jan , V47 (1) : P197-212 doi: 10.1111/pce.14727
Ultraviolet-A1 radiation induced a more favorable light-intercepting leaf-area display than blue light and promoted plant growth.
Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China.; Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.; Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Plants adjust their morphology in response to light environment by sensing an array of light cues. Though the wavelengths of ultraviolet-A1 radiation (UV-A1, 350-400 nm) are close to blue light (B, 400-500 nm) and share same flavoprotein photoreceptors, it remains poorly understood how plant responses to UV-A1 radiation could differ from those to B. We initially grown tomato plants under monochromatic red light (R, 660 nm) as control, subsequently transferred them to four dichromatic light treatments containing ~20 micromol m(-2) s(-1) of UV-A1 radiation, peaking at 370 nm (UV-A(370) ) or 400 nm (V(400) ), or B (450 nm, at ~20 or 1.5 micromol m(-2) s(-1) ), with same total photon irradiance (~200 mumol m(-2) s(-1) ). We show that UV-A(370) radiation was the most effective in inducing light-intercepting leaf-area display formation, resulting in larger leaf area and more shoot biomass, while it triggered weaker and later transcriptome-wide responses than B. Mechanistically, UV-A(370) -promoted leaf-area display response was apparent in less than 12 h and appeared as very weakly related to transcriptome level regulation, which likely depended on the auxin transportation and cell wall acidification. This study revealed wavelength-specific responses within UV-A/blue region challenging usual assumptions that the role of UV-A1 radiation function similarly as blue light in mediating plant processes.
PMID: 37743709
Plant Cell Environ , IF:7.228 , 2023 Dec , V46 (12) : P3902-3918 doi: 10.1111/pce.14709
E3 ubiquitin ligases SINA4 and SINA11 regulate anthocyanin biosynthesis by targeting the IAA29-ARF5-1-ERF3 module in apple.
Apple Technology Innovation Center of Shandong Province, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, China.; CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan, China.
Auxin/indole-3-acetic acid (AUX/IAA) and auxin response factor (ARF) proteins are important components of the auxin signalling pathway, but their ubiquitination modification and the mechanism of auxin-mediated anthocyanin biosynthesis remain elusive. Here, the ARF MdARF5-1 was identified as a negative regulator of anthocyanin biosynthesis in apple, and it integrates auxin and ethylene signals by inhibiting the expression of the ethylene response factor MdERF3. The auxin repressor MdIAA29 decreased the inhibitory effect of MdARF5-1 on anthocyanin biosynthesis by attenuating the transcriptional inhibition of MdERF3 by MdARF5-1. In addition, the E3 ubiquitin ligases MdSINA4 and MdSINA11 played negative and positive regulatory roles in anthocyanin biosynthesis by targeting MdIAA29 and MdARF5-1 for ubiquitination degradation, respectively. MdSINA4 destabilized MdSINA11 to regulate anthocyanin accumulation in response to auxin signalling. In sum, our data revealed the crosstalk between auxin and ethylene signals mediated by the IAA29-ARF5-1-ERF3 module and provide new insights into the ubiquitination modification of the auxin signalling pathway.
PMID: 37658649
Plant Cell Environ , IF:7.228 , 2023 Dec , V46 (12) : P3822-3838 doi: 10.1111/pce.14702
Heat-dependent postpollination limitations on maize pollen tube growth and kernel sterility.
College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.; Department of Agronomy, Kansas State University, Manhattan, Kansas, USA.; College of Agriculture, South China Agricultural University, Guangzhou, China.; Division of Biochemistry, Indian Agricultural Research Institute, Pusa, New Delhi, India.; Institute of Maize and Featured Upland Crops, Zhejiang Academy of Agricultural Sciences, Dongyang, China.; Department of Plant and Soil Science, Texas Tech University, Lubbock, Texas, USA.
Heat stress has a negative impact on pollen development in maize (Zea mays L.) but the postpollination events that determine kernel sterility are less well characterised. The impact of short-term (hours) heat exposure during postpollination was therefore assessed in silks and ovaries. The temperatures inside the kernels housed within the husks was significantly lower than the imposed heat stress. This protected the ovaries and possibly the later phase of pollen tube growth from the adverse effects of heat stress. Failure of maize kernel fertilization was observed within 6 h of heat stress exposure postpollination. This was accompanied by a significant restriction of early pollen tube growth rather than pollen germination. Limitations on early pollen tube growth were therefore a major factor contributing to heat stress-induced kernel sterility. Exposure to heat stress altered the sugar composition of silks, suggesting that hexose supply contributed to the limitations on pollen tube growth. Moreover, the activities of sucrose metabolising enzymes, the expression of sucrose degradation and trehalose biosynthesis genes were decreased following heat stress. Significant increases in reactive oxygen species, abscisic acid and auxin levels accompanied by altered expression of phytohormone-related genes may also be important in the heat-induced suppression of pollen tube growth.
PMID: 37623372
J Integr Plant Biol , IF:7.061 , 2023 Dec doi: 10.1111/jipb.13591
Gibberellin promotes cambium reestablishment during secondary vascular tissue regeneration after girdling in an auxin-dependent manner in Populus.
State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871.
Secondary vascular tissue (SVT) development and regeneration are regulated by phytohormones. In this study, we used an in vitro SVT regeneration system to demonstrate that gibberellin (GA) treatment significantly promotes auxin-induced cambium reestablishment. Altering GA content by overexpressing or knocking down ent-kaurene synthase (KS) affected secondary growth and SVT regeneration in poplar. The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE (PtoGAI) is expressed in a specific pattern during secondary growth and cambium regeneration after girdling. Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration, and the inhibition of cambium regeneration could be partially restored by GA application. Further analysis of the PtaDR5:GUS transgenic plants, the localization of PIN-FORMED 1 (PIN1) and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of PIN1, which mediates auxin transport during SVT regeneration. Taken together, these findings suggest that GA promotes cambium regeneration by stimulating auxin signal transduction. This article is protected by copyright. All rights reserved.
PMID: 38051026
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6889-6892 doi: 10.1093/jxb/erad420
Auxin research: creating tools for a greener future.
Italian Space Agency, Rome, Italy.; Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.; Department of Biology, Duke University, Durham, NC, USA.; School of Biology, University of Leeds, Leeds, UK.
PMID: 38038239
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P13-16 doi: 10.1093/jxb/erad394
How do brassinosteroids fit in bud outgrowth models?
Waite Research Institute, School of Agriculture Food & Wine, The University of Adelaide, Adelaide, SA 5064, Australia.; Australian Research Council Training Centre for Future Crops Development, The University of Adelaide, Adelaide, SA 5064, Australia.; Australian Research Council Centre of Excellence for Plant Success in Nature and Agriculture, The University of Queensland, Brisbane, QLD 4072, Australia.
A network of plant hormonal signals coordinates plant branching. Brassinosteroids are important in this network, acting as repressors of the strigolactone pathway and TEOSINTE BRANCHED1 .
PMID: 37846132
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P241-257 doi: 10.1093/jxb/erad402
Arabidopsis transcription factor TCP13 promotes shade avoidance syndrome-like responses by directly targeting a subset of shade-responsive gene promoters.
Department of Biological Science, Sookmyung Women's University, Seoul 04310, Korea.; Department of Biological Sciences, KAIST, Daejeon 34141, Korea.; Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 17104, Korea.; Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan.
TCP13 belongs to a subgroup of TCP transcription factors implicated in the shade avoidance syndrome (SAS), but its exact role remains unclear. Here, we show that TCP13 promotes the SAS-like response by enhancing hypocotyl elongation and suppressing flavonoid biosynthesis as a part of the incoherent feed-forward loop in light signaling. Shade is known to promote the SAS by activating PHYTOCHROME-INTERACTING FACTOR (PIF)-auxin signaling in plants, but we found no evidence in a transcriptome analysis that TCP13 activates PIF-auxin signaling. Instead, TCP13 mimics shade by activating the expression of a subset of shade-inducible and cell elongation-promoting SAUR genes including SAUR19, by direct targeting of their promoters. We also found that TCP13 and PIF4, a molecular proxy for shade, repress the expression of flavonoid biosynthetic genes by directly targeting both shared and distinct sets of biosynthetic gene promoters. Together, our results indicate that TCP13 promotes the SAS-like response by directly targeting a subset of shade-responsive genes without activating the PIF-auxin signaling pathway.
PMID: 37824096
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P219-240 doi: 10.1093/jxb/erad391
Flavonols affect the interrelated glucosinolate and camalexin biosynthetic pathways in Arabidopsis thaliana.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.; Faculty of Biology, Genetics and Genomics of Plants, Bielefeld University, 33615 Bielefeld, Germany.; Plant Sciences and Agrotechnology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
Flavonols are structurally and functionally diverse biomolecules involved in plant biotic and abiotic stress tolerance, pollen development, and inhibition of auxin transport. However, their effects on global gene expression and signaling pathways are unclear. To explore the roles of flavonol metabolites in signaling, we performed comparative transcriptome and targeted metabolite profiling of seedlings from the flavonol-deficient Arabidopsis loss-of-function mutant flavonol synthase1 (fls1) with and without exogenous supplementation of flavonol derivatives (kaempferol, quercetin, and rutin). RNA-seq results indicated that flavonols modulate various biological and metabolic pathways, with significant alterations in camalexin and aliphatic glucosinolate synthesis. Flavonols negatively regulated camalexin biosynthesis but appeared to promote the accumulation of aliphatic glucosinolates via transcription factor-mediated up-regulation of biosynthesis genes. Interestingly, upstream amino acid biosynthesis genes involved in methionine and tryptophan synthesis were altered under flavonol deficiency and exogenous supplementation. Quercetin treatment significantly up-regulated aliphatic glucosinolate biosynthesis genes compared with kaempferol and rutin. In addition, expression and metabolite analysis of the transparent testa7 mutant, which lacks hydroxylated flavonol derivatives, clarified the role of quercetin in the glucosinolate biosynthesis pathway. This study elucidates the molecular mechanisms by which flavonols interfere with signaling pathways, their molecular targets, and the multiple biological activities of flavonols in plants.
PMID: 37813680
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P454-467 doi: 10.1093/jxb/erad377
Plasmodiophora brassicae affects host gene expression by secreting the transcription factor-type effector PbZFE1.
Graduate School of Agricultural Science, Tohoku University, 468-1 Aramakiaza-Aoba, Aoba-ku, Sendai, Miyagi 980-8572, Japan.; Division of Plant Sciences, The Institute of Agrobiological Sciences, NARO (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan.; Department of Food and Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.; Strategic Planning Headquarters, National Agriculture and Food Research Organization (NARO), 3-1-1 Kan-nondai, Tsukuba, Ibaraki 305-8517, Japan.
The protist pathogen Plasmodiophora brassicae hijacks the metabolism and development of host cruciferous plants and induces clubroot formation, but little is known about its regulatory mechanisms. Previously, the Pnit2int2 sequence, a sequence around the second intron of the nitrilase gene (BrNIT2) involved in auxin biosynthesis in Brassica rapa ssp. pekinensis, was identified as a specific promoter activated during clubroot formation. In this study, we hypothesized that analysis of the transcriptional regulation of Pnit2int2 could reveal how P. brassicae affects the host gene regulatory system during clubroot development. By yeast one-hybrid screening, the pathogen zinc finger protein PbZFE1 was identified to specifically bind to Pnit2int2. Specific binding of PbZFE1 to Pnit2int2 was also confirmed by electrophoretic mobility shift assay. The binding site of PbZFE1 is essential for promoter activity of Pnit2int2 in clubbed roots of transgenic Arabidopsis thaliana (Pnit2int2-2::GUS), indicating that PbZFE1 is secreted from P. brassicae and functions within plant cells. Ectopic expression of PbZEF1 in A. thaliana delayed growth and flowering time, suggesting that PbZFE1 has significant impacts on host development and metabolic systems. Thus, P. brassicae appears to secrete PbZFE1 into host cells as a transcription factor-type effector during pathogenesis.
PMID: 37738570
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P103-122 doi: 10.1093/jxb/erad372
The maize transcription factor CCT regulates drought tolerance by interacting with Fra a 1, E3 ligase WIPF2, and auxin response factor Aux/IAA8.
Beijing Key Laboratory of New Technology in Agricultural Application, National Demonstration Center for Experimental Plant Production Education, College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China.; Agricultural College, Inner Mongolia Agricultural University, Hohhot, China.; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Plants are commonly exposed to abiotic stressors, which can affect their growth, productivity, and quality. Previously, the maize transcription factor ZmCCT was shown to be involved in the photoperiod response, delayed flowering, and quantitative resistance to Gibberella stalk rot. In this study, we demonstrate that ZmCCT can regulate plant responses to drought. ZmCCT physically interacted with ZmFra a 1, ZmWIPF2, and ZmAux/IAA8, which localized to the cell membrane, cytoplasm, and nucleus, respectively, both in vitro and in vivo in a yeast two-hybrid screen in response to abiotic stress. Notably, ZmCCT recruits ZmWIPF2 to the nucleus, which has strong E3 self-ubiquitination activity dependent on its RING-H2 finger domain in vitro. When treated with higher indole-3-acetic acid/abscisic acid ratios, the height and root length of Y331-DeltaTE maize plants increased. Y331-DeltaTE plants exhibited increased responses to exogenously applied auxin or ABA compared to Y331 plants, indicating that ZmCCT may be a negative regulator of ABA signalling in maize. In vivo, ZmCCT promoted indole-3-acetic acid biosynthesis in ZmCCT-overexpressing Arabidopsis. RNA-sequencing and DNA affinity purification-sequencing analyses showed that ZmCCT can regulate the expression of ZmRD17, ZmAFP3, ZmPP2C, and ZmARR16 under drought. Our findings provide a detailed overview of the molecular mechanism controlling ZmCCT functions and highlight that ZmCCT has multiple roles in promoting abiotic stress tolerance.
PMID: 37725963
J Exp Bot , IF:6.992 , 2024 Jan , V75 (1) : P438-453 doi: 10.1093/jxb/erad366
IAR4 mutation enhances cadmium toxicity by disturbing auxin homeostasis in Arabidopsis thaliana.
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.; School of Molecular Science and ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, Crawley, Western Australia 6009, Australia.
Cadmium (Cd) is highly toxic to plants, but the targets and modes of toxicity remain unclear. We isolated a Cd-hypersensitive mutant of Arabidopsis thaliana, Cd-induced short root 2 (cdsr2), in the background of the phytochelatin synthase-defective mutant cad1-3. Both cdsr2 and cdsr2 cad1-3 displayed shorter roots and were more sensitive to Cd than their respective wild type. Using genomic resequencing and complementation, IAR4 was identified as the causal gene, which encodes a putative mitochondrial pyruvate dehydrogenase E1alpha subunit. cdsr2 showed decreased pyruvate dehydrogenase activity and NADH content, but markedly increased concentrations of pyruvate and alanine in roots. Both Cd stress and IAR4 mutation decreased auxin level in the root tips, and the effect was additive. A higher growth temperature rescued the phenotypes in cdsr2. Exogenous alanine inhibited root growth and decreased auxin level in the wild type. Cadmium stress suppressed the expression of genes involved in auxin biosynthesis, hydrolysis of auxin-conjugates and auxin polar transport. Our results suggest that auxin homeostasis is a key target of Cd toxicity, which is aggravated by IAR4 mutation due to decreased pyruvate dehydrogenase activity. Decreased auxin level in cdsr2 is likely caused by increased auxin-alanine conjugation and decreased energy status in roots.
PMID: 37721748
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6950-6963 doi: 10.1093/jxb/erad340
What a tangled web it weaves: auxin coordination of stem cell maintenance and flower production.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Robust agricultural yields require consistent flower production throughout fluctuating environmental conditions. Floral primordia are produced in the inflorescence meristem, which contains a pool of continuously dividing stem cells. Daughter cells of these divisions either retain stem cell identity or are pushed to the SAM periphery, where they become competent to develop into floral primordia after receiving the appropriate signal. Thus, flower production is inherently linked to regulation of the stem cell pool. The plant hormone auxin promotes flower development throughout its early phases and has been shown to interact with the molecular pathways regulating stem cell maintenance. Here, we will summarize how auxin signaling contributes to stem cell maintenance and promotes flower development through the early phases of initiation, outgrowth, and floral fate establishment. Recent advances in this area suggest that auxin may serve as a signal that integrates stem cell maintenance and new flower production.
PMID: 37661937
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P7000-7014 doi: 10.1093/jxb/erad325
Auxin and abiotic stress responses.
Department of Biology, Duke University, Durham, NC 27008, USA.
Plants are exposed to a variety of abiotic stresses; these stresses have profound effects on plant growth, survival, and productivity. Tolerance and adaptation to stress require sophisticated stress sensing, signaling, and various regulatory mechanisms. The plant hormone auxin is a key regulator of plant growth and development, playing pivotal roles in the integration of abiotic stress signals and control of downstream stress responses. In this review, we summarize and discuss recent advances in understanding the intersection of auxin and abiotic stress in plants, with a focus on temperature, salt, and drought stresses. We also explore the roles of auxin in stress tolerance and opportunities arising for agricultural applications.
PMID: 37591508
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6989-6999 doi: 10.1093/jxb/erad297
Roles of auxin pathways in maize biology.
Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011, USA.
Phytohormones play a central role in plant development and environmental responses. Auxin is a classical hormone that is required for organ formation, tissue patterning, and defense responses. Auxin pathways have been extensively studied across numerous land plant lineages, including bryophytes and eudicots. In contrast, our understanding of the roles of auxin in maize morphogenesis and immune responses is limited. Here, we review evidence for auxin-mediated processes in maize and describe promising areas for future research in the auxin field. Several recent transcriptomic and genetic studies have demonstrated that auxin is a key influencer of both vegetative and reproductive development in maize (namely roots, leaves, and kernels). Auxin signaling has been implicated in both maize shoot architecture and immune responses through genetic and molecular analyses of the conserved co-repressor RAMOSA ENHANCER LOCUS2. Polar auxin transport is linked to maize drought responses, root growth, shoot formation, and leaf morphogenesis. Notably, maize has been a key system for delineating auxin biosynthetic pathways and offers many opportunities for future investigations on auxin metabolism. In addition, crosstalk between auxin and other phytohormones has been uncovered through gene expression studies and is important for leaf and root development in maize. Collectively these studies point to auxin as a cornerstone for maize biology that could be leveraged for improved crop resilience and yield.
PMID: 37493143
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P7034-7044 doi: 10.1093/jxb/erad284
A roadmap of haustorium morphogenesis in parasitic plants.
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.
Parasitic plants invade their host through their invasive organ, the haustorium. This organ connects to the vasculature of the host roots and hijacks water and nutrients. Although parasitism has evolved independently in plants, haustoria formation follows a similar mechanism throughout different plant species, highlighting the developmental plasticity of plant tissues. Here, we compare three types of haustoria formed by the root and shoot in the plant parasites Striga and Cuscuta. We discuss mechanisms underlying the interactions with their hosts and how different approaches have contributed to major understanding of haustoria formation and host invasion. We also illustrate the role of auxin and cytokinin in controlling this process.
PMID: 37486862
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6975-6988 doi: 10.1093/jxb/erad288
Auxins and grass shoot architecture: how the most important hormone makes the most important plants.
School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
Cereals are a group of grasses cultivated by humans for their grain. It is from these cereal grains that the majority of all calories consumed by humans are derived. The production of these grains is the result of the development of a series of hierarchical reproductive structures that form the distinct shoot architecture of the grasses. Being spatiotemporally complex, the coordination of grass shoot development is tightly controlled by a network of genes and signals, including the key phytohormone auxin. Hormonal manipulation has therefore been identified as a promising potential approach to increasing cereal crop yields and therefore ultimately global food security. Recent work translating the substantial body of auxin research from model plants into cereal crop species is revealing the contribution of auxin biosynthesis, transport, and signalling to the development of grass shoot architecture. This review discusses this still-maturing knowledge base and examines the possibility that changes in auxin biology could have been a causative agent in the evolution of differences in shoot architecture between key grass species, or could underpin the future selective breeding of cereal crops.
PMID: 37474124
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6904-6921 doi: 10.1093/jxb/erad272
Game of thrones among AUXIN RESPONSE FACTORs-over 30 years of MONOPTEROS research.
Mendel Centre for Genomics and Proteomics of Plants Systems, CEITEC MU - Central European Institute of Technology, Masaryk University, Brno, Czech Republic.; Institute of Biology, Biotechnology, and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice, Poland.; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic.
For many years, research has been carried out with the aim of understanding the mechanism of auxin action, its biosynthesis, catabolism, perception, and transport. One central interest is the auxin-dependent gene expression regulation mechanism involving AUXIN RESPONSE FACTOR (ARF) transcription factors and their repressors, the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins. Numerous studies have been focused on MONOPTEROS (MP)/ARF5, an activator of auxin-dependent gene expression with a crucial impact on plant development. This review summarizes over 30 years of research on MP/ARF5. We indicate the available analytical tools to study MP/ARF5 and point out the known mechanism of MP/ARF5-dependent regulation of gene expression during various developmental processes, namely embryogenesis, leaf formation, vascularization, and shoot and root meristem formation. However, many questions remain about the auxin dose-dependent regulation of gene transcription by MP/ARF5 and its isoforms in plant cells, the composition of the MP/ARF5 protein complex, and, finally, all the genes under its direct control. In addition, information on post-translational modifications of MP/ARF5 protein is marginal, and knowledge about their consequences on MP/ARF5 function is limited. Moreover, the epigenetic factors and other regulators that act upstream of MP/ARF5 are poorly understood. Their identification will be a challenge in the coming years.
PMID: 37450945
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6922-6932 doi: 10.1093/jxb/erad259
To bind or not to bind: how AUXIN RESPONSE FACTORs select their target genes.
Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands.
Most plant growth and development processes are regulated in one way or another by auxin. The best-studied mechanism by which auxin exerts its regulatory effects is through the nuclear auxin pathway (NAP). In this pathway, Auxin Response Factors (ARFs) are the transcription factors that ultimately determine which genes become auxin regulated by binding to specific DNA sequences. ARFs have primarily been studied in Arabidopsis thaliana, but recent studies in other species have revealed family-wide DNA binding specificities for different ARFs and the minimal functional system of the NAP system, consisting of a duo of competing ARFs of the A and B classes. In this review, we provide an overview of key aspects of ARF DNA binding such as auxin response elements (TGTCNN) and tandem repeat motifs, and consider how structural biology and in vitro studies help us understand ARF DNA preferences. We also highlight some recent aspects related to the regulation of ARF levels inside a cell, which may alter the DNA binding profile of ARFs in different tissues. We finally emphasize the need to study minimal NAP systems to understand fundamental aspects of ARF function, the need to characterize algal ARFs to understand how ARFs evolved, how cutting-edge techniques can increase our understanding of ARFs, and which remaining questions can only be answered by structural biology.
PMID: 37431145
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P7015-7033 doi: 10.1093/jxb/erad265
Temperature regulation of auxin-related gene expression and its implications for plant growth.
Fundacion Instituto Leloir and IIBBA-CONICET, Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.; Universidad de Buenos Aires, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisiologicas y Ecologicas Vinculadas a la Agricultura (IFEVA), Facultad de Agronomia, Av. San Martin 4453, Buenos Aires C1417DSE, Argentina.; Instituto de Fisiologia, Biologia Molecular y Neurociencias (IFIBYNE), CONICET-UBA, Buenos Aires C1428EHA, Argentina.
Twenty-five years ago, a seminal paper demonstrated that warm temperatures increase auxin levels to promote hypocotyl growth in Arabidopsis thaliana. Here we highlight recent advances in auxin-mediated thermomorphogenesis and identify unanswered questions. In the warmth, PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF7 bind the YUCCA8 gene promoter and, in concert with histone modifications, enhance its expression to increase auxin synthesis in the cotyledons. Once transported to the hypocotyl, auxin promotes cell elongation. The meta-analysis of expression of auxin-related genes in seedlings exposed to temperatures ranging from cold to hot shows complex patterns of response. Changes in auxin only partially account for these responses. The expression of many SMALL AUXIN UP RNA (SAUR) genes reaches a maximum in the warmth, decreasing towards both temperature extremes in correlation with the rate of hypocotyl growth. Warm temperatures enhance primary root growth, the response requires auxin, and the hormone levels increase in the root tip but the impacts on cell division and cell expansion are not clear. A deeper understanding of auxin-mediated temperature control of plant architecture is necessary to face the challenge of global warming.
PMID: 37422862
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6964-6974 doi: 10.1093/jxb/erad232
Hormonal control of the molecular networks guiding vascular tissue development in the primary root meristem of Arabidopsis.
Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium.; VIB Centre for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.
Vascular tissues serve a dual function in plants, both providing physical support and controlling the transport of nutrients, water, hormones, and other small signaling molecules. Xylem tissues transport water from root to shoot; phloem tissues transfer photosynthates from shoot to root; while divisions of the (pro)cambium increase the number of xylem and phloem cells. Although vascular development constitutes a continuous process from primary growth in the early embryo and meristem regions to secondary growth in the mature plant organs, it can be artificially separated into distinct processes including cell type specification, proliferation, patterning, and differentiation. In this review, we focus on how hormonal signals orchestrate the molecular regulation of vascular development in the Arabidopsis primary root meristem. Although auxin and cytokinin have taken center stage in this aspect since their discovery, other hormones including brassinosteroids, abscisic acid, and jasmonic acid also take leading roles during vascular development. All these hormonal cues synergistically or antagonistically participate in the development of vascular tissues, forming a complex hormonal control network.
PMID: 37343122
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6893-6903 doi: 10.1093/jxb/erad192
Auxin transport at the endoplasmic reticulum: roles and structural similarity of PIN-FORMED and PIN-LIKES.
Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark.; Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany.; Institute of Biology II, 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.
Auxin is a crucial plant hormone that controls a multitude of developmental processes. The directional movement of auxin between cells is largely facilitated by canonical PIN-FORMED proteins in the plasma membrane. In contrast, non-canonical PIN-FORMED proteins and PIN-LIKES proteins appear to reside mainly in the endoplasmic reticulum. Despite recent progress in identifying the roles of the endoplasmic reticulum in cellular auxin responses, the transport dynamics of auxin at the endoplasmic reticulum are not well understood. PIN-LIKES are structurally related to PIN-FORMED proteins, and recently published structures of these transporters have provided new insights into PIN-FORMED proteins and PIN-LIKES function. In this review, we summarize current knowledge on PIN-FORMED proteins and PIN-LIKES in intracellular auxin transport. We discuss the physiological properties of the endoplasmic reticulum and the consequences for transport processes across the ER membrane. Finally, we highlight the emerging role of the endoplasmic reticulum in the dynamics of cellular auxin signalling and its impact on plant development.
PMID: 37279330
J Exp Bot , IF:6.992 , 2023 Dec , V74 (22) : P6933-6949 doi: 10.1093/jxb/erad174
Auxin as an architect of the pectin matrix.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden.; CRRBM, Universite de Picardie Jules Verne, 80000, Amiens, France.
Auxin is a versatile plant growth regulator that triggers multiple signalling pathways at different spatial and temporal resolutions. A plant cell is surrounded by the cell wall, a complex and dynamic network of polysaccharides. The cell wall needs to be rigid to provide mechanical support and protection and highly flexible to allow cell growth and shape acquisition. The modification of the pectin components, among other processes, is a mechanism by which auxin activity alters the mechanical properties of the cell wall. Auxin signalling precisely controls the transcriptional output of several genes encoding pectin remodelling enzymes, their local activity, pectin deposition, and modulation in different developmental contexts. This review examines the mechanism of auxin activity in regulating pectin chemistry at organ, cellular, and subcellular levels across diverse plant species. Moreover, we ask questions that remain to be addressed to fully understand the interplay between auxin and pectin in plant growth and development.
PMID: 37166384
Int J Biol Macromol , IF:6.953 , 2023 Dec , V253 (Pt 4) : P126833 doi: 10.1016/j.ijbiomac.2023.126833
Genome-wide survey, molecular evolution and expression analysis of Auxin Response Factor (ARF) gene family indicating their key role in seed number per pod in pigeonpea (C. cajan L. Millsp.).
ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India. Electronic address: biochemsandhya@gmail.com.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India; ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh 208024, India.; Shoolini Univeristy of Biotechnology and Management Sciences, Himachal Pradesh 173229, India.; ICAR-National Institute for Plant Biotechnology, New Delhi 110012, India. Electronic address: kish2012@gmail.com.
Auxin Response Factors (ARF) are a family of transcription factors that mediate auxin signalling and regulate multiple biological processes. Their crucial role in increasing plant biomass/yield influenced this study, where a systematic analysis of ARF gene family was carried out to identify the key proteins controlling embryo/seed developmental pathways in pigeonpea. A genome-wide scan revealed the presence of 12 ARF genes in pigeonpea, distributed across the chromosomes 1, 3, 4, 8 and 11. Domain analysis of ARF proteins showed the presence of B3 DNA binding, AUX response, and IAA domains. Majority of them are of nuclear origin, and do not exhibit the level of genomic expansion as observed in Glycine max (51 members). The duplication events seem to range from 31.6 to 42.3 million years ago (mya). Promoter analysis revealed the presence of multiple cis-acting elements related to stress responses, hormone signalling and other development processes. The expression atlas data highlighted the expression of CcARF8 in hypocotyl, bud and flower whereas, CcARF7 expression was significantly high in pod. The real-time expression of CcARF2, CcARF3 and CcARF18 was highest in genotypes with high seed number indicating their key role in regulating embryo development and determining seed set in pigeonpea.
PMID: 37709218
Int J Biol Macromol , IF:6.953 , 2023 Dec , V253 (Pt 3) : P126762 doi: 10.1016/j.ijbiomac.2023.126762
CRISPR/Cas9 mutated p-coumaroyl shikimate 3'-hydroxylase 3 gene in Populus tomentosa reveals lignin functioning on supporting tree upright.
Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China.; College of Agriculture, South China Agricultural University, Guangzhou 510642, China.; State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China.; State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China; Department of Biochemistry and Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin, Madison, WI 53726, USA.; College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing 100091, China. Electronic address: qingyin.zeng@ibcas.ac.cn.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou 510642, China. Electronic address: wuaimin@scau.edu.cn.
The lignin plays one of the most important roles in plant secondary metabolism. However, it is still unclear how lignin can contribute to the impressive height of wood growth. In this study, C3'H, a rate-limiting enzyme of the lignin pathway, was used as the target gene. C3'H3 was knocked out by CRISPR/Cas9 in Populus tomentosa. Compared with wild-type popular trees, c3'h3 mutants exhibited dwarf phenotypes, collapsed xylem vessels, weakened phloem thickening, decreased hydraulic conductivity and photosynthetic efficiency, and reduced auxin content, except for reduced total lignin content and significantly increased H-subunit lignin. In the c3'h3 mutant, the flavonoid biosynthesis genes CHS, CHI, F3H, DFR, ANR, and LAR were upregulated, and flavonoid metabolite accumulations were detected, indicating that decreasing the lignin biosynthesis pathway enhanced flavonoid metabolic flux. Furthermore, flavonoid metabolites, such as naringenin and hesperetin, were largely increased, while higher hesperetin content suppressed plant cell division. Thus, studying the c3'h3 mutant allows us to deduce that lignin deficiency suppresses tree growth and leads to the dwarf phenotype due to collapsed xylem and thickened phloem, limiting material exchanges and transport.
PMID: 37683750
Int J Biol Macromol , IF:6.953 , 2023 Dec , V253 (Pt 1) : P126717 doi: 10.1016/j.ijbiomac.2023.126717
Exopolysaccharides from endophytic Glutamicibacter halophytocota KLBMP 5180 functions as bio-stimulants to improve tomato plants growth and salt stress tolerance.
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China.; Jiangsu Runzhong Agricultural Technology Co., Ltd, Xinyi 221424, Jiangsu, PR China.; Xuzhou Kuaibang Biotechnology Development Co., Ltd, Xuzhou, Jiangsu, PR China.; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China. Electronic address: lululiu@jsnu.edu.cn.; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, PR China. Electronic address: shengqin@jsnu.edu.cn.
Microbial exopolysaccharides (EPSs) can promote plants growth and protect them against various abiotic stresses, but the role of actinobacteria-produced EPSs in plant growth promoting is still less known. Here, we aim to explore the effect of EPSs from an endophyte Glutamicibacter halophytocota KLBMP 5180 on tomato seeds germination and seedlings growth under salt stress. Our study revealed that 2.0 g/L EPSs resulted in increased seed germination rate by 23.5 % and 11.0 %, respectively, under 0 and 200 mM NaCl stress conditions. Further pot experiment demonstrated that EPSs significantly promoted seedlings growth under salt stress, with increased height, root length and fibrous roots number. Plant physiological traits revealed that EPSs increased chlorophyll content, enhanced the activity of antioxidant enzymes, soluble sugar, and K(+) concentration in seedlings; malondialdehyde and Na(+) contents were reduced. Additionally, auxin, abscisic acid, jasmonic acid, and salicylic acid were accumulated significantly in seedlings after EPSs treatment. Furthermore, we identified 1233 differentially expressed genes, and they were significantly enriched in phytohormone signal transmission, phenylpropanoid biosynthesis, and protein processing in endogenous reticulum pathways, etc. Our results suggest that KLBMP 5180-produced EPSs effectively ameliorated NaCl stress in tomato plants by triggering complex regulation mechanism, and showed application potentiality in agriculture.
PMID: 37673153
Development , IF:6.868 , 2023 Dec , V150 (23) doi: 10.1242/dev.202014
Local auxin biosynthesis promotes shoot patterning and stem cell differentiation in Arabidopsis shoot apex.
Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Punjab 140306, India.
The shoot apical meristem (SAM) of higher plants comprises distinct functional zones. The central zone (CZ) is located at the meristem summit and harbors pluripotent stem cells. Stem cells undergo cell division within the CZ and give rise to descendants, which enter the peripheral zone (PZ) and become recruited into lateral organs. Stem cell daughters that are pushed underneath the CZ form rib meristem (RM). To unravel the mechanism of meristem development, it is essential to know how stem cells adopt distinct cell fates in the SAM. Here, we show that meristem patterning and floral organ primordia formation, besides auxin transport, are regulated by auxin biosynthesis mediated by two closely related genes of the TRYPTOPHAN AMINOTRANSFERASE family. In Arabidopsis SAM, TAA1 and TAR2 played a role in maintaining auxin responses and the identity of PZ cell types. In the absence of auxin biosynthesis and transport, the expression pattern of the marker genes linked to the patterning of the SAM is perturbed. Our results prove that local auxin biosynthesis, in concert with transport, controls the patterning of the SAM into the CZ, PZ and RM.
PMID: 38054970
Development , IF:6.868 , 2023 Dec , V150 (23) doi: 10.1242/dev.202106
Abscisic acid biosynthesis is necessary for full auxin effects on hypocotyl elongation.
Department of Biology, Washington University, St. Louis, MO 63130, USA.; Center for Biomolecular Condensates, Washington University, St. Louis, MO 63130, USA.; Center for Engineering Mechanobiology, Washington University, St. Louis, MO 63130, USA.; Department of Biology, Duke University, Durham, NC 27708, USA.; Mendel Centre for Genomics and Proteomics of Plant Systems , CEITEC MU - Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic.; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 625 00 Brno, Czechia.; Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada.
In concert with other phytohormones, auxin regulates plant growth and development. However, how auxin and other phytohormones coordinately regulate distinct processes is not fully understood. In this work, we uncover an auxin-abscisic acid (ABA) interaction module in Arabidopsis that is specific to coordinating activities of these hormones in the hypocotyl. From our forward genetics screen, we determine that ABA biosynthesis is required for the full effects of auxin on hypocotyl elongation. Our data also suggest that ABA biosynthesis is not required for the inhibitory effects of auxin treatment on root elongation. Our transcriptome analysis identified distinct auxin-responsive genes in root and shoot tissues, which is consistent with differential regulation of growth in these tissues. Further, our data suggest that many gene targets repressed upon auxin treatment require an intact ABA pathway for full repression. Our results support a model in which auxin stimulates ABA biosynthesis to fully regulate hypocotyl elongation.
PMID: 37846593
Front Cell Dev Biol , IF:6.684 , 2023 , V11 : P1285695 doi: 10.3389/fcell.2023.1285695
The scaffold nucleoporins SAR1 and SAR3 are essential for proper meiotic progression in Arabidopsis thaliana.
Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain.; Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politecnica de Madrid, Madrid, Spain.; GlaxoSmithKline Spain, Madrid, Spain.
Nuclear Pore Complexes (NPCs) are embedded in the nuclear envelope (NE), regulating macromolecule transport and physically interacting with chromatin. The NE undergoes dramatic breakdown and reformation during plant cell division. In addition, this structure has a specific meiotic function, anchoring and positioning telomeres to facilitate the pairing of homologous chromosomes. To elucidate a possible function of the structural components of the NPCs in meiosis, we have characterized several Arabidopsis lines with mutations in genes encoding nucleoporins belonging to the outer ring complex. Plants defective for either SUPPRESSOR OF AUXIN RESISTANCE1 (SAR1, also called NUP160) or SAR3 (NUP96) present condensation abnormalities and SPO11-dependent chromosome fragmentation in a fraction of meiocytes, which is increased in the double mutant sar1 sar3. We also observed these meiotic defects in mutants deficient in the outer ring complex protein HOS1, but not in mutants affected in other components of this complex. Furthermore, our findings may suggest defects in the structure of NPCs in sar1 and a potential link between the meiotic role of this nucleoporin and a component of the RUBylation pathway. These results provide the first insights in plants into the role of nucleoporins in meiotic chromosome behavior.
PMID: 38111849
Environ Res , IF:6.498 , 2023 Dec , V245 : P117977 doi: 10.1016/j.envres.2023.117977
Short-term continuous monocropping reduces peanut yield mainly via altering soil enzyme activity and fungal community.
College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.; Department of Soil-Plant-Microbiome, Institute of Phytopathology, University of Kiel, Germany.; College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China. Electronic address: yadong_tracy@cau.edu.cn.
Continuous monocropping can lead to soil sickness and increase of soil-borne disease, which finally reduces crop yield. Microorganisms benefit plants by increasing nutrient availability, participating in auxin synthesis, and defending against pathogens. However, little is known about the influence of short-term successive peanuts cropping on soil properties, enzyme activities, its yield, plant-associated microbes, and their potential correlations in peanut production. Here, we examined the community structure, composition, network structure and function of microbes in the rhizosphere and bulk soils under different monocropping years. Moreover, we assessed the impact of changes in the soil micro-environment and associated soil microbes on peanut yield. Our results showed that increase of monocropping year significantly decreased most soil properties, enzyme activities and peanut yield (p < 0.05). Principal co-ordinates analysis (PCoA) and analysis of similarities (ANOSIM) indicated that monocropping year significantly influenced the fungal community structure in the rhizosphere and bulk soils (p < 0.01), while had no effect on the bacterial community. With the increase of continuous monocropping year, peanut selectively decreased (e.g., Candidatus_Entotheonella, Bacillus and Bryobacter) or increased (e.g., Nitrospira, Nocardioides, Ensifer, Gaiella, and Novosphingobium) the abundance of some beneficial bacterial genera in the rhizosphere. Continuous monocropping significantly increased the abundance of plant pathogens (e.g., Plectosphaerella, Colletotrichum, Lectera, Gibberella, Metarhizium, and Microdochium) in the rhizosphere and negatively affected the balance of fungal community. Besides, these species were correlated negatively with L-leucine aminopeptidase (LAP) activity. Network co-occurrence analysis showed that continuous monocropping simplified the interaction network of bacteria and fungi. Random forest and partial least squares path modeling (PLS-PM) analysis further showed that fungal community, pathogen abundance, soil pH, and LAP activity negatively affected peanut yield. In conclusion, short-term continuous monocropping decreased LAP activity and increased potential fungal pathogens abundance, leading to reduction of peanut yield.
PMID: 38141923
Food Res Int , IF:6.475 , 2023 Dec , V174 (Pt 1) : P113504 doi: 10.1016/j.foodres.2023.113504
Physiological and transcriptomic analysis of IAA-induced antioxidant defense and cell wall metabolism in postharvest mango fruit.
Life Science and Technology School, Lingnan Normal University, Zhanjiang 524048, China. Electronic address: 286138826@qq.com.; Life Science and Technology School, Lingnan Normal University, Zhanjiang 524048, China.; Agricultural Products Processing Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan Key Laboratory of Storage and Processing of Fruits and Vegetables, Zhanjiang 524001, China.; Life Science and Technology School, Lingnan Normal University, Zhanjiang 524048, China. Electronic address: liukaidong2001@126.com.
Mango fruit tend to oxidize and senescence rapidly after harvesting, significantly reducing their commercial value. This study investigated the effect of exogenous auxin indole-3-acetic acid (IAA) on fruit quality, antioxidant system, and cell wall metabolism of mango fruit during storage. The results showed that the 1.0 mM IAA treatment delayed weight loss and maintained the firmness, pH and contents of total soluble solids (TSS) and titratable acidity (TA) of the mango fruit. The 1.0 mM IAA treatment increased the peroxidase (POD) and phenylalanine ammonia-lyase (PAL) activities and the ascorbic acid (AsA) and total phenols (TP) contents but decreased the polyphenol oxidase (PPO) activity in postharvest mango fruit. Moreover, beta-galactosidase (beta-Gal) and polygalacturonase (PG) activities were increased, but the pectinesterase (PME) activity was decreased in the IAA-treated fruit. Transcriptome analysis showed that the differentially expressed genes (DEGs) in the IAA vs. control groups were mainly associated with oxidative stress responses, cell wall metabolism, and transcription factors (TFs). The IAA treatment upregulated the antioxidant-related genes (SOD, CAT1, PODs, GSTs, Prxs, and Trxs) and MYB TFs, and downregulated cell wall metabolism-related genes (PG, PME31 and two PME63) and 11 ethylene-responsive transcription factors (ERFs). These results suggested that exogenous IAA could improve the antioxidant system and maintain the storage quality of mango fruit by regulating gene expression and metabolic pathways. The results provide insights into the mechanisms involved in IAA-mediated delayed ripening and senescence of mango fruit.
PMID: 37986499
Plant J , IF:6.417 , 2023 Dec , V116 (6) : P1737-1747 doi: 10.1111/tpj.16462
Dicer-like2b suppresses the wiry leaf phenotype in tomato induced by tobacco mosaic virus.
The College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.; Department of Ornamental Horticulture, State Key Laboratory of Agrobiotechnology, Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, College of Horticulture, China Agricultural University, Beijing, 100193, China.
Dicer-like (DCL) proteins are principal components of RNA silencing, a major defense mechanism against plant virus infections. However, their functions in suppressing virus-induced disease phenotypes remain largely unknown. Here, we identified a role for tomato (Solanum lycopersicum) DCL2b in regulating the wiry leaf phenotype during defense against tobacco mosaic virus (TMV). Knocking out SlyDCL2b promoted TMV accumulation in the leaf primordium, resulting in a wiry phenotype in distal leaves. Biochemical and bioinformatics analyses showed that 22-nt virus-derived small interfering RNAs (vsiRNAs) accumulated less abundantly in slydcl2b mutants than in wild-type plants, suggesting that SlyDCL2b-dependent 22-nt vsiRNAs are required to exclude virus from leaf primordia. Moreover, the wiry leaf phenotype was accompanied by upregulation of Auxin Response Factors (ARFs), resulting from a reduction in trans-acting siRNAs targeting ARFs (tasiARFs) in TMV-infected slydcl2b mutants. Loss of tasiARF production in the slydcl2b mutant was in turn caused by inhibition of miRNA390b function. Importantly, silencing SlyARF3 and SlyARF4 largely restored the wiry phenotype in TMV-infected slydcl2b mutants. Our work exemplifies the complex relationship between RNA viruses and the endogenous RNA silencing machinery, whereby SlyDCL2b protects the normal development of newly emerging organs by excluding virus from these regions and thus maintaining developmental silencing.
PMID: 37694805
Plant J , IF:6.417 , 2023 Dec , V116 (6) : P1825-1841 doi: 10.1111/tpj.16456
Fluorescence-activated multi-organelle mapping of subcellular plant hormone distribution.
Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, CZ-78371, Olomouc, Czech Republic.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-90183, Umea, Sweden.; Department of Chemical Biology, Faculty of Science, Palacky University, CZ-78371, Olomouc, Czech Republic.
Auxins and cytokinins are two major families of phytohormones that control most aspects of plant growth, development and plasticity. Their distribution in plants has been described, but the importance of cell- and subcellular-type specific phytohormone homeostasis remains undefined. Herein, we revealed auxin and cytokinin distribution maps showing their different organelle-specific allocations within the Arabidopsis plant cell. To do so, we have developed Fluorescence-Activated multi-Organelle Sorting (FAmOS), an innovative subcellular fractionation technique based on flow cytometric principles. FAmOS allows the simultaneous sorting of four differently labelled organelles based on their individual light scatter and fluorescence parameters while ensuring hormone metabolic stability. Our data showed different subcellular distribution of auxin and cytokinins, revealing the formation of phytohormone gradients that have been suggested by the subcellular localization of auxin and cytokinin transporters, receptors and metabolic enzymes. Both hormones showed enrichment in vacuoles, while cytokinins were also accumulated in the endoplasmic reticulum.
PMID: 37682018
Plant J , IF:6.417 , 2023 Dec , V116 (5) : P1355-1369 doi: 10.1111/tpj.16430
Structure-activity relationship of 2,4-D correlates auxinic activity with the induction of somatic embryogenesis in Arabidopsis thaliana.
Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands.; Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomedical Research, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands.; Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 182, 20014, Donostia San Sebastian, Spain.
2,4-dichlorophenoxyacetic acid (2,4-D) is a synthetic analogue of the plant hormone auxin that is commonly used in many in vitro plant regeneration systems, such as somatic embryogenesis (SE). Its effectiveness in inducing SE, compared to the natural auxin indole-3-acetic acid (IAA), has been attributed to the stress triggered by this compound rather than its auxinic activity. However, this hypothesis has never been thoroughly tested. Here we used a library of forty 2,4-D analogues to test the structure-activity relationship with respect to the capacity to induce SE and auxinic activity in Arabidopsis thaliana. Four analogues induced SE as effectively as 2,4-D and 13 analogues induced SE but were less effective. Based on root growth inhibition and auxin response reporter expression, the 2,4-D analogues were classified into different groups, ranging from very active to not active auxin analogues. A halogen at the 4-position of the aromatic ring was important for auxinic activity, whereas a halogen at the 3-position resulted in reduced activity. Moreover, a small substitution at the carboxylate chain was tolerated, as was extending the carboxylate chain with an even number of carbons. The auxinic activity of most 2,4-D analogues was consistent with their simulated TIR1-Aux/IAA coreceptor binding characteristics. A strong correlation was observed between SE induction efficiency and auxinic activity, which is in line with our observation that 2,4-D-induced SE and stress both require TIR1/AFB auxin co-receptor function. Our data indicate that the stress-related effects triggered by 2,4-D and considered important for SE induction are downstream of auxin signalling.
PMID: 37647363
Ecotoxicol Environ Saf , IF:6.291 , 2023 Dec , V268 : P115729 doi: 10.1016/j.ecoenv.2023.115729
Antifungal triazoles affect key non-target metabolic pathways in Solanum lycopersicum L. plants.
Charles University, Faculty of Science, Department of Biochemistry, Prague 2, Czech Republic.; Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Agroenvironmental Chemistry and Plant Nutrition, Prague-Suchdol, Czech Republic.; Charles University, Faculty of Physical Education and Sport, Sport Sciences-Biomedical Department, Prague 6, Czech Republic.; Centre of the Region Hana for Biotechnological and Agricultural Research, Department of Genetic Resources for Vegetables, Medicinal and Special Plants, Crop Research Institute, Olomouc, Czech Republic; Czech Advanced Technology and Research Institute, Palacky University, Olomouc, Czech Republic.; Charles University, Faculty of Science, Department of Analytical Chemistry, Prague 2, Czech Republic.; Charles University, Faculty of Science, Department of Biochemistry, Prague 2, Czech Republic. Electronic address: helena.ryslava@natur.cuni.cz.
Several 1,2,4-triazoles are widely used as systemic fungicides in agriculture because they inhibit fungal 14a-demethylase. However, they can also act on many non-target plant enzymes, thereby affecting phytohormonal balance, free amino acid content, and adaptation to stress. In this study, tomato plants (Solanum lycopersicum L. var. 'Cherrola') were exposed to penconazole, tebuconazole, or their combination, either by foliar spraying or soil drenching, every week, as an ecotoxicological model. All triazole-exposed plants showed a higher content (1.7-8.8 x) of total free amino acids than the control, especially free glutamine and asparagine were increased most likely in relation to the increase in active cytokinin metabolites 15 days after the first application. Conversely, the Trp content decreased in comparison with control (0.2-0.7 x), suggesting depletion by auxin biosynthesis. Both triazole application methods slightly affected the antioxidant system (antioxidant enzyme activity, antioxidant capacity, and phenolic content) in tomato leaves. These results indicated that the tomato plants adapted to triazoles over time. Therefore, increasing the abscisic and chlorogenic acid content in triazole-exposed plants may promote resistance to abiotic stress.
PMID: 38000304
Int J Mol Sci , IF:5.923 , 2023 Dec , V24 (24) doi: 10.3390/ijms242417534
Transcriptomic Analyses Reveal the Role of Cytokinin and the Nodal Stem in Microtuber Sprouting in Potato (Solanum tuberosum L.).
Graduate School of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
In potatoes, tuber secondary growth, especially sprouting, deforms the tubers and severely lowers their commercial value. Tuber sprouting is induced by signal substances, such as gibberellin (GA), which are transported to the tuber from the plant body. The molecular mechanism underlying GA-induced sprouting remains ambiguous. Here, we tried to recreate tuber secondary growth using in vitro stemmed microtubers (MTs) (with the nodal stem attached) and MT halves (with the nodal stem entirely removed). Our experiments showed that GA alone could initiate the sprouting of stemmed microtubers; however, GA failed to initiate MT halves unless 6-benzyladenine, a synthetic cytokinin CK, was co-applied. Here, we analyzed the transcriptional profiles of sprouting buds using these in vitro MTs. RNA-seq analysis revealed a downregulation of cytokinin-activated signaling but an upregulation of the "Zeatin biosynthesis" pathway, as shown by increased expression of CYP735A, CISZOG, and UGT85A1 in sprouting buds; additionally, the upregulation of genes, such as IAA15, IAA22, and SAUR50, associated with auxin-activated signaling and one abscisic acid (ABA) negative regulator, PLY4, plays a vital role during sprouting growth. Our findings indicate that the role of the nodal stem is synonymous with CK in sprouting growth, suggesting that CK signaling and homeostasis are critical to supporting GA-induced sprouting. To effectively control tuber sprouting, more effort is required to be devoted to these critical genes.
PMID: 38139361
Int J Mol Sci , IF:5.923 , 2023 Dec , V24 (24) doi: 10.3390/ijms242417359
Elucidation of the Mechanism of Rapid Growth Recovery in Rice Seedlings after Exposure to Low-Temperature Low-Light Stress: Analysis of Rice Root Transcriptome, Metabolome, and Physiology.
Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang 330045, China.
Late spring cold is a disastrous weather condition that often affects early rice seedlings in southern China, limiting the promotion of direct seeding cultivation. However, there are few reports on the effect of these events and on the growth recovery mechanism of rice root systems after rice seedlings are exposed to this stress. This study selected the strong-growth-recovery variety B116 (R310/R974, F(17)) and the slow-recovery variety B811 (Zhonghui 286) for direct seeding cultivation and exposed them to low temperature and low-light stress to simulate a late spring cold event in an artificial climate chamber. The treatment consisted of 4 days of exposure to a day/night temperature of 14/10 degrees C and a light intensity of 266 micromol m(-2)s(-1) while the control group was kept at a day/night temperature of 27/25 degrees C and light intensity of 533 micromol m(-2)s(-1). The results showed that 6 days after stress, the total length, surface area, and volume of B116 roots increased by 335.5%, 290.1%, and 298.5%, respectively, while those of B811 increased by 228.8%, 262.0%, and 289.1%, respectively. In B116, the increase in root fresh weight was 223.1%, and that in B811 was 165.6%, demonstrating rapid root recovery after stress and significant differences among genotypes. The content of H(2)O(2) and MDA in the B116 roots decreased faster than that in the B811 roots after normal light intensity and temperature conditions were restored, and the activity of ROS metabolism enzymes was stronger in B116 roots than in B811 roots. The correlation analysis between the transcriptome and metabolome showed that endogenous signal transduction and starch and sucrose metabolism were the main metabolic pathways affecting the rapid growth of rice seedling roots after exposure to combined stress from low temperature and low light intensities. The levels of auxin and sucrose in the roots of the strong-recovery variety B116 were higher, and this variety's metabolism was downregulated significantly faster than that of B811. The auxin response factor and sucrose synthesis-related genes SPS1 and SUS4 were significantly upregulated. This study contributes to an understanding of the rapid growth recovery mechanism in rice after exposure to combined stress from low-temperature and low-light conditions.
PMID: 38139187
Int J Mol Sci , IF:5.923 , 2023 Dec , V24 (23) doi: 10.3390/ijms242317061
Exogenous Serotonin (5-HT) Promotes Mesocotyl and Coleoptile Elongation in Maize Seedlings under Deep-Seeding Stress through Enhancing Auxin Accumulation and Inhibiting Lignin Formation.
State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China.; State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; Swift Current Research and Development Centre, Agriculture and Agri-Food Canada, Swift Current, SK S9H 3X2, Canada.
Serotonin (5-HT), an indoleamine compound, has been known to mediate many physiological responses of plants under environmental stress. The deep-seeding (>/=20 cm) of maize seeds is an important cultivation strategy to ensure seedling emergence and survival under drought stress. However, the role of 5-HT in maize deep-seeding tolerance remains unexplored. Understanding the mechanisms and evaluating the optimal concentration of 5-HT in alleviating deep-seeding stress could benefit maize production. In this study, two maize inbred lines were treated with or without 5-HT at both sowing depths of 20 cm and 3 cm, respectively. The effects of different concentrations of 5-HT on the growth phenotypes, physiological metabolism, and gene expression of two maize inbred lines were examined at the sowing depths of 20 cm and 3 cm. Compared to the normal seedling depth of 3 cm, the elongation of the mesocotyl (average elongation 3.70 cm) and coleoptile (average elongation 0.58 cm), secretion of indole-3-acetic acid (IAA; average increased 3.73 and 0.63 ng g(-1) FW), and hydrogen peroxide (H(2)O(2); average increased 1.95 and 0.63 muM g(-1) FW) in the mesocotyl and coleoptile were increased under 20 cm stress, with a concomitant decrease in lignin synthesis (average decreased 0.48 and 0.53 A(280) g(-1)). Under 20 cm deep-seeding stress, the addition of 5-HT activated the expression of multiple genes of IAA biosynthesis and signal transduction, including Zm00001d049601, Zm00001d039346, Zm00001d026530, and Zm00001d049659, and it also stimulated IAA production in both the mesocotyl and coleoptile of maize seedlings. On the contrary, 5-HT suppressed the expression of genes for lignin biosynthesis (Zm00001d016471, Zm00001d005998, Zm00001d032152, and Zm00001d053554) and retarded the accumulation of H(2)O(2) and lignin, resulting in the elongation of the mesocotyl and coleoptile of maize seedlings. A comprehensive evaluation analysis showed that the optimum concentration of 5-HT in relieving deep-seeding stress was 2.5 mg/L for both inbred lines, and 5-HT therefore could improve the seedling emergence rate and alleviate deep-seeding stress in maize seedlings. These findings could provide a novel strategy for improving maize deep-seeding tolerance, thus enhancing yield potential under drought and water stress.
PMID: 38069387
Int J Mol Sci , IF:5.923 , 2023 Nov , V24 (23) doi: 10.3390/ijms242316988
YUCCA2 (YUC2)-Mediated 3-Indoleacetic Acid (IAA) Biosynthesis Regulates Chloroplast RNA Editing by Relieving the Auxin Response Factor 1 (ARF1)-Dependent Inhibition of Editing Factors in Arabidopsis thaliana.
Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China.; Department of Basic Medicine, Chongqing Medical University, Chongqing 400016, China.
Although recent research progress on the abundant C-to-U RNA editing events in plant chloroplasts and mitochondria has uncovered many recognition factors and their molecular mechanisms, the intrinsic regulation of RNA editing within plants remains largely unknown. This study aimed to establish a regulatory relationship in Arabidopsis between the plant hormone auxin and chloroplast RNA editing. We first analyzed auxin response elements (AuxREs) present within promoters of chloroplast editing factors reported to date. We found that each has more than one AuxRE, suggesting a potential regulatory role of auxin in their expression. Further investigation unveiled that the depletion of auxin synthesis gene YUC2 reduces the expression of several editing factors. However, in yuc2 mutants, only the expression of CRR4, DYW1, ISE2, and ECD1 editing factors and the editing efficiency of their corresponding editing sites, ndhD-2 and rps14-149, were simultaneously suppressed. In addition, exogenous IAA and the overexpression of YUC2 enhanced the expression of these editing factors and the editing efficiency at the ndhD-2 and rps14-149 sites. These results suggested a direct effect of auxin upon the editing of the ndhD-2 and rps14-149 sites through the modulation of the expression of the editing factors. We further demonstrated that ARF1, a downstream transcription factor in the auxin-signaling pathway, could directly bind to and inactivate the promoters of CRR4, DYW1, and ISE2 in a dual-luciferase reporter system, thereby inhibiting their expression. Moreover, the overexpression of ARF1 in Arabidopsis significantly reduced the expression of the three editing factors and the editing efficiency at the ndhD-2 and rps14-149 sites. These data suggest that YUC2-mediated auxin biosynthesis governs the RNA-editing process through the ARF1-dependent signal transduction pathway.
PMID: 38069311
Int J Mol Sci , IF:5.923 , 2023 Nov , V24 (23) doi: 10.3390/ijms242316974
SMALL PLANT AND ORGAN 1 (SPO1) Encoding a Cellulose Synthase-like Protein D4 (OsCSLD4) Is an Important Regulator for Plant Architecture and Organ Size in Rice.
State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, China.; College of Agronomy, Northwest A&F University, Yangling 712100, China.
Plant architecture and organ size are considered as important traits in crop breeding and germplasm improvement. Although several factors affecting plant architecture and organ size have been identified in rice, the genetic and regulatory mechanisms remain to be elucidated. Here, we identified and characterized the small plant and organ 1 (spo1) mutant in rice (Oryza sativa), which exhibits narrow and rolled leaf, reductions in plant height, root length, and grain width, and other morphological defects. Map-based cloning revealed that SPO1 is allelic with OsCSLD4, a gene encoding the cellulose synthase-like protein D4, and is highly expressed in the roots at the seedling and tillering stages. Microscopic observation revealed the spo1 mutant had reduced number and width in leaf veins, smaller size of leaf bulliform cells, reduced cell length and cell area in the culm, and decreased width of epidermal cells in the outer glume of the grain. These results indicate the role of SPO1 in modulating cell division and cell expansion, which modulates plant architecture and organ size. It is showed that the contents of endogenous hormones including auxin, abscisic acid, gibberellin, and zeatin tested in the spo1 mutant were significantly altered, compared to the wild type. Furthermore, the transcriptome analysis revealed that the differentially expressed genes (DEGs) are significantly enriched in the pathways associated with plant hormone signal transduction, cell cycle progression, and cell wall formation. These results indicated that the loss of SPO1/OsCSLD4 function disrupted cell wall cellulose synthase and hormones homeostasis and signaling, thus leading to smaller plant and organ size in spo1. Taken together, we suggest the functional role of SPO1/OsCSLD4 in the control of rice plant and organ size by modulating cell division and expansion, likely through the effects of multiple hormonal pathways on cell wall formation.
PMID: 38069299
J Fungi (Basel) , IF:5.816 , 2023 Dec , V9 (12) doi: 10.3390/jof9121184
Manipulation of Auxin Signaling by Smut Fungi during Plant Colonization.
Department of Plant Pathology, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, 53115 Bonn, Germany.
A common feature of many plant-colonizing organisms is the exploitation of plant signaling and developmental pathways to successfully establish and proliferate in their hosts. Auxins are central plant growth hormones, and their signaling is heavily interlinked with plant development and immunity responses. Smuts, as one of the largest groups in basidiomycetes, are biotrophic specialists that successfully manipulate their host plants and cause fascinating phenotypes in so far largely enigmatic ways. This review gives an overview of the growing understanding of how and why smut fungi target the central and conserved auxin growth signaling pathways in plants.
PMID: 38132785
Front Plant Sci , IF:5.753 , 2023 , V14 : P1303417 doi: 10.3389/fpls.2023.1303417
Genome-wide family prediction unveils molecular mechanisms underlying the regulation of agronomic traits in Urochloa ruziziensis.
Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil.; Department of Plant Biology, Biology Institute, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil.; Embrapa Gado de Corte, Brazilian Agricultural Research Corporation, Campo Grande, Mato Grosso, Brazil.; Embrapa Cerrados, Brazilian Agricultural Research Corporation, Brasilia, Brazil.; Department of Statistics, University of Campinas (UNICAMP), Campinas, Sao Paulo, Brazil.
Tropical forage grasses, particularly those belonging to the Urochloa genus, play a crucial role in cattle production and serve as the main food source for animals in tropical and subtropical regions. The majority of these species are apomictic and tetraploid, highlighting the significance of U. ruziziensis, a sexual diploid species that can be tetraploidized for use in interspecific crosses with apomictic species. As a means to support breeding programs, our study investigates the feasibility of genome-wide family prediction in U. ruziziensis families to predict agronomic traits. Fifty half-sibling families were assessed for green matter yield, dry matter yield, regrowth capacity, leaf dry matter, and stem dry matter across different clippings established in contrasting seasons with varying available water capacity. Genotyping was performed using a genotyping-by-sequencing approach based on DNA samples from family pools. In addition to conventional genomic prediction methods, machine learning and feature selection algorithms were employed to reduce the necessary number of markers for prediction and enhance predictive accuracy across phenotypes. To explore the regulation of agronomic traits, our study evaluated the significance of selected markers for prediction using a tree-based approach, potentially linking these regions to quantitative trait loci (QTLs). In a multiomic approach, genes from the species transcriptome were mapped and correlated to those markers. A gene coexpression network was modeled with gene expression estimates from a diverse set of U. ruziziensis genotypes, enabling a comprehensive investigation of molecular mechanisms associated with these regions. The heritabilities of the evaluated traits ranged from 0.44 to 0.92. A total of 28,106 filtered SNPs were used to predict phenotypic measurements, achieving a mean predictive ability of 0.762. By employing feature selection techniques, we could reduce the dimensionality of SNP datasets, revealing potential genotype-phenotype associations. The functional annotation of genes near these markers revealed associations with auxin transport and biosynthesis of lignin, flavonol, and folic acid. Further exploration with the gene coexpression network uncovered associations with DNA metabolism, stress response, and circadian rhythm. These genes and regions represent important targets for expanding our understanding of the metabolic regulation of agronomic traits and offer valuable insights applicable to species breeding. Our work represents an innovative contribution to molecular breeding techniques for tropical forages, presenting a viable marker-assisted breeding approach and identifying target regions for future molecular studies on these agronomic traits.
PMID: 38148869
Front Plant Sci , IF:5.753 , 2023 , V14 : P1294643 doi: 10.3389/fpls.2023.1294643
Physiological and transcriptomic analyses of response of walnuts (Juglans regia) to Pantoea agglomerans infection.
National Engineering Research Center for Agriculture in Northern Mountainous Areas, Agricultural Technology Innovation Center in Mountainous Areas of Hebei Province, Hebei Agricultural University, Baoding, Hebei, China.; College of Life Sciences, Hebei Agricultural University, Baoding, China.
INTRODUCTION: Walnut blight is a serious bacterial disease that affects the yield and quality of walnuts. Pantoea agglomerans is one of the main causative agents of walnut blight. However, there have been few studies on the response of walnuts to P. agglomerans infection. METHODS: In this study, the soluble sugar, photosynthesis, antioxidant enzyme activities, and secondary metabolites were measured, and the transcriptomic analysis was performed to determine the response of walnut tissue cultures to P. agglomerans infection. RESULTS: After pathogen inoculation, the soluble sugar content decreased, and photosynthesis was inhibited. Antioxidant enzyme (superoxide dismutase and peroxidase) activities and secondary metabolites (phenol and flavonoid) contents increased, especially in the early stages of inoculation. Transcriptomic analysis revealed that the phenylpropanoid biosynthesis pathway is induced after infection, and pathogen infection promotes ABA and ethylene signal transduction and inhibits auxin signaling. In addition, SA and JA-related gene expression was altered after inoculation with P. agglomerans, and the FLS- and calcium-mediated disease resistance signaling pathways were activated. Furthermore, our results suggested an involvement of the R-protein RPM-mediated disease resistance pathway in the response of walnuts to bacterial infections. DISCUSSION: Our findings indicated that phenylpropanoid biosynthesis, hormone signal transduction, and plant-pathogen interaction have key roles in pathogenic inoculation, which provide insights into the molecular mechanisms in the response of walnuts to P. agglomerans infection.
PMID: 38116156
Theor Appl Genet , IF:5.699 , 2023 Dec , V137 (1) : P6 doi: 10.1007/s00122-023-04516-6
Genetic control of pod morphological traits and pod edibility in a common bean RIL population.
Plant Genetic Group, Regional Service for Agrofood Research and Development (SERIDA), 33300, Villaviciosa, Asturias, Spain. cgarcia@serida.org.; Plant Genetic Group, Regional Service for Agrofood Research and Development (SERIDA), 33300, Villaviciosa, Asturias, Spain.; Department of Agricultural, Food, and Environmental Sciences, Marche Polytechnic University, Via Brecce Bianche, 60131, Ancona, Italy.
QTL mapping, association analysis, and colocation study with previously reported QTL revealed three main regions controlling pod morphological traits and two loci for edible pod characteristics on the common bean chromosomes Pv01 and Pv06. Bean pod phenotype is a complex characteristic defined by the combination of different traits that determine the potential use of a genotype as a snap bean. In this study, the TUM RIL population derived from a cross between 'TU' (dry) and 'Musica' (snap) was used to investigate the genetic control of pod phenotype. The character was dissected into pod morphological traits (PMTs) and edible pod characteristics (EPC). The results revealed 35 QTL for PMTs located on seven chromosomes, suggesting a strong QTL colocation on chromosomes Pv01 and Pv06. Some QTL were colocated with previously reported QTL, leading to the mapping of 15 consensus regions associated with bean PMTs. Analysis of EPC of cooked beans revealed that two major loci with epistatic effect, located on chromosomes Pv01 and Pv06, are involved in the genetic control of this trait. An association study using a subset of the Spanish Diversity Panel (snap vs. non-snap) detected 23 genomic regions, with three regions being mapped at a position similar to those of two loci identified in the TUM population. The results demonstrated the relevant roles of Pv01 and Pv06 in the modulation of bean pod phenotype. Gene ontology enrichment analysis revealed a significant overrepresentation of genes regulating the phenylpropanoid metabolic process and auxin response in regions associated with PMTs and EPC, respectively. Both biological functions converged in the lignin biosynthetic pathway, suggesting the key role of the pathway in the genetic control of bean pod phenotype.
PMID: 38091106
Mol Plant Pathol , IF:5.663 , 2023 Dec doi: 10.1111/mpp.13409
NIT24 and NIT29-mediated IAA synthesis of Xanthomonas oryzae pv. oryzicola suppresses immunity and boosts growth in rice.
State Key Laboratory of Crop Biology, Shandong Provincial Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, China.; Shike Modern Agriculture Investment Co., Ltd, Heze, China.
Auxin plays a pivotal role in the co-evolution of plants and microorganisms. Xanthomonas oryzae pv. oryzicola (Xoc) stands as a significant factor that affects rice yield and quality. However, the current understanding of Xoc's capability for indole 3-acetic acid (IAA) synthesis and its mechanistic implications remains elusive. In this study, we performed a comprehensive genomic analysis of Xoc strain RS105, leading to the identification of two nitrilase enzyme family (NIT) genes, designated as AKO15524.1 and AKO15829.1, subsequently named NIT24 and NIT29, respectively. Our investigation unveiled that the deletion of NIT24 and NIT29 resulted in a notable reduction in IAA synthesis capacity within RS105, thereby impacting extracellular polysaccharide production. This deficiency was partially ameliorated through exogenous IAA supplementation. The study further substantiated that NIT24 and NIT29 have nitrilase activity and the ability to catalyse IAA production in vitro. The lesion length and bacterial population statistics experiments confirmed that NIT24 and NIT29 positively regulated the pathogenicity of RS105, suggesting that NIT24 and NIT29 may regulate Xoc invasion by affecting IAA synthesis. Furthermore, our analysis corroborated mutant strains, RS105_DeltaNIT24 and RS105_DeltaNIT29, which elicited the outbreak of reactive oxygen species, the deposition of callose and the upregulation of defence-related gene expression in rice. IAA exerted a significant dampening effect on the immune responses incited by these mutant strains in rice. In addition, the absence of NIT24 and NIT29 affected the growth-promoting effect of Xoc on rice. This implies that Xoc may promote rice growth by secreting IAA, thus providing a more suitable microenvironment for its own colonization. In summary, our study provides compelling evidence for the existence of a nitrilase-dependent IAA biosynthesis pathway in Xoc. IAA synthesis-related genes promote Xoc colonization by inhibiting rice immune defence response and affecting rice growth by increasing IAA content in Xoc.
PMID: 38069667
Microbiol Res , IF:5.415 , 2023 Dec , V280 : P127566 doi: 10.1016/j.micres.2023.127566
Phenotypic, genomic and in planta characterization of Bacillus sensu lato for their phosphorus biofertilization and plant growth promotion features in soybean.
Bioinsumos, Area de Recursos Naturales, Produccion y Ambiente, Instituto Nacional de Investigacion Agropecuaria (INIA Uruguay), Uruguay.; Unidad Mixta Pasteur+INIA, Institut Pasteur de Montevideo, Uruguay.; Bioinsumos, Area de Recursos Naturales, Produccion y Ambiente, Instituto Nacional de Investigacion Agropecuaria (INIA Uruguay), Uruguay; Area Mejoramiento Genetico y Biotecnologia Vegetal, Instituto Nacional de Investigacion Agropecuaria (INIA Uruguay), Uruguay.; Bioinsumos, Area de Recursos Naturales, Produccion y Ambiente, Instituto Nacional de Investigacion Agropecuaria (INIA Uruguay), Uruguay. Electronic address: eabreo@inia.org.uy.
Bacillus sensu lato were screened for their capacity to mineralize organic phosphorus (P) and promote plant growth, improving nitrogen (N) and P nutrition of soybean. Isolates were identified through Type Strain Genome Server (TYGS) and Average Nucleotide Identity (ANI). ILBB95, ILBB510 and ILBB592 were identified as Priestia megaterium, ILBB139 as Bacillus wiedmannii, ILBB44 as a member of a sister clade of B. pumilus, ILBB15 as Peribacillus butanolivorans and ILBB64 as Lysinibacillus sp. These strains were evaluated for their capacity to mineralize sodium phytate as organic P and solubilize inorganic P in liquid medium. These assays ranked ILBB15 and ILBB64 with the highest orthophosphate production from phytate. Rhizocompetence and plant growth promotion traits were evaluated in vitro and in silico. Finally, plant bioassays were conducted to assess the effect of the co-inoculation with rhizobial inoculants on nodulation, N and P nutrition. These bioassays showed that B. pumilus, ILBB44 and P. megaterium ILBB95 increased P-uptake in plants on the poor substrate of sand:vermiculite and also on a more fertile mix. Priestia megaterium ILBB592 increased nodulation and N content in plants on the sand:vermiculite:peat mixture. Peribacillus butanolivorans ILBB15 reduced plant growth and nutrition on both substrates. Genomes of ILBB95 and ILBB592 were characterized by genes related with plant growth and biofertilization, whereas ILBB15 was differentiated by genes related to bioremediation. Priestia megaterium ILBB592 is considered as nodule-enhancing rhizobacteria and together with ILBB95, can be envisaged as prospective PGPR with the capacity to exert positive effects on N and P nutrition of soybean plants.
PMID: 38100951
J Agric Food Chem , IF:5.279 , 2023 Dec , V71 (50) : P19958-19969 doi: 10.1021/acs.jafc.3c05350
Enhanced Rice Resistance to Sheath Blight through Nitrate Transporter 1.1B Mutation without Yield Loss under NH(4)(+) Fertilization.
College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning 110866, People's Republic of China.; Institute of Agricultural Quality Standards and Testing Technology, Liaoning Academy of Agricultural Sciences, Shenyang, Liaoning 110161, People's Republic of China.; Microelement Research Center, College of Resources & Environment, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
Nitrogen fertilization can promote rice yield but decrease resistance to sheath blight (ShB). In this study, the nitrate transporter 1.1b (nrt1.1b) mutant that exhibited less susceptibility to ShB but without compromising yield under NH(4)(+) fertilization was screened. NRT1.1B's regulation of ShB resistance was independent of the total nitrogen concentration in rice under NH(4)(+) conditions. In nrt1.1b mutant plants, the NH(4)(+) application modulated auxin signaling, chlorophyll content, and phosphate signaling to promote ShB resistance. Furthermore, the findings indicated that NRT1.1B negatively regulated ShB resistance by positively modulating the expression of H(+)-ATPase gene OSA3 and phosphate transport gene PT8. The mutation of OSA3 and PT8 promoted ShB resistance by increasing the apoplastic pH in rice. Our study identified the ShB resistance mutant nrt1.1b, which maintained normal nitrogen use efficiency without compromising yield.
PMID: 38085756
J Agric Food Chem , IF:5.279 , 2023 Dec , V71 (50) : P19970-19985 doi: 10.1021/acs.jafc.3c05907
Exogenous Melatonin Promotes Cold Tolerance in Grape Seedlings: Physiological, Transcriptomic, and Functional Evidence.
College of Enology and Horticulture, Ningxia University, Yinchuan 750021, Ningxia, China.; Key Laboratory of Modern Molecular Breeding for Dominant and Special Crops in Ningxia, Yinchuan 750021, China.; State Key Laboratory of Efficient Production of Forest Resources, Yinchuan 750021, China.; Engineering Research Center of Grape and Wine, Ministry of Education, Ningxia University, Yinchuan 750021, Ningxia, China.
Melatonin (MEL) is an antioxidant molecule that enhances plant tolerance to environmental stress. However, the mechanisms by which MEL regulates cold signaling pathways in grapes under cold stress remain elusive. Here, we investigated the physiological and transcriptomic changes in grape seedlings treated with exogenous MEL to determine their protective role under cold stress. Results showed that 150 muM MEL effectively attenuated cold-induced cell damage by reducing reactive oxygen species (ROS) and preserving the chloroplast structure and function. MEL also inhibited tannin degradation, which contributed to its protective effect. Exogenous MEL promoted the synthesis of endogenous MEL, abscisic acid, auxin, and cytokinin while inhibiting gibberellin. Transcriptomic profiling revealed 776 differentially expressed transcripts in MEL-treated samples compared to controls. Functional analysis of a candidate hub gene, VvHSFA6b, showed that its overexpression in grape calli enhances cold tolerance by activating jasmonic acid synthesis pathway genes, promoting JA accumulation, and inhibiting JAZ-repressed transcription factors.
PMID: 38055343
J Agric Food Chem , IF:5.279 , 2023 Dec , V71 (48) : P18999-19009 doi: 10.1021/acs.jafc.3c05843
Glycosylation of Secondary Metabolites: A Multifunctional UDP-Glycosyltransferase, CsUGT74Y1, Promotes the Growth of Plants.
College of Tea Science, Guizhou University, Guiyang 550025, Guizhou, China.; School of Chemistry and Materials Science, Hunan Agricultural University, Changsha 410128, China.; Hunan Optical Agriculture Engineering Technology Research Center, Changsha 410128, China.; State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 230036 Hefei, Anhui, China.; School of Life Science, Anhui Agricultural University, 230036 Hefei, Anhui, China.
Camellia sinensis contains numerous glycosylated secondary metabolites that provide various benefits to plants and humans. However, the genes that catalyze the glycosylation of multitype metabolites in tea plants remain unclear. Here, 180 uridine diphosphate-dependent glycosyltransferases that may be involved in the biosynthesis of glycosylated secondary metabolites were identified from the National Center for Biotechnology Information public databases. Subsequently, CsUGT74Y1 was screened through phylogenetic analysis and gene expression profiling. Compositional and induced expression analyses revealed that CsUGT74Y1 was highly expressed in tea tender shoots and was induced under biotic and abiotic stress conditions. In vitro enzymatic assays revealed that rCsUGT74Y1 encoded a multifunctional UGT that catalyzed the glycosylation of flavonoids, phenolic acids, lignins, and auxins. Furthermore, CsUGT74Y1-overexpressing Arabidopsis thaliana exhibited enhanced growth and accumulation of flavonol and auxin glucosides. Our findings provide insights into identifying specific UGTs and demonstrate that CsUGT74Y1 is a multifunctional UGT that promotes plant development.
PMID: 37997954
J Biol Chem , IF:5.157 , 2023 Dec , V299 (12) : P105456 doi: 10.1016/j.jbc.2023.105456
Resolving binding pathways and solvation thermodynamics of plant hormone receptors.
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA. Electronic address: diwakar@illinois.edu.
Plant hormones are small molecules that regulate plant growth, development, and responses to biotic and abiotic stresses. They are specifically recognized by the binding site of their receptors. In this work, we resolved the binding pathways for eight classes of phytohormones (auxin, jasmonate, gibberellin, strigolactone, brassinosteroid, cytokinin, salicylic acid, and abscisic acid) to their canonical receptors using extensive molecular dynamics simulations. Furthermore, we investigated the role of water displacement and reorganization at the binding site of the plant receptors through inhomogeneous solvation theory. Our findings predict that displacement of water molecules by phytohormones contributes to free energy of binding via entropy gain and is associated with significant free energy barriers for most systems analyzed. Also, our results indicate that displacement of unfavorable water molecules in the binding site can be exploited in rational agrochemical design. Overall, this study uncovers the mechanism of ligand binding and the role of water molecules in plant hormone perception, which creates new avenues for agrochemical design to target plant growth and development.
PMID: 37949229
Biomolecules , IF:4.879 , 2023 Dec , V13 (12) doi: 10.3390/biom13121734
Hormonal Status of Transgenic Birch with a Pine Glutamine Synthetase Gene during Rooting In Vitro and Budburst Outdoors.
Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 142290 Pushchino, Russia.; Ufa Institute of Biology of the Ufa Federal Research Center of the Russian Academy of Sciences, 450054 Ufa, Russia.
Improving nitrogen use efficiency (NUE) is one of the main ways of increasing plant productivity through genetic engineering. The modification of nitrogen (N) metabolism can affect the hormonal content, but in transgenic plants, this aspect has not been sufficiently studied. Transgenic birch (Betula pubescens) plants with the pine glutamine synthetase gene GS1 were evaluated for hormone levels during rooting in vitro and budburst under outdoor conditions. In the shoots of the transgenic lines, the content of indoleacetic acid (IAA) was 1.5-3 times higher than in the wild type. The addition of phosphinothricin (PPT), a glutamine synthetase (GS) inhibitor, to the medium reduced the IAA content in transgenic plants, but it did not change in the control. In the roots of birch plants, PPT had the opposite effect. PPT decreased the content of free amino acids in the leaves of nontransgenic birch, but their content increased in GS-overexpressing plants. A three-year pot experiment with different N availability showed that the productivity of the transgenic birch line was significantly higher than in the control under N deficiency, but not excess, conditions. Nitrogen availability did not affect budburst in the spring of the fourth year; however, bud breaking in transgenic plants was delayed compared to the control. The IAA and abscisic acid (ABA) contents in the buds of birch plants at dormancy and budburst depended both on N availability and the transgenic status. These results enable a better understanding of the interaction between phytohormones and nutrients in woody plants.
PMID: 38136605
Plant Sci , IF:4.729 , 2023 Nov , V339 : P111936 doi: 10.1016/j.plantsci.2023.111936
Differential influence of Bacillus subtilis strains on Arabidopsis root architecture through common and distinct plant hormonal pathways.
Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark; Plant Health Innovation, Chr-Hansen A/S, Taastrup, Denmark.; Bacterial Interactions and Evolution Group, DTU Bioengineering, Technical University of Denmark, Kgs. Lyngby, Denmark.; Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.; Plant Health Innovation, Chr-Hansen A/S, Taastrup, Denmark.; Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark. Electronic address: als@plen.ku.dk.
Plant growth-promoting microbes (PGPM) can enhance crop yield and health, but knowledge of their mode-of-action is limited. We studied the influence of two Bacillus subtilis strains, the natural isolate ALC_02 and the domesticated 168 Go, on Arabidopsis and hypothesized that they modify the root architecture by modulating hormone transport or signaling. Both bacteria promoted increase of shoot and root surface area in vitro, but through different root anatomical traits. Mutant plants deficient in auxin transport or signaling responded less to the bacterial strains than the wild-type, and application of the auxin transport inhibitor NPA strongly reduced the influence of the strains. Both bacteria produced auxin and enhanced shoot auxin levels in DR5::GUS reporter plants. Accordingly, most of the beneficial effects of the strains were dependent on functional auxin transport and signaling, while only 168 Go depended on functional ethylene signaling. As expected, only ALC_02 stimulated plant growth in soil, unlike 168 Go that was previously reported to have reduced biofilms. Collectively, the results highlight that B. subtilis strains can have strikingly different plant growth-promoting properties, dependent on what experimental setup they are tested in, and the importance of choosing the right PGPM for a desired root phenotype.
PMID: 38042415
Plant Sci , IF:4.729 , 2024 Jan , V338 : P111915 doi: 10.1016/j.plantsci.2023.111915
FtsH proteases confer protection against salt and oxidative stress in Medicago sativa L.
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.; Institute of Animal Sciences, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan 750002, PR China.; Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China. Electronic address: dragongodsgod@163.com.
Plant filamentation temperature-sensitive H (FtsH) proteins are ATP-dependent zinc proteases that play an important role in regulating abiotic stress adaptions. Here we explore their potential role in abiotic stress tolerance in alfalfa, an important legume crop. Genomic analysis revealed seventeen MsFtsH genes in five clusters, which generally featured conserved domains and gene structures. Furthermore, the expression of MsFtsHs was found to be tightly associated with abiotic stresses, including osmotic, salt and oxidative stress. In addition, numerous stress responsive cis-elements, including those related to ABA, auxin, and salicylic acid, were identified in their promoter regions. Moreover, MsFtsH8 overexpression was shown to confer tolerance to salt and oxidative stress which was associated with reduced levels of reactive oxygen species, and enhanced expression and activity of antioxidant enzymes. Our results highlight MsFtsHs as key factors in abiotic stress tolerance, and show their potential usefulness for breeding alfalfa and other crops with improved yield and stress tolerance.
PMID: 37944702
Plant Sci , IF:4.729 , 2024 Jan , V338 : P111902 doi: 10.1016/j.plantsci.2023.111902
Modulation in gene expression and enzyme activity suggested the roles of monodehydroascorbate reductase in development and stress response in bread wheat.
Department of Botany, Panjab University, Chandigarh 160014, India.; Department of Biotechnology, Panjab University, Chandigarh 160014, India.; Department of Botany, Panjab University, Chandigarh 160014, India. Electronic address: skupadhyay@pu.ac.in.
Monodehydroascorbate reductase (MDHAR) is a crucial enzymatic antioxidant of the ascorbate-glutathione pathway involved in reactive oxygen species scavenging. Herein, we identified 15 TaMDHAR genes in bread wheat. Phylogenetic analysis revealed their clustering into three groups, which are also related to the subcellular localization in the peroxisome matrix, peroxisome membrane, and chloroplast. Each TaMDHAR protein consisted of two conserved domains; Pyr_redox and Pyr_redox_2 of the pyridine nucleotide disulfide oxidoreductase family. The occurrence of diverse groups of cis-regulatory elements in the promoter region and their interaction with numerous transcription factors suggest assorted functions of TaMDHARs in growth and development and in light, phytohormones, and stress responses. Expression analysis in various tissues further revealed their importance in vegetative and reproductive development. In addition, the differential gene expression and enhanced enzyme activity during drought, heat, and salt treatments exposed their role in abiotic stress response. Interaction of MDHARs with various antioxidant enzymes and biochemicals related to the ascorbate-glutathione cycle exposed their synchronized functioning. Interaction with auxin indicated the probability of cross-talk between antioxidants and auxin signaling. The miR168a, miR169, miR172 and others interaction with various TaMDHARs further directed their association with developmental processes and stress responses. The current study provides extensive information about the importance of TaMDHARs, moreover, the precise role of each gene needs to be established in future studies.
PMID: 37879539
Plant Sci , IF:4.729 , 2024 Jan , V338 : P111869 doi: 10.1016/j.plantsci.2023.111869
The miR156-SPL4/SPL9 module regulates leaf and lateral branch development in Betula platyphylla.
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150036, China.; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150036, China. Electronic address: lihuiyu2017@126.com.
The miR156 gene is known to play an important role in regulating growth and development in plants. This gene is involved in the transition from juvenile to adult stages, leaf morphology, and root development, among other processes. While the function of miR156 is similar in many plants, there are also differences in the function of this gene between herbaceous and native species. We obtained BpmiR156 overexpression transgenic lines in Betula platyphylla, and the transgenic lines exhibited traits such as delayed development, dwarfism, increased leaf epidermal hairs, larger leaf basal angle and altered stem curvature, which were highly consistent with the overexpression miR156 in Arabidopsis, rice and tomato. However, we also observed a lack of apical dominance, increased number of lateral branches and increased diameter of lateral branches in transgenic B. platyphylla, which is different from the effects reported in other plants. Transgenic plants showed changes in the distribution of IAA, GA3, and Zeatin in lateral branches and main stem, and the ratio of the content of the three hormones was significantly higher than in the non-transgenic plants served as control. Additionally, overexpression of BpmiR156 caused down-regulation of BpSPL4 and BpSPL9 expression, as well as differential expression of genes involved in auxin and cytokinin synthesis such as BpARR3, BpARR11 and BpmiR172.
PMID: 37827250
Plant Sci , IF:4.729 , 2024 Jan , V338 : P111892 doi: 10.1016/j.plantsci.2023.111892
Integrating the multiple functions of CHLH into chloroplast-derived signaling fundamental to plant development and adaptation as well as fruit ripening.
College of Horticulture, China Agricultural University, Beijing 100193, China; College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China.; College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing 102206, China. Electronic address: sflmn@163.com.
Chlorophyll (Chl)-mediated oxygenic photosynthesis sustains life on Earth. Greening leaves play fundamental roles in plant growth and crop yield, correlating with the idea that more Chls lead to better adaptation. However, they face significant challenges from various unfavorable environments. Chl biosynthesis hinges on the first committed step, which involves inserting Mg(2+) into protoporphyrin. This step is facilitated by the H subunit of magnesium chelatase (CHLH) and features a conserved mechanism from cyanobacteria to plants. For better adaptation to fluctuating land environments, especially drought, CHLH evolves multiple biological functions, including Chl biosynthesis, retrograde signaling, and abscisic acid (ABA) responses. Additionally, it integrates into various chloroplast-derived signaling pathways, encompassing both retrograde signaling and hormonal signaling. The former comprises ROS (reactive oxygen species), heme, GUN (genomes uncoupled), MEcPP (methylerythritol cyclodiphosphate), beta-CC (beta-cyclocitral), and PAP (3'-phosphoadenosine-5'-phosphate). The latter involves phytohormones like ABA, ethylene, auxin, cytokinin, gibberellin, strigolactone, brassinolide, salicylic acid, and jasmonic acid. Together, these elements create a coordinated regulatory network tailored to plant development and adaptation. An intriguing example is how drought-mediated improvement of fruit quality provides insights into chloroplast-derived signaling, aiding the shift from vegetative to reproductive growth. In this context, we explore the integration of CHLH's multifaceted roles into chloroplast-derived signaling, which lays the foundation for plant development and adaptation, as well as fruit ripening and quality. In the future, manipulating chloroplast-derived signaling may offer a promising avenue to enhance crop yield and quality through the homeostasis, function, and regulation of Chls.
PMID: 37821024
Plant Cell Rep , IF:4.57 , 2023 Dec , V43 (1) : P26 doi: 10.1007/s00299-023-03086-7
A novel single nucleotide mutation of TFL1 alters the plant architecture of Gossypium arboreum through changing the pre-mRNA splicing.
National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, 572024, China.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, 572024, China. wangzhi01@caas.cn.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China. wangzhi01@caas.cn.; Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China. wangzhi01@caas.cn.
A single nucleotide mutation from G to A at the 201st position changed the 5' splice site and deleted 31 amino acids in the first exon of GaTFL1. Growth habit is an important agronomic trait that plays a decisive role in the plant architecture and crop yield. Cotton (Gossypium) tends to indeterminate growth, which is unsuitable for the once-over mechanical harvest system. Here, we identified a determinate growth mutant (dt1) in Gossypium arboreum by EMS mutagenesis, in which the main axis was terminated with the shoot apical meristem (SAM) converted into flowers. The map-based cloning of the dt1 locus showed a single nucleotide mutation from G to A at the 201st positions in TERMINAL FLOWER 1 (GaTFL1), which changed the alternative RNA 5' splice site and resulted in 31 amino acids deletion and loss of function of GaTFL1. Comparative transcriptomic RNA-Seq analysis identified many transporters responsible for the phytohormones, auxin, sugar, and flavonoids, which may function downstream of GaTFL1 to involve the plant architecture regulation. These findings indicate a novel alternative splicing mechanism involved in the post-transcriptional modification and TFL1 may function upstream of the auxin and sugar pathways through mediating their transport to determine the SAM fate and coordinate the vegetative and reproductive development from the SAM of the plant, which provides clues for the TFL1 mechanism in plant development regulation and provide research strategies for plant architecture improvement.
PMID: 38155318
Plant Cell Rep , IF:4.57 , 2023 Dec , V43 (1) : P21 doi: 10.1007/s00299-023-03081-y
The role of strigolactone analog (GR24) in endogenous hormone metabolism and hormone-related gene expression in tobacco axillary buds.
College of Tobacco Science, Guizhou University/Guizhou Key Laboratory for Tobacco Quality Research, Guiyang, 550025, People's Republic of China.; Yimen County Branch of Yuxi Tobacco Company, Yimen, 651100, Yunnan, People's Republic of China.; College of Tobacco Science, Guizhou University/Guizhou Key Laboratory for Tobacco Quality Research, Guiyang, 550025, People's Republic of China. 1416383890@qq.com.
Strigolactone has the potential to influence hormone metabolism, in addition to having a role in inhibiting axillary bud elongation, which could be regulated by the expression of phytohormones-related genes. The elongation of axillary buds affects the economic benefits of tobacco. In this study, it was investigated the effect of strigolactone (SL) on the elongation of tobacco axillary buds and its endogenous hormone metabolism and related gene expression by applying the artificial analog of SL, GR24, and an inhibitor of SL synthesis, TIS-108, to the axillary buds. The results showed that the elongation of axillary buds was significantly inhibited by GR24 on day 2 and day 9. Ultra-high-performance liquid-chromatography-mass spectrometry results further showed that SL significantly affected the metabolism of endogenous plant hormones, altering both their levels and the ratios between each endogenous hormone. Particularly, the levels of auxin (IAA), trans-zeatin-riboside (tZR), N6-(∆(2)-isopentenyl) adenine (iP), gibberellin A(4) (GA(4)), jasmonic acid (JA), and jasmonoyl isoleucine (JA-Ile) were decreased after GR24 treatment on day 9, but the levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and gibberellin A(1) (GA(1)) were significantly increased. Further analysis of endogenous hormonal balance revealed that after the treatment with GR24 on day 9, the ratio of IAA to cytokinin (CTK) was markedly increased, but the ratios of IAA to abscisic acid (ABA), salicylic acid (SA), ACC, JAs, and, GAs were notably decreased. In addition, according to RNA-seq analysis, multiple differentially expressed genes were found, such as GH3.1, AUX/IAA, SUAR20, IPT, CKX1, GA2ox1, ACO3, ERF1, PR1, and HCT, which may play critical roles in the biosynthesis, deactivation, signaling pathway of phytohormones, and the biosynthesis of flavonoids to regulate the elongation of axillary buds in tobacco. This work lays the certain theoretical foundation for the application of SL in regulating the elongation of axillary buds of tobacco.
PMID: 38150090
Plant Cell Rep , IF:4.57 , 2023 Dec , V43 (1) : P4 doi: 10.1007/s00299-023-03119-1
Parallel auxin transport via PINs and plasmodesmata during the Arabidopsis leaf hyponasty response.
College of Life Sciences, Northwest A & F University, Yangling, 712100, China.; Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China.; State Key Laboratory of Stress Biology for Arid Areas, Northwest A & F University, Yangling, 712100, China.; Institute for Molecular Physiology, University of Dusseldorf, 40225, Dusseldorf, Germany.; College of Life Sciences, Northwest A & F University, Yangling, 712100, China. johannes.liesche@uni-graz.at.; Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China. johannes.liesche@uni-graz.at.; State Key Laboratory of Stress Biology for Arid Areas, Northwest A & F University, Yangling, 712100, China. johannes.liesche@uni-graz.at.; Institute of Biology, University of Graz, Schubertstrasse 51, 8010, Graz, Austria. johannes.liesche@uni-graz.at.
The leaf hyponasty response depends on tip-to-petiole auxin transport. This transport can happen through two parallel pathways: active trans-membrane transport mediated by PIN proteins and passive diffusion through plasmodesmata. A plant's ability to counteract potential shading by neighboring plants depends on transport of the hormone auxin. Neighbor sensing at the leaf tip triggers auxin production. Once this auxin reaches the abaxial petiole epidermis, it causes cell elongation, which leads to leaf hyponasty. Two pathways are known to contribute to this intercellular tip-to-petiole auxin movement: (i) transport facilitated by plasma membrane-localized PIN auxin transporters and (ii) diffusion enabled by plasmodesmata. We tested if these two modes of transport are arranged sequentially or in parallel. Moreover, we investigated if they are functionally linked. Mutants in which one of the two pathways is disrupted indicated that both pathways are necessary for a full hyponasty response. Visualization of PIN3-GFP and PIN7-GFP localization indicated PIN-mediated transport in parallel to plasmodesmata-mediated transport along abaxial midrib epidermis cells. We found plasmodesmata-mediated cell coupling in the pin3pin4pin7 mutant to match wild-type levels, indicating no redundancy between pathways. Similarly, PIN3, PIN4 and PIN7 mRNA levels were unaffected in a mutant with disrupted plasmodesmata pathway. Our results provide mechanistic insight on leaf hyponasty, which might facilitate the manipulation of the shade avoidance response in crops.
PMID: 38117314
Plant Cell Rep , IF:4.57 , 2023 Dec , V42 (12) : P1845-1873 doi: 10.1007/s00299-023-03071-0
Epigenetic modifications and miRNAs determine the transition of somatic cells into somatic embryos.
State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Key Laboratory of National Forestry and Grassland Administration On Subtropical Forest Biodiversity Conservation, School of Life Sciences, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.; State Key Laboratory of Subtropical Silviculture, Bamboo Industry Institute, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China.; Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-Efficiency Utilization, Zhejiang A&F University, Lin'an, Hangzhou, 311300, Zhejiang, China.; Department of Biosciences, Rajagiri College of Social Sciences (Autonomous), Kalamassery, Kochi, 683104, Kerala, India.; State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, Jiangsu, China.; Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Key Laboratory of National Forestry and Grassland Administration On Subtropical Forest Biodiversity Conservation, School of Life Sciences, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China. weiqiang@njfu.edu.cn.
This review discusses the epigenetic changes during somatic embryo (SE) development, highlights the genes and miRNAs involved in the transition of somatic cells into SEs as a result of epigenetic changes, and draws insights on biotechnological opportunities to study SE development. Somatic embryogenesis from somatic cells occurs in a series of steps. The transition of somatic cells into somatic embryos (SEs) is the most critical step under genetic and epigenetic regulations. Major regulatory genes such as SERK, WUS, BBM, FUS3/FUSA3, AGL15, and PKL, control SE steps and development by turning on and off other regulatory genes. Gene transcription profiles of somatic cells during SE development is the result of epigenetic changes, such as DNA and histone protein modifications, that control and decide the fate of SE formation. Depending on the type of somatic cells and the treatment with plant growth regulators, epigenetic changes take place dynamically. Either hypermethylation or hypomethylation of SE-related genes promotes the transition of somatic cells. For example, the reduced levels of DNA methylation of SERK and WUS promotes SE initiation. Histone modifications also promote SE induction by regulating SE-related genes in somatic cells. In addition, miRNAs contribute to the various stages of SE by regulating the expression of auxin signaling pathway genes (TIR1, AFB2, ARF6, and ARF8), transcription factors (CUC1 and CUC2), and growth-regulating factors (GRFs) involved in SE formation. These epigenetic and miRNA functions are unique and have the potential to regenerate bipolar structures from somatic cells when a pluripotent state is induced. However, an integrated overview of the key regulators involved in SE development and downstream processes is lacking. Therefore, this review discusses epigenetic modifications involved in SE development, SE-related genes and miRNAs associated with epigenetics, and common cis-regulatory elements in the promoters of SE-related genes. Finally, we highlight future biotechnological opportunities to alter epigenetic pathways using the genome editing tool and to study the transition mechanism of somatic cells.
PMID: 37792027
PLoS Comput Biol , IF:4.475 , 2023 Nov , V19 (11) : Pe1011646 doi: 10.1371/journal.pcbi.1011646
Fluctuations in auxin levels depend upon synchronicity of cell divisions in a one-dimensional model of auxin transport.
School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom.; School of Biosciences, University of Nottingham, Nottingham, United Kingdom.; Department of Mathematics, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Auxin is a well-studied plant hormone, the spatial distribution of which remains incompletely understood. Here, we investigate the effects of cell growth and divisions on the dynamics of auxin patterning, using a combination of mathematical modelling and experimental observations. In contrast to most prior work, models are not designed or tuned with the aim to produce a specific auxin pattern. Instead, we use well-established techniques from dynamical systems theory to uncover and classify ranges of auxin patterns as exhaustively as possible as parameters are varied. Previous work using these techniques has shown how a multitude of stable auxin patterns may coexist, each attainable from a specific ensemble of initial conditions. When a key parameter spans a range of values, these steady patterns form a geometric curve with successive folds, often nicknamed a snaking diagram. As we introduce growth and cell division into a one-dimensional model of auxin distribution, we observe new behaviour which can be explained in terms of this diagram. Cell growth changes the shape of the snaking diagram, and this corresponds in turn to deformations in the patterns of auxin distribution. As divisions occur this can lead to abrupt creation or annihilation of auxin peaks. We term this phenomenon 'snake-jumping'. Under rhythmic cell divisions, we show how this can lead to stable oscillations of auxin. We also show that this requires a high level of synchronisation between cell divisions. Using 18 hour time-lapse imaging of the auxin reporter DII:Venus in roots of Arabidopsis thaliana, we show auxin fluctuates greatly, both in terms of amplitude and periodicity, consistent with the snake-jumping events observed with non-synchronised cell divisions. Periodic signals downstream of the auxin signalling pathway have previously been recorded in plant roots. The present work shows that auxin alone is unlikely to play the role of a pacemaker in this context.
PMID: 38032890
Sci Rep , IF:4.379 , 2023 Dec , V13 (1) : P22258 doi: 10.1038/s41598-023-49093-2
Global gene regulatory network underlying miR165a in Arabidopsis shoot apical meristem.
National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110067, India.; European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany.; School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.; National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110067, India. hasthi.ram@nipgr.ac.in.; European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany. hasthi.ram@nipgr.ac.in.; European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany. marcus.heisler@sydney.edu.au.; School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia. marcus.heisler@sydney.edu.au.
Arabidopsis microRNA165a (miR165a) targets Class III Homeodomain Leucine-Zipper (HD-ZIPIII) transcription factors to regulate various aspects of plant development and stress response. Over-expression of miR165a mimics the loss-of-function phenotype of HD-ZIPIII genes and leading to ectopic organ formation, shoot apical meristem (SAM) termination, loss of leaf polarity, and defective vasculature development. However, the molecular mechanisms underlying these phenotypes remain unresolved. Here, we over-expressed miR165a in a dexamethasone inducible manner and identified differentially expressed genes in the SAM through RNA-Seq. Simultaneously, using multi-channel FACS combined with RNA-Seq approach, we characterized global transcriptome patterns in miR165a expressing cell-types compared to HD-ZIPIII expressing cell-types and other cell-types in SAM. By integrating our results we identified sets of genes which are up-regulated by miR165a as well have enriched expression in miR165a cell-types, and vice-versa. Known plant development related genes such as HD-ZIPIII and their targets LITTLE ZIPPERs, Like AUXIN RESISTANT 2, BEL1-like homeodomain 6, ROTUNDIFOLIA like 16 were found to be down-regulated. Among the up-regulated genes, GIBBERELLIN 2-OXIDASEs, various elemental transporters (YSL3, ZIFL1, SULTR), and other transporter genes were prominent. Thus, the genes identified in this study help to unravel the molecular mechanism of miR165a and HD-ZIPIII regulated plant development and stress response.
PMID: 38097643
Plant Physiol Biochem , IF:4.27 , 2023 Dec , V206 : P108259 doi: 10.1016/j.plaphy.2023.108259
The molecular paradigm of reactive oxygen species (ROS) and reactive nitrogen species (RNS) with different phytohormone signaling pathways during drought stress in plants.
Post Graduate Department of Biotechnology, St. Xavier's College (Autonomous), 30, Mother Teresa Sarani, Kolkata, 700016, West Bengal, India.; Department of Botany, University of Delhi, New Delhi, 110007, Delhi, India.; Discipline of Life Sciences, School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi, 110068, India. Electronic address: aryadeep.rc@gmail.com.
Drought is undoubtedly a major environmental constraint that negatively affects agricultural yield and productivity throughout the globe. Plants are extremely vulnerable to drought which imposes several physiological, biochemical and molecular perturbations. Increased generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in different plant organs is one of the inevitable consequences of drought. ROS and RNS are toxic byproducts of metabolic reactions and poise oxidative stress and nitrosative stress that are detrimental for plants. In spite of toxic effects, these potentially active radicals also play a beneficial role in mediating several signal transduction events that lead to plant acclimation and enhanced survival under harsh environmental conditions. The precise understanding of ROS and RNS signaling and their molecular paradigm with different phytohormones, such as auxin, gibberellin, cytokinin, abscisic acid, ethylene, brassinosteroids, strigolactones, jasmonic acid, salicylic acid and melatonin play a pivotal role for maintaining plant fitness and resilience to counteract drought toxicity. Therefore, the present review provides an overview of integrated systemic signaling between ROS, RNS and phytohormones during drought stress based on past and recent advancements and their influential role in conferring protection against drought-induced damages in different plant species. Indeed, it would not be presumptuous to hope that the detailed knowledge provided in this review will be helpful for designing drought-tolerant crop cultivars in the forthcoming times.
PMID: 38154293
Plant Physiol Biochem , IF:4.27 , 2023 Dec , V205 : P108212 doi: 10.1016/j.plaphy.2023.108212
Ethylene and ROS mediate root growth inhibition induced by the endocrine disruptor bisphenol A (BPA).
Department of Molecular Biology, South Korea; Department of Bioindustry and Bioresource Engineering, South Korea; Plant Engineering Research Institute, Sejong University, Seoul, 143-747, South Korea.; Department of Molecular Biology, South Korea; Department of Bioindustry and Bioresource Engineering, South Korea; Plant Engineering Research Institute, Sejong University, Seoul, 143-747, South Korea. Electronic address: sbhwang@sejong.ac.kr.
Bisphenol A (BPA) functions as a detrimental substance that disrupts the endocrine system in animals while also impeding the growth and development of plants. In our previous study, we demonstrated that BPA hinders the growth of roots in Arabidopsis by diminishing cell division and elongation, which is ascribed to the increased accumulation and redistribution of auxin. Here, we examined the mediation of ROS and ethylene in BPA-induced auxin accumulation and root growth inhibition. BPA enhanced ROS levels, and ROS increased auxin contents but reduced cell division activity and the expression of EXPA8 involved in root elongation. ROS scavenger treatment reversed BPA-triggered root growth retardation, auxin accumulation, and cell division inhibition. In addition, BPA induced ethylene, and ethylene synthesis inhibitor treatment reversed BPA-triggered root growth retardation and auxin accumulation. Taken together, ROS and ethylene are involved in BPA-inhibited cell elongation and cell division by mediating auxin accumulation and redistribution.
PMID: 38008009
Plant Physiol Biochem , IF:4.27 , 2023 Dec , V205 : P108210 doi: 10.1016/j.plaphy.2023.108210
Auxin homeostasis in plant responses to heavy metal stress.
School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.; School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China. Electronic address: jiehuawang@tju.edu.cn.
Expeditious industrialization and anthropogenic activities have resulted in large amounts of heavy metals (HMs) being released into the environment. These HMs affect crop yields and directly threaten global food security. Therefore, significant efforts have been made to control the toxic effects of HMs on crops. When HMs are taken up by plants, various mechanisms are stimulated to alleviate HM stress, including the biosynthesis and transport of auxin in the plant. Interestingly, researchers have noted the significant potential of auxin in mediating resistance to HM stress, primarily by reducing uptake of metals, promoting chelation and sequestration in plant tissues, and mitigating oxidative damage. Both exogenous administration of auxin and manipulation of intrinsic auxin status are effective strategies to protect plants from the negative consequences of HMs stress. Regulation of genes and transcription factors related to auxin homeostasis has been shown to be related to varying degrees to the type and concentration of HMs. Therefore, to derive the maximum benefit from auxin-mediated mechanisms to attenuate HM toxicities, it is essential to gain a comprehensive understanding of signaling pathways involved in regulatory actions. This review primarily emphases on the auxin-mediated mechanisms participating in the injurious effects of HMs in plants. Thus, it will pave the way to understanding the mechanism of auxin homeostasis in regulating HM tolerance in plants and become a tool for developing sustainable strategies for agricultural growth in the future.
PMID: 38006792
Plant Physiol Biochem , IF:4.27 , 2023 Dec , V205 : P108207 doi: 10.1016/j.plaphy.2023.108207
The apple transcription factor MdbHLH4 regulates plant morphology and fruit development by promoting cell enlargement.
State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.; State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China. Electronic address: fwm64@nwsuaf.edu.cn.; State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China. Electronic address: maoke2002@nwsuaf.edu.cn.
The bHLH family, the second largest transcription factor (TF) family in plants, plays a crucial role in regulating plant growth and development processes. However, the biological functions and mechanisms of most bHLH proteins remain unknown, particularly in apples. In this study, we found that MdbHLH4 positively modulates plant growth and development by enhancing cell expansion. Overexpression (OE) of MdbHLH4 resulted in increased biomass, stem and root length, leaf area, and larger areas of pith, xylem, and cortex with greater cell size compared with wild-type apple plants. Conversely, RNA interference (RNAi)-mediated silencing of MdbHLH4 led to reduced xylem and phloem as well as smaller cell size compared to wild-type apple plants. Ectopic expression of MdbHLH4 in tomatoes resulted in enlarged fruits with impaired color appearance, decreased accumulation of soluble solids, and decreased flesh firmness along with larger seeds. Subsequent investigations have shown that MdbHLH4 directly binds to the promoters of MdARF6b and MdPIF4b, enhancing their expression levels. These findings suggest that MdbHLH4 potentially regulates plant cell expansion through auxin and light signaling pathways. These study results not only provide new insights into the roles of bHLH transcription factors in regulating plant growth and development but also contribute to a deeper understanding of their underlying mechanisms.
PMID: 38006791
Plant Physiol Biochem , IF:4.27 , 2023 Dec , V205 : P108160 doi: 10.1016/j.plaphy.2023.108160
Suppression of a hexokinase gene SlHXK1 in tomato affects fruit setting and seed quality.
Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: micy180605@163.com.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: 2446874907@qq.com.; Laboratory of Plant Germplasm Innovation and Utilization, School of Life Sciences, Liaocheng University, Liaocheng, China. Electronic address: zhangjianling0520@126.com.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: 2362779800@qq.com.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: qiaolixie@cqu.edu.cn.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: chenguoping@cqu.edu.cn.; Institute of Grassland, Flowers and Ecology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Chongqing, China. Electronic address: huzongli71@163.com.
Hexokinase is considered to be the key molecule in sugar signaling and metabolism. Here, we reported that silencing SlHXK1 resulted in a decrease in flower number, increased rate of flower dropping, abnormal thickening of the anther wall, and reduced pollen and seed viability. An anatomical analysis revealed the loss of small cells and abnormal thickening of anther walls in SlHXK1-RNAi lines. Treatment with auxin and 1-methylcyclopropene inhibited flower dropping from the pedicel abscission zone. qRT-PCR analysis revealed that the effect of SlHXK1 on abscission was associated with the expression levels of genes related to key meristem, auxin, ethylene, cell wall metabolism and programmed cell death. Pollen germination and pollen staining experiments showed that pollen viability was significantly reduced in the SlHXK1-RNAi lines. Physiological and biochemical analyses showed that hexokinase activity and starch content were markedly decreased in the transgenic lines. The expression of genes related to tomato pollen development was also suppressed in the transgenic lines. Although the RNAi lines eventually produced some viable seeds, the yield and quality of the seeds was lower than that of wild-type plants. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that SlHXK1 interacted with SlKINgamma. Furthermore, SlPIF4 inhibited the transcriptional expression of SlHXK1. In conclusion, our results demonstrate that SlHXK1 may play important roles in pollen, anther, seed and the pedicel abscission zone by affecting starch accumulation or cell wall synthesis, as well as by regulating the number of the transcripts of genes that are involved in auxin, ethylene and cell wall degradation.
PMID: 37944243
BMC Plant Biol , IF:4.215 , 2023 Dec , V23 (1) : P665 doi: 10.1186/s12870-023-04669-y
Embryological observations on seed abortion in Hibiscus syriacus L. and physiological studies on nutrients, enzyme activity and endogenous hormones.
College of Landscape Architecture, Central South University of Forestry & Technology, Changsha, 410004, China. t19960222@csuft.edu.cn.; Hunan Big Data Engineering Technology Research Center of Natural Protected Areas Landscape Resources, Changsha, 410004, China. t19960222@csuft.edu.cn.; College of Landscape Architecture, Central South University of Forestry & Technology, Changsha, 410004, China.; Hunan Big Data Engineering Technology Research Center of Natural Protected Areas Landscape Resources, Changsha, 410004, China.; YeZi Biotechnology company, Yiyang, 413000, China.
Under natural conditions, most Hibiscus syriacus L. individuals form very few mature seeds or the mature seeds that do form are of poor quality. As a result, seed yield is poor and seeds have low natural germinability. These phenomena strongly hinder utilization of the excellent germplasm resources of H. syriacus. The study has shown that pollen activity and stigma receptivity were high on the day of anthesis, and the pistils and stamens were fertile. Pollen release and stigma receptivity were synchronous. But in styles following self and cross-pollination, pollen tube abnormalities (distortion and twisting of the pollen tubes) and callose deposition were observed. Cross-pollinated pollen tubes elongated faster and fewer pollen tube abnormalities were observed compared with self-pollinated pollen tubes. And during embryo development, abnormalities during the heart-shaped embryo stage led to embryo abortion. Imbalance in antioxidant enzyme activities and low contents of auxin and cytokinin during early stages of embryo development may affect embryo development. Therefore, a low frequency of outcrossing and mid-development embryo abortion may be important developmental causes of H. syriacus seed abortion. Nutrient deficiencies, imbalance in antioxidant enzyme activities, and a high content of abscisic acid at advanced stages of seed development may be physiological causes of seed abortion.
PMID: 38129795
BMC Plant Biol , IF:4.215 , 2023 Dec , V23 (1) : P622 doi: 10.1186/s12870-023-04598-w
Genome-wide identification, characterization, and expression analysis of the sweet potato (Ipomoea batatas [L.] Lam.) ARF, Aux/IAA, GH3, and SAUR gene families.
The Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad & Tobago. sarah.mathura@my.uwi.edu.; ScienceVisions Inc, Brookings, SD, USA.; The Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad & Tobago.
BACKGROUND: Auxins are known to have roles in the tuberization process in sweet potato (Ipomoea batatas [L.] Lam.) and these effects are mediated by various auxin signalling gene families. In this study, an analysis of the sweet potato genome was performed to identify the ARF, Aux/IAA, GH3, and SAUR auxin signalling gene family members in this crop. RESULTS: A total of 29 ARF, 39 Aux/IAA, 13 GH3, and 200 SAUR sequences were obtained, and their biochemical properties and gene expression profiles were analysed. The sequences were relatively conserved based on exon-intron structure, motif analysis, and phylogenetic tree construction. In silico expression analyses of the genes in fibrous and storage roots indicated that many sequences were not differentially expressed in tuberizing and non-tuberizing roots. However, some ARF, Aux/IAA, and SAUR genes were up-regulated in tuberizing storage roots compared to non-tuberizing fibrous roots while many GH3 genes were down-regulated. Additionally, these genes were expressed in a variety of plant parts, with some genes being highly expressed in shoots, leaves, and stems while others had higher expression in the roots. Some of these genes are up-regulated during the plant's response to various hormone treatments and abiotic stresses. Quantitative RT-PCR confirmation of gene expression was also conducted, and the results were concordant with the in silico analyses. A protein-protein interaction network was predicted for the differentially expressed genes, suggesting that these genes likely form part of a complex regulatory network that controls tuberization. These results confirm those of existing studies that show that auxin signalling genes have numerous roles in sweet potato growth and development. CONCLUSION: This study provides useful information on the auxin signalling gene families in Ipomoea batatas and suggests putative candidates for further studies on the role of auxin signalling in tuberization and plant development.
PMID: 38057702
BMC Plant Biol , IF:4.215 , 2023 Dec , V23 (1) : P609 doi: 10.1186/s12870-023-04612-1
Arabidopsis seedlings respond differentially to nutrient efficacy of three rock meals by regulating root architecture and endogenous auxin homeostasis.
School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin, 300072, China.; School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin, 300072, China. jianchaozhang@tju.edu.cn.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin, 300072, China. jiehuawang@tju.edu.cn.; School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Weijin Rd. 92, Nankai District, Tianjin, 300072, China.
BACKGROUND: Plants show developmental plasticity with variations in environmental nutrients. Considering low-cost rock dust has been identified as a potential alternative to artificial fertilizers for more sustainable agriculture, the growth responses of Arabidopsis seedlings on three rock meals (basalt, granite, and marlstone) were examined for the different foraging behavior, biomass accumulation, and root architecture. RESULTS: Compared to (1/2) MS medium, basalt and granite meal increased primary root length by 13% and 38%, respectively, but marlstone caused a 66% decrease, and they all drastically reduced initiation and elongation of lateral roots but lengthened root hairs. Simultaneous supply of organic nutrients and trace elements increased fresh weight due to the increased length of primary roots and root hairs. When nitrogen (N), phosphorus (P), and potassium (K) were supplied individually, N proved most effective in improving fresh weight of seedlings growing on basalt and granite, whereas K, followed by P, was most effective for those growing on marlstone. Unexpectedly, the addition of N to marlstone negatively affected seedling growth, which was associated with repressed auxin biosynthesis in roots. CONCLUSIONS: Our data indicate that plants can recognize and adapt to complex mineral deficiency by adjusting hormonal homeostasis to achieve environmental sensitivity and developmental plasticity, which provide a basis for ecologically sound and sustainable strategies to maximize the use of natural resources and reduce the production of artificial fertilizers.
PMID: 38036956
Tree Physiol , IF:4.196 , 2023 Dec doi: 10.1093/treephys/tpad153
The microRNA7833-AUX6 module plays a critical role in wood development by modulating cellular auxin influx in Populus tomentosa.
Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, 400715, China.
The critical role of auxin on secondary vascular development in woody plants has been demonstrated. The concentration gradient of endogenous IAA and the cellular and molecular pathways contributing to the auxin-directed vascular organization and wood growth have been uncovered in recent decades. However, our understanding of the roles and regulations of auxin influx in wood formation in trees remains limited. Here, we reported that a microRNA, miR7833, participates in the negative regulation of stem cambial cell division and secondary xylem development in Populus tomentosa. miR7833 is mainly expressed in the vascular cambium during stem radical growth and specifically targets and represses two AUX/LAX family auxin influx carriers, AUX5 and 6, in poplar. We further revealed that poplar AUX6, the most abundant miR7833 target in the stem, is preferentially enriched in the developing xylem and is a positive regulator for cell division and differentiation events during wood formation. Moreover, inhibition of auxin influx carriers by 1-naphthoxyacetic acids (1-NOA) abolished the regulatory effects of miR7833 and AUX6 on secondary xylem formation in poplar. Our results revealed the essential roles of the miR7833-AUX6 module in regulating cellular events in secondary xylem development and demonstrated an auxin influx-dependent mechanism for wood formation in poplar.
PMID: 38113530
Mol Plant Microbe Interact , IF:4.171 , 2023 Dec doi: 10.1094/MPMI-10-23-0170-R
AefR, a TetR family transcriptional repressor, regulates several auxin responses in Pseudomonas syringae strain PtoDC3000.
Washington University, Biology Dept., St. Louis, Missouri, United States; johnsonjosh@wustl.edu.; Washington University, Biology Dept., Campus Box 1137, 1 Brookings Dr., St. Louis, Missouri, United States, 63130-4899; kunkel@wustl.edu.
The plant hormone Indole-3-acetic acid (IAA), also known as auxin, plays important roles in plant growth and development, as well as in several plant-microbe interactions. IAA also acts as a microbial signal and in many bacteria regulates metabolism, stress responses and virulence. In the bacterial plant pathogen Pseudomonas syringae pv. tomato strain DC3000 (PtoDC3000), exposure to IAA results in large scale transcriptional reprogramming, including the differential expression of several known virulence genes. However, how PtoDC3000 senses and responds to IAA and what aspects of its biology are regulated by IAA is not understood. To investigate the mechanisms involved in perceiving and responding to IAA, we carried out a genetic screen for mutants with altered responses to IAA. One group of mutants of particular interest carried disruptions in the aefR gene encoding a TetR family transcriptional regulator. Gene expression analysis confirmed that the aefR mutants have altered responses to IAA. Thus, AefR is the first demonstrated auxin response regulator in PtoDC3000. We also investigated several aspects of PtoDC3000 biology that are regulated by both AefR and IAA, including antibiotic resistance, motility, and virulence. The observation that the aefR mutant has altered virulence on Arabidopsis, suggests that the sector of the IAA response regulated by aefR is important during pathogenesis. Our findings also provide evidence that AefR plays a role in coordinating changes in gene expression during the transition from early to late stages of infection.
PMID: 38079389
Plant Mol Biol , IF:4.076 , 2023 Dec , V113 (6) : P367-382 doi: 10.1007/s11103-023-01394-w
The interplay between cell wall integrity and cell cycle progression in plants.
Faculty of Natural Sciences, Institute for Biology, Norwegian University of Science and Technology, 5 Hogskoleringen, 7491, Trondheim, Norway.; Faculty of Natural Sciences, Institute for Biology, Norwegian University of Science and Technology, 5 Hogskoleringen, 7491, Trondheim, Norway. laura.bacete@umu.se.; Department of Plant Physiology, Umea Plant Science Centre (UPSC), Umea University, 901 87, Umea, Sweden. laura.bacete@umu.se.
Plant cell walls are dynamic structures that play crucial roles in growth, development, and stress responses. Despite our growing understanding of cell wall biology, the connections between cell wall integrity (CWI) and cell cycle progression in plants remain poorly understood. This review aims to explore the intricate relationship between CWI and cell cycle progression in plants, drawing insights from studies in yeast and mammals. We provide an overview of the plant cell cycle, highlight the role of endoreplication in cell wall composition, and discuss recent findings on the molecular mechanisms linking CWI perception to cell wall biosynthesis and gene expression regulation. Furthermore, we address future perspectives and unanswered questions in the field, such as the identification of specific CWI sensing mechanisms and the role of CWI maintenance in the growth-defense trade-off. Elucidating these connections could have significant implications for crop improvement and sustainable agriculture.
PMID: 38091166
Plant Mol Biol , IF:4.076 , 2023 Dec , V113 (6) : P383-400 doi: 10.1007/s11103-023-01391-z
Xylobiose treatment triggers a defense-related response and alters cell wall composition.
Laboratory of Plant Cell Wall Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, Haryana, 121001, India.; Laboratory of Plant Cell Wall Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, Haryana, 121001, India. prashant.pawar@rcb.res.in.
Plant cell wall-derived oligosaccharides, i.e., damage-associated molecular patterns (DAMPs), could be generated after pathogen attack or during normal plant development, perceived by cell wall receptors, and can alter immunity and cell wall composition. Therefore, we hypothesised that xylo-oligosaccharides (XOS) could act as an elicitor and trigger immune responses. To test this, we treated Arabidopsis with xylobiose (XB) and investigated different parameters. XB-treatment significantly triggered the generation of reactive oxygen species (ROS), activated MAPK protein phosphorylation, and induced callose deposition. The combination of XB (DAMP) and flg22 a microbe-associated molecular pattern (MAMP) further enhanced ROS response and gene expression of PTI marker genes. RNA sequencing analysis revealed that more genes were differentially regulated after 30 min compared to 24 h XB-treated leaves, which correlated with ROS response. Increased xylosidase activity and soluble xylose level after 30 min and 3 h of XB-treatment were observed which might have weakened the DAMP response. However, an increase in total cell wall sugar and a decrease in uronic acid level was observed at both 30 min and 24 h. Additionally, arabinose, rhamnose, and xylose levels were increased in 30 min, and glucose was increased in 24 h compared to mock-treated leaves. The level of jasmonic acid, abscisic acid, auxin, and cytokinin were also affected after XB treatment. Overall, our data revealed that the shortest XOS can act as a DAMP, which triggers the PTI response and alters cell wall composition and hormone level.
PMID: 37991689
Phytochemistry , IF:4.072 , 2023 Dec , V216 : P113883 doi: 10.1016/j.phytochem.2023.113883
Auxin and light-mediated regulation of growth, morphogenesis, and alkaloid biosynthesis in Crinum x powellii 'Album' callus.
Department of Chemistry, Biochemistry and Physics, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, Canada.; Department of Chemistry, Biochemistry and Physics, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, Canada; Plant Biology Research Group, Trois-Rivieres, Quebec, Canada. Electronic address: Isabel.Desgagne-Penix@uqtr.ca.
Crinum x powellii 'Album' belongs to the Amaryllidaceae medicinal plant family that produces a range of structurally diverse alkaloids with potential therapeutic properties. The optimal conditions for in vitro tissue growth, morphogenesis, and alkaloid biosynthesis remain unclear. Auxin and light play critical roles in regulating plant growth, development, and alkaloid biosynthesis in several Amaryllidaceae plants. Here, we have succeeded in showing, for the first time, that the combination of auxin and light significantly influence C. x powellii "Album" in vitro tissue growth, survival, and morphogenesis compared to individual treatments. Furthermore, this combination also upregulates the expression of alkaloid biosynthetic genes and led to an increase in the content of certain alkaloids, suggesting a positive impact on the defense and therapeutic potential of the calli. Our findings provide insights into the regulation of genes involved in alkaloid biosynthesis in C. x powellii "Album" callus and underline the potential of auxin and light as tools for enhancing their production in plants. This study provides a foundation for further exploration of C. x powellii "Album" calli as a sustainable source of bioactive alkaloids for pharmaceutical and agricultural applications. Furthermore, this study paves the way to the discovery of the biosynthetic pathway of specialized metabolites from C. x powellii "Album", such as cherylline and lycorine.
PMID: 37820888
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244149
Construction of an Efficient Genetic Transformation System for Watercress (Nasturtium officinale W. T. Aiton).
State Key Laboratory of Crop Genetics & Germplasm Enhancement, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (East China), Ministry of Agriculture and Rural Affairs of China, Engineering Research Center of Germplasm Enhancement and Utilization of Horticultural Crops, Ministry of Education of China, Nanjing Agricultural University, Nanjing 210095, China.
Based on the established efficient regeneration system for watercress in our laboratory, we optimized the processes of pretreatment, co-culture, and differentiation culture. Through GFP fluorescence and PCR identification, we successfully obtained transgenic watercress with the DR5 gene, which allowed us to investigate the distribution details of auxin in the growth process of watercress. Our findings provide an effective method for gene function research and lay the foundation for innovative utilization of germplasm resources of watercress.
PMID: 38140475
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244126
Studies on Improving the Efficiency of Somatic Embryogenesis in Grapevine (Vitis vinifera L.) and Optimising Ethyl Methanesulfonate Treatment for Mutation Induction.
The New Zealand Institute for Plant and Food Research Limited, Batchelar Road, Palmerston North 4472, New Zealand.; Istituto di Bioscienze e BioRisorse (IBBR), Consiglio Nazionale delle Ricerche, Via Ugo la Malfa, 153, 90146 Palermo, Italy.
Somatic embryogenesis (SE) has many applications in grapevine biotechnology including micropropagation, eradicating viral infections from infected cultivars, mass production of hypocotyl explants for micrografting, as a continuous source for haploid and doubled haploid plants, and for germplasm conservation. It is so far the only pathway for the genetic modification of grapevines through transformation. The single-cell origin of somatic embryos makes them an ideal explant for mutation breeding as the resulting mutants will be chimera-free. In the present research, two combinations of plant growth regulators and different explants from flower buds at two stages of maturity were tested in regard to the efficiency of callusing and embryo formation from the callus produced in three white grape cultivars. Also, the treatment of somatic embryos with the chemical mutagen ethyl methanesulfonate (EMS) was optimised. Medium 2339 supplemented with beta-naphthoxyacetic acid (5 muM) and 6-benzylaminopurine (BAP-9.0 muM) produced significantly more calluses than medium 2337 supplemented with 2,4-dichlorophenoxyacetic acid (4.5 microM) and BAP (8.9 microM) in all explants. The calluses produced on medium 2337 were harder and more granular and produced more SEs. Although the stage of the maturity of floral bud did not have a significant effect on the callusing of the explants, calluses produced from immature floral bud explants in the premeiotic stage produced significantly more SEs than those from more mature floral buds. Overall, immature ovaries and cut floral buds exposing the cut ends of filaments, style, etc., tested for the first time in grapevine SE, produced the highest percentage of embryogenic calluses. It is much more efficient to cut the floral bud and culture than previously reported explants such as anthers, ovaries, stigmas and styles during the short flowering period when the immature flower buds are available. When the somatic embryos of the three cultivars were incubated for one hour with 0.1% EMS, their germination was reduced by 50%; an ideal treatment considered to obtain a high frequency of mutations for screening. Our research findings will facilitate more efficient SE induction in grapevines and inducing mutations for improving individual traits without altering the genetic background of the cultivar.
PMID: 38140453
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244111
The Roles of GRETCHEN HAGEN3 (GH3)-Dependent Auxin Conjugation in the Regulation of Plant Development and Stress Adaptation.
College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.; State Key Laboratory 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.
The precise control of free auxin (indole-3-acetic acid, IAA) gradient, which is orchestrated by biosynthesis, conjugation, degradation, hydrolyzation, and transport, is critical for all aspects of plant growth and development. Of these, the GRETCHEN HAGEN 3 (GH3) acyl acid amido synthetase family, pivotal in conjugating IAA with amino acids, has garnered significant interest. Recent advances in understanding GH3-dependent IAA conjugation have positioned GH3 functional elucidation as a hot topic of research. This review aims to consolidate and discuss recent findings on (i) the enzymatic mechanisms driving GH3 activity, (ii) the influence of chemical inhibitor on GH3 function, and (iii) the transcriptional regulation of GH3 and its impact on plant development and stress response. Additionally, we explore the distinct biological functions attributed to IAA-amino acid conjugates.
PMID: 38140438
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244103
Hydrangea arborescens 'Annabelle' Flower Formation and Flowering in the Current Year.
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, China National Engineering Research Center for Floriculture, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China.; Beijing Flower Engineering Technology Research Center, Plant Institute, China National Botanical Garden North Garden, Beijing 100093, China.
The perennial woody plant Hydrangea arborescens 'Annabelle' is of great research value due to its unique mechanism of flower development that occurs in the current year, resulting in decorative flowers that can be enjoyed for a relatively long period of time. However, the mechanisms underlying the regulation of current-year flower development in H. arborescens 'Annabelle' are still not fully understood. In this study, we conducted an associated analysis to explore the core regulating network in H. arborescens 'Annabelle' by combining phenological observations, physiological assays, and transcriptome comparisons across seven flower developmental stages. Through this analysis, we constructed a gene co-expression network (GCN) based on the highest reciprocal rank (HRR), using 509 differentially expressed genes (DEGs) identified from seven flowering-related pathways, as well as the biosynthesis of eight flowering-related phytohormones and signal transduction in the transcriptomic analysis. According to the analysis of the GCN, we identified 14 key genes with the highest functional connectivity that played critical roles in specific development stages. We confirmed that 135 transcription factors (AP2/ERF, bHLH, CO-like, GRAS, MIKC, SBP, WRKY) were highly co-expressed with the 14 key genes, indicating their close associations with the development of current-year flowers. We further proposed a hypothetical model of a gene regulatory network for the development of the whole flower. This model suggested that the photoperiod, aging, and gibberellin pathways, along with the phytohormones abscisic acid (ABA), gibberellin (GA), brassinosteroid (BR), and jasmonic acid (JA), work synergistically to promote the floral transition. Additionally, auxin, GA, JA, ABA, and salicylic acid (SA) regulated the blooming process by involving the circadian clock. Cytokinin (CTK), ethylene (ETH), and SA were key regulators that affected flower senescence. Additionally, several floral integrators (HaLFY, HaSOC1-2, HaAP1, HaFULL, HaAGL24, HaFLC, etc.) were dominant contributors to the development of H. arborescens flowers. Overall, this research provides a comprehensive understanding of the dynamic mechanism underlying the entire process of current-year flower development, thereby offering valuable insights for further studies on the flower development of H. arborescens 'Annabelle'.
PMID: 38140430
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244095
Proteomic Approach during the Induction of Somatic Embryogenesis in 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 CP 97205, Yucatan, Mexico.; Red de Estudios Moleculares Avanzados, Cluster Cientifico y Tecnologico BioMimic(R), Instituto de Ecologia A.C. (INECOL), Carretera Antigua a Coatepec No. 351, Congregacion el Haya, Xalapa CP 91070, Veracruz, Mexico.
Plant growth regulators (PGR) are essential for somatic embryogenesis (SE) in different species, and Coffea canephora is no exception. In our study model, previously, we have been able to elucidate the participation of various genes involved in SE by using different strategies; however, until now, we have not used a proteomic approach. This research seeks to contribute to understanding the primary cellular pathways involved in developing SE in C. canephora. The process of our model consists of two stages: (1) preconditioning in MS medium with auxin (NAA) and cytokinin (KIN), and (2) induction in Yasuda liquid medium added with cytokinin (BA). Therefore, in this study, we analyzed different days of the SE induction process using shotgun label-free proteomics. An amount of 1630 proteins was found among different sampling days of the process, of which the majority were accumulated during the induction stage. We found that some of the most enriched pathways during this process were the biosynthesis of amino acids and secondary metabolites. Eighteen proteins were found related to auxin homeostasis and two to cytokinin metabolism, such as ABC, BIG, ILR, LOG, and ARR. Ten proteins and transcription factors related to SE were also identified, like SERK1, SKP1, nuclear transcription factor Y, MADS-box, and calreticulin, and 19 related to other processes of plant development, among which the 14-3-3 and PP2A proteins stand out. This is the first report on the proteomic approach to elucidate the mechanisms that operate during the induction of SE in C. canephora. So, our findings provide the groundwork for future, more in-depth research. Data are available via ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD047172.
PMID: 38140424
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (24) doi: 10.3390/plants12244076
Arabidopsis Root Development Regulation by the Endogenous Folate Precursor, Para-Aminobenzoic Acid, via Modulation of the Root Cell Cycle.
Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland.; Faculty of Biology, Institute of Biology II, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany.; Department of Biology, Faculty of Sciences, Science and Technology University of Masuku, Franceville P.O. Box 913, Gabon.; Lighthouse Core Facility, Medical Center University of Freiburg, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany.; Bio Imaging Core Light Microscopy (BiMiC), Institute for Disease Modelling and Targeted Medicine (IMITATE), Medical Center University of Freiburg, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany.
The continuous growth of roots depends on their ability to maintain a balanced ratio between cell production and cell differentiation at the tip. This process is regulated by the hormonal balance of cytokinin and auxin. However, other important regulators, such as plant folates, also play a regulatory role. In this study, we investigated the impact of the folate precursor para-aminobenzoic acid (PABA) on root development. Using pharmacological, genetic, and imaging approaches, we show that the growth of Arabidopsis thaliana roots is repressed by either supplementing the growth medium with PABA or overexpressing the PABA synthesis gene GAT-ADCS. This is associated with a smaller root meristem consisting of fewer cells. Conversely, reducing the levels of free root endogenous PABA results in longer roots with extended meristems. We provide evidence that PABA represses Arabidopsis root growth in a folate-independent manner and likely acts through two mechanisms: (i) the G2/M transition of cell division in the root apical meristem and (ii) promoting premature cell differentiation in the transition zone. These data collectively suggest that PABA plays a role in Arabidopsis root growth at the intersection between cell division and cell differentiation.
PMID: 38140403
Plants (Basel) , IF:3.935 , 2023 Dec , V12 (23) doi: 10.3390/plants12234058
Deficiency of Auxin Efflux Carrier OsPIN1b Impairs Chilling and Drought Tolerance in Rice.
College of Agriculture, Henan University of Science and Technology, Luoyang 471000, China.
Significant progress has been made in the functions of auxin efflux transporter PIN-FORMED (PIN) genes for the regulation of growth and development in rice. However, knowledge on the roles of OsPIN genes in abiotic stresses is limited. We previously reported that the mutation of OsPIN1b alters rice architecture and root gravitropism, while the role of OsPIN1b in the regulation of rice abiotic stress adaptations is still largely elusive. In the present study, two homozygous ospin1b mutants (C1b-1 and C1b-2) were employed to investigate the roles of OsPIN1b in regulating abiotic stress adaptations. Low temperature gradually suppressed OsPIN1b expression, while osmotic stress treatment firstly induced and then inhibited OsPIN1b expression. Most OsPIN genes and auxin biosynthesis key genes OsYUC were up-regulated in ospin1b leaves, implying that auxin homeostasis is probably disturbed in ospin1b mutants. The loss of function of OsPIN1b significantly decreased rice chilling tolerance, which was evidenced by decreased survival rate, increased death cells and ion leakage under chilling conditions. Compared with the wild-type (WT), ospin1b mutants accumulated more hydrogen peroxide (H(2)O(2)) and less superoxide anion radicals (O2-) after chilling treatment, indicating that reactive oxygen species (ROS) homeostasis is disrupted in ospin1b mutants. Consistently, C-repeat binding factor (CBF)/dehydration-responsive element binding factor (DREB) genes were downregulated in ospin1b mutants, implying that OsDREB genes are implicated in OsPIN1b-mediated chilling impairment. Additionally, the mutation of OsPIN1b led to decreased sensitivity to abscisic acid (ABA) treatment in seed germination, impaired drought tolerance in the seedlings and changed expression of ABA-associated genes in rice roots. Taken together, our investigations revealed that OsPIN1b is implicated in chilling and drought tolerance in rice and provide new insight for improving abiotic stress tolerance in rice.
PMID: 38068693
Gene , IF:3.688 , 2023 Dec : P148080 doi: 10.1016/j.gene.2023.148080
Transcriptomic Changes in Soybean Underlying Growth Promotion and Defense Against Cyst Nematode After Bacillus simplex Sneb545 Treatment.
College of Environment, Shenyang University, Shenyang 110044, PR China.; College of plant protection, Shenyang Agricultural University, Shenyang 110866, PR China.; Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, PR China. Electronic address: piaolei9411@163.com.
Bacillus simplex Sneb45 is a plant-growth-promoting rhizobacterium that promotes soybean growth and systemic resistance to cyst nematode. To investigate transcriptional changes in soybean roots in response to B. simplex Sneb45 treatment, transcriptome analysis and quantitative real-time PCR were conducted to detect and validate the differentially expressed genes (DEGs). In total, 19,109 DEGs were obtained. After B. simplex Sneb545 treatment, 970 and 1265 genes were up- and down-regulated at 5 days post-inoculation (dpi), respectively, and 142 and 47 genes were up- and down-regulated at 10 dpi, respectively, compared with untreated soybean roots. Functional annotation of DEGs indicated that B. simplex Sneb545 regulated soybean growth and defense against cyst nematode possibly through genes related to auxin, gibberellin, and NB-LRR protein. In addition, GO and KEGG enrichment analyses indicated that the DEGs were enriched in metabolism, signal transduction, and plant-pathogen interaction pathways. Moreover, the auxin and gibberellin contents were lower in B. simplex Sneb545-treated soybean roots than in untreated roots at 5 dpi. B. simplex Sneb545 possibly altered the expression of wound-induced protein and NAC transcription factor to regulate soybean growth and defense against cyst nematode. Our study provided deep insights into the alterations in soybean transcriptome after exposure to B. simplex Sneb45 and a theoretical basis for further exploring molecular functions underlying the biological control activity of B. simplex Sneb545.
PMID: 38101712
Gene , IF:3.688 , 2023 Dec , V888 : P147758 doi: 10.1016/j.gene.2023.147758
Cloning and functional analysis prohibitins protein-coding gene EuPHB1 in Eucommia ulmoides Oliver.
The 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.; Guizhou Plant Conservation Technology Center, Biotechnology Institute of Guizhou, Guizhou Academy of Agricultural Sciences, Guiyang 550006, China. Electronic address: dgzhao@gzu.edu.cn.
As multifunctional proteins, prohibitins(PHBs) participate in many cellular processes and play essential roles in organisms. In this study, using rapid amplification of cDNA end (RACE) technology, EuPHB1 was cloned from Eucommia ulmoides Oliver (E. ulmoides). A subcellular localization assay preliminarily located EuPHB1 in mitochondria. Then EuPHB1 was transformed into tobacco, and phenotype analyses showed that overexpression of EuPHB1 caused leaves to become chlorotic and shrivel. Furthermore, genes related to hormone and auxin signal transduction, auxin binding, and transport, such as ethylene-responsive transcription factor CRF4-like and ABC transporter B family member 11-like, were significantly inhibited in response to EuPHB1 overexpression. Its overexpression disturbs the original signal transduction pathway, thus causing the corresponding phenotypic changes in transgenic tobacco. Indeed, such overexpression caused fading of palisade tissue and an increase in the number of certain mesophyll cells. It also increased adenosine triphosphate (ATP) synthase activity, mitochondrial membrane potential, ATP content, and reactive oxygen species (ROS) levels in cells. Our results suggest that EuPHB1 expression promotes cellular energy metabolism by accelerating the oxidative phosphorylation of the mitochondrial respiratory chain. Elevated levels of EuPHB1 in the mitochondria, which helps supply the extra energy required to support rapid rates of cell division.
PMID: 37661028
J Plant Physiol , IF:3.549 , 2023 Dec , V291 : P154117 doi: 10.1016/j.jplph.2023.154117
Dormancy-Associated Gene 1 (OsDRM1) as an axillary bud dormancy marker: Retarding Plant Development, and Modulating Auxin Response in Rice (Oryza sativa L.).
Horticultural Science Research Center, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: chenruihong@nwafu.edu.cn.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.; College of Forest, Northwest A&F University, Yangling, Shaanxi, 712100, China.; Horticultural Science Research Center, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Dormancy-Associated Genes 1/Auxin-Repressed Proteins (DRM1/ARP) are associated with bud dormancy, repression of plant growth, and responsiveness to hormones. To further explore the function of DRM1 proteins in rice, we isolated a dormancy-associated gene1 (OsDRM1) through microarray analysis. In situ hybridization analyses revealed that OsDRM1 is predominantly expressed in dormant axillary buds, while it is weakly expressed in growing buds, indicating that OsDRM1 gene can be used as a molecular marker for bud dormancy in rice. Overexpression of OsDRM1 in transgenic plants delayed axillary bud outgrowth by suppressing cell division within the buds. Further studies in OsDRM1-overexpressing transgenic plants showed a reduction in plant height, inhibition of root and hypocotyl elongation, and delayed heading time. Under auxin treatment, overexpression of OsDRM1 in transgenic lines partially rescued the shortened length of the primary and crown root. Taken together, these results indicated that OsDRM1 delayed bud growth by arresting the cell cycle and act as a growth repressor affect rice development by modulated auxin signaling.
PMID: 37924628
J Biotechnol , IF:3.307 , 2023 Dec , V379 : P87-97 doi: 10.1016/j.jbiotec.2023.12.007
Adventitious root culture of Lessertia frutescens for the production of triterpenoid saponins and polysaccharides.
Agricultural College of Yanbian University, Park Road 977, Jilin, Yanji 133002, China.; Department of Horticultural Science, Chungbuk National University, Cheongju, Republic of Korea.; Agricultural College of Yanbian University, Park Road 977, Jilin, Yanji 133002, China. Electronic address: nyypxc@ybu.edu.cn.; Agricultural College of Yanbian University, Park Road 977, Jilin, Yanji 133002, China. Electronic address: lianmeilan2001@163.com.
Lessertia frutescens is a perennial shrub of commercial importance in South Africa, but the scarcity of plant resources has limited current product production. In this study, to provide an alternative approach for obtaining L. frutescens material, adventitious roots (ARs) were induced from sterilized seedlings and cultured in a suspension culture system. During this process, selection tests were conducted to find a suitable auxin and its concentration for AR induction and a suitable basal medium for AR growth and metabolite accumulation; a kinetic study was then performed to constructure kinetic models. The results showed that compared to other auxins and concentrations, indole-3-butyric acid at 3 mg/L was suitable for increasing the number and length of ARs during AR induction. In AR suspension culture, Schenk and Hildebrandt (SH) was better than other basal media, and the maximum AR fresh (86.9 g/L) or dry weight (5.5 g/L), total triterpenoid saponin (92.6 mg/g DW), and polysaccharide (114.7 mg/g DW) contents were determined in the 1.5xSH medium. In addition, AR biomass and metabolite contents reached the maximum on day 42. The kinetic models for AR growth and triterpenoid and polysaccharide production were constructed, providing the basis for further optimization of culture conditions and large-scale culture.
PMID: 38103580
PLoS One , IF:3.24 , 2023 , V18 (12) : Pe0285241 doi: 10.1371/journal.pone.0285241
AtMYB50 regulates root cell elongation by upregulating PECTIN METHYLESTERASE INHIBITOR 8 in Arabidopsis thaliana.
Faculty of Agriculture, Meijo University, Nagoya, Aichi, Japan.; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan.; Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, Kasugai, Aichi, Japan.
Plant root development involves multiple signal transduction pathways. Notably, phytohormones like auxin and cytokinin are well characterized for their molecular mechanisms of action. Reactive oxygen species (ROS) serve as crucial signaling molecules in controlling root development. The transcription factor, UPBEAT1 (UPB1) is responsible for maintaining ROS homeostasis at the root tip, influencing the transition from cell proliferation to differentiation. While UPB1 directly regulates peroxidase expression to control ROS homeostasis, it targets genes other than peroxidases, suggesting its involvement in root growth through non-ROS signals. Our investigation focused on the transcription factor MYB50, a direct target of UPB1, in Arabidopsis thaliana. By analyzing multiple fluorescent proteins and conducting RNA-seq and ChIP-seq, we unraveled a step in the MYB50 regulatory gene network. This analysis, in conjunction with the UPB1 regulatory network, demonstrated that MYB50 directly regulates the expression of PECTIN METHYLESTERASE INHIBITOR 8 (PMEI8). Overexpressing PMEI8, similar to the MYB50, resulted in reduced mature cell length. These findings establish MYB50 as a regulator of root growth within the UPB1 gene regulatory network. Our study presents a model involving transcriptional regulation by MYB50 in the UPB1 regulated root growth system and sheds light on cell elongation via pectin modification.
PMID: 38134185
PLoS One , IF:3.24 , 2023 , V18 (11) : Pe0287084 doi: 10.1371/journal.pone.0287084
Diversity and plant growth promoting ability of rice root-associated bacteria in Burkina-Faso and cross-comparison with metabarcoding data.
INERA, Institut de l'Environnement et de Recherches Agricoles du Burkina Faso, Bobo-Dioulasso, Burkina Faso.; PHIM Plant Health Institute, IRD, CIRAD, INRAE, Institut Agro, Univ. Montpellier, Montpellier, France.; Universite Joseph Ki Zerbo, Ouagadougou, Burkina Faso.; LMI Pathobios, Observatoire des Agents Phytopathogenes en Afrique de l'Ouest, Bobo-Dioulasso, Burkina Faso.
Plant-associated bacteria are essential partners in plant health and development. In addition to taking advantage of the rapid advances recently achieved in high-throughput sequencing approaches, studies on plant-microbiome interactions require experiments with culturable bacteria. A study on the rice root microbiome was recently initiated in Burkina Faso. As a follow up, the aim of the present study was to develop a collection of corresponding rice root-associated bacteria covering maximum diversity, to assess the diversity of the obtained isolates based on the culture medium used, and to describe the taxonomy, phenotype and abundance of selected isolates in the rice microbiome. More than 3,000 isolates were obtained using five culture media (TSA, NGN, NFb, PCAT, Baz). The 16S rRNA fragment sequencing of 1,013 selected isolates showed that our working collection covered four bacterial phyla (Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes) and represented 33% of the previously described diversity of the rice root microbiome at the order level. Phenotypic in vitro analysis of the plant growth promoting capacity of the isolates revealed an overall ammonium production and auxin biosynthesis capacity, while siderophore production and phosphate solubilisation were enriched in Burkholderia, Ralstonia, Acinetobacter and Pseudomonas species. Of 45 representative isolates screened for growth promotion on seedlings of two rice cultivars, five showed an ability to improve the growth of both cultivars, while five others were effective on only one cultivar. The best results were obtained with Pseudomonas taiwanensis ABIP 2315 and Azorhizobium caulinodans ABIP 1219, which increased seedling growth by 158% and 47%, respectively. Among the 14 best performing isolates, eight appeared to be abundant in the rice root microbiome dataset from previous study. The findings of this research contribute to the in vitro and in planta PGP capacities description of rice root-associated bacteria and their potential importance for plants by providing, for the first time, insight into their prevalence in the rice root microbiome.
PMID: 38032916
Int J Phytoremediation , IF:3.212 , 2024 , V26 (1) : P27-44 doi: 10.1080/15226514.2023.2216311
2,4-D mediated moderation of aluminum tolerance in Salvinia molesta D. Mitch. with regards to bioexclusion and related physiological and metabolic changes.
Department of Botany, Plant Physiology, Biochemistry and Plant Molecular Biology Research Unit, University of Kalyani, Kalyani, India.; Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.; Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Takamatsu, Japan.
We examined the efficacy of 2,4-dichlorophenoxy acetic acid (2,4-D; 500 microM) in enhancing the potential of Salvinia species for tolerance to aluminum (Al) toxicity (240 and 480 microM, seven days). Salvinia showed better efficacy in removal of toxicity of Al by sorption mechanism with changes of bond energy shifting on cell wall residues and surface structure. Plants recorded tolerance to Al concentration (480 microM) when pretreated with 2,4-D through adjustment of relative water content, proline content, osmotic potential, and improved the pigment fluorescence for energy utilization under Al stress. Photosynthetic activities with regards to NADP-malic enzyme and malic dehydrogenase and sugar metabolism with wall and cytosolic invertase activities were strongly correlated with compatible solutes. A less membrane peroxidation and protein carbonylation had reduced ionic loss over the membrane that was studied with reduced electrolyte leakage with 2,4-D pretreated plants. Membrane stabilization was also recorded with higher ratio of K(+) to Na(+), thereby suggesting roles of 2,4-D in ionic balance. Better sustenance of enzymatic antioxidation with peroxidase and glutathione metabolism reduced reactive oxygen species accumulation and save the plant for oxidative damages. Moreover, gene polymorphism for antioxidant, induced by 2,4-D varied through Al concentrations would suggest an improved biomarker for tolerance. Collectively, analysis and discussion of plant's responses assumed that auxin herbicide could be a potential phytoprotectant for Salvinia as well as improving the stability to Al toxicity and its bioremediation efficacy.
PMID: 37259532
Funct Plant Biol , IF:3.101 , 2023 Dec , V50 (12) : P1086-1098 doi: 10.1071/FP23013
Integrated analysis of transcriptomic and proteomic data reveals novel regulators of soybean (Glycine max) hypocotyl development.
Hypocotyl elongation directly affects the seedling establishment and soil-breaking after germination. In soybean (Glycine max ), the molecular mechanisms regulating hypocotyl development remain largely elusive. To decipher the regulatory landscape, we conducted proteome and transcriptome analysis of soybean hypocotyl samples at different development stages. Our results showed that during hypocotyl development, many proteins were with extreme high translation efficiency (TE) and may act as regulators. These potential regulators include multiple peroxidases and cell wall reorganisation related enzymes. Peroxidases may produce ROS including H2 O2 . Interestingly, exogenous H2 O2 application promoted hypocotyl elongation, supporting peroxidases as regulators of hypocotyl development. However, a vast variety of proteins were shown to be with dramatically changed TE during hypocotyl development, including multiple phytochromes, plasma membrane intrinsic proteins (PIPs) and aspartic proteases. Their potential roles in hypocotyl development were confirmed by that ectopic expression of GmPHYA1 and GmPIP1-6 in Arabidopsis thaliana affected hypocotyl elongation. In addition, the promoters of these potential regulatory genes contain multiple light/gibberellin/auxin responsive elements, while the expression of some members in hypocotyls was significantly regulated by light and exogenous auxin/gibberellin. Overall, our results revealed multiple novel regulatory factors of soybean hypocotyl elongation. Further research on these regulators may lead to new approvals to improve soybean hypocotyl traits.
PMID: 37866377
3 Biotech , IF:2.406 , 2023 Dec , V13 (12) : P420 doi: 10.1007/s13205-023-03837-z
Groundnut harbours non-nodulating non-rhizobial plant growth-promoting bacterial endophytes.
Department of Microbiology, College of Basic Sciences and Humanities, Punjab Agricultural University, Ludhiana, Punjab 141004 India. ROR: https://ror.org/02qbzdk74. GRID: grid.412577.2. ISNI: 0000 0001 2176 2352; Department of Soil Science, College of Agriculture, Punjab Agricultural University, Ludhiana, Punjab 141004 India. ROR: https://ror.org/02qbzdk74. GRID: grid.412577.2. ISNI: 0000 0001 2176 2352; Oilseed Section, Department of Plant Breeding and Genetics, College of Agriculture, Punjab Agricultural University, Ludhiana, Punjab 141004 India. ROR: https://ror.org/02qbzdk74. GRID: grid.412577.2. ISNI: 0000 0001 2176 2352
The present study was carried out to assess the growth-promoting ability of non-rhizobial endophytes in groundnut (Arachis hypogaea). Thirteen endophytic bacteria with different morphologies were isolated from the root and nodules of groundnut. These isolates significantly enhanced the growth of groundnut in sterilised vermiculite, though the isolates were unable to nodulate the host plant. The endophytic nature of these isolates was confirmed by their re-isolation from the sterilised and macerated roots of the plants. The isolates exhibited in vitro tricalcium phosphate and zinc solubilization, production of siderophores, auxins and ammonia as well as growth on different nitrogen-free media. The phosphate solubilization and auxin production varied from 50 to 196 and 17 to 71 microg/ml, respectively by the isolates. Based on phenotypic tests and 16S rRNA gene sequencing, four potential strains were identified as Klebsiella sp. R3, Pseudomonas putida R6, Klebsiella oxytoca GRE5 and Pseudomonas proteolytica GRE6. A significant increase in plant growth, chlorophyll content, nodule count and shoot nutrient content of groundnut was observed with these bacterial inoculations over the uninoculated control in greenhouse. The bacterial treatments resulted in increased N, P and K content in the shoot up to 87, 96 and 44%, respectively, over the control. Physico-chemical properties and available nutrient content of soil were also improved on bacterial inoculations. The results indicated that groundnut harbours beneficial non-rhizobial bacterial endophytes with the potential to be used as microbial inoculants in groundnut. Klebsiella oxytoca as a non-nodulating nodule endophyte of groundnut is reported for the first time.
PMID: 38037659
Behav Pharmacol , IF:2.293 , 2023 Dec , V34 (8) : P488-493 doi: 10.1097/FBP.0000000000000758
MA-5 ameliorates autism-like behavior in mice prenatally exposed to valproic acid.
Specialty Medicine Research Laboratories II, Daiichi Sankyo Co., Ltd., Tokyo, Japan.
Indole-3-acetic acid is a common naturally occurring auxin in plants. A synthesized derivative of this compound, 4-(2,4-difluorophenyl)-2-(1H-indol-3-yl)-4-oxobutanoic acid also called mitochonic acid 5 (MA-5), has shown to increase the survival ratio of fibroblasts from patients with mitochondrial disease under stress-induced conditions. Further studies verified its efficacy in pathological models, such as an ischemia-reperfusion model, possibly by increasing ATP production. However, the efficacy of MA-5 in mental disorders, such as anxiety, schizophrenia, and autism spectrum disorders (ASD), has not been investigated. Our study focused on examining the effect of MA-5 in a mouse model of ASD induced by prenatal exposure to valproic acid (VPA). VPA exposure significantly deteriorated the level of anxiety and exploratory behavior in an open field test. We fed mice an MA-5-containing diet for 5 weeks and observed an improvement in the above behavior in the MA-5-fed groups. The efficacy of MA-5 was also observed in the elevated plus maze and three-chambered tests. These findings suggest that MA-5 could potentially be used to treat ASD, especially in patients with mitochondrial dysfunction.
PMID: 37917568
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2270835 doi: 10.1080/15592324.2023.2270835
Quercetin induces pathogen resistance through the increase of salicylic acid biosynthesis in Arabidopsis.
Division of Applied Life Science (BK21 Four Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Republic of Korea.
Quercetin is a flavonol belonging to the flavonoid group of polyphenols. Quercetin is reported to have a variety of biological functions, including antioxidant, pigment, auxin transport inhibitor and root nodulation factor. Additionally, quercetin is known to be involved in bacterial pathogen resistance in Arabidopsis through the transcriptional increase of pathogenesis-related (PR) genes. However, the molecular mechanisms underlying how quercetin promotes pathogen resistance remain elusive. In this study, we showed that the transcriptional increases of PR genes were achieved by the monomerization and nuclear translocation of nonexpressor of pathogenesis-related proteins 1 (NPR1). Interestingly, salicylic acid (SA) was approximately 2-fold accumulated by the treatment with quercetin. Furthermore, we showed that the increase of SA biosynthesis by quercetin was induced by the transcriptional increases of typical SA biosynthesis-related genes. In conclusion, this study strongly suggests that quercetin induces bacterial pathogen resistance through the increase of SA biosynthesis in Arabidopsis.
PMID: 37902267
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2261744 doi: 10.1080/15592324.2023.2261744
The HOS1-PIF4/5 module controls callus formation in Arabidopsis leaf explants.
Department of Chemistry, Seoul National University, Seoul, Korea.; Research Institute of Basic Sciences, Seoul National University, Seoul, Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul, Korea.
A two-step plant regeneration has been widely exploited to genetic manipulation and genome engineering in plants. Despite technical importance, understanding of molecular mechanism underlying in vitro plant regeneration remains to be fully elucidated. Here, we found that the HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1 (HOS1)-PHYTOCHROME INTERACTING FACTOR 4/5 (PIF4/5) module participates in callus formation. Consistent with the repressive role of HOS1 in PIF transcriptional activation activity, hos1-3 mutant leaf explants exhibited enhanced callus formation, whereas pif4-101 pif5-3 mutant leaf explants showed reduced callus size. The HOS1-PIF4/5 function would be largely dependent on auxin biosynthesis and signaling, which are essential for callus initiation and proliferation. Our findings suggest that the HOS1-PIF4/5 module plays a pivotal role in auxin-dependent callus formation in Arabidopsis.
PMID: 37747842
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2218670 doi: 10.1080/15592324.2023.2218670
ChIFNalpha regulates adventitious root development in Lotus japonicus via an auxin-mediated pathway.
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, Guizhou Province, China.; Department of Genetics, University of Georgia, Athens, GA, USA.
Adventitious roots (ARs), developing from non-root tissue, play an important role in some plants. Here, the molecular mechanism of AR differentiation in Lotus japonicus L. (L. japonicus) with the transformed chicken interferon alpha gene (ChIFNalpha) encoding cytokine was studied. ChIFNalpha transgenic plants (TP) were identified by GUS staining, PCR, RT-PCR, and ELISA. Up to 0.175 mug/kg rChIFNalpha was detected in TP2 lines. Expressing rChIFNalpha promotes AR development by producing longer roots than controls. We found that the effect was enhanced with the auxin precursor IBA treatment in TP. IAA contents, POD, and PPO activities associated with auxin regulation were higher than wild type (WT) in TP and exogenous ChIFNalpha treatment plants. Transcriptome analysis revealed 48 auxin-related differentially expressed genes (DEGs) (FDR < 0.05), which expression levels were verified by RT-qPCR analysis. GO enrichment analysis of DEGs also highlighted the auxin pathway. Further analysis found that ChIFNalpha significantly enhanced auxin synthesis and signaling mainly with up-regulated genes of ALDH, and GH3. Our study reveals that ChIFNalpha can promote plant AR development by mediating auxin regulation. The findings help explore the role of ChIFNalpha cytokines and expand animal gene sources for the molecular breeding of growth regulation of forage plants.
PMID: 37288791
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2207845 doi: 10.1080/15592324.2023.2207845
Mendel-200: Pea as a model system to analyze hormone-mediated stem elongation.
I- Cultiver, Inc, Manteca, CA 95336 & Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA.
In a recent Review Article on Gregor Mendel's (1822-1884) work with pea (Pisum sativum)-plants, it was proposed that this crop species should be re-vitalized as a model organism for the study of cell- and organ growth. Here, we describe the effect of exogenous gibberellic acid (GA(3)) on the growth of the second internode in 4-day-old light-grown pea seedlings (Pisum sativum, large var. "Senator"). lnjection of glucose into the internode caused a growth-promoting effect similar to that of the hormone GA(3). Imbibition of dry pea seeds in GA(3), or water as control, resulted in a drastic enhancement in organ development in this tall variety. Similar results were reported for dwarf peas. These "classical" experimental protocols are suitable to study the elusive effect of gibberellins (which act in coordination with auxin) on the regulation of plant development at the biochemical and molecular levels.
PMID: 37166004
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163342 doi: 10.1080/15592324.2022.2163342
Cloning and expression study of a high-affinity nitrate transporter gene from Zea mays L.
Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China.; Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China.; Aulin College, Northeast Forestry University, Harbin, Heilongjiang, China.
A nitrate transporter gene, named B46NRT2.1, from salt-tolerant Zea mays L. B46 has been cloned. B46NRT2.1 contained the same domain belonging to the major facilitator superfamily (PLN00028). The results of the phylogenetic tree indicated that B46NRT2.1 exhibits sequence similarity and the closest relationship with those known nitrate transporters of the NRT2 family. Through RT-qPCR, we found that the expression of B46NRT2.1 mainly happens in the root and leaf. Moreover, the treatment with NaCl, Na(2)CO(3), and NaHCO(3) could significantly increase the expression of B46NRT2.1. B46NRT2.1 was located in the plasma membrane. Through the study of yeast and plant salt response brought by B46NRT2.1 overexpression, we have preliminary knowledge that the expression of B46NRT2.1 makes yeast and plants respond to salt shock. There are 10 different kinds of cis-acting regulatory elements (CRES) in the promotor sequences of B46NRT2.1 gene using the PlantCARE web server to analyze. It mainly includes hormone response, abscisic acid, salicylic acid, gibberellin, methyl jasmonate, and auxin. The B46NRT2.1 gene's co-expression network showed that it was co-expressed with a number of other genes in several biological pathways, including regulation of NO(3) long-distance transit, modulation of nitrate sensing and metabolism, nitrate assimilation, and transduction of Jasmonic acid-independent wound signal. The results of this work should serve as a good scientific foundation for further research on the functions of the NRT2 gene family in plants (inbred line B46), and this research adds to our understanding of the molecular mechanisms under salt tolerance.
PMID: 36645908
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2081397 doi: 10.1080/15592324.2022.2081397
Genetic regulation of lateral root development.
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, Hebei, China.; Pear Engineering and Technology Research Center of Hebei, College of Horticulture, Hebei Agricultural University, Baoding, Hebei, China.; Ministry of Education, Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China.; College of Life Sciences, Hengshui University, Hengshui, Hebei, China.; College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, China.; College of Agronomy, Hebei Agricultural University, Baoding, Hebei, China.
Lateral roots (LRs) are an important part of plant root systems. In dicots, for example, after plants adapted from aquatic to terrestrial environments, filamentous pseudorhizae evolved to allow nutrient absorption. A typical plant root system comprises a primary root, LRs, root hairs, and a root cap. Classical plant roots exhibit geotropism (the tendency to grow downward into the ground) and can synthesize plant hormones and other essential substances. Root vascular bundles and complex spatial structures enable plants to absorb water and nutrients to meet their nutrient quotas and grow. The primary root carries out most functions during early growth stages but is later overtaken by LRs, underscoring the importance of LR development water and mineral uptake and the soil fixation capacity of the root. LR development is modulated by endogenous plant hormones and external environmental factors, and its underlying mechanisms have been dissected in great detail in Arabidopsis, thanks to its simple root anatomy and the ease of obtaining mutants. This review comprehensively and systematically summarizes past research (largely in Arabidopsis) on LR basic structure, development stages, and molecular mechanisms regulated by different factors, as well as future prospects in LR research, to provide broad background knowledge for root researchers.
PMID: 35642513
Sci Bull (Beijing) , 2023 Dec , V68 (24) : P3133-3136 doi: 10.1016/j.scib.2023.10.005
Creating a C(4)-like vein pattern in rice by manipulating SHORT ROOT and auxin levels.
New Cornerstone Science Laboratory, National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai 200032, China; Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China.; New Cornerstone Science Laboratory, National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics, Shanghai Center for Plant Stress Biology, CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.; Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China. Electronic address: nyu@shnu.edu.cn.; New Cornerstone Science Laboratory, National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, SIBS, Chinese Academy of Sciences, Shanghai 200032, China; School of Life Science and Technology, Shanghai Tech University, Shanghai 201210, China. Electronic address: etwang@cemps.ac.cn.
PMID: 37977916
J Genet Genomics , 2023 Dec , V50 (12) : P983-992 doi: 10.1016/j.jgg.2023.04.008
PIFs interact with SWI2/SNF2-related 1 complex subunit 6 to regulate H2A.Z deposition and photomorphogenesis in Arabidopsis.
Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China.; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China. Electronic address: zhileimao@shnu.edu.cn.
Light is an essential environmental signal perceived by a broad range of photoreceptors in plants. Among them, the red/far-red light receptor phytochromes function to promote photomorphogenesis, which is critical to the survival of seedlings after seeds germination. The basic-helix-loop-helix transcription factors phytochrome-interacting factors (PIFs) are the pivotal direct downstream components of phytochromes. H2A.Z is a highly conserved histone variant regulating gene transcription, and its incorporation into nucleosomes is catalyzed by SWI2/SNF2-related 1 complex, in which SWI2/SNF2-related 1 complex subunit 6 (SWC6) and actin-related protein 6 (ARP6) serve as core subunits. Here, we show that PIFs physically interact with SWC6 in vitro and in vivo, leading to the disassociation of HY5 from SWC6. SWC6 and ARP6 regulate hypocotyl elongation partly through PIFs in red light. PIFs and SWC6 coregulate the expression of auxin-responsive genes such as IAA6, IAA19, IAA20, and IAA29 and repress H2A.Z deposition at IAA6 and IAA19 in red light. Based on previous studies and our findings, we propose that PIFs inhibit photomorphogenesis, at least in part, through repression of H2A.Z deposition at auxin-responsive genes mediated by the interactions of PIFs with SWC6 and promotion of their expression in red light.
PMID: 37120038