Nature , IF:42.778 , 2020 Sep doi: 10.1038/s41586-020-2778-7
A single bacterial genus maintains root growth in a complex microbiome.
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Plant and Environmental Sciences, Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel.; Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Future Food Beacon of Excellence, School of Biosciences, University of Nottingham, Sutton Bonington, UK.; Department of Biology, 'Luiz de Queiroz' College of Agriculture (ESALQ), University of Sao Paulo (USP), Piracicaba, Brazil.; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. dangl@email.unc.edu.
Plants grow within a complex web of species that interact with each other and with the plant(1-10). These interactions are governed by a wide repertoire of chemical signals, and the resulting chemical landscape of the rhizosphere can strongly affect root health and development(7-9,11-18). Here, to understand how interactions between microorganisms influence root growth in Arabidopsis, we established a model system for interactions between plants, microorganisms and the environment. We inoculated seedlings with a 185-member bacterial synthetic community, manipulated the abiotic environment and measured bacterial colonization of the plant. This enabled us to classify the synthetic community into four modules of co-occurring strains. We deconstructed the synthetic community on the basis of these modules, and identified interactions between microorganisms that determine root phenotype. These interactions primarily involve a single bacterial genus (Variovorax), which completely reverses the severe inhibition of root growth that is induced by a wide diversity of bacterial strains as well as by the entire 185-member community. We demonstrate that Variovorax manipulates plant hormone levels to balance the effects of our ecologically realistic synthetic root community on root growth. We identify an auxin-degradation operon that is conserved in all available genomes of Variovorax and is necessary and sufficient for the reversion of root growth inhibition. Therefore, metabolic signal interference shapes bacteria-plant communication networks and is essential for maintaining the stereotypic developmental programme of the root. Optimizing the feedbacks that shape chemical interaction networks in the rhizosphere provides a promising ecological strategy for developing more resilient and productive crops.
PMID: 32999461
Nat Plants , IF:13.256 , 2020 Sep doi: 10.1038/s41477-020-00769-x
Primary transcript of miR858 encodes regulatory peptide and controls flavonoid biosynthesis and development in Arabidopsis.
CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research (CSIR-NBRI), Lucknow, India.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.; National Institute of Plant Genome Research, New Delhi, India.; CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research (CSIR-NBRI), Lucknow, India. prabodht@nbri.res.in.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India. prabodht@nbri.res.in.; Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, India. prabodht@nbri.res.in.
MicroRNAs (miRNAs) are processed products of primary miRNAs (pri-miRNAs) and regulate the target gene expression. Though the regulatory roles of the several mature plant miRNAs have been studied in detail, the functions of other regions of the pri-miRNAs are still unrecognized. Recent studies suggest that a few pri-miRNAs may encode small peptides, miRNA-encoded peptides (miPEPs); however, the functions of these peptides have not been studied in detail. We report that the pri-miR858a of Arabidopsis thaliana encodes a small peptide, miPEP858a, which regulates the expression of pri-miR858a and associated target genes. miPEP858a-edited and miPEP858a-overexpressing lines showed altered plant development and accumulated modulated levels of flavonoids due to changes in the expression of genes associated with the phenylpropanoid pathway and auxin signalling. The exogenous treatment of the miPEP858a-edited plants with synthetic miPEP858a complemented the phenotypes and the gene function. This study suggests the importance of miPEP858a in exerting control over plant development and the phenylpropanoid pathway.
PMID: 32958895
Nat Plants , IF:13.256 , 2020 Sep , V6 (9) : P1136-1145 doi: 10.1038/s41477-020-00756-2
Auxin-mediated root branching is determined by the form of available nitrogen.
Molecular Plant Nutrition, Leibniz-Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.; Department of Biochemistry and Molecular Biology, Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, USA.; Molecular Plant Nutrition, Leibniz-Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany. vonwiren@ipk-gatersleben.de.
To improve water and nutrient acquisition from the soil, plants can modulate their root system architecture. Despite the importance of changes in root architecture to exploit local nutrient patches occurring in heterogenous soils or after placed fertilization, mechanisms integrating external nutrient signals into the root developmental programme remain poorly understood. Here, we show that local ammonium supply stimulates the accumulation of shoot-derived auxin in the root vasculature and promotes lateral root emergence to build a highly branched root system. Activities of pH and auxin reporters indicate that ammonium uptake mediated by ammonium transporters acidifies the root apoplast, which increases pH-dependent import of protonated auxin into cortical and epidermal cells overlaying lateral root primordia, and subsequently promotes their emergence from the parental root. Thereby, ammonium-induced and H(+)-ATPase-mediated acidification of the apoplast allows auxin to bypass the auxin importers AUX1 and LAX3. In nitrogen-deficient plants, auxin also accumulates in the root vasculature but a more alkaline apoplast leads to retention of auxin in these tissues and prevents lateral root formation. Our study highlights the impact of externally available nitrogen forms on pH-dependent radial auxin mobility and its regulatory function in organ development.
PMID: 32917974
Biosens Bioelectron , IF:10.257 , 2020 Oct , V165 : P112374 doi: 10.1016/j.bios.2020.112374
An impedance-coupled microfluidic device for single-cell analysis of primary cell wall regeneration.
School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.; State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, 300072, China.; School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China. Electronic address: jiehuawang@tju.edu.cn.; State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, 300072, China. Electronic address: xduan@tju.edu.cn.
Primary cell wall (PCW) is a rigid yet flexible cell wall surrounding plant cells and it plays key roles in plant growth, cell differentiation, intercellular communication, water movement and defence. As a technique widely used to study the characteristics of mammalian cells, electrical impedance spectroscopy (EIS) is rarely used in plant science. In this work, we designed and fabricated an EIS based biosensor coupled with microfluidic platform to investigate the formation process of PCWat the single-cell level. Arabidopsis mesophyll cells with completely regenerated PCW showed significantly higher impedance values compared to the nascent protoplasts without PCW, demonstrating that PCW formation caused a dramatic change in cell electrical properties. The device could also discriminate plant mutant cells with modified PCW compositions, thus provided a novel tool for physical phenotyping of plant cells. The dose-dependent effects of exogenously applied auxin on PCW regeneration were corroborated on this platform which revealed its potential to sensitively detect the influences of in vitro stimuli. This work not only provided one novel application of impedance-based biosensor to characterize a plant-specific developmental event, but also revealed the promises of EIS integrated microfluidic system as a sensitive, time-effective and low-cost platform to characterize single plant cells and make new scientific discoveries in plant science.
PMID: 32729506
Dev Cell , IF:10.092 , 2020 Sep , V54 (6) : P689-690 doi: 10.1016/j.devcel.2020.09.008
ATACing Somatic Embryogenesis.
Department of Plant Systems Physiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands. Electronic address: j.xu@science.ru.nl.
How does auxin induce somatic embryogenesis? In this issue of Developmental Cell, Wang et al. uncover a regulatory role for auxin in the dynamics of chromatin accessibility and gene expression, which is critical for the establishment of developmental time-specific transcriptional regulatory networks orchestrating somatic-to-embryonic cell reprogramming and somatic embryo development.
PMID: 32991834
Dev Cell , IF:10.092 , 2020 Sep , V54 (6) : P742-757.e8 doi: 10.1016/j.devcel.2020.07.003
Chromatin Accessibility Dynamics and a Hierarchical Transcriptional Regulatory Network Structure for Plant Somatic Embryogenesis.
National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai 200032, China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai 200032, China; ShanghaiTech University, Shanghai 200031, China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai 200032, China; University of Chinese Academy of Sciences (UCAS), Shanghai 200032, China; Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences (CAS), Shanghai 200032, China; ShanghaiTech University, Shanghai 200031, China. Electronic address: jwwang@sippe.ac.cn.
Plant somatic embryogenesis refers to a phenomenon where embryos develop from somatic cells in the absence of fertilization. Previous studies have revealed that the phytohormone auxin plays a crucial role in somatic embryogenesis by inducing a cell totipotent state, although its underlying mechanism is poorly understood. Here, we show that auxin rapidly rewires the cell totipotency network by altering chromatin accessibility. The analysis of chromatin accessibility dynamics further reveals a hierarchical gene regulatory network underlying somatic embryogenesis. Particularly, we find that the embryonic nature of explants is a prerequisite for somatic cell reprogramming. Upon cell reprogramming, the B3-type totipotent transcription factor LEC2 promotes somatic embryo formation by direct activation of the early embryonic patterning genes WOX2 and WOX3. Our results thus shed light on the molecular mechanism by which auxin promotes the acquisition of plant cell totipotency and establish a direct link between cell totipotent genes and the embryonic development pathway.
PMID: 32755547
Plant Cell , IF:9.618 , 2020 Sep doi: 10.1105/tpc.18.00471
Developmental Genetics of Corolla Tube Formation: Role of the tasiRNA-ARF Pathway and a Conceptual Model.
University of Connecticut CITY: Storrs STATE: CT United States Of America [US].; South China Agricultural University CITY: Guangzhou STATE: Guangdong POSTAL_CODE: 510640 China [CN].; Donald Danforth Plant Science Center CITY: St. Louis STATE: Missouri POSTAL_CODE: 63132 United States Of America [US].; University of Connecticut CITY: Storrs STATE: CT POSTAL_CODE: 06269-3043 United States Of America [US] yaowu.yuan@uconn.edu.
Over 80,000 angiosperm species produce flowers with petals fused into a corolla tube. The corolla tube contributes to the tremendous diversity of flower morphology and plays a critical role in plant reproduction; yet it remains one of the least understood plant structures from a developmental genetics perspective. Through mutant analyses and transgenic experiments, we show that the tasiRNA-ARF pathway is required for corolla tube formation in the monkeyflower species Mimulus lewisii. Loss-of-function mutations in the M. lewisii orthologs of ARGONAUTE7 and SUPPRESSOR OF GENE SILENCING 3 cause a dramatic decrease in abundance of TAS3-derived small RNAs and a moderate up-regulation of AUXIN RESPONSE FACTOR 3 (ARF3) and ARF4, which lead to inhibition of lateral expansion of the bases of petal primordia and complete arrest of the upward growth of the inter-primordial regions, resulting in unfused corollas. Using the DR5 auxin responsive promoter, we discovered that auxin signaling is continuous along the petal primordium base and the inter-primordial region during the critical stage of corolla tube formation in the wild-type, similar to the spatial pattern of MlARF4 expression. Auxin response is also much weaker and more restricted in the mutant. Furthermore, exogenous application of polar auxin transport inhibitor to wild-type floral apices disrupted petal fusion. Together, these results suggest a new conceptual model highlighting the central role of auxin-directed synchronized growth of the petal primordium base and the inter-primordial region in corolla tube formation.
PMID: 32917737
Curr Biol , IF:9.601 , 2020 Sep doi: 10.1016/j.cub.2020.08.053
Pluripotent Pericycle Cells Trigger Different Growth Outputs by Integrating Developmental Cues into Distinct Regulatory Modules.
ZMBP-Center for Plant Molecular Biology, University of Tubingen, Auf der Morgenstelle 32, 72076 Tubingen, Germany.; Institute of Biology, University of Neuchatel, Rue Emile-Argand 11, 2000 Neuchatel, Switzerland.; ZMBP-Center for Plant Molecular Biology, University of Tubingen, Auf der Morgenstelle 32, 72076 Tubingen, Germany. Electronic address: laura.ragni@zmbp.uni-tuebingen.de.
During post-embryonic development, the pericycle specifies the stem cells that give rise to both lateral roots (LRs) and the periderm, a suberized barrier that protects the plant against biotic and abiotic stresses. Comparable auxin-mediated signaling hubs regulate meristem establishment in many developmental contexts; however, it is unknown how specific outputs are achieved. Using the Arabidopsis root as a model, we show that while LR formation is the main auxin-induced program after de-etiolation, plants with age become competent to form a periderm in response to auxin. The establishment of the vascular cambium acts as the developmental switch required to trigger auxin-mediated periderm initiation. Moreover, distinct auxin signaling components and targets control LR versus periderm formation. Among the periderm-specific-promoting transcription factors, WUSCHEL-RELATED HOMEOBOX 4 (WOX4) and KNAT1/BREVIPEDICELLUS (BP) stand out as their specific overexpression in the periderm results in an increased number of periderm layers, a trait of agronomical importance in breeding programs targeting stress tolerance. These findings reveal that specificity in pericycle stem cell fate is achieved by the integration of developmental cues into distinct regulatory modules.
PMID: 32916110
Proc Natl Acad Sci U S A , IF:9.412 , 2020 Sep , V117 (39) : P24557-24566 doi: 10.1073/pnas.2009554117
Architecture of DNA elements mediating ARF transcription factor binding and auxin-responsive gene expression in Arabidopsis.
Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, The Netherlands.; Laboratory of Cell Biology, 6708 PE Wageningen University, Wageningen, The Netherlands.; Alba Synchrotron, Cerdanyola del Valles, 08290 Barcelona, Spain.; Laboratory of Biophysics, Wageningen University, 6708 WE Wageningen, The Netherlands.; Institute of Cytology and Genetics, 630090 Novosibirsk, Russian Federation.; Computational Transcriptomics and Evolutionary Bioinformatics Laboratory, Novosibirsk State University, 630090 Novosibirsk, Russian Federation.; Microspectroscopy Research Facility, Wageningen University, 6708 WE Wageningen, The Netherlands.; Institute of Cytology and Genetics, 630090 Novosibirsk, Russian Federation; victoria.v.mironova@gmail.com dolf.weijers@wur.nl.; Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, The Netherlands; victoria.v.mironova@gmail.com dolf.weijers@wur.nl.
The hormone auxin controls many aspects of the plant life cycle by regulating the expression of thousands of genes. The transcriptional output of the nuclear auxin signaling pathway is determined by the activity of AUXIN RESPONSE transcription FACTORs (ARFs), through their binding to cis-regulatory elements in auxin-responsive genes. Crystal structures, in vitro, and heterologous studies have fueled a model in which ARF dimers bind with high affinity to distinctly spaced repeats of canonical AuxRE motifs. However, the relevance of this "caliper" model, and the mechanisms underlying the binding affinities in vivo, have remained elusive. Here we biochemically and functionally interrogate modes of ARF-DNA interaction. We show that a single additional hydrogen bond in Arabidopsis ARF1 confers high-affinity binding to individual DNA sites. We demonstrate the importance of AuxRE cooperativity within repeats in the Arabidopsis TMO5 and IAA11 promoters in vivo. Meta-analysis of transcriptomes further reveals strong genome-wide association of auxin response with both inverted (IR) and direct (DR) AuxRE repeats, which we experimentally validated. The association of these elements with auxin-induced up-regulation (DR and IR) or down-regulation (IR) was correlated with differential binding affinities of A-class and B-class ARFs, respectively, suggesting a mechanistic basis for the distinct activity of these repeats. Our results support the relevance of high-affinity binding of ARF transcription factors to uniquely spaced DNA elements in vivo, and suggest that differential binding affinities of ARF subfamilies underlie diversity in cis-element function.
PMID: 32929017
New Phytol , IF:8.512 , 2020 Sep doi: 10.1111/nph.16956
Trehalose 6-phosphate promotes seed filling by activating auxin biosynthesis.
Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstr. 3, 06466, Stadt Seeland OT Gatersleben, Germany.; DeepTrait S.A, Dobrzanskiego 3, 20-262, Lublin, Poland.; School of Natural Sciences, University of Tasmania, Sandy Bay, 7001, Australia.; Ludwig Maximilians University of Munich, Faculty of Biology, Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.; Max Planck Institute of Molecular Plant Physiology, Am Muhlenberg 1, 14476, Potsdam, Germany.
Plants undergo several developmental transitions during their life cycle. One of these, the differentiation of the young embryo from a meristem-like structure into a highly-specialized storage organ, is believed to be controlled by local connections between sugars and hormonal response systems. However, we know little about the regulatory networks underpinning the sugar-hormone interactions in developing seeds. By modulating the trehalose 6-phosphate (T6P) content in growing embryos of garden pea (Pisum sativum), we investigate here the role of this signaling sugar during the seed filling process. Seeds deficient in T6P are compromised in size and starch production, resembling the wrinkled seeds studied by Gregor Mendel. We show also that T6P exerts these effects by stimulating the biosynthesis of the pivotal plant hormone, auxin. We found that T6P promotes the expression of the auxin biosynthesis gene TRYPTOPHAN AMINOTRANSFERASE RELATED2 (TAR2), and the resulting effect on auxin levels is required to mediate the T6P-induced activation of storage processes. Our results suggest that auxin acts downstream of T6P to facilitate seed filling, thereby providing a salient example of how a metabolic signal governs the hormonal control of an integral phase transition in a crop plant.
PMID: 32984971
New Phytol , IF:8.512 , 2020 Sep doi: 10.1111/nph.16915
Salicylic acid regulates PIN2 auxin transporter hyperclustering and root gravitropic growth via Remorin-dependent lipid nanodomain organisation in Arabidopsis thaliana.
College of Life Science and Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Centre, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.; School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore.; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore.; Institute of Science and Technology Austria (IST Austria), Am Campus 1, Klosterneuburg, 3400, Austria.; Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.
To adapt to the diverse array of biotic and abiotic cues, plants have evolved sophisticated mechanisms to sense changes in environmental conditions and modulate their growth. Growth-promoting hormones and defence signalling fine tune plant development antagonistically. During host-pathogen interactions, this defence-growth trade-off is mediated by the counteractive effects of the defence hormone salicylic acid (SA) and the growth hormone auxin. Here we revealed an underlying mechanism of SA regulating auxin signalling by constraining the plasma membrane dynamics of PIN2 auxin efflux transporter in Arabidopsis thaliana roots. The lateral diffusion of PIN2 proteins is constrained by SA signalling, during which PIN2 proteins are condensed into hyperclusters depending on REM1.2-mediated nanodomain compartmentalisation. Furthermore, membrane nanodomain compartmentalisation by SA or Remorin (REM) assembly significantly suppressed clathrin-mediated endocytosis. Consequently, SA-induced heterogeneous surface condensation disrupted asymmetric auxin distribution and the resultant gravitropic response. Our results demonstrated a defence-growth trade-off mechanism by which SA signalling crosstalked with auxin transport by concentrating membrane-resident PIN2 into heterogeneous compartments.
PMID: 32901934
New Phytol , IF:8.512 , 2020 Sep doi: 10.1111/nph.16914
Studies of moss reproductive development indicate that auxin biosynthesis in apical stem cells may constitute an ancestral function for focal growth control.
Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre for Plant Biology in Uppsala, SE-750 07, Uppsala, Sweden.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), SE-901 83, Umea, Sweden.
The plant hormone auxin is a key factor for regulation of plant development, and this function was most likely reinforced during early land plant evolution. We have extended the available tool box to allow detailed studies of how auxin biosynthesis and responses are regulated in moss reproductive organs, their stem cells and gametes to better elucidate the function of auxin in early land plants morphogenesis. We measured auxin metabolites and identified IPyA as the main biosynthesis pathway in Physcomitrium (Physcomitrella) patens and established knock-out, overexpressor and reporter lines for biosynthesis genes which were analyzed alongside previously reported auxin sensing and transport reporters. Vegetative and reproductive apical stem cells synthesize auxin. Sustained stem cell activity depend on an inability to sense the auxin produced while progeny of the stem cells responds to the auxin, aiding in the control of cell division, expansion and differentiation. Gamete precursors are dependent on a certain degree of auxin sensing, while the final differentiation is a low auxin sensing process. Presented data indicate that low auxin activity may represent a conserved hallmark of land plant gametes, and that local auxin biosynthesis in apical stem cells may be part of an ancestral mechanism to control focal growth.
PMID: 32901452
Plant Biotechnol J , IF:8.154 , 2020 Sep doi: 10.1111/pbi.13484
GhARF16-1 Modulates Leaf Development by Transcriptionally Regulating the GhKNOX2-1 Gene in Cotton.
College of Life Sciences, Shaanxi Normal University, Xi'an, China.; Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria.; College of Life Sciences, Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, Shihezi University, Shihezi, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.; Key Laboratory of Biological and Genetic Breeding of Cotton, The Ministry of Agriculture, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.; Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, China.
The leaf is a crucial organ evolved with remarkable morphological diversity to maximize plant photosynthesis. The leaf shape is a key trait that affects photosynthesis, flowering rates, disease resistance, and yield. Although many genes regulating leaf development have been identified in the past years, the precise regulatory architecture underlying the generation of diverse leaf shapes remains to be elucidated. We used cotton as a reference model to probe the genetic framework underlying divergent leaf forms. Comparative transcriptome analysis revealed that the GhARF16-1 and GhKNOX2-1 genes might be potential regulators of leaf shape. We functionally characterized the auxin-responsive factor ARF16-1 acting upstream of GhKNOX2-1 to determine leaf morphology in cotton. The transcription of GhARF16-1 was significantly higher in lobed-leaved cotton than in smooth-leaved cotton. Furthermore, the overexpression of GhARF16-1 led to the upregulation of GhKNOX2-1 and resulted in more and deeper serrations in cotton leaves, similar to the leaf shape of cotton plants overexpressing GhKNOX2-1. We found that GhARF16-1 specifically bound to the promoter of GhKNOX2-1 to induce its expression. The heterologous expression of GhARF16-1 and GhKNOX2-1 in Arabidopsis led to lobed and curly leaves, and a genetic analysis revealed that GhKNOX2-1 is epistatic to GhARF16-1 in Arabidopsis, suggesting that the GhARF16-1 and GhKNOX2-1 interaction paradigm also functions to regulate leaf shape in Arabidopsis. To our knowledge, our results uncover a novel mechanism by which auxin, through the key component ARF16-1 and its downstream-activated gene KNOX2-1, determines leaf morphology in eudicots.
PMID: 32981232
Plant Physiol , IF:6.902 , 2020 Sep doi: 10.1104/pp.20.00587
Mediator Subunit MED25 Physically Interacts with PHYTOCHROME INTERACTING FACTOR 4PIF4 to Regulate Shade-induced Hypocotyl Elongation in Tomato.
State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University CITY: Tai'an STATE: Shandong China [CN].; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences No.1 West Beichen Road, Chaoyang District CITY: Beijing POSTAL_CODE: 100101 China [CN].; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences CITY: Beijing STATE: Beijing China [CN].; Institute of Genetics and Developmental Biology CITY: beijing China [CN].; Shandong Agricultural University CITY: Tai'an, Shandong China [CN].; Institute of Genetics and Developmental Biology, CAS CITY: Beijing China [CN] qzzhai@genetics.ac.cn.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences CITY: Beijing STATE: Beijing POSTAL_CODE: 100101 China [CN].
Shade triggers important adaptive responses such as the shade-avoidance syndrome (SAS), which enable plants to respond to the depletion of photosynthetically active light. The basic helix-loop-helix (bHLH) transcription factors PHYTOCHROME INTERACTING FACTORS (PIFs) play a key role in the SAS network by regulating the biosynthesis of multiple phytohormones and the expression of cell expansion-related genes. Although much has been learned about the regulation of PIFs in response to shade at the protein level, relatively little is known about the PIF-dependent transcriptional regulation of shade-responsive genes. Mediator is an evolutionarily conserved transcriptional coactivator complex that bridges gene-specific transcription factors with the RNA polymerase II (Pol II) machinery to regulate gene transcription. Here, we report that tomato (Solanum lycopersicum) PIF4 plays an important role in shade-induced hypocotyl elongation by regulating the expression of genes that encode auxin biosynthesis and auxin signaling proteins. During this process, Mediator subunit25 (MED25) physically interacts with PIF4 at the promoter regions of PIF4 target genes and also recruits Pol II to induce gene transcription. Thus, MED25 directly bridges the communication between PIF4 and Pol II general transcriptional machinery to regulate shade-induced hypocotyl elongation. Overall, our results reveal a novel role of MED25 in PIF4-mediated transcriptional regulation under shade.
PMID: 32938743
Plant Physiol , IF:6.902 , 2020 Sep doi: 10.1104/pp.20.00536
OsHOX1 and OsHOX28 redundantly shape rice tiller angle by reducing HSFA2D expression and auxin content.
National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research CITY: Wuhan China [CN].; National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences CITY: Wuhan; Anyang China [CN].; Department of Integrative Biology, University of Texas at Austin CITY: Austin United States Of America [US].; Huazhong Agricultural University CITY: Wuhan STATE: Hubei China [CN].; Huazhong Agriculture University CITY: Wuhan China [CN].; Huazhong Agricultural University CITY: Wuhan POSTAL_CODE: 430070 China [CN].; Hubei Academy of Agricultural Sciences CITY: Wuhan China [CN].; National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research CITY: Wuhan POSTAL_CODE: 430070 China [CN] yzxing@mail.hzau.edu.cn.
Tiller angle largely determines plant architecture, which in turn substantially influences crop production by affecting planting density. A recent study revealed that HEAT STRESS TRANSCRIPTION FACTOR 2D (HSFA2D) acts upstream of LAZY1 (LA1) to regulate tiller angle establishment in rice (Oryza sativa L.). However, the mechanisms underlying transcriptional regulation of HSFA2D remain unknown. In this study, two class II homeodomain-leucine zipper (HD-ZIP II) genes, OsHOX1 and OsHOX28, were identified as positive regulators of tiller angle through affecting shoot gravitropism. OsHOX1 and OsHOX28 showed strong transcriptional suppressive activity in rice protoplasts and formed intricate self- and mutual- transcriptional negative feedback loops. Moreover, OsHOX1 and OsHOX28 bound to the pseudopalindromic sequence CAAT(C/G)ATTG within the promoter of HSFA2D, thus suppressing its expression. In contrast to HSFA2D and LA1, OsHOX1 and OsHOX28 attenuated lateral auxin transport (LAT), thus repressing the expression of WUSCHEL-RELATED HOMEOBOX 6 (WOX6) and WOX11 in the lower side of the shoot base of plants subjected to gravistimulation. Genetic analysis further confirmed that OsHOX1 and OsHOX28 act upstream of HSFA2D. Additionally, both OsHOX1 and OsHOX28 inhibit the expression of multiple OsYUCCA genes and decrease auxin biosynthesis. Taken together, these results demonstrated that OsHOX1 and OsHOX28 regulate the local distribution of auxin and thus tiller angle establishment through suppression of the HSFA2D-LA1 pathway and reduction of endogenous auxin content. Our finding increases the knowledge concerning the fine tuning of tiller angles to optimize plant architecture in rice.
PMID: 32913047
Anal Chem , IF:6.785 , 2020 Sep doi: 10.1021/acs.analchem.0c02854
Label-Free and Simultaneous Mechanical and Electrical Characterization of Single Plant Cells Using Microfluidic Impedance Flow Cytometry.
State Key Laboratory of Precision Measuring Technology and Instruments, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.; School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Despite that single-cell-type-level analyses have been extensively conducted on animal models to gain new insights into complex biological processes; the unique biological and physiological properties of plant cells have not been widely studied at single-cell resolution. In this work, an electrical impedance flow cytometry was fabricated based on microfluidics with constriction microchannel to simultaneously characterize the mechanical and electrical properties of single plant cells. Protoplasts from two model plant species, the herbaceous Arabidopsis thaliana and the woody Populus trichocarpa, could be readily discriminated by their respective mechanical traits, but not by electrical impedance. On the contrary, overexpression of a red fluorescent protein on plasma membrane resulted in changes in cell electrical impedance instead of cell deformability. During primary cell wall (PCW) regeneration, this extracellular layer outside of protoplasts introduced dramatic variations in both mechanical and electrical properties of single plant cells. Furthermore, the effects of auxin, an essential phytohormone regulating PCW reformation, were validated on this platform. Taken together, our results revealed a novel application of microfluidic impedance flow cytometry in the field of plant science to simultaneously characterize dual biophysical properties at single-cell resolution, which could be further developed as a powerful and reliable tool for plant cell phenotyping and cell fate specification.
PMID: 32911928
Plant Cell Environ , IF:6.362 , 2020 Oct , V43 (10) : P2551-2570 doi: 10.1111/pce.13817
Volatiles from the fungal phytopathogen Penicillium aurantiogriseum modulate root metabolism and architecture through proteome resetting.
Instituto de Agrobiotecnologia (Consejo Superior de Investigaciones Cientificas/Gobierno de Navarra), Mutilva, 31192, Spain.; Department of Chemical Biology and Genetics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacky University, Olomouc, CZ-78371, Czech Republic.; Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Germany.; Instituto de Bioquimica Vegetal y Fotosintesis, Consejo Superior de Investigaciones Cientificas and Universidad de Sevilla, Sevilla, 41092, Spain.
Volatile compounds (VCs) emitted by the fungal phytopathogen Penicillium aurantiogriseum promote root growth and developmental changes in Arabidopsis. Here we characterised the metabolic and molecular responses of roots to fungal volatiles. Proteomic analyses revealed that these compounds reduce the levels of aquaporins, the iron carrier IRT1 and apoplastic peroxidases. Fungal VCs also increased the levels of enzymes involved in the production of mevalonate (MVA)-derived isoprenoids, nitrogen assimilation and conversion of methionine to ethylene and cyanide. Consistently, fungal VC-treated roots accumulated high levels of hydrogen peroxide (H2 O2 ), MVA-derived cytokinins, ethylene, cyanide and long-distance nitrogen transport amino acids. qRT-PCR analyses showed that many proteins differentially expressed by fungal VCs are encoded by VC non-responsive genes. Expression patterns of hormone reporters and developmental characterisation of mutants provided evidence for the involvement of cyanide scavenging and enhanced auxin, ethylene, cytokinin and H2 O2 signalling in the root architecture changes promoted by fungal VCs. Our findings show that VCs from P. aurantiogriseum modify root metabolism and architecture, and improve nutrient and water use efficiencies through transcriptionally and non-transcriptionally regulated proteome resetting mechanisms. Some of these mechanisms are subject to long-distance regulation by photosynthesis and differ from those triggered by VCs emitted by beneficial microorganisms.
PMID: 32515071
Plant J , IF:6.141 , 2020 Sep doi: 10.1111/tpj.14996
Molecular pathways regulating elongation of aerial plant organs: a focus on light, the circadian clock, and temperature.
RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan.; Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan.
Organs like hypocotyls and petioles rapidly elongate in response to shade and temperature cues, contributing to adaptive responses that improve plant fitness. Growth plasticity in these organs is achieved through a complex network of molecular signals. Besides conveying information from the environment, this signaling network also transduces internal signals, such as those associated with the circadian clock. A number of studies performed in Arabidopsis hypocotyls, and to a lesser degree in petioles, have been informative for understanding the signaling networks that regulate elongation of aerial plant organs. In particular, substantial progress has been made towards understanding the molecular mechanisms that regulate responses to light, the circadian clock, and temperature. Signals derived from these three stimuli converge on the BAP module, a set of three different types of transcription factors that interdependently promote gene transcription and growth. Additional key positive regulators of growth that are also affected by environmental cues include the CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and SUPPRESSOR OF PHYA-105 (SPA) E3 ubiquitin ligase proteins. In this review, we summarize the key signaling pathways that regulate growth of hypocotyls and petioles, focusing specifically on molecular mechanisms important for transducing signals derived from light, the circadian clock, and temperature. While it is clear that similarities abound between the signaling networks at play in these two organs, there are also important differences between the mechanisms regulating growth in hypocotyls and petioles.
PMID: 32986276
Plant J , IF:6.141 , 2020 Sep doi: 10.1111/tpj.14984
FERONIA mediates root nutating growth.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.; State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
Root nutation indicates the behavior that roots grow in a waving and skewing way due to unequal growth rates on different sides. Although a few developmental and environmental factors have been reported, genetic pathways mediating this process are obscure. We report here that the Arabidopsis CrRLK1L family member FERONIA (FER) is critical for root nutation. Functional loss of FER resulted in enhanced root waviness on tilted plates or roots forming anti-clockwise coils on horizontal plates. Suppressing polar auxin transport, either by pharmacological treatment or by introducing mutations at PIN-FORMED2 (PIN2) or AUXIN RESISTANT1 (AUX1), suppressed the asymmetric root growth (ARG) in fer-4, a null mutant of FER, indicating that FER suppression of ARG depends on polar auxin transport. We further showed by pharmacological treatments that dynamic microtubule organization and Ca(2+) signaling are both critical for FER-mediated ARG. Results presented here demonstrate a key role of FER in mediating root nutating growth, through PIN2- and AUX1-mediated auxin transport, through dynamic microtubule organization, and through Ca(2+) signaling.
PMID: 32891072
Plant J , IF:6.141 , 2020 Sep doi: 10.1111/tpj.14978
Rice plants respond to ammonium stress by adopting a helical root growth pattern.
State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent, B-9052, Belgium.; VIB-UGent Center for Plant Systems Biology, Technologiepark 71, Ghent, B-9052, Belgium.; Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China.
High levels of ammonium nutrition reduce plant growth and different plant species have developed distinct strategies to maximize ammonium acquisition while alleviating ammonium toxicity through modulating root growth. To date, the mechanisms underlying plant tolerance or sensitivity towards ammonium remain unclear. Rice (Oryza sativa) uses ammonium as its main N source. Here we show that ammonium supply restricts rice root elongation and induces a helical growth pattern, which is attributed to root acidification resulting from ammonium uptake. Ammonium-induced low pH triggers the asymmetric distribution of auxin in rice root tips through changes in auxin signaling, thereby inducing a helical growth response. Blocking auxin signaling completely inhibited this root response. In contrast, this root response is not activated in ammonium-treated Arabidopsis. Acidification of Arabidopsis roots leads to the protonation of indole-3-acetic acid and dampening of the intracellular auxin signaling levels that are required for maintaining root growth. Our study suggests a different mode of action by ammonium on the root pattern and auxin response machinery in rice versus Arabidopsis, and the rice-specific helical root response towards ammonium is an expression of the ability of rice to moderate auxin signaling and root growth to utilize ammonium while confronting acidic stress.
PMID: 32890411
Plant J , IF:6.141 , 2020 Sep doi: 10.1111/tpj.14982
Leaflet initiation and blade expansion are separable in compound leaf development.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University, PO Box 12, Rehovot, 76100, Israel.; Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Compound leaves are composed of multiple separate blade units termed leaflets. In tomato (Solanum lycopersicum) compound leaves, auxin promotes both leaflet initiation and blade expansion. However, it is unclear how these two developmental processes interact. With highly variable complexity, tomato compound leaves provide an ideal system to address this question. In this study, we obtained and analyzed mutants of the WUSCHEL-RELATED HOMEOBOX (WOX) family gene SlLAM1 from tomato, whose orthologs in tobacco (Nicotiana sylvestris) and other species are indispensable for blade expansion. We show that SlLAM1 is expressed in the middle and marginal domains of leaves, and is required for blade expansion in leaflets. We demonstrate that sllam1 mutants cause a delay of leaflet initiation and slightly alter the arrangement of first-order leaflets, whereas the overall leaflet number is comparable to that of wild-type leaves. Analysis of the genetic interactions between SlLAM1 and key auxin signaling components revealed an epistatic effect of SlLAM1 in determining the final leaf form. Finally, we show that SlLAM1 is also required for floral organ growth and affects the fertility of gametophytes. Our data suggest that SlLAM1 promotes blade expansion in multiple leaf types, and leaflet initiation can be largely uncoupled from blade expansion during compound leaf morphogenesis.
PMID: 32889762
J Exp Bot , IF:5.908 , 2020 Sep doi: 10.1093/jxb/eraa430
Rab-dependent vesicular traffic affects female gametophyte development in Arabidopsis.
Faculty of Biology, University of Gdansk, Wita Stwosza, Gdansk, Poland.; Waite Research Institute, School of Agriculture, Food and Wine, The University of Adelaide, Urrbrae, South Australia, Australia.; LAQV REQUIMTE, Departamento de Biologia, Faculdade de Ciencias, Universidade do Porto, Porto, Portugal.; Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama, Gdansk, Poland.; Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego, Warsaw, Poland.; Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova, Czech Republic.; Faculty of Biology, University of Warsaw, Miecznikowa, Warsaw, Poland.
Eukaryotic cells rely on the accuracy and efficiency of vesicular traffic. In plants, disturbances in vesicular trafficking are well studied in quickly dividing root meristem cells or polar growing root hairs and pollen tubes. The development of the female gametophyte, a unique haploid reproductive structure located in the ovule, has received far less attention in studies of vesicular transport. Key molecules providing the specificity of vesicle formation and its subsequent recognition and fusion with the acceptor membrane are Rab proteins. Rabs are anchored to membranes by covalently linked geranylgeranyl group(s) that are added by the Rab geranylgeranyl transferase (RGT) enzyme. Here we show that Arabidopsis plants carrying mutations in the gene encoding the beta subunit of RGT (rgtb1) exhibit severely disrupted female gametogenesis and this effect is of sporophytic origin. Mutations in rgtb1 lead to internalization of the PIN1 and PIN3 proteins from the basal membranes to vesicles in pro-vascular cells of the funiculus. Decreased transport of auxin out of the ovule is accompanied by auxin accumulation in a tissue surrounding the growing gametophyte. In addition, female gametophyte development arrests at the uni- or binuclear stage in a significant portion of the rgtb1 ovules. These observations suggest that communication between the sporophyte and the developing female gametophyte relies on Rab dependent vesicular traffic of the PIN1 and PIN3 transporters and auxin efflux out of the ovule.
PMID: 32939545
J Exp Bot , IF:5.908 , 2020 Sep , V71 (18) : P5348-5364 doi: 10.1093/jxb/eraa209
Homeobox transcription factor OsZHD2 promotes root meristem activity in rice by inducing ethylene biosynthesis.
Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, Korea.; Department of Plant Bioscience, Pusan National University, Miryang, Korea.; Department of Crop Genomics and Genetic Improvement, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.; Agricultural Research Centre For International Development, Paris, France.; Department of Biology, Sunchon National University, Sunchon, Chonnam, Korea.; National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China.; Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University Shanghai, China.; School of Agriculture, Food and Wine, University of Adelaide Urrbrae, SA, Australia.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
Root meristem activity is the most critical process influencing root development. Although several factors that regulate meristem activity have been identified in rice, studies on the enhancement of meristem activity in roots are limited. We identified a T-DNA activation tagging line of a zinc-finger homeobox gene, OsZHD2, which has longer seminal and lateral roots due to increased meristem activity. The phenotypes were confirmed in transgenic plants overexpressing OsZHD2. In addition, the overexpressing plants showed enhanced grain yield under low nutrient and paddy field conditions. OsZHD2 was preferentially expressed in the shoot apical meristem and root tips. Transcriptome analyses and quantitative real-time PCR experiments on roots from the activation tagging line and the wild type showed that genes for ethylene biosynthesis were up-regulated in the activation line. Ethylene levels were higher in the activation lines compared with the wild type. ChIP assay results suggested that OsZHD2 induces ethylene biosynthesis by controlling ACS5 directly. Treatment with ACC (1-aminocyclopropane-1-carboxylic acid), an ethylene precursor, induced the expression of the DR5 reporter at the root tip and stele, whereas treatment with an ethylene biosynthesis inhibitor, AVG (aminoethoxyvinylglycine), decreased that expression in both the wild type and the OsZHD2 overexpression line. These observations suggest that OsZHD2 enhances root meristem activity by influencing ethylene biosynthesis and, in turn, auxin.
PMID: 32449922
FASEB J , IF:4.966 , 2020 Sep doi: 10.1096/fj.202001523R
Npa3 interacts with Gpn3 and assembly factor Rba50 for RNA polymerase II biogenesis.
College of Life Sciences, Hebei Agricultural University, Baoding, China.; State Key Laboratory of North China Crop Improvement and Regulation, Baoding, China.; Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, The College of Life Sciences, Peking University, Beijing, China.
RNA polymerase II is one of the most vital macromolecular complexes in eukaryotes and the assembly of such complete enzyme requires many factors. Three members of GPN-loop GTPase family Npa3/Gpn1, Gpn2, and Gpn3 participate in the biogenesis of RNA polymerase II with nonredundant roles. We show here that rapid degradation of each GPN protein in yeast leads to cytoplasmic accumulation of Rpb1 and defects in the assembly of RNA polymerase II, suggesting conserved functions of GPN paralogs for RNA polymerase II biogenesis as in humans. Taking advantage of a multicopy genetic screening, we identified GPN3 and assembly factor RBA50 among others as strong suppressors of npa3(ts) mutants. We further demonstrated that Npa3 interacts with Gpn3 and Rba50, similarly human Gpn1 physically interacts with Gpn3 and RPAP1 (human analog of Rba50). Moreover, a mutual dependency of protein levels of Npa3 and Gpn3 was also clearly presented in yeast using an auxin-inducible degron (AID) system. Interestingly, Rpb2, the second largest subunit of RNA polymerase II was determined to be the subunit that interacts with both Gpn1 and Rba50, indicating a close association of Npa3 and Rba50 in Rpb2 subcomplex assembly. Based on these results, we conclude that Npa3 interacts with Gpn3 and Rba50, for RNA polymerase II biogenesis. We therefore propose that multiple factors may coordinate through conserved regulatory mechanisms in the assembly of RNA polymerase complex.
PMID: 32985767
Environ Microbiol , IF:4.933 , 2020 Sep doi: 10.1111/1462-2920.15242
Serendipita bescii promotes winter wheat growth and modulates the host root transcriptome under phosphorus and nitrogen starvation.
Noble Research Institute, LLC, Ardmore, Oklahoma, 73401, USA.
Serendipita vermifera ssp. bescii, hereafter referred to as S. bescii, is a root-associated fungus that promotes plant growth in both its native switchgrass host, and a variety of monocots and dicots. Winter wheat (Triticum aestivum L.), a dual-purpose crop, used for both forage and grain production, significantly contributes to the agricultural economies of the Southern Great Plains, USA. In this study, we investigated the influence of S. bescii on growth and transcriptome regulation of nitrogen (N) and phosphorus (P) metabolism in winter wheat. S. bescii significantly improved lateral root growth and forage biomass under a limited N or P regime. Further, S. bescii activated sets of host genes regulating N and P starvation responses. These genes include, root specific auxin transport, strigolactone and gibberellin biosynthesis, degradation of phospholipids and biosynthesis of glycerolipid, downregulation of ammonium transport and nitrate assimilation, restriction of protein degradation by autophagy and subsequent N remobilization. All these genes are hypothesized to regulate acquisition, assimilation and remobilization of N and P. Based on transcriptional level gene regulation and physiological responses to N or P limitation; we suggest S. bescii plays a critical role in modulating stress imposed by limitation of these two critical nutrients in winter wheat. This article is protected by copyright. All rights reserved.
PMID: 32959463
J Integr Plant Biol , IF:4.885 , 2020 Oct , V62 (10) : P1500-1517 doi: 10.1111/jipb.12931
SHY2 as a node in the regulation of root meristem development by auxin, brassinosteroids, and cytokinin.
Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610064, China.; School of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, 467044, China.; Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University, Mianyang, 621000, China.
In multicellular organisms, the balance between cell division and differentiation determines organ size, and represents a central unknown in developmental biology. In Arabidopsis roots, this balance is mediated between cytokinin and auxin through a regulatory circuit converging on the IAA3/SHORT HYPOCOTYL 2 (SHY2) gene. Here, we show that crosstalk between brassinosteroids (BRs) and auxin occurs in the vascular transition zone to promote root meristem development. We found that BR increases root meristem size by up-regulating expression of the PINFORMED 7 (PIN7) gene and down-regulating expression of the SHY2 gene. In addition, BES1 could directly bind to the promoter regions of both PIN7 and SHY2, indicating that PIN7 and SHY2 mediate the BR-induced growth of the root meristem by serving as direct targets of BES1. Moreover, the PIN7 overexpression and loss-of-function SHY2 mutant were sensitive to the effects of BR and could partially suppress the short-root phenotypes associated with deficient BR signaling. Interestingly, BRs could inhibit the accumulation of SHY2 protein in response to cytokinin. Taken together, these findings suggest that a complex equilibrium model exists in which regulatory interactions among BRs, auxin, and cytokinin regulate optimal root growth.
PMID: 32239656
J Integr Plant Biol , IF:4.885 , 2020 Oct , V62 (10) : P1625-1637 doi: 10.1111/jipb.12927
Phytohormone dynamics in developing endosperm influence rice grain shape and quality.
School of Life Science and Technology, Shanghai Tech University, Shanghai, 201210, China.; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha, 410128, China.; Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Joint Center for Single Cell Biology/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, the Chinese Academy of Sciences, Shanghai, 200032, China.
Hormones are important signaling molecules regulating developmental processes and responses to environmental stimuli in higher plants. Rice endosperm, the portion of the seed surrounding the embryo, is the main determinant of rice grain shape and yield; however, the dynamics and exact functions of phytohormones in developing endosperm remain elusive. Through a systemic study including transcriptome analysis, hormone measurement, and transgene-based endosperm-specific expression of phytohormone biosynthetic enzymes, we demonstrated that dynamic phytohormone levels play crucial roles in the developing rice endosperm, particularly in regard to grain shape and quality. We detected diverse, differential, and dramatically changing expression patterns of genes related to hormone biosynthesis and signaling during endosperm development, especially at early developmental stages. Liquid chromatography measurements confirmed the dynamic accumulation of hormones in developing endosperm. Further transgenic analysis performed on plants expressing hormone biosynthesis genes driven by an endosperm-specific promoter revealed differential effects of the hormones, especially auxin and brassinosteroids, in regulating grain shape and quality. Our studies help elucidate the distinct roles of hormones in developing endosperm and provide novel and useful tools for influencing crop seed shape and yield.
PMID: 32198820
Int J Mol Sci , IF:4.556 , 2020 Sep , V21 (18) doi: 10.3390/ijms21186848
Drought Disrupts Auxin Localization in Abscission Zone and Modifies Cell Wall Structure Leading to Flower Separation in Yellow Lupine.
Department of Plant Physiology and Biotechnology, Nicolaus Copernicus University, 1 Lwowska Street, 87-100 Torun, Poland.; Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences-SGGW (WULS-SGGW), Nowoursynowska 159 Street, 02-776 Warsaw, Poland.; Department of Plant Cytology and Embryology, University of Gdansk, 59 Wita Stwosza, 80-308 Gdansk, Poland.
Drought causes the excessive abscission of flowers in yellow lupine, leading to yield loss and serious economic consequences in agriculture. The structure that determines the time of flower shedding is the abscission zone (AZ). Its functioning depends on the undisturbed auxin movement from the flower to the stem. However, little is known about the mechanism guiding cell-cell adhesion directly in an AZ under water deficit. Therefore, here, we seek a fuller understanding of drought-dependent reactions and check the hypothesis that water limitation in soil disturbs the natural auxin balance within the AZ and, in this way, modifies the cell wall structure, leading to flower separation. Our strategy combined microscopic, biochemical, and chromatography approaches. We show that drought affects indole-3-acetic acid (IAA) distribution and evokes cellular changes, indicating AZ activation and flower abortion. Drought action was manifested by the accumulation of proline in the AZ. Moreover, cell wall-related modifications in response to drought are associated with reorganization of methylated homogalacturonans (HG) in the AZ, and upregulation of pectin methylesterase (PME) and polygalacturonase (PG)-enzymes responsible for pectin remodeling. Another symptom of stress action is the accumulation of hemicelluloses. Our data provide new insights into cell wall remodeling events during drought-induced flower abscission, which is relevant to control plant production.
PMID: 32961941
Int J Mol Sci , IF:4.556 , 2020 Sep , V21 (18) doi: 10.3390/ijms21186849
Hypermethylation of Auxin-Responsive Motifs in the Promoters of the Transcription Factor Genes Accompanies the Somatic Embryogenesis Induction in Arabidopsis.
Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland.
The auxin-induced embryogenic reprogramming of plant somatic cells is associated with extensive modulation of the gene expression in which epigenetic modifications, including DNA methylation, seem to play a crucial role. However, the function of DNA methylation, including the role of auxin in epigenetic regulation of the SE-controlling genes, remains poorly understood. Hence, in the present study, we analysed the expression and methylation of the TF genes that play a critical regulatory role during SE induction (LEC1, LEC2, BBM, WUS and AGL15) in auxin-treated explants of Arabidopsis. The results showed that auxin treatment substantially affected both the expression and methylation patterns of the SE-involved TF genes in a concentration-dependent manner. The auxin treatment differentially modulated the methylation of the promoter (P) and gene body (GB) sequences of the SE-involved genes. Relevantly, the SE-effective auxin treatment (5.0 microM of 2,4-D) was associated with the stable hypermethylation of the P regions of the SE-involved genes and a significantly higher methylation of the P than the GB fragments was a characteristic feature of the embryogenic culture. The presence of auxin-responsive (AuxRE) motifs in the hypermethylated P regions suggests that auxin might substantially contribute to the DNA methylation-mediated control of the SE-involved genes.
PMID: 32961931
Int J Mol Sci , IF:4.556 , 2020 Sep , V21 (17) doi: 10.3390/ijms21176438
FRUITFULL Is a Repressor of Apical Hook Opening in Arabidopsis thaliana.
Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria.; Department of Biochemistry and Biotechnology, Faculty of Agronomy and Bioengineering, Poznan University of Life Sciences, Dojazd 11, 60-632 Poznan, Poland.
Plants adjust their architecture to a constantly changing environment, requiring adaptation of differential growth. Despite their importance, molecular switches, which define growth transitions, are largely unknown. Apical hook development in dark grown Arabidopsis thaliana (A. thaliana) seedlings serves as a suitable model for differential growth transition in plants. Here, we show that the phytohormone auxin counteracts the light-induced growth transition during apical hook opening. We, subsequently, identified genes which are inversely regulated by light and auxin. We used in silico analysis of the regulatory elements in this set of genes and subsequently used natural variation in gene expression to uncover correlations between underlying transcription factors and the in silico predicted target genes. This approach uncovered that MADS box transcription factor AGAMOUS-LIKE 8 (AGL8)/FRUITFULL (FUL) modulates apical hook opening. Our data shows that transient FUL expression represses the expression of growth stimulating genes during early phases of apical hook development and therewith guards the transition to growth promotion for apical hook opening. Here, we propose a role for FUL in setting tissue identity, thereby regulating differential growth during apical hook development.
PMID: 32899394
J Biol Chem , IF:4.238 , 2020 Sep , V295 (37) : P13094-13105 doi: 10.1074/jbc.RA120.014104
Auxin-transporting ABC transporters are defined by a conserved D/E-P motif regulated by a prolylisomerase.
Department of Biology, University of Fribourg, Fribourg, Switzerland.; Department of Plant Molecular Physiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.; NanoBioMedical Centre, Adam Mickiewicz University, Poznan, Poland.; Institute for Plant and Microbial Biology, Zurich, Switzerland.; Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, Poznan, Poland.; Department of Biology, University of Fribourg, Fribourg, Switzerland markus.geisler@unifr.ch.
The plant hormone auxin must be transported throughout plants in a cell-to-cell manner to affect its various physiological functions. ABCB transporters are critical for this polar auxin distribution, but the regulatory mechanisms controlling their function is not fully understood. The auxin transport activity of ABCB1 was suggested to be regulated by a physical interaction with FKBP42/Twisted Dwarf1 (TWD1), a peptidylprolyl cis-trans isomerase (PPIase), but all attempts to demonstrate such a PPIase activity by TWD1 have failed so far. By using a structure-based approach, we identified several surface-exposed proline residues in the nucleotide binding domain and linker of Arabidopsis ABCB1, mutations of which do not alter ABCB1 protein stability or location but do affect its transport activity. P1008 is part of a conserved signature D/E-P motif that seems to be specific for auxin-transporting ABCBs, which we now refer to as ATAs. Mutation of the acidic residue also abolishes auxin transport activity by ABCB1. All higher plant ABCBs for which auxin transport has been conclusively proven carry this conserved motif, underlining its predictive potential. Introduction of this D/E-P motif into malate importer, ABCB14, increases both its malate and its background auxin transport activity, suggesting that this motif has an impact on transport capacity. The D/E-P1008 motif is also important for ABCB1-TWD1 interactions and activation of ABCB1-mediated auxin transport by TWD1. In summary, our data imply a new function for TWD1 acting as a putative activator of ABCB-mediated auxin transport by cis-trans isomerization of peptidyl-prolyl bonds.
PMID: 32699109
Microorganisms , IF:4.152 , 2020 Sep , V8 (10) doi: 10.3390/microorganisms8101472
Novel Insights into the Effect of Pythium Strains on Rapeseed Metabolism.
Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague 2, Czech Republic.; Biopreparaty, spol. s r.o., Tylisovska 1, 160 00 Prague 6, Czech Republic.; Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4, Czech Republic.; Department of Botany, Faculty of Science, Charles University, Benatska 2, 128 01 Prague 2, Czech Republic.; Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojova 263, 165 02 Prague 6, Czech Republic.; Department of Analytical chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague 2, Czech Republic.
Pythium oligandrum is a unique biological control agent. This soil oomycete not only acts as a mycoparasite, but also interacts with plant roots and stimulates plant defense response via specific elicitors. In addition, P. oligandrum can synthetize auxin precursors and stimulate plant growth. We analyzed the secretomes and biochemical properties of eleven Pythium isolates to find a novel and effective strain with advantageous features for plants. Our results showed that even closely related P. oligandrum isolates significantly differ in the content of compounds secreted into the medium, and that all strains secrete proteins, amino acids, tryptamine, phenolics, and hydrolytic enzymes capable of degrading cell walls (endo-beta-1,3-glucanase, chitinase, and cellulase), exoglycosidases (especially beta-glucosidase), proteases, and phosphatases. The most different strain was identified as a not yet described Pythium species. The changes in metabolism of Brassica napus plants grown from seeds coated with the tested Pythium spp. were characterized. Enhanced levels of jasmonates, ethylene precursor, and salicylic acid may indicate better resistance to a wide variety of pathogens. Glucosinolates, as defense compounds against insects and herbivores, were enhanced in young plants. Altogether, P. oligandrum strains varied in their life strategies, and either they could perform equally as plant growth promoters and mycoparasites or they had developed one of these strategies better.
PMID: 32992822
Microorganisms , IF:4.152 , 2020 Sep , V8 (9) doi: 10.3390/microorganisms8091349
Modulating Wine Aromatic Amino Acid Catabolites by Using Torulaspora delbrueckii in Sequentially Inoculated Fermentations or Saccharomyces cerevisiae Alone.
Departamento de Nutricion y Bromatologia, Toxicologia y Medicina Legal, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.; Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Italy.
Yeasts are the key microorganisms that transform grape juice into wine, and nitrogen is an essential nutrient able to affect yeast cell growth, fermentation kinetics and wine quality. In this work, we focused on the intra- and extracellular metabolomic changes of three aromatic amino acids (tryptophan, tyrosine, and phenylalanine) during alcoholic fermentation of two grape musts by two Saccharomyces cerevisiae strains and the sequential inoculation of Torulaspora delbrueckii with Saccharomyces cerevisiae. An UPLC-MS/MS method was used to monitor 33 metabolites, and 26 of them were detected in the extracellular samples and 8 were detected in the intracellular ones. The results indicate that the most intensive metabolomic changes occurred during the logarithm cellular growth phase and that pure S. cerevisiae fermentations produced higher amounts of N-acetyl derivatives of tryptophan and tyrosine and the off-odour molecule 2-aminoacetophenone. The sequentially inoculated fermentations showed a slower evolution and a higher production of metabolites linked to the well-known plant hormone indole acetic acid (auxin). Finally, the production of sulfonated tryptophol during must fermentation was confirmed, which also may explain the bitter taste of wines produced by Torulaspora delbrueckii co-fermentations, while sulfonated indole carboxylic acid was detected for the first time in such an experimental design.
PMID: 32899614
Physiol Plant , IF:4.148 , 2020 Sep doi: 10.1111/ppl.13219
Comprehensive RNA-seq analysis revealed molecular pathways and genes associated with drought tolerance in Wild Soybean (Glycine soja Sieb. & Zucc.).
National Center for Soybean Improvement, Key Laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.; College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, P.R. China.; Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan.; Institute of Plant Breeding and Biotechnology, MNS University of Agriculture, Multan, 60000, Pakistan.
Drought stress at the germination stage is an important environmental stress limiting crop yield. Hence, our study investigated comparative root transcriptome profiles of four contrasting soybean genotypes viz., drought-tolerant (PI342618B/DTP and A214/DTL) and drought-sensitive (NN86-4/DSP and A195/DSL) under drought stress using RNA-Seq approach. A total of 4850 and 6272 differentially expressed genes (DEGs) were identified in tolerant (DTP and DTL) and sensitive (DSP and DSL) genotypes, respectively. Principle component analysis (PCA) and correlation analysis revealed higher correlation between DTP and DTL. Both gene ontology (GO) and MapMan analyses showed that the drought response was enriched in DEGs associated with water and auxin transport, cell wall/membrane, antioxidant activity, catalytic activity, secondary metabolism, signaling and transcription factor (TF) activities. Out of 981 DEGs screened from above terms, only 547 showed consistent opposite expression between contrasting genotypes. Twenty-eight DEGs of 547 were located on Chr.08 rich in QTLs and "Hotspot regions" associated with drought stress, and eight of them showed non-synonymous SNP polymorphism. Hence, ten genes (including above eight genes plus two hub genes) were predicated as possible candidates regulating drought tolerance, which needs further functional validation. Overall, the transcriptome profiling provided in-depth understanding about the genetic mechanism and candidate genes underlying drought tolerance in soybean. This article is protected by copyright. All rights reserved.
PMID: 32984966
Sci Rep , IF:3.998 , 2020 Sep , V10 (1) : P15835 doi: 10.1038/s41598-020-72474-w
Understanding salt tolerance mechanism using transcriptome profiling and de novo assembly of wild tomato Solanum chilense.
Division of Crop Improvement and Biotechnology, Indian Institute of Vegetable Research, Indian Council of Agricultural Research, Varanasi, Uttar Pradesh, 221 305, India.; Department of Botany, Mahila Maha Vidyalaya, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.; Division of Crop Improvement and Biotechnology, Indian Institute of Vegetable Research, Indian Council of Agricultural Research, Varanasi, Uttar Pradesh, 221 305, India. prasanna.c@icar.gov.in.; Division of Vegetable Crops, Indian Institute of Horticultural Research, Indian Council of Agricultural Research, Hessaraghatta, Lake Post, Bengaluru, Karnataka, 560 089, India. prasanna.c@icar.gov.in.
Soil salinity affects the plant growth and productivity detrimentally, but Solanum chilense, a wild relative of cultivated tomato (Solanum lycopersicum L.), is known to have exceptional salt tolerance. It has precise adaptations against direct exposure to salt stress conditions. Hence, a better understanding of the mechanism to salinity stress tolerance by S. chilense can be accomplished by comprehensive gene expression studies. In this study 1-month-old seedlings of S. chilense and S. lycopersicum were subjected to salinity stress through application of sodium chloride (NaCl) solution. Through RNA-sequencing here we have studied the differences in the gene expression patterns. A total of 386 million clean reads were obtained through RNAseq analysis using the Illumina HiSeq 2000 platform. Clean reads were further assembled de novo into a transcriptome dataset comprising of 514,747 unigenes with N50 length of 578 bp and were further aligned to the public databases. Genebank non-redundant (Nr), Viridiplantae, Gene Ontology (GO), KOG, and KEGG databases classification suggested enrichment of these unigenes in 30 GO categories, 26 KOG, and 127 pathways, respectively. Out of 265,158 genes that were differentially expressed in response to salt treatment, 134,566 and 130,592 genes were significantly up and down-regulated, respectively. Upon placing all the differentially expressed genes (DEG) in known signaling pathways, it was evident that most of the DEGs involved in cytokinin, ethylene, auxin, abscisic acid, gibberellin, and Ca(2+) mediated signaling pathways were up-regulated. Furthermore, GO enrichment analysis was performed using REVIGO and up-regulation of multiple genes involved in various biological processes in chilense under salinity were identified. Through pathway analysis of DEGs, "Wnt signaling pathway" was identified as a novel pathway for the response to the salinity stress. Moreover, key genes for salinity tolerance, such as genes encoding proline and arginine metabolism, ROS scavenging system, transporters, osmotic regulation, defense and stress response, homeostasis and transcription factors were not only salt-induced but also showed higher expression in S. chilense as compared to S. lycopersicum. Thus indicating that these genes may have an important role in salinity tolerance in S. chilense. Overall, the results of this study improve our understanding on possible molecular mechanisms underlying salt tolerance in plants in general and tomato in particular.
PMID: 32985535
Plant Reprod , IF:3.957 , 2020 Sep doi: 10.1007/s00497-020-00396-8
Comparative transcriptome analysis of gynoecious and monoecious inflorescences reveals regulators involved in male flower development in the woody perennial plant Jatropha curcas.
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Innovation Academy for Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Innovation Academy for Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. chenms@xtbg.org.cn.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. chenms@xtbg.org.cn.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Innovation Academy for Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. zfxu@xtbg.ac.cn.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China. zfxu@xtbg.ac.cn.
KEY MESSAGE: ABCE model genes along with genes related to GA biosynthesis and auxin signalling may play significant roles in male flower development in Jatropha curcas. Flowering plants exhibit extreme reproductive diversity. Jatropha curcas, a woody plant that is promising for biofuel production, is monoecious. Here, two gynoecious Jatropha mutants (bearing only female flowers) were used to identify key genes involved in male flower development. Using comparative transcriptome analysis, we identified 17 differentially expressed genes (DEGs) involved in floral organ development between monoecious plants and the two gynoecious mutants. Among these DEGs, five floral organ identity genes, Jatropha AGAMOUS, PISTILLATA, SEPALLATA 2-1 (JcSEP2-1), JcSEP2-2, and JcSEP3, were downregulated in ch mutant inflorescences; two gibberellin (GA) biosynthesis genes, Jatropha GA REQUIRING 1 and GIBBERELLIN 3-OXIDASE 1, were downregulated in both the ch and g mutants; and two genes involved in the auxin signalling pathway, Jatropha NGATHA1 and STYLISH1, were downregulated in the ch mutant. Furthermore, four hub genes involved in male flower development, namely Jatropha SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1, CRYPTOCHROME 2, SUPPRESSOR OF OVEREXPRESSION OF CO 1 and JAGGED, were identified using weighted gene correlation network analysis. These results suggest that floral organ identity genes and genes involved in GA biosynthesis and auxin signalling may participate in male flower development in Jatropha. This study will contribute to understanding sex differentiation in woody perennial plants.
PMID: 32997187
Plant Cell Rep , IF:3.825 , 2020 Sep doi: 10.1007/s00299-020-02596-y
Auxins, the hidden player in chloroplast development.
Centro de Investigacion Cientifica de Yucatan, Unidad de Biotecnologia, Calle 43 No. 130 x 32 y 34. Col. Chuburna de Hidalgo, 97205, Merida, Yucatan, Mexico.; Centro de Investigacion Cientifica de Yucatan, Unidad de Biotecnologia, Calle 43 No. 130 x 32 y 34. Col. Chuburna de Hidalgo, 97205, Merida, Yucatan, Mexico. clelia@cicy.mx.
Throughout decades of plant research, the plant hormones known as auxins have been found to be of vital importance in most plant development processes. Indole-3-acetic acid (IAA) represents the most common auxin in plants and can be synthesized from its tryptophan precursor, which is synthesized in the chloroplast. The chloroplast constitutes an organelle of great relevance to plants since the photosynthesis process by which plants get most of their energy is carried out there. The role of auxins in photosynthesis has been studied for at least 50 years, and in this time, it has been shown that auxins have an effect on several of the essential components and structure of the chloroplast. In recent decades, a high number of genes have been reported to be expressed in the chloroplast and some of their mutants have been shown to alter different auxin-mediated pathways. Genes in signaling pathways such as IAA/AUX, ARF, GH.3, SAUR and TIR, biosynthesis-related genes such as YUCCA and transport-related genes such as PIN have been identified among the most regulated genes in mutants related to alterations in the chloroplast. This review aims to provide a complete and updated summary of the relationship between auxins and several processes that involve the chloroplast, including chloroplast development, plant albinism, redox regulation and pigment synthesis.
PMID: 32960306
Plant Cell Rep , IF:3.825 , 2020 Sep doi: 10.1007/s00299-020-02594-0
tRNA ADENOSINE DEAMINASE 3 is required for telomere maintenance in Arabidopsis thaliana.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.; Facultad de Ciencias, Instituto de Ciencias Ambientales Y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.; KWS Gateway Research Center, LLC, 1005 N Warson Rd, BRDG Park, St. Louis, MO, 63132, USA.; Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA. dshippen@tamu.edu.; Department of Biochemistry and Biophysics, 300 Olsen Blvd, Room 413, College Station, TX, 77843-2128, USA. dshippen@tamu.edu.
KEY MESSAGE: tRNA Adenosine Deaminase 3 helps to sustain telomere tracts in a telomerase-independent fashion, likely through regulating cellular metabolism. Telomere length maintenance is influenced by a complex web of chromatin and metabolism-related factors. We previously reported that a lncRNA termed AtTER2 regulates telomerase activity in Arabidopsis thaliana in response to DNA damage. AtTER2 was initially shown to partially overlap with the 5' UTR of the tRNA ADENOSINE DEAMINASE 3 (TAD3) gene. However, updated genome annotation showed that AtTER2 was completely embedded in TAD3, raising the possibility that phenotypes ascribed to AtTER2 could be derived from TAD3. Here we show through strand-specific RNA-Seq, strand-specific qRT-PCR and bioinformatic analyses that AtTER2 does not encode a stable lncRNA. Further examination of the original tad3 (ter2-1/tad3-1) mutant revealed expression of an antisense transcript driven by a cryptic promoter in the T-DNA. Hence, a new hypomorphic allele of TAD3 (tad3-2) was examined. tad3-2 mutants showed hypersensitivity to DNA damage, but no deregulation of telomerase, suggesting that the telomerase phenotype of tad3-1 mutants reflects an off-target effect. Unexpectedly, however, tad3-2 plants displayed progressive loss of telomeric DNA over successive generations that was not accompanied by alteration of terminal architecture or end protection. The phenotype was exacerbated in plants lacking the telomerase processivity factor POT1a, indicating that TAD3 promotes telomere maintenance through a non-canonical, telomerase-independent pathway. The transcriptome of tad3-2 mutants revealed significant dysregulation of genes involved in auxin signaling and glucosinolate biosynthesis, pathways that intersect the stress response, cell cycle regulation and DNA metabolism. These findings indicate that the TAD3 locus indirectly contributes to telomere length homeostasis by altering the metabolic profile in Arabidopsis.
PMID: 32959123
Plant Cell Rep , IF:3.825 , 2020 Sep doi: 10.1007/s00299-020-02591-3
Characterization of the leaf rust responsive ARF genes in wheat (Triticum aestivum L.).
Department of Bio-Engineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India.; Department of Plant Sciences, University of Idaho, Moscow, ID, 83844, USA.; Faculty of Agriculture, Usha Martin University, Angara, Ranchi, Jharkhand, 835103, India.; Department of Genetics, IARI New Delhi, New Delhi, 110012, India.; Department of Bio-Engineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, 835215, India. kmukhopadhyay@bitmesra.ac.in.
KEY MESSAGE: Genome-wide identification, classification, functional characterization and expression analysis of Auxin Responsive Factor (ARF) gene family in wheat reveal their attributes and role during leaf rust infection. Auxins are important plant growth regulators that also impact plant-pathogen interaction. Auxin responsive factors (ARF) are plant specific transcription factors that control responses to auxins. Whole genome investigation of ARF gene family is limited in allohexaploid wheat (Triticum aestivum L.). Comprehensive study of this gene family was carried out by employing the currently available reference genome sequence of wheat. In total, 27 ARF genes were identified and located on the wheat genome as well as were positioned on wheat chromosome arms. Additionally, examination of the predicted genes unveiled a decent degree of relatedness within and among the phylogenetic clades. Leaf rust, caused by the obligate biotrophic fungal pathogen Puccinia triticina, is responsible for drastic loss of wheat crop worldwide reducing grain yield by 10-90%. Expression profiling of ARF genes in retort to leaf rust infection indicated their differential regulation during this plant-pathogen interaction. Highest expression of ARF genes were observed at 12 hpi that was maintained up to 72 hpi during incompatible interaction, whereas the high expression levels receded at 48 hpi during compatible interactions. Few of the identified ARF genes were likely to be post-transcriptionally regulated by microRNAs. Many light and stress responsive elements were detected in the promoter regions of ARF genes. Microsynteny analysis showed the conservation of ARF genes within the members of the Poaceae family. This study provides fundamental details for understanding the different types of ARF genes in wheat and there putative roles during leaf rust-wheat interaction.
PMID: 32892289
Genes (Basel) , IF:3.759 , 2020 Sep , V11 (10) doi: 10.3390/genes11101124
Comparative Transcriptomics and Co-Expression Networks Reveal Tissue- and Genotype-Specific Responses of qDTYs to Reproductive-Stage Drought Stress in Rice (Oryza sativa L.).
Department of Crop Sciences, College of Agricultural, Consumer & Environmental Sciences, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA.; International Rice Research Institute, Los Banos, Laguna 4031, Philippines.; Southern Cross Plant Science, Southern Cross University, Military Rd, East Lismore NSW 2480, Australia.; Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
Rice (Oryza sativa L.) is more sensitive to drought stress than other cereals. To dissect molecular mechanisms underlying drought-tolerant yield in rice, we applied differential expression and co-expression network approaches to transcriptomes from flag-leaf and emerging panicle tissues of a drought-tolerant yield introgression line, DTY-IL, and the recurrent parent Swarna, under moderate reproductive-stage drought stress. Protein turnover and efficient reactive oxygen species scavenging were found to be the driving factors in both tissues. In the flag-leaf, the responses further included maintenance of photosynthesis and cell wall reorganization, while in the panicle biosynthesis of secondary metabolites was found to play additional roles. Hub genes of importance in differential drought responses included an expansin in the flag-leaf and two peroxidases in the panicle. Overlaying differential expression data with allelic variation in DTY-IL quantitative trait loci allowed for the prioritization of candidate genes. They included a differentially regulated auxin-responsive protein, with DTY-IL-specific amino acid changes in conserved domains, as well as a protein kinase with a DTY-IL-specific frameshift in the C-terminal region. The approach highlights how the integration of differential expression and allelic variation can aid in the discovery of mechanism and putative causal contribution underlying quantitative trait loci for drought-tolerant yield.
PMID: 32987927
Pest Manag Sci , IF:3.75 , 2020 Sep doi: 10.1002/ps.6097
Dicamba Resistance in Kochia from Kansas and Nebraska Evolved Independently.
Department of Agronomy, Kansas State University, 2004 Throckmorton Plant Sciences Center, 1712 Claflin Road, Manhattan, Kansas, 66506, USA.; Department of Bioagricultural Sciences and Pest Management, Colorado State University, 1177 Campus Delivery, Fort Collins, Colorado, 80523, USA.; Agricultural Research Center-Hays, Kansas State University, 1232 240th Avenue, Hays, Kansas, 67601, USA.
BACKGROUND: Evolution and spread of resistance to glyphosate in kochia (Bassia scoparia (L.) A.J. Scott) is a major challenge for the sustainability of glyphosate-resistant crop technology in this region. Dicamba offers a viable option to manage glyphosate-resistant kochia. However, the recent and rapid evolution of dicamba resistance in glyphosate-resistant kochia populations in Kansas (KS), and other states in the US is a threat to the management of this weed. Our previous research suggests that two distinct mechanisms confer dicamba resistance in KS (KSUR) and NE (CSUR) kochia. CSUR kochia is dicamba-resistant due to a double mutation in an auxin and dicamba coreceptor gene (Aux/IAA16), and CSUR kochia plants show reduced dicamba translocation. However, the mechanism of dicamba resistance in KSUR is not known. The objective of this research was to determine if dicamba resistance in KSUR is due to a different mechanism and therefore evolved independently from CSUR, by measuring whether the resistance traits are chromosomally linked. RESULTS: The F1 and F2 progenies from KSUR x CSUR were generated. Single dicamba rate tests were conducted using the F1 and F2 progeny. The results indicate that two different genes confer dicamba resistance in KSUR and CSUR; importantly, these two genes are not linked. CONCLUSION: This research provides evidence that different populations of kochia have independently evolved resistance to dicamba by different mechanisms, and we confirmed that the genes conferring resistance to the same herbicide in different populations are not chromosomally linked. This article is protected by copyright. All rights reserved.
PMID: 32954607
Pest Manag Sci , IF:3.75 , 2020 Sep doi: 10.1002/ps.6080
A dicamba resistance-endowing IAA16 mutation leads to significant vegetative growth defects and impaired competitiveness in kochia (Bassia scoparia)(dagger).
Bayer CropScience, Chesterfield, MO, USA.; Department of Agricultural Biology, Colorado State University, Wentzville, MO, USA.; Sammons BFC LLC, Wentzville, Wentzville, MO, 63365, USA.
BACKGROUND: Precise quantification of the fitness cost of synthetic auxin resistance has been impeded by lack of knowledge about the genetic basis of resistance in weeds. Recent elucidation of a resistance-endowing IAA16 mutation (G73N) in the key weed species kochia (Bassia scoparia), allows detailed characterization of the contribution of resistance alleles to weed fitness, both in the presence and absence of herbicides. Different G73N genotypes from a segregating resistant parental line (9425) were characterized for cross-resistance to dicamba, 2,4-d and fluroxypyr, and changes on stem/leaf morphology and plant architecture. Plant competitiveness and dominance of the fitness effects was quantified through measuring biomass and seed production of three F2 lines in two runs of glasshouse replacement series studies. RESULTS: G73N confers robust resistance to dicamba but only moderate to weak resistance to 2,4-D and fluroxypyr. G73N mutant plants displayed significant vegetative growth defects: (i) they were 30-50% shorter, with a more tumbling style plant architecture, and (ii) they had thicker and more ovate (versus lanceolate and linear) leaf blades with lower photosynthesis efficiency, and 40-60% smaller stems with less-developed vascular bundle systems. F2 mutant plants had impaired plant competitiveness, which can lead to 80-90% less biomass and seed production in the replacement series study. The pleiotropic effects of G73N were mostly semidominant (0.5) and fluctuated with the environments and traits measured. CONCLUSION: G73N is associated with significant vegetative growth defects and reduced competitiveness in synthetic auxin-resistant kochia. Management practices should target resistant kochia's high vulnerability to competition in order to effectively contain the spread of resistance.
PMID: 32909332
BMC Genomics , IF:3.594 , 2020 Sep , V21 (1) : P653 doi: 10.1186/s12864-020-07046-3
Comparative transcriptome analysis revealed the cooperative regulation of sucrose and IAA on adventitious root formation in lotus (Nelumbo nucifera Gaertn).
School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, P. R. China. lbcheng@yzu.edu.cn.; School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, P. R. China.; Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, Henan, P. R. China.; College of Guangling, Yangzhou University, Yangzhou, Jiangsu, P. R. China. lsydbnd@163.com.
BACKGROUND: In China, lotus is an important cultivated crop with multiple applications in ornaments, food, and environmental purification. Adventitious roots (ARs), a secondary root is necessary for the uptake of nutrition and water as the lotus principle root is underdeveloped. Therefore, AR formation in seedlings is very important for lotus breeding due to its effect on plant early growth. As lotus ARs formation was significantly affected by sucrose treatment, we analyzed the expression of genes and miRNAs upon treatment with differential concentrations of sucrose, and a crosstalk between sucrose and IAA was also identified. RESULTS: Notably, 20 mg/L sucrose promoted the ARs development, whereas 60 mg/L sucrose inhibited the formation of ARs. To investigate the regulatory pathway during ARs formation, the expression of genes and miRNAs was evaluated by high-throughput tag-sequencing. We observed that the expression of 5438, 5184, and 5345 genes was enhanced in the GL20/CK0, GL60/CK0, and CK1/CK0 libraries, respectively. Further, the expression of 73, 78, and 71 miRNAs was upregulated in the ZT20/MCK0, ZT60/MCK0, and MCK1/MCK0 libraries, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that most of the differentially expressed genes and miRNAs in the GL20/GL60 and ZT20/ZT60 libraries were involved in signal transduction. A large number of these genes (29) and miRNAs (53) were associated with plant hormone metabolism. We observed an association between five miRNAs (miR160, miR156a-5p, miR397-5p_1, miR396a and miR167d) and nine genes (auxin response factor, protein brassinosteroid insensitive 1, laccase, and peroxidase 27) in the ZT20/ ZT60 libraries during ARs formation. Quantitative polymerase chain reaction (qRT-PCR) was used to validate the high-throughput tag-sequencing data. CONCLUSIONS: We found that the expression of many critical genes involved in IAA synthesis and IAA transport was changed after treatment with various concentration of sucrose. Based on the change of these genes expression, IAA and sucrose content, we concluded that sucrose and IAA cooperatively regulated ARs formation. Sucrose affected ARs formation by improving IAA content at induction stage, and increased sucrose content might be also required for ARs development according to the changes tendency after application of exogenous IAA.
PMID: 32967611
Plant Sci , IF:3.591 , 2020 Oct , V299 : P110622 doi: 10.1016/j.plantsci.2020.110622
Knock-down of delta-aminolevulinic acid dehydratase via virus-induced gene silencing alters the microRNA biogenesis and causes stress-related reactions in citrus plants.
Department of Plant Pathology, Citrus Research and Education Center, IFAS, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA. Electronic address: nabilkilliny@ufl.edu.; Department of Plant Pathology, Citrus Research and Education Center, IFAS, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, 33850, USA.
The delta-aminolevulinic acid (delta-ALA) is an intermediate in the biosynthetic pathway of tetrapyrroles. Tetrapyrroles play vital roles in many biological processes such as photosynthesis, respiration, and light-sensing. ALA-dehydratase (ALAD) combines two molecules of delta-ALA to form porphobilinogen. In citrus, the silencing of ALAD caused discrete yellow spots and necrosis in leaves and stems. Additionally, it caused rapid death in developing new shoots. Herein, we hypothesize that the accumulation of delta-ALA results in severe stress and reduced meristem development. For that reason, we investigated the dynamic changes in the expression profiles of 23 microRNA (miRNA) identified through small RNA sequencing, from CTV-tALAD plants in comparison with healthy C. macrophylla and C. macrophylla infiltrated with CTV-wt. Furthermore, we reported the effect of ALAD silencing on the total phenolics, H2O2, and reactive oxygen species (ROS) levels, to examine the possibilities of miRNAs involving the regulation of these pathways. Our results showed that the total phenolics content, H2O2, and O2(-) levels were increased in CTV-tALAD plants. Moreover, 63 conserved miRNA members belonging to 23 different miRNA families were differentially expressed in CTV-tALAD plants compared to controls. The identified miRNAs are implicated in auxin biosynthesis and signaling, axillary shoot meristem formation and leaf morphology, starch metabolism, and oxidative stress. Collectively, our findings suggested that ALAD silencing initiates stress on citrus plants. As a result, CTV-tALAD plants exhibit reduced metabolic rate, growth, and development in order to cope with the stress that resulted from the accumulation of delta-ALA. This cascade of events led to leaf, stem, and meristem necrosis and failure of new shoot development.
PMID: 32900450
Appl Microbiol Biotechnol , IF:3.53 , 2020 Oct , V104 (20) : P8549-8565 doi: 10.1007/s00253-020-10890-8
Auxins of microbial origin and their use in agriculture.
Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India.; Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India.; Instituto de Biotecnologia de Leon (INBIOTEC), Parque Cientifico de Leon, Av, Real, 1, 24006, Leon, Spain.; Departamento de Ciencias Biomedicas, Universidad de Leon, Campus de Vegazana s/n, 24071, Leon, Spain.; Departement de Microbiologie Faculte SNV, LMA UFA Setif 1, Setif, Algeria.; Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand.; Humboldt-Universitat zu Berlin, Institut fur Biologie, Berlin, Germany.; Nord Reet UG, Marienstr. 27a, 17489, Greifswald, Germany.; Instituto de Biologia Molecular y Celular de Plantas, CSIC-Universitat Politecnica de Valencia, 46022, Valencia, Spain.; Facultad De Ciencias Quimicas, Benemerita Universidad Autonoma De Puebla, 72590, Puebla, Pue, Mexico. estisansi@yahoo.com.mx.
To maintain the world population demand, a sustainable agriculture is needed. Since current global vision is more friendly with the environment, eco-friendly alternatives are desirable. In this sense, plant growth-promoting rhizobacteria could be the choice for the management of soil-borne diseases of crop plants. These rhizobacteria secrete chemical compounds which act as phytohormones. Indole-3-acetic acid (IAA) is the most common plant hormone of the auxin class which regulates various processes of plant growth. IAA compound, in which structure can be found a carboxylic acid attached through a methylene group to the C-3 position of an indole ring, is produced both by plants and microorganisms. Plant growth-promoting rhizobacteria and fungi secrete IAA to promote the plant growth. In this review, IAA production and mechanisms of action by bacteria and fungi along with the metabolic pathways evolved in the IAA secretion and commercial prospects are revised.Key points* Many microorganisms produce auxins which help the plant growth promotion.* These auxins improve the plant growth by several mechanisms.* The auxins are produced through different mechanisms.
PMID: 32918584
BMC Plant Biol , IF:3.497 , 2020 Sep , V20 (1) : P433 doi: 10.1186/s12870-020-02643-6
Interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via promoting proton motive force and reducing proton gradient in alfalfa.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China. anyuan@sjtu.edu.cn.; Key Laboratory of Urban Agriculture, Ministry of Agriculture, Shanghai, 201101, China. anyuan@sjtu.edu.cn.
BACKGROUND: In acidic soils, aluminum (Al) competing with Zn results in Zn deficiency in plants. Zn is essential for auxin biosynthesis. Zn-mediated alleviation of Al toxicity has been rarely studied, the mechanism of Zn alleviation on Al-induced photoinhibition in photosystems remains unclear. The objective of this study was to investigate the effects of Zn and IAA on photosystems of Al-stressed alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or100 muM AlCl3 combined with 0 or 50 muM ZnCl2, and then foliar spray with water or 6 mg L(- 1) IAA. RESULTS: Our results showed that Al stress significantly decreased plant growth rate, net photosynthetic rate (Pn), quantum yields and electron transfer rates of PSI and PSII. Exogenous application of Zn and IAA significantly alleviated the Al-induced negative effects on photosynthetic machinery, and an interaction of Zn and IAA played an important role in the alleviative effects. After removing apical buds of Al-stressed alfalfa seedlings, the values of pmf, gH(+) and Y(II) under exogenous spraying IAA were significantly higher, and DeltapHpmf was significantly lower in Zn addition than Al treatment alone, but the changes did not occur under none spraying IAA. The interaction of Zn and IAA directly increased Y(I), Y(II), ETRI and ETRII, and decreased O2(-) content of Al-stressed seedlings. In addition, the transcriptome analysis showed that fourteen functionally noted genes classified into functional category of energy production and conversion were differentially expressed in leaves of alfalfa seedlings with and without apical buds. CONCLUSION: Our results suggest that the interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via increasing pmf and decreasing DeltapHpmf between lumen and stroma.
PMID: 32948141
BMC Plant Biol , IF:3.497 , 2020 Sep , V20 (1) : P429 doi: 10.1186/s12870-020-02637-4
Revealing the full-length transcriptome of caucasian clover rhizome development.
College of Animal Science and Technology, Northeast Agricultural University, No.600 Changjiang Street, Xiangfang District, Harbin, 150030, Heilongjiang, China.; College of Animal Science and Technology, Northeast Agricultural University, No.600 Changjiang Street, Xiangfang District, Harbin, 150030, Heilongjiang, China. cuigw603@126.com.
BACKGROUND: Caucasian clover (Trifolium ambiguum M. Bieb.) is a strongly rhizomatous, low-crowned perennial leguminous and ground-covering grass. The species may be used as an ornamental plant and is resistant to cold, arid temperatures and grazing due to a well-developed underground rhizome system and a strong clonal reproduction capacity. However, the posttranscriptional mechanism of the development of the rhizome system in caucasian clover has not been comprehensively studied. Additionally, a reference genome for this species has not yet been published, which limits further exploration of many important biological processes in this plant. RESULT: We adopted PacBio sequencing and Illumina sequencing to identify differentially expressed genes (DEGs) in five tissues, including taproot (T1), horizontal rhizome (T2), swelling of taproot (T3), rhizome bud (T4) and rhizome bud tip (T5) tissues, in the caucasian clover rhizome. In total, we obtained 19.82 GB clean data and 80,654 nonredundant transcripts were analysed. Additionally, we identified 78,209 open reading frames (ORFs), 65,227 coding sequences (CDSs), 58,276 simple sequence repeats (SSRs), 6821 alternative splicing (AS) events, 2429 long noncoding RNAs (lncRNAs) and 4501 putative transcription factors (TFs) from 64 different families. Compared with other tissues, T5 exhibited more DEGs, and co-upregulated genes in T5 are mainly annotated as involved in phenylpropanoid biosynthesis. We also identified betaine aldehyde dehydrogenase (BADH) as a highly expressed gene-specific to T5. A weighted gene co-expression network analysis (WGCNA) of transcription factors and physiological indicators were combined to reveal 11 hub genes (MEgreen-GA3), three of which belong to the HB-KNOX family, that are up-regulated in T3. We analysed 276 DEGs involved in hormone signalling and transduction, and the largest number of genes are associated with the auxin (IAA) signalling pathway, with significant up-regulation in T2 and T5. CONCLUSIONS: This study contributes to our understanding of gene expression across five different tissues and provides preliminary insight into rhizome growth and development in caucasian clover.
PMID: 32938399
BMC Plant Biol , IF:3.497 , 2020 Sep , V20 (1) : P410 doi: 10.1186/s12870-020-02628-5
Integrating transcriptomic and metabolomic analysis of hormone pathways in Acer rubrum during developmental leaf senescence.
Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui, 230031, P.R. China.; College of Forestry and Landscape Architecture, Anhui Agricultural University, 130 Changjiangxilu, Hefei, Anhui, 230036, P.R. China.; Institute of Agricultural Engineering, Anhui Academy of Agricultural Sciences, 40 Nongkenanlu, Hefei, Anhui, 230031, P.R. China. renjieaaas@sina.com.
BACKGROUND: To fully elucidate the roles and mechanisms of plant hormones in leaf senescence, we adopted an integrated analysis of both non-senescing and senescing leaves from red maple with transcriptome and metabolome data. RESULTS: Transcription and metabolite profiles were generated through a combination of deep sequencing, third-generation sequencing data analysis, and ultrahigh-performance liquid chromatograph Q extractive mass spectrometry (UHPLC-QE-MS), respectively. We investigated the accumulation of compounds and the expression of biosynthesis and signaling genes for eight hormones. The results revealed that ethylene and abscisic acid concentrations increased during the leaf senescence process, while the contents of cytokinin, auxin, jasmonic acid, and salicylic acid continued to decrease. Correlation tests between the hormone content and transcriptional changes were analyzed, and in six pathways, genes closely linked with leaf senescence were identified. CONCLUSIONS: These results will enrich our understanding of the mechanisms of plant hormones that regulate leaf senescence in red maple, while establishing a foundation for the genetic modification of Acer in the future.
PMID: 32883206
Planta , IF:3.39 , 2020 Sep , V252 (4) : P51 doi: 10.1007/s00425-020-03452-9
Tomato auxin biosynthesis/signaling is reprogrammed by the geminivirus to enhance its pathogenicity.
Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; Division of Biochemistry, ICAR-National Rice Research Institute, Cuttack, Orissa, 753006, India.; Division of Plant Pathology-Advanced Centre for Plant Virology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; ICAR-Division of Physiology, Biochemistry and PHT, ICAR-Central Plantation Crops Research Institute, Kasaragod, Kerala, 671124, India. rameshsvbio@gmail.com.; Division of Biochemistry, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India. shellypraveen@hotmail.com.
MAIN CONCLUSION: Tomato leaf curl New Delhi virus-derived AC4 protein interacts with host proteins involved in auxin biosynthesis and reprograms auxin biosynthesis/signaling to help in viral replication and manifestation of the disease-associated symptoms. Perturbations of phytohormone-mediated gene regulatory network cause growth and developmental defects. Furthermore, plant viral infections cause characteristic disease symptoms similar to hormone-deficient mutants. Tomato leaf curl New Delhi Virus (ToLCNDV)-encoded AC4 is a small protein that attenuates the host transcriptional gene silencing, and aggravated disease severity in tomato is correlated with transcript abundance of AC4. Hence, investigating the role of AC4 in pathogenesis divulged that ToLCNDV-AC4 interacted with host TAR1 (tryptophan amino transferase 1)-like protein, CYP450 monooxygenase-the key enzyme of indole acetic acid (IAA) biosynthesis pathway-and with a protein encoded by senescence-associated gene involved in jasmonic acid pathway. Also, ToLCNDV infection resulted in the upregulation of host miRNAs, viz., miR164, miR167, miR393 and miR319 involved in auxin signaling and leaf morphogenesis concomitant with the decline in endogenous IAA levels. Ectopic overexpression of ToLCNDV-derived AC4 in tomato recapitulated the transcriptomic and disruption of auxin biosynthesis/signaling features of the infected leaves. Furthermore, exogenous foliar application of IAA caused remission of the characteristic disease-related symptoms in tomato. The roles of ToLCNDV-AC4 in reprogramming auxin biosynthesis, signaling and cross-talk with JA pathway to help viral replication and manifest the disease-associated symptoms during ToLCNDV infection are discussed.
PMID: 32940767
Planta , IF:3.39 , 2020 Sep , V252 (4) : P50 doi: 10.1007/s00425-020-03448-5
Long-distance regulation of shoot gravitropism by Cyclophilin 1 in tomato (Solanum lycopersicum) plants.
Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, 68 HaMaccabim Road, P.O. Box 15159, 7505101, Rishon LeZion, Israel. ziv.spi@volcani.agri.gov.il.; Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, 68 HaMaccabim Road, P.O. Box 15159, 7505101, Rishon LeZion, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
MAIN CONCLUSION: The phloem-mobile protein SlCyp1 traffics to distant parts of the shoot to regulate its gravitropic response. In addition, SlCyp1 targets specific cells in the root to promote lateral root development. The tomato (Solanum lycopersicum) Cyclophilin 1 (SlCyp1) gene encodes a peptidyl-prolyl isomerase required for auxin response, lateral root development and gravitropic growth. The SlCyp1 protein is a phloem-mobile signal that moves from shoot to root to regulate lateral root development (Spiegelman et al., Plant J 83:853-863, 2015; J Exp Bot 68:953-964, 2017a). Here, we explored the mechanism of SlCyp1 movement by fusing it to the fluorescent protein mCherry. We found that, once trafficked to the root, SlCyp1 is unloaded from the phloem to the surrounding tissues, including the pericycle and lateral root primordia. Interestingly, SlCyp1 not only moves to the root system, but also to distant parts of the shoot. Grafting of the SlCyp1 mutant diageotropica (dgt) scions on VFN8 control rootstocks resulted in recovery of dgt shoot gravitropism, which was associated with the restoration of auxin-response capacity. Application of the cyclophilin inhibitor cyclosporine A suppressed gravitropic recovery, indicating that SlCyp1 must be active in the target tissue to affect the gravitropic response. These results provide new insights on the mechanism of SlCyp1 transport and functioning as a long-distance signal regulating shoot gravitropism.
PMID: 32939624
Planta , IF:3.39 , 2020 Sep , V252 (3) : P46 doi: 10.1007/s00425-020-03451-w
Indole-3-butyric acid priming reduced cadmium toxicity in barley root tip via NO generation and enhanced glutathione peroxidase activity.
Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, 84523, Bratislava, Slovak Republic.; Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, 84523, Bratislava, Slovak Republic. Ladislav.Tamas@savba.sk.
MAIN CONCLUSION: Activation of GPX and enhanced NO level play a key role in IBA-mediated enhanced Cd tolerance in young barley roots. Application of exogenous indole-3-acetic acid (IAA) or an IAA precursor improves the tolerance of plants to heavy metals. However, the physiology of these tolerance mechanisms remains largely unknown. Therefore, we studied the priming effect of indole-3-butyric acid (IBA), an IAA precursor, on mild and severe cadmium (Cd) stress-induced responses in roots of young barley seedlings. IBA, similarly to mild Cd stress, significantly increased the glutathione peroxidase (GPX) activity in the apexes of barley roots, which remained elevated after the IBA pretreatment as well. IBA pretreatment-evoked high nitric oxide generation in roots effectively reduced the high superoxide level under the severe Cd stress, leading to less toxic peroxynitrite accumulation accompanied by markedly reduced Cd-induced cell death. On the other hand, the IBA-evoked changes in IAA homeostasis resulted in root growth reorientation from longitudinal elongation to radial swelling. However, the application of an IAA signaling inhibitor, following the activation of defense responses by IBA, was able to promote root growth even at high concentrations of Cd. Based on the results, it can be concluded that the application of IBA, as an effective activator of Cd tolerance mechanisms in young barley roots, and the subsequent use of an IAA signaling inhibitor for the inhibition of root morphogenic responses induced by altered auxin metabolism, results in a high degree of root Cd tolerance, helping it to withstand even the transient exposure to lethal Cd concentration without the absolute inhibition of root growth.
PMID: 32885283
Planta , IF:3.39 , 2020 Sep , V252 (3) : P47 doi: 10.1007/s00425-020-03449-4
Shoot tip necrosis of in vitro plant cultures: a reappraisal of possible causes and solutions.
, Miki-cho Post Office, 3011-2, P. O. Box 7, Ikenobe, Kagawa-ken, 761-0799, Japan. jaimetex@yahoo.com.; Research Institute of Nyiregyhaza, IAREF, University of Debrecen, P. O. Box 12, Nyiregyhaza, 4400, Hungary. jaimetex@yahoo.com.; Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, 36310, Vigo, Spain.; Pinar Biotech. Co., Ltd., East Azarbaijan Science and Technology Park , Tabriz, Iran.; School of Science (SOS), GSFC University, P. O. Fertilizernagar, Vadodara, 391750, Gujarat, India.; Division of Biotechnology, Generasi Biologi Indonesia (Genbinesia) Foundation, Jl. Swadaya Barat No. 4, Gresik Regency, 61171, Indonesia. adhitwicaksono@genbinesia.or.id.; Research Institute of Nyiregyhaza, IAREF, University of Debrecen, P. O. Box 12, Nyiregyhaza, 4400, Hungary.; Department of Pharmacology, Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago, Santiago de Compostela, Spain.; Driver Consulting Inc., 2601 Tim Bell Road, Waterford, CA, 95386, USA.
MAIN CONCLUSION: Shoot tip necrosis is a physiological condition that negatively impacts the growth and development of in vitro plant shoot cultures across a wide range of species. Shoot tip necrosis is a physiological condition and disorder that can arise in plantlets or shoots in vitro that results in death of the shoot tip. This condition, which can spread basipetally and affect the emergence of axillary shoots from buds lower down the stem, is due to the cessation of apical dominance. STN can occur at both shoot multiplication and rooting stages. One of the most common factors that cause STN is nutrient deficiency or imbalance. Moreover, the presence or absence of plant growth regulators (auxins or cytokinins) at specific developmental stages may impact STN. The cytokinin to auxin ratio within an in vitro plant can be modified by varying the concentration of cytokinins used in the culture medium. The supply of nutrients to in vitro shoots or plantlets might also affect their hormonal balance, thus modifying the occurrence of STN. High relative humidity within culture vessels and hyperhydricity are associated with STN. An adequate supply of calcium as the divalent cation (Ca(2+)) can hinder STN by inhibiting the accumulation of phenolic compounds and thus programmed cell death. Moreover, the level of Ca(2+) affects auxin transport and ethylene production, and higher ethylene production, which can occur as a result of high relative humidity in or poor ventilation of the in vitro culture vessel, induces STN. High relative humidity can decrease the mobility of Ca(2+) within a plant, resulting in Ca(2+) deficiency and STN. STN of in vitro shoots or plantlets can be halted or reversed by altering the basal medium, mainly the concentration of Ca(2+), adjusting the levels of auxins or cytokinins, or modifying culture conditions. This review examines the literature related to STN, seeks to discover the associated factors and relations between them, proposes practical solutions, and attempts to better understand the mechanism(s) underlying this condition in vitro.
PMID: 32885282
Plant Mol Biol , IF:3.302 , 2020 Sep doi: 10.1007/s11103-020-01075-y
Class I TCP proteins TCP14 and TCP15 are required for elongation and gene expression responses to auxin.
Instituto de Agrobiotecnologia del Litoral, Catedra de Biologia Celular y Molecular, Facultad de Bioquimica y Ciencias Biologicas, CONICET-Universidad Nacional del Litoral, Centro Cientifico Tecnologico CONICET Santa Fe. Colectora Ruta Nac. N masculine 168 km 0, Paraje el Pozo s/n, 3000, Santa Fe, Argentina.; Instituto de Agrobiotecnologia del Litoral, Catedra de Biologia Celular y Molecular, Facultad de Bioquimica y Ciencias Biologicas, CONICET-Universidad Nacional del Litoral, Centro Cientifico Tecnologico CONICET Santa Fe. Colectora Ruta Nac. N masculine 168 km 0, Paraje el Pozo s/n, 3000, Santa Fe, Argentina. dhgonza@fbcb.unl.edu.ar.
KEY MESSAGE: Two class I TCP transcription factors are required for an efficient elongation of hypocotyls in response to auxin and for the correct expression of a subset of auxin-inducible genes In this work, we analyzed the response to auxin of plants with altered function of the class I TEOSINTE BRANCHED 1, CYCLOIDEA, PCF (TCP) transcription factors TCP14 and TCP15. Several SMALL AUXIN UP RNA (SAUR) genes showed decreased expression in mutant plants defective in these TCPs after an increase in ambient temperature to 29 degrees C, a condition that causes an increase in endogenous auxin levels. Overexpression of SAUR63 caused a more pronounced elongation response in the mutant than in the wild-type at 29 degrees C, suggesting that the decreased expression of SAUR genes is partly responsible for the defective elongation at warm temperature. Notably, several SAUR genes and the auxin response gene IAA19 also showed reduced expression in the mutant after auxin treatment, while the expression of other SAUR genes and of IAA29 was not affected or was even higher. Expression of the auxin reporter DR5::GUS was also higher in a tcp15 mutant than in a wild-type background after auxin treatment. However, the elongation of hypocotyls in response to auxin was impaired in the mutant. Remarkably, a significant proportion of auxin inducible genes and of targets of the AUXIN RESPONSE FACTOR 6 are regulated by TCP15 and often contain putative TCP recognition motifs in their promoters. Furthermore, we demonstrated that several among them are recognized by TCP15 in vivo. Our results indicate that TCP14 and TCP15 are required for an efficient elongation response to auxin, most likely by regulating a subset of auxin inducible genes related to cell expansion.
PMID: 32935297
Plant Mol Biol , IF:3.302 , 2020 Sep doi: 10.1007/s11103-020-01062-3
Mapping quantitative trait loci associated with stem-related traits in maize (Zea mays L.).
College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing, 102206, China.; Institute of Crop Science, The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China.; Institute of Crop Science, The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China. lixinhai@caas.cn.; College of Plant Science and Technology, Beijing University of Agriculture, 7 Beinong Road, Changping District, Beijing, 102206, China. shiliyu321@sina.com.
KEY MESSAGE: Mapping QTL for stem-related traits using RIL population with ultra-high density bin map can better dissect pleiotropic QTL controlling stem architecture that can provide valuable information for maize genetic improvement. The maize stem is one of the most important parts of the plant and is also a component of many agronomic traits in maize. This study aimed to advance our understanding of the genetic mechanisms underlying maize stem traits. A recombinant inbred line (RIL) population derived from a cross between Ye478 and Qi319 was used to identify quantitative trait loci (QTL) controlling stem height (SH), ear height (EH), stem node number (SN), ear node (EN), and stem diameter (SD), and two derived traits (ear height coefficient (EHc) and ear node coefficient (ENc)). Using an available ultra-high density bin map, 46 putative QTL for these traits were detected on chromosomes 1, 3, 4, 5, 6, 7, 8, and 10. Individual QTL explained 3.5-17.7% of the phenotypic variance in different environments. Two QTL for SH, three for EH, two for EHc, one for SN, one for EN, and one for SD were detected in more than one environment. QTL with pleiotropic effects or multiple linked QTL were also identified on chromosomes 1, 3, 4, 6, 8, and 10, which are potential target regions for fine-mapping and marker-assisted selection in maize breeding programs. Further, we discussed segregation of bin markers (mk1630 and mk4452) associated with EHc QTL in the RIL population. We had identified two putative WRKY DNA-binding domain proteins, AC209050.3_FG003 and GRMZM5G851490, and a putative auxin response factor, GRMZM2G437460, which might be involved in regulating plant growth and development, as candidate genes for the control of stem architecture.
PMID: 32901412
J Struct Biol , IF:3.071 , 2020 Sep : P107632 doi: 10.1016/j.jsb.2020.107632
Crystal structure of the indole-3-acetic acid-catabolizing enzyme DAO1 from Arabidopsis thaliana.
Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.; Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea. Electronic address: srheesnu@snu.ac.kr.
Indole-3-acetic acid (IAA), the major form of the plant hormone auxin, regulates almost every aspect of plant growth and development. Therefore, auxin homeostasis is an essential process in plants. Different metabolic routes are involved in auxin homeostasis, but the catabolic pathway has remained elusive until recent studies identified DIOXYGENASE FOR AUXIN OXIDATION (DAO) from rice and Arabidopsis thaliana. DAO, a member of the 2-oxoglutarate/Fe(II)-dependent oxygenase (2ODO) family, constitutes a major enzyme for IAA catabolism. This enzyme catalyzes, with the cosubstrate 2-oxoglutarate, the conversion of IAA into 2-oxoindole-3-acetic acid, a functionally inactive oxidative product of IAA. Here, we report a crystal structure of the unliganded DAO1 from A. thaliana (AtDAO1) and its complex with 2-oxoglutarate. AtDAO1 is structurally homologous with members of the 2ODO family but exhibits unique features in the prime substrate IAA binding site. We provide structural analyses of a putative binding site for IAA, supporting possible structural determinants for the substrate specificity of AtDAO1 toward IAA.
PMID: 32980521
Fungal Genet Biol , IF:3.071 , 2020 Sep , V144 : P103466 doi: 10.1016/j.fgb.2020.103466
Pseudoflowers produced by Fusarium xyrophilum on yellow-eyed grass (Xyris spp.) in Guyana: A novel floral mimicry system?
Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA. Electronic address: imane.laraba@usda.gov.; Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA.; Functional Food Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL 61604-3999, USA.; Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907-2054, USA.; Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-2012, USA.
Pseudoflower formation is arguably the rarest outcome of a plant-fungus interaction. Here we report on a novel putative floral mimicry system in which the pseudoflowers are composed entirely of fungal tissues in contrast to modified leaves documented in previous mimicry systems. Pseudoflowers on two perennial Xyris species (yellow-eyed grass, X. setigera and X. surinamensis) collected from savannas in Guyana were produced by Fusarium xyrophilum, a novel Fusarium species. These pseudoflowers mimic Xyris flowers in gross morphology and are ultraviolet reflective. Axenic cultures of F. xyrophilum produced two pigments that had fluorescence emission maxima in light ranges that trichromatic insects are sensitive to and volatiles known to attract insect pollinators. One of the volatiles emitted by F. xyrophilum cultures (i.e., 2-ethylhexanol) was also detected in the head space of X. laxifolia var. iridifolia flowers, a perennial species native to the New World. Results of microscopic and PCR analyses, combined with examination of gross morphology of the pseudoflowers, provide evidence that the fungus had established a systemic infection in both Xyris species, sterilized them and formed fungal pseudoflowers containing both mating type idiomorphs. Fusarium xyrophilum cultures also produced the auxin indole-3-acetic acid (IAA) and the cytokinin isopentenyl adenosine (iPR). Field observations revealed that pseudoflowers and Xyris flowers were both visited by bees. Together, the results suggest that F. xyrophilum pseudoflowers are a novel floral mimicry system that attracts insect pollinators, via visual and olfactory cues, into vectoring its conidia, which might facilitate outcrossing of this putatively heterothallic fungus and infection of previously uninfected plants.
PMID: 32956810
Environ Sci Pollut Res Int , IF:3.056 , 2020 Sep doi: 10.1007/s11356-020-10851-8
Lead (Pb)-resistant bacteria inhibit Pb accumulation in dill (Anethum graveolens L.) by improving biochemical, physiological, and antioxidant enzyme response of plants.
Department of Horticulture, Faculty of Agricultural Sciences and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.; Department of Horticulture, Faculty of Agricultural Sciences and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran. behsmaiel@yahoo.com.; Department of Environmental Sciences and Engineering, Government College University, Faisalabad, Pakistan.; Department of Soil Science, Faculty of Agricultural Sciences and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
The accumulation of heavy metal in the soil is a serious concern for sustainable food production due to their toxic effects on plants and other living things. The strategies are required on urgent bases for the management of metal-contaminated soils. Thus, the microbes from the genus Pseudomonas were characterized for different traits and lead (Pb)-resistant ability and their effects were assessed on growth, photosynthesis, antioxidant capacity, and Pb uptake by dill (Anethum graveolens L.). Furthermore, soil basal respiration and induced respiration in soil were also assessed under microbes and Pb stress. Among the tested three strains, Pseudomonas P159 and P150 were more tolerant to Pb stress than Pseudomonas P10, whereas P159 showed the highest values for phosphorus (P), siderophore, auxin, and hydrogen cyanide production. The bacterial inoculation increased the plant shoot dry weights, carbohydrates, proline, and chlorophyll contents under Pb stress. The catalase (CAT) and peroxidase (POD) activities of the plants were higher in bacterial-treated plants than control. The bacterial inoculation decreased Pb concentration in plants, and the response varied with the type of microbes. The bacterial strains enhanced the soil basal and induced respiration than respective Pb treatments alone. Overall, Pseudomonas P159 is potentially suitable for the remediation of Pb-contaminated soils. Graphical abstract.
PMID: 32968907
J Plant Physiol , IF:3.013 , 2020 Sep , V254 : P153281 doi: 10.1016/j.jplph.2020.153281
Low nitrogen induces root elongation via auxin-induced acid growth and auxin-regulated target of rapamycin (TOR) pathway in maize.
College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China. Electronic address: 915634280@qq.com.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China. Electronic address: 13538807170@163.com.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China. Electronic address: wp.102300@163.com.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China. Electronic address: caucfj@cau.edu.cn.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China. Electronic address: yuanlixing@cau.edu.cn.; College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China. Electronic address: miguohua@cau.edu.cn.
Under low nitrogen (N) supply, an important adaption of the maize root system is to promote the root elongation so as to increase N uptake from a larger soil space. The underlying physiological mechanism is largely unknown. In the present study, two maize inbred lines (Ye478 and Wu312) were used to study the possible involvement of the auxin and target of rapamycin (TOR) pathway in low-N-induced root elongation. Compared to Wu312, primary root elongation of Ye478 was more sensitive to low nitrate supply. Correspondingly, more auxin was accumulated in the root tip, and more protons were secreted, increasing the acidity of the apoplast space. On the other hand, low-N-induced root elongation was greatly reduced when shoot-to-root auxin transport was inhibited by applying N-1-naphthylphthalamic acid (NPA) at the plant base or by pruning the top leaf where auxin is mostly synthesized. Furthermore, exogenous application of TOR inhibitor also eliminated the response of root elongation under low N. The content of TOR kinase and the expression of TOR pathway-related genes were significantly changed when shoot-to-root auxin transport was reduced by NPA treatment. Taken together, it is concluded that low-N stress increases shoot-to-root auxin transport which enhances root elongation via auxin-dependent acid growth and the auxin-regulated TOR pathway in maize.
PMID: 32971423
Biochem Biophys Res Commun , IF:2.985 , 2020 Sep doi: 10.1016/j.bbrc.2020.09.065
Auxin regulates anthocyanin biosynthesis through the auxin repressor protein MdIAA26.
National Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.; National Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China. Electronic address: fap_296566@163.com.; National Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong, 271018, China. Electronic address: haoyujin@sdau.edu.cn.
Auxin plays an important role in plant growth and development; for example, it regulates the elongation and division of plant cells, the formation of plantlet's geotropism and phototropism, and the growth of main lateral roots and hypocotyl. IAA gene is associated with auxin and can response to biotic and abiotic stress in plants. However, the regulatory effect of auxin on anthocyanin accumulation has been rarely reported. In this study, we show that auxin inhibites the accumulation of anthocyanin and decreases the expression of genes related to anthocyanin synthesis in calli, leaves, and seedlings of apple. The expression levels of MdIAA family genes were determined, and we found that MdIAA26 significantly responded to auxin, which also induced MdIAA26 degradation. Functional analysis of MdIAA26 showed that overexpressing MdIAA26 in apple calli and Arabidopsis could promote the accumulation of anthocyanin and up-regulate the genes related to anthocyanin synthesis. Furthermore, the MdIAA26-overexpressing Arabidopsis could counteract auxin-induced inhibition on anthocyanin accumulation, which indicates that auxin inhibits the accumulation of anthocyanin in apple by degrading MdIAA26 protein.
PMID: 32981681
Biochem Biophys Res Commun , IF:2.985 , 2020 Sep doi: 10.1016/j.bbrc.2020.09.039
Overexpression of a phosphate transporter gene ZmPt9 from maize influences growth of transgenic Arabidopsis thaliana.
School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, China; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China.; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China.; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China. Electronic address: lixiaoyu@ahau.edu.cn.; School of Agriculture, Yunnan University, Kunming, 650504, China; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China. Electronic address: liufang0019@ynu.edu.cn.
Phosphate transporters (PHTs) are well-known for their roles in phosphate uptake in plants. However, their actions in imparting plant growth in plants are still not so clear. In our previous study, we observed that maize PHT1 gene ZmPt9 plays a significant role in phosphate uptake. In this study, we further characterized ZmPt9 in response to low phosphate condition through ZmPt9 promoter inductive analysis by GUS staining and quantification. To elucidate the function of ZmPt9, we generated overexpression plant in Arabidopsis. ZmPt9 overexpressing Arabidopsis plants conferred small leaves and early flowering compared with the wild-type plants. In addition, ZmPt9 can complement the late flowering phenotype of Arabidopsis mutant pht1;2. The qRT-PCR analysis revealed that overexpression of ZmPt9 in Arabidopsis changed expression levels of some flowering-related genes. Further expressed detection of hormone related genes revealed that GA and auxin maybe the main determinant for growth influences of ZmPt9. In conclusion, these results suggest that apart from phosphate transport activity, ZmPt9 can be further exploited for improving crops growth.
PMID: 32962860
Biochem Biophys Res Commun , IF:2.985 , 2020 Sep doi: 10.1016/j.bbrc.2020.08.057
Nitrate reductase is a key enzyme responsible for nitrogen-regulated auxin accumulation in Arabidopsis roots.
College of Resources, Sichuan Agricultural University, Chengdu, 611130, China.; College of Resources, Sichuan Agricultural University, Chengdu, 611130, China. Electronic address: roundtree318@hotmail.com.
Nitrate reductase (NR) is one of the key enzymes for plant nitrogen assimilation and root architecture remodeling. However, crosstalk between NR-mediated signaling and auxin-mediated root development in nitrogen-status responses has not been investigated in details before. In this study, root phenotype and auxin distribution in nia1/nia2 (nitrate reductase) double mutant and chl1-5 (nitrate transporter NRT1.1) mutant under different nitrogen availabilities were compared. The nia1/nia2 mutant showed very low expression levels of auxin biosynthetic/signaling genes and was insensitive to nitrogen changes. While the chl1-5 mutant showed a high NR activity with a high level of auxin in the meristematic zone and a weaker response to nitrogen changes, when compared with the wild-type plants. We firstly found that NR activity was roughly positive-correlated with the root auxin level, and there is a crosstalk between nitrate signaling and auxin signaling. The putative signaling pathways downstream of NR have been discussed.
PMID: 32907713
Plants (Basel) , IF:2.762 , 2020 Sep , V9 (9) doi: 10.3390/plants9091248
Global Trends in Phytohormone Research: Google Trends Analysis Revealed African Countries Have Higher Demand for Phytohormone Information.
Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman.; Department of Botany, North Orissa University, Sri Ramchandra Vihar, Takatpur, Baripada, Odisha 757003, India.; Department of Medical Biotechnology, Yeungnam University Gyeongsan, Gyeongsangbuk-do 38541, Korea.; Botany and Microbiology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.; Mycology and Plant Disease Survey Department, Plant Pathology Research Institute, ARC, Giza 12511, Egypt.; Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
The lines of research conducted within a country often reflect its focus on current and future economic needs. Analyzing "search" trends on the internet can provide important insight into predicting the direction of a country in regards to agriculture, health, economy, and other areas. 'Google Trends' collects data on search terms from different countries, and this information can be used to better understand sentiments in different countries and regions. Agricultural output is responsible for feeding the world and there is a continuous quest to find ways to make agriculture more productive, safe, and reliable. The application of phytohormones has been used in agriculture world-wide for many years to improve crop production and continues to be an active area of research for the application in plants. Therefore, in the current study, we searched 'Google Trends' using the phytohormone search terms, abscisic acid, auxins, brassinosteroids, cytokinin, ethylene, gibberellins, jasmonic acid, salicylic acid, and strigolactones. The results indicated that the African country Zambia had the greatest number of queries on auxin research, and Kenya had the most queries in cytokinin and gibberellin research world-wide. For other phytohormones, India had the greatest number of queries for abscisic acid and South Korea had the greatest number of ethylene and jasmonic acid search world-wide. Queries on salicylic acid have been continuously increasing while the least number of queries were related to strigolactones. Only India and United States of America had significant numbers of queries on all nine phytohormones while queries on one or more phytohormones were absent in other countries. India is one of the top five crop-producing countries in the world for apples, millet, orange, potato, pulses, rice, sugarcane, tea, and wheat. Similarly, the United States of America is one of the top five crop-producing countries of the world for apples, grapes, maze, orange, potato, sorghum, sugarcane, and wheat. These might be the most possible factors for the search queries found for all the nine phytohormones in India and the United States of America.
PMID: 32971736
Plants (Basel) , IF:2.762 , 2020 Sep , V9 (9) doi: 10.3390/plants9091204
Variable Light Condition Improves Root Distribution Shallowness and P Uptake of Soybean in Maize/Soybean Relay Strip Intercropping System.
College of Agronomy, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.; College of pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China.; Institute of Sorghum Potato, Yibin Academy of Agricultural Sciences, Yibin 644000, Sichuan, China.; Agricultural and Rural Bureau of Sishui County, Jining 273200, Shandong, China.
In this study, soybean root distribution in an inter-cropping system was influenced by various environmental and biotic cues. However, it is still unknown how root development and distribution in inter-cropping responds to aboveground light conditions. Herein, soybeans were inter- and monocropped with P (phosphorus) treatments of 0 and 20 kg P ha yr(-1) (P0 and P20, respectively) in field experiment over 4 years. In 2019, a pot experiment was conducted as the supplement to the field experiment. Shade from sowing to V5 (Five trifoliolates unroll) and light (SL) was used to imitate the light condition of soybeans in a relay trip inter-cropping system, while light then shade from V5 to maturity (LS) was used to imitate the light condition of soybeans when monocropped. Compared to monocropping, P uptake and root distribution in the upper 0-15 cm soil layer increased when inter-cropped. Inter-cropped soybeans suffered serious shade by maize during a common-growth period, which resulted in the inhibition of primary root growth and a modified auxin synthesis center and response. During the solo-existing period, plant photosynthetic capacity and sucrose accumulation increased under ameliorated light in SL (shade-light). Increased light during the reproductive stage significantly decreased leaf P concentration in SL under both P-sufficient and P-deficient conditions. Transcripts of a P starvation response gene (GmPHR25) in leaves and genes (GmEXPB2) involved in root growth were upregulated by ameliorated light during the reproductive stage. Furthermore, during the reproductive stage, more light interception increased the auxin concentration and expression of GmYUCCA14 (encoding the auxin synthesis) and GmTIR1C (auxin receptor) in roots. Across the field and pot experiments, increased lateral root growth and shallower root distribution were associated with inhibited primary root growth during the seedling stage and ameliorated light conditions in the reproductive stage. Consequently, this improved topsoil foraging and P uptake of inter-cropped soybeans. It is suggested that the various light conditions (shade-light) mediating leaf P status and sucrose transport can regulate auxin synthesis and respond to root formation and distribution.
PMID: 32942525
Plants (Basel) , IF:2.762 , 2020 Sep , V9 (9) doi: 10.3390/plants9091149
Response of Downy Oak (Quercus pubescens Willd.) to Climate Change: Transcriptome Assembly, Differential Gene Analysis and Targeted Metabolomics.
CNRS, Aix-Marseille University, Avignon University, IRD, IMBE, 13331 Marseille, France.; TGML-TAGC-Inserm UMR1090 Aix-Marseille Universite 163 avenue de Luminy, 13288 Marseille, France.; CNRS, Sorbonne Universite, FR2424, ABiMS platform, Station Biologique, 29680 Roscoff, France.; Metabolomics Core Technology Platform Ruprecht-Karls-University Heidelberg Centre for Organismal Studies (COS) Im Neuenheimer Feld 360, 69120 Heidelberg, Germany.; Research Federation ECCOREV FR3098, CNRS, 13545 Aix-en-Provence, France.
Global change scenarios in the Mediterranean basin predict a precipitation reduction within the coming hundred years. Therefore, increased drought will affect forests both in terms of adaptive ecology and ecosystemic services. However, how vegetation might adapt to drought is poorly understood. In this report, four years of climate change was simulated by excluding 35% of precipitation above a downy oak forest. RNASeq data allowed us to assemble a genome-guided transcriptome. This led to the identification of differentially expressed features, which was supported by the characterization of target metabolites using a metabolomics approach. We provided 2.5 Tb of RNASeq data and the assembly of the first genome guided transcriptome of Quercus pubescens. Up to 5724 differentially expressed transcripts were obtained; 42 involved in plant response to drought. Transcript set enrichment analysis showed that drought induces an increase in oxidative pressure that is mitigated by the upregulation of ubiquitin-like protein protease, ferrochelatase, oxaloacetate decarboxylase and oxo-acid-lyase activities. Furthermore, the downregulation of auxin biosynthesis and transport, carbohydrate storage metabolism were observed as well as the concomitant accumulation of metabolites, such as oxalic acid, malate and isocitrate. Our data suggest that early metabolic changes in the resistance of Q. pubescens to drought involve a tricarboxylic acid (TCA) cycle shunt through the glyoxylate pathway, galactose metabolism by reducing carbohydrate storage and increased proteolytic activity.
PMID: 32899727
PLoS One , IF:2.74 , 2020 , V15 (9) : Pe0239705 doi: 10.1371/journal.pone.0239705
Genome-wide identification and characterization of Respiratory Burst Oxidase Homolog genes in six Rosaceae species and an analysis of their effects on adventitious rooting in apple.
College of Horticulture, Qingdao Agricultural University, Qingdao, China.; Qingdao Key Laboratory of Genetic Development and Breeding in Horticultural Plants, Qingdao Agricultural University, Qingdao, China.; Qingdao Key Lab of Modern Agriculture Quality and Safety Engineering, Qingdao Agricultural University, Qingdao, China.; Laixi Elite Cultivars Propagation Farm, Laixi, Qingdao, China.
Adventitious root formation is essential for plant propagation, development, and response to various stresses. Reactive oxygen species (ROS) are essential for adventitious root formation. However, information on Respiratory Burst Oxidase Homolog (RBOH), a key enzyme that catalyzes the production ROS, remains limited in woody plants. Here, a total of 44 RBOH genes were identified from six Rosaceae species (Malus domestica, Prunus avium, Prunus dulcis 'Texas', Rubus occidentalis, Fragaria vesca and Rosa chinensis), including ten from M. domestica. Their phylogenetic relationships, conserved motifs and gene structures were analyzed. Exogenous treatment with the RBOH protein inhibitor diphenyleneiodonium (DPI) completely inhibited adventitious root formation, whereas exogenous H2O2 treatment enhanced adventitious root formation. In addition, we found that ROS accumulated during adventitious root primordium inducing process. The expression levels of MdRBOH-H, MdRBOH-J, MdRBOH-A, MdRBOH-E1 and MdRBOH-K increased more than two-fold at days 3 or 9 after auxin treatment. In addition, cis-acting element analysis revealed that the MdRBOH-E1 promoter contained an auxin-responsive element and the MdRBOH-K promoter contained a meristem expression element. Based on the combined results from exogenous DPI and H2O2 treatment, spatiotemporal expression profiling, and cis-element analysis, MdRBOH-E1 and MdRBOH-K appear to be candidates for the control of adventitious rooting in apple.
PMID: 32976536
Funct Plant Biol , IF:2.617 , 2020 Sep doi: 10.1071/FP20071
The hot issue: TOR signalling network in plants.
The target of rapamycin (TOR) signalling network plays a pivotal role in regulating sugar metabolism and life-span in yeast, plants and mammals, in which TOR functions as a crucial protein. In plants, the TOR complex comprises TOR, RAPTOR (regulatory-associated protein of TOR) and LST8 (lethal with SEC13 protein 8). Factors like light, auxin, glucose, sucrose and amino acid can activate TOR protein as upstream signals to further phosphorylate downstream factors of TOR which promote cell proliferation and growth in plants. In this review, we analyse the TOR signalling network in plants and discuss the relationship between glucose and TOR, as well as the dynamic balance between TOR and sucrose-non-fermenting-related protein kinases (SnRKs). Given that 63 novel TOR-regulated proteins have been identified in previous studies, we also believe there are many unknown functions of TOR that need to be further investigated.
PMID: 32905758
J Sci Food Agric , IF:2.614 , 2020 Sep doi: 10.1002/jsfa.10822
Seed priming and foliar application with jasmonic acid enhance salinity stress tolerance of soybean (Glycine max L.) seedlings.
Salt-Soil Agricultural Center, Institute of Agriculture Resources and Environment, Jiangsu Academy of Agricultural Sciences (JAAS), Nanjing, 210014, China.; Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt.; College of Environment and Safety Engineering, Qingdao University of Science & Technology, Qingdao, 266000, China.; Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Yancheng Teachers University, Yancheng, 224002, China.; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, People's Republic of China.; 4State Key Laboratory of Silviculture, Zhejiang A&F University, Hangzhou, China.; College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, China.; College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China.; Botany Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Seed Science Center, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.
BACKGROUND: Jasmonic acid (JA) is an important molecule, has a regulatory effect on many physiological processes in plant growth and development under abiotic stress. This study investigated the effect of 60 muM of JA as priming (P) at 15 degrees C in darkness for 24 h, foliar (F) and/or their combination effect (P+F) on two soybean cultivars (Nannong 99-6 (salt tolerant) and Lee 68 (salt sensitive)) under salinity stress (100 mM NaCl). RESULTS: Salinity stress reduced seedling growth and biomass as compared to that in the control condition. Priming and foliar application with JA and/or their combination significantly improved water potential, osmotic potential, water use efficiency (WUE) and relative water content (RWC) of both cultivars under salinity stress. Similarly, the priming, foliar application with JA and/or their combination significantly improved the net photosynthetic (Pn) by 68.03%, 59.85% and 76.67%; transpiration rate (Tr) by 74.85%, 55.10% and 80.26%; stomatal conductance (gs) by 69.88%, 78.25% and 26.24%; intercellular CO2 concentration (Ci) by 61.64%, 40.06% and 65.79% and total chlorophyll content (Chl) by 47.41%, 41.02% and 55.73%, respectively under salinity stress as compared to the untreated seedlings. Soybean plants primed, sprayed with JA or treated with their combination enhanced the chlorophyll fluorescence, which was damaged by salinity stress. JA treatments improved abscisic acid (ABA), gibberellic acid (GA) and JA levels by 60.57%, 62.50% and 52.25%, respectively under salt stress as compared to those in the control condition. The transcriptional levels of the FeSOD, POD, CAT and APX genes increased significantly in the NaCl-stressed seedlings irrespective of JA treatments. Moreover, JA treatment resulted in a reduction of Na(+) concentration and an increase of K(+) concentrations in the leaf and root of both cultivars regardless of salinity stress. Monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and proline contents decreased in the seedlings treated with JA under salinity stress, whereas the ascorbate (AsA) content increased with JA treatment combined with NaCl stress. CONCLUSION: The application of 60 muM JA improved plant growth by regulating the interaction between plant hormones and hydrogen peroxide (H2 O2 ), which may involved in auxin signaling and stomatal closing under salt stress. These methods could efficiently protect early seedlings and alleviate salt stress damage and provide possibilities to be used for improving soybean growth and inducing tolerance against excessive soil salinity. This article is protected by copyright. All rights reserved.
PMID: 32949013
Environ Manage , IF:2.561 , 2020 Sep doi: 10.1007/s00267-020-01351-z
Assessing the Plant Growth Promoting and Arsenic Tolerance Potential of Bradyrhizobium japonicum CB1809.
School of Engineering, RMIT University, Melbourne, VIC, Australia.; Department of Environmental Science and Management, North South University, Dhaka, Bangladesh.; Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh.; School of Science, RMIT University, Bundoora, VIC, Australia.; School of Engineering, RMIT University, Melbourne, VIC, Australia. suzie.reichman@unimelb.edu.au.; Centre for Anthropogenic Pollution Impact and Management, School of BioSciences, University of Melbourne, Parkville, VIC, Australia. suzie.reichman@unimelb.edu.au.
Accumulation of heavy metals in soil is of concern to the agricultural production sector, because of the potential threat to food quality and quantity. Inoculation with plant growth-promoting bacteria (PGPR) has previously been shown to alleviate heavy metal stress but the mechanisms are unclear. Potential mechanisms by which inoculation with Bradyrhizobium japonicum CB1809 affected the legume soybean (Glycine max cv. Zeus) and the non-legume sunflower (Helianthus annus cv. Hyoleic 41) were investigated in solution culture under 5 muM As stress. Adding As resulted in As tissue concentrations of up to 5 mg kg(-1) (shoots) and 250 mg kg(-1) (roots) in both species but did not reduce shoot or root biomass. Inoculation increased root biomass but only in the legume (soybean) and only with As. Inoculation resulted in large (up to 100%) increases in siderophore concentration but relatively small changes (+/-10-15%) in auxin concentration in the rhizosphere. However, the increase in siderophore concentration in the rhizosphere did not result in the expected increases in tissue N or Fe, especially in soybean, suggesting that their function was different. In conclusion, siderophores and auxins may be some of the mechanisms by which both soybean and sunflower maintained plant growth in As-contaminated media.
PMID: 32918111
Arch Microbiol , IF:1.884 , 2020 Sep doi: 10.1007/s00203-020-02051-2
Serratia sp., an endophyte of Mimosa pudica nodules with nematicidal, antifungal activity and growth-promoting characteristics.
Centro de investigacion en Biotecnologia, Universidad Autonoma del Estado de Morelos, Cuernavaca, , Morelos, Mexico.; Laboratorio de Helmintologia, Centro Nacional de Investigacion Disciplinaria en Salud Animal E Inocuidad, INIFAP, Carretera Federal Cuernavaca-Cuautla No. 8534 Col. Progreso, C. P. 62550, Jiutepec, Morelos, Mexico.; Colegio de Postgraduados, Carretera Mexico-Texcoco, Km. 36.5, Moncecillo, Texcoco, Mexico.; CONACYT-Instituto Politecnico Nacional, CIIDIR-IPN. Unidad Michoacan, Justo Sierra 28, 59510, Jiquilpan, Michoacan, Mexico.; Laboratorio de Helmintologia, Centro Nacional de Investigacion Disciplinaria en Salud Animal E Inocuidad, INIFAP, Carretera Federal Cuernavaca-Cuautla No. 8534 Col. Progreso, C. P. 62550, Jiutepec, Morelos, Mexico. aguilar.liliana@inifap.gob.mx.; Division Agroalimentaria, Universidad Tecnologica de La Selva, Ocosingo, Chiapas, Mexico. wova79@hotmail.com.
In the present study, the nematicidal activity of an isolated strain of Mimosa pudica nodules was evaluated against the Nacobbus aberrans (J2) phytonymatodes with a mortality of 88.8%, while against the gastrointestinal nematode Haemonchus contortus (L3) and free-living Panagrellus redivivus was 100%. The ability to inhibit the growth of phytopathogenic fungi Fusarium sp., and Alternaria solani, as well as the oomycete Phytophthora capsici, this antifungal activity may be related to the ability to produce cellulases, siderophores and chitinases by this bacterial strain. Another important finding was the detection of plant growth promoter characteristics, such as auxin production and phosphate solubilization. The strain identified by sequences of the 16S and rpoB genes as Serratia sp. is genetically related to Serratia marcescens and Serratia nematodiphila. The promoter activity of plant growth, antifungal and nematicide of the Serratia sp. strain makes it an alternative for the biocontrol of fungi and nematodes that affect both the livestock and agricultural sectors, likewise, candidate as a growth-promoting bacterium.
PMID: 32980917
Plant Signal Behav , IF:1.671 , 2020 Sep : P1813998 doi: 10.1080/15592324.2020.1813998
Nitroxin and arbuscular mycorrhizal fungi alleviate negative effects of drought stress on Sorghum bicolor yield through improving physiological and biochemical characteristics.
Department of Agriculture, Zahedan Branch, Islamic Azad University , Zahedan, Iran.
Soil microorganisms play an important role in enhancing soil fertility and plant health. Nitroxin is a bio-fertilizer that is a combination of Azospirilium and Azotobacter rhizobacteria. Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria can enhance biotic and abiotic stress tolerance in plants, whereas little is known regarding their roles in sorghum (Sorghum bicolor L.) growth under drought stress conditions. Therefore, this experiment was conducted to investigate the inoculation of grain sorghum with the bio-fertilizers of Nitroxin and Glomus mosseae effects on some physiological and biochemical traits and yield of grain sorghum under drought stress conditions in the region of Saravan, Iran, in 2017 and 2018. The results of this experiment showed that severe and moderate drought stress conditions decreased the amounts of grain protein percentage, auxin (IAA) content, root colonization, grain yield, and protein yield of grain, whereas grain starch percentage, the activity of catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) enzymes and content of total carotenoid, total anthocyanin, total flavonoid, electrolyte leakage, and malondialdehyde (MDA) were increased. Inoculation of sorghum plants with bio-fertilizers improved these traits (except starch content, electrolyte leakage, and MDA) under drought stress conditions as well as non-stress conditions. As a result, grain yield and protein yield of sorghum decreased by 43.77 and 43.99%, respectively, under severe drought stress conditions but co-inoculation with Nitroxin and AMF under severe drought stress conditions increased grain yield and protein yield of sorghum by 27 and 19.63%, respectively, compared to non-application of these bio-fertilizers. Thus, Nitroxin and AMF can be recommended for profitable sorghum production under drought stress conditions.
PMID: 32902363
Plant Signal Behav , IF:1.671 , 2020 Sep : P1816320 doi: 10.1080/15592324.2020.1816320
A sustained CYCLINB1;1 and STM expression in the neoplastic tissues induced by Rhodococcus fascians on Arabidopsis underlies the persistence of the leafy gall structure.
Department of Plant Developmental Biology, Faculty of Biological Sciences, Institute of Experimental Biology, University of Wroclaw , Wroclaw, Poland.; Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University , Ghent, Belgium.; Department of Entomology, Plant Pathology, and Weed Sciences, New Mexico State University , NM, USA.
RHODOCOCCUS FASCIANS: is a gram-positive phytopathogen that infects a wide range of plant species. The actinomycete induces the formation of neoplastic growths, termed leafy galls, that consist of a gall body covered by small shoots of which the outgrowth is arrested due to an extreme form of apical dominance. In our previous work, we demonstrated that in the developing gall, auxin drives the transdifferentiation of parenchyma cells into vascular elements. In this work, with the use of transgenic Arabidopsis thaliana plants carrying molecular reporters for cell division (pCYCB1;1:GUS) and meristematic activity (pSTM:GUS), we analyzed the fate of cells within the leafy gall. Our results indicate that the size of the gall body is determined by ongoing mitotic cell divisions as illustrated by strong CYCB1;1 expression combined with the de novo formation of new meristematic areas triggered by STM expression. The shoot meristems that develop in the peripheral parts of the gall are originating from high ectopic STM expression. Altogether the presented data provide further insight into the cellular events that accompany the development of leafy galls in response to R. fascians infection.
PMID: 32897774
Plant Signal Behav , IF:1.671 , 2020 Oct , V15 (10) : P1794394 doi: 10.1080/15592324.2020.1794394
Nitrate deficiency induces differential endocytosis in roots through NRT1.1.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University , Tai'an, China.; College of Horticulture, Qingdao Agricultural University , Qingdao, China.
Roots grow asymmetrically, sometimes helically, around their growth direction likely to facilitate environmental sensing. We recently demonstrated that nitrate deficiency induces root coiling on horizontal surface through nitrate transporter/sensor NRT1.1 and PIN2- and AUX-mediated polar auxin transport. Here, we show that nitrate deficiency or NRT1.1 loss-of-function induces differential distribution of PIN2 between the future concave and concave sides in root epidermal cells. Treatment with pharmacological drugs suggests that enhanced endocytosis at the future convex side leads to reduced plasma membrane (PM) association of PIN2. A reduction of PIN2 at the PM would maintain a low auxin response to further enhance endocytosis at the convex side, leading to root coiling.
PMID: 32686596
Mol Biol Rep , IF:1.402 , 2020 Sep doi: 10.1007/s11033-020-05839-z
Comparative transcriptome profiling of rice colonized with beneficial endophyte, Piriformospora indica, under high salinity environment.
Department of Biotechnology, Jamia Hamdard, New Delhi, 110062, India.; Centro de Bioiencias e Biotecnologia, Universidade Estadual do Norte Fluminense "Darcy Ribeiro" University, Campos dos goytacazes, Rio de Janeiro, Brazil.; Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India.; Department of Electrical Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India.; Department of Biotechnology, Jamia Hamdard, New Delhi, 110062, India. mzabdin@jamiahamdard.ac.in.
The salinity stress tolerance in plants has been studied enormously, reflecting its agronomic relevance. Despite the extensive research, limited success has been achieved in relation to the plant tolerance mechanism. The beneficial interaction between Piriformospora indica and rice could essentially improve the performance of the plant during salt stress. In this study, the transcriptomic data between P. indica treated and untreated rice roots were compared under control and salt stress conditions. Overall, 661 salt-responsive differentially expressed genes (DEGs) were detected with 161 up- and 500 down-regulated genes in all comparison groups. Gene ontology analyses indicated the DEGs were mainly enriched in "auxin-activated signaling pathway", "water channel activity", "integral component of plasma membrane", "stress responses", and "metabolic processes". Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were primarily related to "Zeatin biosynthesis", "Fatty acid elongation", "Carotenoid biosynthesis", and "Biosynthesis of secondary metabolites". Particularly, genes related to cell wall modifying enzymes (e.g. invertase/pectin methylesterase inhibitor protein and arabinogalactans), phytohormones (e.g. Auxin-responsive Aux/IAA gene family, ent-kaurene synthase, and 12-oxophytodienoate reductase) and receptor-like kinases (e.g. AGC kinase and receptor protein kinase) were induced in P. indica colonized rice under salt stress condition. The differential expression of these genes implies that the coordination between hormonal crosstalk, signaling, and cell wall dynamics contributes to the higher growth and tolerance in P. indica-inoculated rice. Our results offer a valuable resource for future functional studies on salt-responsive genes that should improve the resilience and adaptation of rice against salt stress.
PMID: 32979167