Cell Host Microbe , IF:15.923 , 2019 Aug , V26 (2) : P163-172 doi: 10.1016/j.chom.2019.07.006
Stressed Out About Hormones: How Plants Orchestrate Immunity.
Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA. Electronic address: mburger@salk.edu.; Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Plants are under relentless challenge by pathogenic bacteria, fungi, and oomycetes, for whom they provide a resource of living space and nutrients. Upon detection of pathogens, plants carry out multiple layers of defense response, orchestrated by a tightly organized network of hormones. In this review, we provide an overview of the phytohormones involved in immunity and the ways pathogens manipulate their biosynthesis and signaling pathways. We highlight recent developments, including the discovery of a defense signaling molecule, new insights into hormone biosynthesis, and the increasing importance of signaling hubs at which hormone pathways intersect.
PMID: 31415749
Trends Plant Sci , IF:14.416 , 2019 Aug , V24 (8) : P677-687 doi: 10.1016/j.tplants.2019.05.008
Plants Neither Possess nor Require Consciousness.
Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA. Electronic address: ltaiz@ucsc.edu.; Neurotrope, Inc., 1185 Avenue of the Americas, 3rd Floor, New York, NY 10036, USA.; Institut fur Physiologie und Pathophysiologie, Medizinische Fakultat Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany.; Department of Plant Science and Landscape Architecture, 2104 Plant Sciences Building, College Park, MD 20742, USA.; Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK.; Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK.; Department of Biology, Technische Universitat Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany.; Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany.
In claiming that plants have consciousness, 'plant neurobiologists' have consistently glossed over the remarkable degree of structural and functional complexity that the brain had to evolve for consciousness to emerge. Here, we outline a new hypothesis proposed by Feinberg and Mallat for the evolution of consciousness in animals. Based on a survey of the brain anatomy, functional complexity, and behaviors of a broad spectrum of animals, criteria were established for the emergence of consciousness. The only animals that satisfied these criteria were the vertebrates (including fish), arthropods (e.g., insects, crabs), and cephalopods (e.g., octopuses, squids). In light of Feinberg and Mallat's analysis, we consider the likelihood that plants, with their relative organizational simplicity and lack of neurons and brains, have consciousness to be effectively nil.
PMID: 31279732
Trends Plant Sci , IF:14.416 , 2019 Aug , V24 (8) : P741-754 doi: 10.1016/j.tplants.2019.05.006
Auxin Metabolism Controls Developmental Decisions in Land Plants.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden. Electronic address: ruben.casanova.saez@slu.se.; School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK. Electronic address: ute.voss@nottingham.ac.uk.
Unlike animals, whose body plans are set during embryo development, plants maintain the ability to initiate new organs throughout their life cycle. Auxin is a key regulator of almost all aspects of plant development, including morphogenesis and adaptive responses. Cellular auxin concentrations influence whether a cell will divide, grow, or differentiate, thereby contributing to organ formation, growth, and ultimately plant shape. Auxin gradients are established and maintained by a tightly regulated interplay between metabolism, signalling, and transport. Auxin is synthesised, stored, and inactivated by a multitude of parallel pathways that are all tightly regulated. Here we summarise the remarkable progress that has been achieved in identifying some key components of these pathways and the genetic complexity underlying their precise regulation.
PMID: 31230894
Nat Commun , IF:12.121 , 2019 Aug , V10 (1) : P3810 doi: 10.1038/s41467-019-11774-w
The regulatory landscape of a core maize domestication module controlling bud dormancy and growth repression.
Plant Gene Expression Center/USDA, University of California, Berkeley, Albany, CA, 94710, USA.; Brigham Young University, Provo, UT, 84602, USA.; West Virginia University, Morgantown, WV, 26506, USA.; Max Planck Institute of Molecular Plant Physiology, Muehlenberg, 14476, Potsdam-Golm, Germany.; Brigham Young University, Provo, UT, 84602, USA. whipple@byu.edu.; Plant Gene Expression Center/USDA, University of California, Berkeley, Albany, CA, 94710, USA. georgechuck@berkeley.edu.
Many domesticated crop plants have been bred for increased apical dominance, displaying greatly reduced axillary branching compared to their wild ancestors. In maize, this was achieved through selection for a gain-of-function allele of the TCP transcription factor teosinte branched1 (tb1). The mechanism for how a dominant Tb1 allele increased apical dominance, is unknown. Through ChIP seq, RNA seq, hormone and sugar measurements on 1 mm axillary bud tissue, we identify the genetic pathways putatively regulated by TB1. These include pathways regulating phytohormones such as gibberellins, abscisic acid and jasmonic acid, but surprisingly, not auxin. In addition, metabolites involved in sugar sensing such as trehalose 6-phosphate were increased. This suggests that TB1 induces bud suppression through the production of inhibitory phytohormones and by reducing sugar levels and energy balance. Interestingly, TB1 also putatively targets several other domestication loci, including teosinte glume architecture1, prol1.1/grassy tillers1, as well as itself. This places tb1 on top of the domestication hierarchy, demonstrating its critical importance during the domestication of maize from teosinte.
PMID: 31444327
Nat Commun , IF:12.121 , 2019 Aug , V10 (1) : P3704 doi: 10.1038/s41467-019-11709-5
Plant circadian rhythms regulate the effectiveness of a glyphosate-based herbicide.
School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.; Syngenta, Jealott's Hill International Research Centre, Warfield, Bracknell, RG42 6EY, UK.; School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK. antony.dodd@bristol.ac.uk.
Herbicides increase crop yields by allowing weed control and harvest management. Glyphosate is the most widely-used herbicide active ingredient, with $11 billion spent annually on glyphosate-containing products applied to >350 million hectares worldwide, using about 8.6 billion kg of glyphosate. The herbicidal effectiveness of glyphosate can depend upon the time of day of spraying. Here, we show that the plant circadian clock regulates the effectiveness of glyphosate. We identify a daily and circadian rhythm in the inhibition of plant development by glyphosate, due to interaction between glyphosate activity, the circadian oscillator and potentially auxin signalling. We identify that the circadian clock controls the timing and extent of glyphosate-induced plant cell death. Furthermore, the clock controls a rhythm in the minimum effective dose of glyphosate. We propose the concept of agricultural chronotherapy, similar in principle to chronotherapy in medical practice. Our findings provide a platform to refine agrochemical use and development, conferring future economic and environmental benefits.
PMID: 31420556
Nat Commun , IF:12.121 , 2019 Aug , V10 (1) : P3540 doi: 10.1038/s41467-019-11483-4
Cytokinin functions as an asymmetric and anti-gravitropic signal in lateral roots.
Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria.; Department of Biology, Stanford University, 260 Panama Street, Stanford, CA, 94305, USA.; Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA, 94305, USA.; Laboratory of Growth Regulators, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science of Palacky University and Institute of Experimental Botany of the Czech Academy of Sciences, Slechtitelu 27, 78371, Olomouc, Czech Republic.; Plant Ecophysiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands.; Centro de Biotecnologia y Genomica de Plantas (Universidad Politecnica de Madrid - Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria), Autopista M-40, Km 38-Pozuelo de Alarcon, 28223, Madrid, Spain.; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190, Vienna, Austria. juergen.kleine-vehn@boku.ac.at.
Directional organ growth allows the plant root system to strategically cover its surroundings. Intercellular auxin transport is aligned with the gravity vector in the primary root tips, facilitating downward organ bending at the lower root flank. Here we show that cytokinin signaling functions as a lateral root specific anti-gravitropic component, promoting the radial distribution of the root system. We performed a genome-wide association study and reveal that signal peptide processing of Cytokinin Oxidase 2 (CKX2) affects its enzymatic activity and, thereby, determines the degradation of cytokinins in natural Arabidopsis thaliana accessions. Cytokinin signaling interferes with growth at the upper lateral root flank and thereby prevents downward bending. Our interdisciplinary approach proposes that two phytohormonal cues at opposite organ flanks counterbalance each other's negative impact on growth, suppressing organ growth towards gravity and allow for radial expansion of the root system.
PMID: 31387989
Nat Commun , IF:12.121 , 2019 Aug , V10 (1) : P3480 doi: 10.1038/s41467-019-11471-8
Evolution of fast root gravitropism in seed plants.
Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria.; College of Life Sciences, Shaanxi Normal University, 710119, Xi'an, China.; College of Life Sciences, Northwest University, 710069, Xi'an, China.; Institute of Science and Technology (IST) Austria, 3400, Klosterneuburg, Austria. jiri.friml@ist.ac.at.
An important adaptation during colonization of land by plants is gravitropic growth of roots, which enabled roots to reach water and nutrients, and firmly anchor plants in the ground. Here we provide insights into the evolution of an efficient root gravitropic mechanism in the seed plants. Architectural innovation, with gravity perception constrained in the root tips along with a shootward transport route for the phytohormone auxin, appeared only upon the emergence of seed plants. Interspecies complementation and protein domain swapping revealed functional innovations within the PIN family of auxin transporters leading to the evolution of gravitropism-specific PINs. The unique apical/shootward subcellular localization of PIN proteins is the major evolutionary innovation that connected the anatomically separated sites of gravity perception and growth response via the mobile auxin signal. We conclude that the crucial anatomical and functional components emerged hand-in-hand to facilitate the evolution of fast gravitropic response, which is one of the major adaptations of seed plants to dry land.
PMID: 31375675
Mol Plant , IF:12.084 , 2019 Aug , V12 (8) : P1143-1156 doi: 10.1016/j.molp.2019.05.014
OsBRXL4 Regulates Shoot Gravitropism and Rice Tiller Angle through Affecting LAZY1 Nuclear Localization.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China; Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Plant Phenomics Research Center, Nanjing Agriculture University, Nanjing 210095, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China.; Root Biology Center, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China. Electronic address: jyli@genetics.ac.cn.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100039, China; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: yhwang@genetics.ac.cn.
Rice tiller angle is a key agronomic trait that contributes to ideal plant architecture and grain production. LAZY1 (LA1) was previously shown to control tiller angle via affecting shoot gravitropism, but the underlying molecular mechanism remains largely unknown. In this study, we identified an LA1-interacting protein named Brevis Radix Like 4 (OsBRXL4). We showed that the interaction between OsBRXL4 and LA1 occurs at the plasma membrane and that their interaction determines nuclear localization of LA1. We found that nuclear localization of LA1 is essential for its function, which is different from AtLA1, its Arabidopsis ortholog. Overexpression of OsBRXL4 leads to a prostrate growth phenotype, whereas OsBRXLs RNAi plants, in which the expression levels of OsBRXL1, OsBRXL4, and OsBRXL5 were decreased, display a compact phenotype. Further genetic analysis also supported that OsBRXL4 controls rice tiller angle by affecting nuclear localization of LA1. Consistently, we demonstrated that OsBRXL4 regulates the shoot gravitropism through affecting polar auxin transport as did LA1. Taken together, our study not only identifies OsBRXL4 as a regulatory component of rice tiller angle but also provides new insights into genetic regulation of rice plant architecture.
PMID: 31200078
Mol Plant , IF:12.084 , 2019 Aug , V12 (8) : P1123-1142 doi: 10.1016/j.molp.2019.04.012
Translational Regulation of Plant Response to High Temperature by a Dual-Function tRNA(His) Guanylyltransferase in Rice.
National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China.; National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai 200032, China.; National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai 200032, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.; College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.; National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, China.; University of the Chinese Academy of Sciences, Beijing 100049, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, China.; National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai 200032, China. Electronic address: jxshan@sibs.ac.cn.; National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences and Collaborative Innovation Center of Genetics & Development, Shanghai Institute of Plant Physiology & Ecology, Shanghai Institute for Biological Sciences, Chinese Academic of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China. Electronic address: hxlin@sibs.ac.cn.
As sessile organisms, plants have evolved numerous strategies to acclimate to changes in environmental temperature. However, the molecular basis of this acclimation remains largely unclear. In this study we identified a tRNA(His) guanylyltransferase, AET1, which contributes to the modification of pre-tRNA(His) and is required for normal growth under high-temperature conditions in rice. Interestingly, AET1 possibly interacts with both RACK1A and eIF3h in the endoplasmic reticulum. Notably, AET1 can directly bind to OsARF mRNAs including the uORFs of OsARF19 and OsARF23, indicating that AET1 is associated with translation regulation. Furthermore, polysome profiling assays suggest that the translational status remains unaffected in the aet1 mutant, but that the translational efficiency of OsARF19 and OsARF23 is reduced; moreover, OsARF23 protein levels are obviously decreased in the aet1 mutant under high temperature, implying that AET1 regulates auxin signaling in response to high temperature. Our findings provide new insights into the molecular mechanisms whereby AET1 regulates the environmental temperature response in rice by playing a dual role in tRNA modification and translational control.
PMID: 31075443
Plant Cell , IF:9.618 , 2019 Aug , V31 (8) : P1767-1787 doi: 10.1105/tpc.18.00757
Danger-Associated Peptides Interact with PIN-Dependent Local Auxin Distribution to Inhibit Root Growth in Arabidopsis.
State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093 Jiangsu, China.; Department of Plant and Microbial Biology, University of California, Berkeley, California 94720.; College of Life Sciences, Northwest University, Xi'an 710069, China.; Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Nanjing 210093 Jiangsu, China.; State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093 Jiangsu, China lanw@nju.edu.cn sluan@berkeley.edu.; Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 lanw@nju.edu.cn sluan@berkeley.edu.
Plant elicitor peptides (Peps) are damage/danger-associated molecular patterns that are perceived by the receptor-like kinases, PEPR1 and PEPR2, to enhance innate immunity and to inhibit root growth in Arabidopsis (Arabidopsis thaliana). Here, we show that Arabidopsis Pep1 inhibits root growth in a PEPR2-dependent manner, which is accompanied by swelling epidermal and cortex cells and root hair formation in the transition zone (TZ). These Pep1-induced changes were mimicked by exogenous auxin application and were suppressed in the auxin perception mutants transport inhibitor response1 (tir1) and tir1 afb1 afb2 Pep1-induced auxin accumulation in the TZ region preceded cell expansion in roots. Because local auxin distribution depends on PIN-type auxin transporters, we examined Pep1-PEPR-induced root growth inhibition in several pin mutants and found that pin2 was highly sensitive but pin3 was less sensitive to Pep1. The pin2 pin3 double mutant was as sensitive to Pep1 treatment as wild-type plants. Pep1 reduced the abundance of PIN2 in the plasma membrane through activating endocytosis while increasing PIN3 expression in the TZ, leading to changes in local auxin distribution and inhibiting root growth. These results suggest that Pep-PEPR signaling undergoes crosstalk with auxin accumulation to control cell expansion and differentiation in roots during immune responses.
PMID: 31123046
Curr Biol , IF:9.601 , 2019 Aug , V29 (15) : P2443-2454.e5 doi: 10.1016/j.cub.2019.06.039
Cytoskeleton Dynamics Are Necessary for Early Events of Lateral Root Initiation in Arabidopsis.
Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.; Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland.; Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Japan; Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan.; Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan.; Department of Plant and Microbial Biology, University of Zurich, 8008 Zurich, Switzerland. Electronic address: joop.vermeer@botinst.uzh.ch.; Center for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany. Electronic address: alexis.maizel@cos.uni-heidelberg.de.
How plant cells re-establish differential growth to initiate organs is poorly understood. Morphogenesis of lateral roots relies on the asymmetric cell division of initially symmetric founder cells. This division is preceded by the tightly controlled asymmetric radial expansion of these cells. The cellular mechanisms that license and ensure the coordination of these events are unknown. Here, we quantitatively analyze microtubule and F-actin dynamics during lateral root initiation. Using mutants and pharmacological and tissue-specific genetic perturbations, we show that dynamic reorganization of both microtubule and F-actin networks is necessary for the asymmetric expansion of the founder cells. This cytoskeleton remodeling intertwines with auxin signaling in the pericycle and endodermis in order for founder cells to acquire a basic polarity required for initiating lateral root development. Our results reveal the conservation of cell remodeling and polarization strategies between the Arabidopsis zygote and lateral root founder cells. We propose that coordinated, auxin-driven reorganization of the cytoskeleton licenses asymmetric cell growth and divisions during embryonic and post-embryonic organogenesis.
PMID: 31327713
Proc Natl Acad Sci U S A , IF:9.412 , 2019 Aug , V116 (34) : P17105-17114 doi: 10.1073/pnas.1907968116
CsBRC1 inhibits axillary bud outgrowth by directly repressing the auxin efflux carrier CsPIN3 in cucumber.
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Ministry of Education Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193 Beijing, China.; Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, 201602 Shanghai, China.; Shanghai Center for Plant Stress Biology, University of Chinese Academy of Sciences, 100049 Beijing, China.; Center for Agroforestry Mega Data Science, Fujian Agriculture and Forestry University, 350002 Fuzhou, China.; Fujian Agriculture and Forestry University-University of California, Riverside (FAFU-UCR) Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, China.; Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Ministry of Education Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, 100193 Beijing, China; zhxiaolan@cau.edu.cn.
Shoot branching is an important agronomic trait that directly determines plant architecture and affects crop productivity. To promote crop yield and quality, axillary branches need to be manually removed during cucumber production for fresh market and thus are undesirable. Auxin is well known as the primary signal imposing for apical dominance and acts as a repressor for lateral bud outgrowth indirectly. The TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family gene BRANCHED1 (BRC1) has been shown to be the central integrator for multiple environmental and developmental factors that functions locally to inhibit shoot branching. However, the direct molecular link between auxin and BRC1 remains elusive. Here we find that cucumber BRANCHED1 (CsBRC1) is expressed in axillary buds and displays a higher expression level in cultivated cucumber than in its wild ancestor. Knockdown of CsBRC1 by RNAi leads to increased bud outgrowth and reduced auxin accumulation in buds. We further show that CsBRC1 directly binds to the auxin efflux carrier PIN-FORMED (CsPIN3) and negatively regulates its expression in vitro and in vivo. Elevated expression of CsPIN3 driven by the CsBRC1 promoter results in highly branched cucumber with decreased auxin levels in lateral buds. Therefore, our data suggest that CsBRC1 inhibits lateral bud outgrowth by direct suppression of CsPIN3 functioning and thus auxin accumulation in axillary buds in cucumber, providing a strategy to breed for cultivars with varying degrees of shoot branching grown in different cucumber production systems.
PMID: 31391306
New Phytol , IF:8.512 , 2019 Aug , V223 (3) : P1420-1432 doi: 10.1111/nph.15877
A role for the auxin precursor anthranilic acid in root gravitropism via regulation of PIN-FORMED protein polarity and relocalisation in Arabidopsis.
Umea Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden.; Department of Chemical Biology and Genetics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacky University, 783 71, Olomouc, Czech Republic.; Department of Chemistry, Umea University, 90736, Umea, Sweden.; Laboratory of Growth Regulators, Institute of Experimental Botany at The Czech Academy of Sciences and Faculty of Science at Palacky University, 78371, Olomouc, Czech Republic.; Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), 9052, Ghent, Belgium.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium.; Central European Institute of Technology (CEITEC), Masaryk University, 62500, Brno, Czech Republic.
distribution of auxin within plant tissues is of great importance for developmental plasticity, including root gravitropic growth. Auxin flow is directed by the subcellular polar distribution and dynamic relocalisation of auxin transporters such as the PIN-FORMED (PIN) efflux carriers, which can be influenced by the main natural plant auxin indole-3-acetic acid (IAA). Anthranilic acid (AA) is an important early precursor of IAA and previously published studies with AA analogues have suggested that AA may also regulate PIN localisation. Using Arabidopsis thaliana as a model species, we studied an AA-deficient mutant displaying agravitropic root growth, treated seedlings with AA and AA analogues and transformed lines to over-produce AA while inhibiting its conversion to downstream IAA precursors. We showed that AA rescues root gravitropic growth in the AA-deficient mutant at concentrations that do not rescue IAA levels. Overproduction of AA affects root gravitropism without affecting IAA levels. Treatments with, or deficiency in, AA result in defects in PIN polarity and gravistimulus-induced PIN relocalisation in root cells. Our results revealed a previously unknown role for AA in the regulation of PIN subcellular localisation and dynamics involved in root gravitropism, which is independent of its better known role in IAA biosynthesis.
PMID: 31038751
New Phytol , IF:8.512 , 2019 Aug , V223 (3) : P1143-1158 doi: 10.1111/nph.15793
MADS-box genes underground becoming mainstream: plant root developmental mechanisms.
Departamento de Ecologia Funcional, Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, 3er Circuito Exterior, Ciudad Universitaria, Coyoacan, D.F. 04510, Mexico.; Centro de Ciencias de la Complejidad, Universidad Nacional Autonoma de Mexico, 3er Circuito Exterior, Ciudad Universitaria, Coyoacan, D.F. 04510, Mexico.; Instituto de Fisica, Universidad Autonoma de San Luis Potosi, Manuel Nava 6, Zona Universitaria, San Luis Potosi, CP 78290, Mexico.; Departamento de Produccion Agricola y Animal, Universidad Autonoma Metropolitana Xochimilco, Ciudad de Mexico, 04960, Mexico.
Plant growth is largely post-embryonic and depends on meristems that are active throughout the lifespan of an individual. Developmental patterns rely on the coordinated spatio-temporal expression of different genes, and the activity of transcription factors is particularly important during most morphogenetic processes. MADS-box genes constitute a transcription factor family in eukaryotes. In Arabidopsis, their proteins participate in all major aspects of shoot development, but their role in root development is still not well characterized. In this review we synthetize current knowledge pertaining to the function of MADS-box genes highly expressed in roots: XAL1, XAL2, ANR1 and AGL21, as well as available data for other MADS-box genes expressed in this organ. The role of Trithorax group and Polycomb group complexes on MADS-box genes' epigenetic regulation is also discussed. We argue that understanding the role of MADS-box genes in root development of species with contrasting architectures is still a challenge. Finally, we propose that MADS-box genes are key components of the gene regulatory networks that underlie various gene expression patterns, each one associated with the distinct developmental fates observed in the root. In the case of XAL1 and XAL2, their role within these networks could be mediated by regulatory feedbacks with auxin.
PMID: 30883818
Plant Physiol , IF:6.902 , 2019 Aug , V180 (4) : P1860-1876 doi: 10.1104/pp.19.00300
Metabolic Alterations in the Enoyl-CoA Hydratase 2 Mutant Disrupt Peroxisomal Pathways in Seedlings.
University of Missouri-St. Louis, St. Louis, Missouri 63121.; University of Missouri-St. Louis, St. Louis, Missouri 63121 zolmanb@umsl.edu.
Mobilization of seed storage compounds, such as starch and oil, is required to provide energy and metabolic building blocks during seedling development. Over 50% of fatty acids in Arabidopsis (Arabidopsis thaliana) seed oil have a cis-double bond on an even-numbered carbon. Degradation of these substrates requires peroxisomal fatty acid beta-oxidation plus additional enzyme activities. Such auxiliary enzymes, including the enoyl-CoA hydratase ECH2, convert (R)-3-hydroxyacyl-CoA intermediates to the core beta-oxidation substrate (S)-3-hydroxyacyl-CoA. ECH2 was suggested to function in the peroxisomal conversion of indole-3-butyric acid (IBA) to indole-3-acetic acid, because ech2 seedlings have altered IBA responses. The underlying mechanism connecting ECH2 activity and IBA metabolism is unclear. Here, we show that ech2 seedlings have reduced root length, smaller cotyledons, and arrested pavement cell expansion. At the cellular level, reduced oil body mobilization and enlarged peroxisomes suggest compromised beta-oxidation. ech2 seedlings accumulate 3-hydroxyoctenoate (C8:1-OH) and 3-hydroxyoctanoate (C8:0-OH), putative hydrolysis products of catabolic intermediates for alpha-linolenic acid and linoleic acid, respectively. Wild-type seedlings treated with 3-hydroxyoctanoate have ech2-like growth defects and altered IBA responses. ech2 phenotypes are not rescued by Suc or auxin application. However, ech2 phenotypes are suppressed in combination with the core beta-oxidation mutants mfp2 or ped1, and ech2 mfp2 seedlings accumulate less C8:1-OH and C8:0-OH than ech2 seedlings. These results indicate that ech2 phenotypes require efficient core beta-oxidation. Our findings suggest that low ECH2 activity causes metabolic alterations through a toxic effect of the accumulating intermediates. These effects manifest in altered lipid metabolism and IBA responses leading to disrupted seedling development.
PMID: 31138624
Semin Cell Dev Biol , IF:6.691 , 2019 Aug , V92 : P122-125 doi: 10.1016/j.semcdb.2019.03.011
Plant responses to gravity.
Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27412, USA; School of Biological Sciences, Louisiana Tech University, Ruston, LA, 71272, USA.; Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, 27412, USA. Electronic address: jzkiss@uncg.edu.
Tropisms are directed growth-mediated plant movements which allow plants to respond to their environment. Gravitropism is the ability of plants to perceive and respond to the gravity vector and orient themselves accordingly. The gravitropic pathway can be divided into three main components: perception, biochemical signaling, and differential growth. Perception of the gravity signal occurs through the movement/sedimentation of starch-filled plastids (termed statoliths) in gravity sensing cells. Once perceived, proteins interact with the settling statoliths to set a cascade of plant hormones to the elongation zones in the roots or shoots. Plant growth regulators that play a role in gravitropism include auxin, ethylene, gibberellic acid, jasmonic acid, among others. Differential growth on opposing sides of the root or shoot allow for the plant to grow relative to the direction of the perceived gravity vector. In this review, we detail how plants perceive gravity and respond biochemically in response to gravity as well as synthesize the recent literature on this important topic in plant biology. Keywords: auxin, gravitropism, gravity perception, plant growth regulators, space biology, statolith.
PMID: 30935972
Plant Cell Environ , IF:6.362 , 2019 Aug , V42 (8) : P2372-2383 doi: 10.1111/pce.13559
Negative gravitropic response of roots directs auxin flow to control root gravitropism.
Department of Grass Science, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangzhou, 510642, China.; Laboratory of Plant Genetics and Development, Noble Research Institute, Ardmore, 73401, Oklahoma.; School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
Root tip is capable of sensing and adjusting its growth direction in response to gravity, a phenomenon known as root gravitropism. Previously, we have shown that negative gravitropic response of roots (NGR) is essential for the positive gravitropic response of roots. Here, we show that NGR, a plasma membrane protein specifically expressed in root columella and lateral root cap cells, controls the positive root gravitropic response by regulating auxin efflux carrier localization in columella cells and the direction of lateral auxin flow in response to gravity. Pharmacological and genetic studies show that the negative root gravitropic response of the ngr mutants depends on polar auxin transport in the root elongation zone. Cell biology studies further demonstrate that polar localization of the auxin efflux carrier PIN3 in root columella cells and asymmetric lateral auxin flow in the root tip in response to gravistimulation is reversed in the atngr1;2;3 triple mutant. Furthermore, simultaneous mutations of three PIN genes expressed in root columella cells impaired the negative root gravitropic response of the atngr1;2;3 triple mutant. Our work revealed a critical role of NGR in root gravitropic response and provided an insight of the early events and molecular basis of the positive root gravitropism.
PMID: 30968964
Plant J , IF:6.141 , 2019 Aug , V99 (4) : P717-732 doi: 10.1111/tpj.14356
Arabidopsis and sunflower plants with increased xylem area show enhanced seed yield.
Instituto de Agrobiotecnologia del Litoral, Universidad Nacional del Litoral, CONICET, Centro Cientifico Tecnologico CONICET Santa Fe, Colectora Ruta Nacional N degrees 168 km. 0, Paraje El Pozo, (3000), Santa Fe, Argentina.
Plant architecture plasticity determines the efficiency at harvesting and plays a major role defining biomass and seed yield. We observed that several previously described transgenic genotypes exhibiting increased seed yield also show wider stems and more vascular bundles than wild-type plants. Here, the relationship between these characteristics and seed yield was investigated. Hanging weight on the main stem of Arabidopsis plants provoked significant stem widening. Such widening was accompanied by an increase in the number of vascular bundles and about 100% of yield increase. In parallel, lignin deposition diminished. Vascular bundle formation started in the upper internode and continued downstream. AUX/LAX carriers were essential for this response. The increase of vascular bundles was reverted 3 weeks after the treatment leading to an enlarged xylem area. Aux1, lax1, and lax3 mutant plants were also able to enlarge their stems after the treatment, whereas lax2 plants did not. However, none of these mutants exhibited more vascular bundles or seed yield compared with untreated plants. Weight-induced xylem area enhancement and increased seed yield were also observed in sunflower plants. Altogether these results showed a strong correlation between the number of vascular bundles and enhanced seed yield under a long-day photoperiod. Furthermore, changes in the levels of auxin carriers affected both these processes in the same manner, suggesting that there may be an underlying causality.
PMID: 31009150
Plant J , IF:6.141 , 2019 Aug , V99 (3) : P536-555 doi: 10.1111/tpj.14343
Cystathionine beta-lyase is crucial for embryo patterning and the maintenance of root stem cell niche in Arabidopsis.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642, China.; Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.; South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
The growth and development of roots in plants depends on the specification and maintenance of the root apical meristem. Here, we report the identification of CBL, a gene required for embryo and root development in Arabidopsis, and encodes cystathionine beta-lyase (CBL), which catalyzes the penultimate step in methionine (Met) biosynthesis, and which also led to the discovery of a previous unknown, but crucial, metabolic contribution by the Met biosynthesis pathway. CBL is expressed in embryos and shows quiescent center (QC)-enriched expression pattern in the root. cbl mutant has impaired embryo patterning, defective root stem cell niche, stunted root growth, and reduces accumulation of the root master regulators PLETHORA1 (PLT1) and PLT2. Furthermore, mutation in CBL severely decreases abundance of several PIN-FORMED (PIN) proteins and impairs auxin-responsive gene expression in the root tip. cbl seedlings also exhibit global reduction in histone H3 Lys-4 trimethylation (H3K4me3) and DNA methylation. Importantly, mutation in CBL reduces the abundance of H3K4me3 modification in PLT1/2 genes and downregulates their expression. Overexpression of PLT2 partially rescues cbl root meristem defect, suggesting that CBL acts in part through PLT1/2. Moreover, exogenous supplementation of Met also restores the impaired QC activity and the root growth defects of cbl. Taken together, our results highlight the unique role of CBL to maintain the root stem cell niche by cooperative actions between Met biosynthesis and epigenetic modification of key developmental regulators.
PMID: 31002461
J Exp Bot , IF:5.908 , 2019 Aug , V70 (17) : P4405-4417 doi: 10.1093/jxb/erz350
Nitric oxide in the physiology and quality of fleshy fruits.
Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Estacion Experimental del Zaidin, CSIC, Granada, Spain.; Laboratorio de Fisiologia do Desenvolvimento Vegetal, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, Brazil.
Fruits are unique to flowering plants and confer a selective advantage as they facilitate seed maturation and dispersal. In fleshy fruits, development and ripening are associated with numerous structural, biochemical, and physiological changes, including modifications in the general appearance, texture, flavor, and aroma, which ultimately convert the immature fruit into a considerably more attractive and palatable structure for seed dispersal by animals. Treatment with exogenous nitric oxide (NO) delays fruit ripening, prevents chilling damage, promotes disease resistance, and enhances the nutritional value. The ripening process is influenced by NO, which operates antagonistically to ethylene, but it also interacts with other regulatory molecules such as abscisic acid, auxin, jasmonic acid, salicylic acid, melatonin, and hydrogen sulfide. NO content progressively declines during fruit ripening, with concomitant increases in protein nitration and nitrosation, two post-translational modifications that are promoted by reactive nitrogen species. Dissecting the intimate interactions of NO with other ripening-associated factors, including reactive oxygen species, antioxidants, and the aforementioned phytohormones, remains a challenging subject of research. In this context, integrative 'omics' and gene-editing approaches may provide additional knowledge of the impact of NO in the regulatory processes involved in controlling physiology and quality traits in both climacteric and non-climacteric fruits.
PMID: 31359063
J Exp Bot , IF:5.908 , 2019 Aug , V70 (15) : P3911-3926 doi: 10.1093/jxb/erz201
Cellular and molecular characterization of a thick-walled variant reveal a pivotal role of shoot apical meristem in transverse development of bamboo culm.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China.; Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA.; International Education College, Nanjing Forestry University, Nanjing, Jiangsu, China.; Libo Forestry Bureau, Libo, Guizhou, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Little is known about the mechanisms underlying the development of bamboo culm. Using anatomical, mathematical modeling, and genomics methods, we investigated the role of shoot apical meristem (SAM) in the development of the transverse morphology of bamboo culm and explored the underlying cellular and molecular processes. We discovered that maintenance of SAM morphology that can produce circular culm and increase in SAM cell numbers, especially corpus cells, is the means by which bamboo makes a larger culm with a regular pith cavity and culm wall during development. A less cellular form of SAM with a lower proportion of corpus cells causes an abnormal higher ratio of wall component cells to pith cells, which breaks the balance of their interaction and triggers the random invasion of wall component cells into pith tissues during development, and finally results in the various thick culm walls of Phyllostachys nidularia f. farcta. The smaller SAM also results in a lower level of hormones such as cytokinin and auxin, and down-regulates hormone signaling and the downstream functional genes such as those related to metabolism, which finally results in a dwarf and smaller diameter culm with lower biomass. These results provide an important perspective on the culm development of bamboo, and support a plausible mechanism causing the size-reduced culm and various thick culm walls of P. nidularia f. farcta.
PMID: 31037305
Development , IF:5.611 , 2019 Aug , V146 (15) doi: 10.1242/dev.168088
PIN-FORMED and PIN-LIKES auxin transport facilitators.
Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany michael.sauer@uni-potsdam.de juergen.kleine-vehn@boku.ac.at.; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria michael.sauer@uni-potsdam.de juergen.kleine-vehn@boku.ac.at.
The phytohormone auxin influences virtually all aspects of plant growth and development. Auxin transport across membranes is facilitated by, among other proteins, members of the PIN-FORMED (PIN) and the structurally similar PIN-LIKES (PILS) families, which together govern directional cell-to-cell transport and intracellular accumulation of auxin. Canonical PIN proteins, which exhibit a polar localization in the plasma membrane, determine many patterning and directional growth responses. Conversely, the less-studied non-canonical PINs and PILS proteins, which mostly localize to the endoplasmic reticulum, attenuate cellular auxin responses. Here, and in the accompanying poster, we provide a brief summary of current knowledge of the structure, evolution, function and regulation of these auxin transport facilitators.
PMID: 31371525
Ecotoxicol Environ Saf , IF:4.872 , 2019 Aug , V178 : P33-42 doi: 10.1016/j.ecoenv.2019.04.027
Regulation of antioxidant production, ion uptake and productivity in potato (Solanum tuberosum L.) plant inoculated with growth promoting salt tolerant Bacillus strains.
Department of Environmental Sciences, COMSATS University Islamabad, Vehari-Campus, Vehari, 61100, Pakistan.; Department of Environmental Sciences, COMSATS University Islamabad, Vehari-Campus, Vehari, 61100, Pakistan. Electronic address: iftikharahmad@ciitvehari.edu.pk.; Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, 38040, Pakistan.; Department of Agronomy, Bahauddin Zakarrya University, Multan, 60000, Pakistan.; Department of Environmental Sciences, COMSATS University Islamabad, Vehari-Campus, Vehari, 61100, Pakistan. Electronic address: zakirali@ciitvehari.edu.pk.
The exchangeable sodium (Na(+)) in salt affected soils is a major constraint in potassium (K(+)) availability to plants that disturb ion transport and inhibit plant growth, adversely. Salt tolerant plant growth promoting rhizobacteria (PGPR) may regulate the Na(+)/K(+) efflux and increase K(+) uptake by the plant from the soil. Therefore, a pot study was performed to examine the effect of salt tolerant PGPR Bacillus sp. alone and in consortium, on antioxidant enzyme activity, ion uptake and potato (Solanum tuberosum L.) tuber yield in normal and salt affected soils. We observed that Bacillus sp. (strains SR-2-1 and SR-2-1/1) solubilized insoluble phosphorous and produced indole-3-acetic acid while only SR-2-1/1 produced ACC deaminase in culture medium supplemented with various concentrations of NaCl (0-6%). In the pot experiment, the consortium treatment of strains was found to increase relative leaf water contents whereas decreased the electrolyte leakage and antioxidant enzyme activity both in normal and salt affected soils. Similarly, consortium treatment decreased Na(+) whereas increased K(+), Ca(+2), K(+)/Na(+) and Ca(+2)/Na(+) in plant dry matter in both soils. It has been investigated that inoculation of PGPR significantly (p<0.05) increased plant biomass, number of tubers per plant and tuber weight as compared to un-inoculated plants in both soils. In addition, PGPR inoculation enhanced auxin production in root exudates of young potato plants and bacterial population dynamics in both soils. Na(+) ion regulation (R(2)=0.95) and tuber weight (R(2)=0.90) in salt affected soil were significantly correlated with auxin production in the rhizosphere. Results of this study conferred that consortium of Bacillus strains (SR-2-1, SR-2-1/1) enhanced auxin production in the rhizosphere of potato plants and that ultimately regulated antioxidant enzyme production and uptake of Na(+), K(+) and Ca(+2) in potato plants resulted into a higher tuber yield in both normal and salt affected soils.
PMID: 30991245
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (17) doi: 10.3390/ijms20174227
The Reason for Growth Inhibition of Ulmus pumila 'Jinye': Lower Resistance and Abnormal Development of Chloroplasts Slow Down the Accumulation of Energy.
Institute of Forest Biotechnology, Forestry College, Agricultural University of Hebei, Baoding 071000, China.; Hebei Key Laboratory for Tree Genetic Resources and Forest Protection, Baoding 071000, China.; College of Landscape and Ecological Engineering, Hebei University of Engineering, Handan 056000, China.; Hebei Forestry Research Institute, Shijiazhuang 050000, China.; Institute of Forest Biotechnology, Forestry College, Agricultural University of Hebei, Baoding 071000, China. yangms100@126.com.; Hebei Key Laboratory for Tree Genetic Resources and Forest Protection, Baoding 071000, China. yangms100@126.com.; Institute of Forest Biotechnology, Forestry College, Agricultural University of Hebei, Baoding 071000, China. swjs224@aliyun.com.; Hebei Key Laboratory for Tree Genetic Resources and Forest Protection, Baoding 071000, China. swjs224@aliyun.com.
Ulmus pumila 'Jinye', the colorful leaf mutant of Ulmus pumila L., is widely used in landscaping. In common with most leaf color mutants, U. pumila 'Jinye' exhibits growth inhibition. In this study, U. pumila L. and U. pumila 'Jinye' were used to elucidate the reasons for growth inhibition at the physiological, cellular microstructural, and transcriptional levels. The results showed that the pigment (chlorophyll a, chlorophyll b, and carotenoids) content of U. pumila L. was higher than that of U. pumila 'Jinye', whereas U. pumila 'Jinye' had a higher proportion of carotenoids, which may be the cause of the yellow leaves. Examination of the cell microstructure and RNA sequencing analysis showed that the leaf color and growth inhibition were mainly due to the following reasons: first, there were differences in the structure of the thylakoid grana layer. U. pumila L. has a normal chloroplast structure and clear thylakoid grana slice layer structure, with ordered and compact thylakoids. However, U. pumila 'Jinye' exhibited the grana lamella stacking failures and fewer thylakoid grana slice layers. As the pigment carrier and the key location for photosynthesis, the close stacking of thylakoid grana could combine more chlorophyll and promote efficient electron transfer promoting the photosynthesis reaction. In addition, U. pumila 'Jinye' had a lower capacity for light energy absorption, transformation, and transportation, carbon dioxide (CO2) fixation, lipopolysaccharide biosynthesis, auxin synthesis, and protein transport. The genes related to respiration and starch consumption were higher than those of U. pumila L., which indicated less energy accumulation caused the growth inhibition of U. pumila 'Jinye'. Finally, compared with U. pumila 'Jinye', the transcription of genes related to stress resistance all showed an upward trend in U. pumila L. That is to say, U. pumila L. had a greater ability to resist adversity, which could maintain the stability of the intracellular environment and maintain normal progress of physiological metabolism. However, U. pumila 'Jinye' was more susceptible to changes in the external environment, which affected normal physiological metabolism. This study provides evidence for the main cause of growth inhibition in U. pumila 'Jinye', information for future cultivation, and information on the mutation mechanism for the breeding of colored leaf trees.
PMID: 31470529
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (17) doi: 10.3390/ijms20174141
PtrARF2.1 Is Involved in Regulation of Leaf Development and Lignin Biosynthesis in Poplar Trees.
Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.; Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China.; Department of Life Sciences and Technology, Yangtze Normal University, Fuling District, Chongqing 408100, China.; Chongqing Key Laboratory of Plant Resource Conservation and Germplasm Innovation, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China. kemingl@swu.edu.cn.; Key Laboratory of Eco-Environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing 400715, China. kemingl@swu.edu.cn.
Auxin response factors (ARFs) are important regulators modulating the expression of auxin-responsive genes in various biological processes in plants. In the Populus genome, a total of 39 ARF members have been identified, but their detailed functions are still unclear. In this study, six poplar auxin response factor 2 (PtrARF2) members were isolated from P. trichocarpa. Expression pattern analysis showed that PtrARF2.1 is highly expressed in leaf tissues compared with other PtrARF2 genes and significantly repressed by exogenous auxin treatment. PtrARF2.1 is a nuclear-localized protein without transcriptional activation activity. Knockdown of PtrARF2.1 by RNA interference (RNAi) in poplars led to the dwarf plant, altered leaf shape, and reduced size of the leaf blade, while overexpression of PtrARF2.1 resulted in a slight reduction in plant height and the similar leaf phenotype in contrast to the wildtype. Furthermore, histological staining analysis revealed an ectopic deposition of lignin in leaf veins and petioles of PtrARF2.1-RNAi lines. RNA-Seq analysis showed that 74 differential expression genes (DEGs) belonging to 12 transcription factor families, such as NAM, ATAF and CUC (NAC), v-myb avian myeloblastosis viral oncogene homolog (MYB), ethylene response factors (ERF) and basic helix-loop-helix (bHLH), were identified in PtrARF2.1-RNAi leaves and other 24 DEGs were associated with the lignin biosynthetic pathway. Altogether, the data indicate that PtrARF2.1 plays an important role in regulating leaf development and influences the lignin biosynthesis in poplars.
PMID: 31450644
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (16) doi: 10.3390/ijms20164065
The Roles of Plant Hormones and Their Interactions with Regulatory Genes in Determining Meristem Activity.
Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan.; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi-shi, Saitama 332-0012, Japan.; Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan. itot@bs.naist.jp.
Plants, unlike animals, have developed a unique system in which they continue to form organs throughout their entire life cycle, even after embryonic development. This is possible because plants possess a small group of pluripotent stem cells in their meristems. The shoot apical meristem (SAM) plays a key role in forming all of the aerial structures of plants, including floral meristems (FMs). The FMs subsequently give rise to the floral organs containing reproductive structures. Studies in the past few decades have revealed the importance of transcription factors and secreted peptides in meristem activity using the model plant Arabidopsis thaliana. Recent advances in genomic, transcriptomic, imaging, and modeling technologies have allowed us to explore the interplay between transcription factors, secreted peptides, and plant hormones. Two different classes of plant hormones, cytokinins and auxins, and their interaction are particularly important for controlling SAM and FM development. This review focuses on the current issues surrounding the crosstalk between the hormonal and genetic regulatory network during meristem self-renewal and organogenesis.
PMID: 31434317
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (16) doi: 10.3390/ijms20164056
A SNP Mutation of SiCRC Regulates Seed Number Per Capsule and Capsule Length of cs1 Mutant in Sesame.
Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China.; Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China. miaohongmeichina@yahoo.com.; Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China. zhanghaiyang@zzu.edu.cn.
Seed number per capsule (SNC) is a major factor influencing seed yield and is an important trait with complex gene interaction effects. We first performed genetic analysis, gene cloning, and molecular mechanism study for an EMS-induced sesame mutant cs1 with fewer SNC and shorter capsule length (CL). The mutant traits were due to the pleiotropism of a regressive gene (Sics1). Capsule hormone determination showed that five out of 12 hormones, including auxin indole-3-acetic acid (IAA), had significantly different levels between wild type (WT) and mutant type (MT). KEGG pathway analysis showed that plant hormone signal transduction, especially the auxin signal transduction pathway, was the most abundant differentially expressed signaling pathway. After the cross-population association and regional genome screening, we found that three homozygous loci were retained in cs1. Further analysis of these three loci resulted in the identification of SiCRC as the candidate gene for cs1. SiCRC consists of seven exons and six introns encoding 163 amino acids. The SiCRC in cs1 showed a point mutation at intron 5 and exon 6 junction, resulting in the splice site being frame-shifted eight nucleotides further downstream, causing incorrect splicing. Taken together, we assumed the SNP mutation in SiCRC disrupted the function of the transcription factor, which might act downstream of the CRC-auxin signal transduction pathway, resulting in a shorter CL and less SNC mutation of cs1 in sesame. Our results highlight the molecular framework underlying the transcription factor CRC-mediated role of auxin transduction in SNC and CL development.
PMID: 31434218
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (16) doi: 10.3390/ijms20163989
Durum Wheat Stress Tolerance Induced by Endophyte Pantoea agglomerans with Genes Contributing to Plant Functions and Secondary Metabolite Arsenal.
Laboratory of Applied Microbiology, Department of Microbiology, Faculty of Natural and Life Sciences, Ferhat Abbas University, Setif 19000, Algeria.; School of Computing, Engineering and Physical Sciences, University of the West of Scotland, PA12BE Paisley, UK.; Plant Protection Research Department, East Azarbaijan Agricultural and Natural Resources Research and Education Center, AREEO, Tabriz 5355179854, Iran.; Food Science and Technology Department, Faculty of Agriculture, University of Tripoli, Tripoli 13275, Libya.; NextBiotech, 98 Rue Ali Belhouane, Agareb 3030, Tunisia.; Neuchatel Platform of Analytical Chemistry, Institute of Chemistry, University of Neuchatel, 2000 Neuchatel, Switzerland.; Department of Biology and Genetics, Institute of Biology, University of Veterinary Medicine and Pharmacy, Zoology and Radiobiology, Komenskeho, 04181 Kosice, Slovakia.; CONIPHY, Parc d'activitesen Chuel, Route de Chasselay, 69650 Quincieux, France.; Laboratory of Soil Biology, University of Neuchatel, 2000 Neuchatel, Switzerland. lassaad.belbahri@unine.ch.
In the arid region Bou-Saada at the South of Algeria, durum wheat Triticum durum L. cv Waha production is severely threatened by abiotic stresses, mainly drought and salinity. Plant growth-promoting rhizobacteria (PGPR) hold promising prospects towards sustainable and environmentally-friendly agriculture. Using habitat-adapted symbiosis strategy, the PGPR Pantoea agglomerans strain Pa was recovered from wheat roots sampled in Bou-Saada, conferred alleviation of salt stress in durum wheat plants and allowed considerable growth in this unhostile environment. Strain Pa showed growth up to 35 degrees C temperature, 5-10 pH range, and up to 30% polyethylene glycol (PEG), as well as 1 M salt concentration tolerance. Pa strain displayed pertinent plant growth promotion (PGP) features (direct and indirect) such as hormone auxin biosynthesis, production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia and phosphate solubilization. PGPR features were stable over wide salt concentrations (0-400 mM). Pa strain was also able to survive in seeds, in the non-sterile and sterile wheat rhizosphere, and was shown to have an endophytic life style. Phylogenomic analysis of strain Pa indicated that Pantoea genus suffers taxonomic imprecision which blurs species delimitation and may have impacted their practical use as biofertilizers. When applied to plants, strain Pa promoted considerable growth of wheat seedlings, high chlorophyll content, lower accumulation of proline, and favored K(+) accumulation in the inoculated plants when compared to Na(+) in control non-inoculated plants. Metabolomic profiling of strain Pa under one strain many compounds (OSMAC) conditions revealed a wide diversity of secondary metabolites (SM) with interesting salt stress alleviation and PGP activities. All these findings strongly promote the implementation of Pantoea agglomerans strain Pa as an efficient biofertilizer in wheat plants culture in arid and salinity-impacted regions.
PMID: 31426312
Int J Mol Sci , IF:4.556 , 2019 Aug , V20 (15) doi: 10.3390/ijms20153772
Selenium Modulates the Level of Auxin to Alleviate the Toxicity of Cadmium in Tobacco.
National Tobacco Cultivation & Physiology & Biochemistry Research Centre, College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.; China Tobacco Hubei Industrial Co., Ltd., Wuhan 430040, China.; Guangxi Zhuang Autonomous Region Provincial Branch of China National Tobacco Corporation, Nanning 530000, China.; National Tobacco Cultivation & Physiology & Biochemistry Research Centre, College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. jiahongfang@henau.edu.cn.; National Tobacco Cultivation & Physiology & Biochemistry Research Centre, College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. yunpengfu@henau.edu.cn.
Cadmium (Cd) is an environmental pollutant that potentially threatens human health worldwide. Developing approaches for efficiently treating environmental Cd is a priority. Selenium (Se) plays important role in the protection of plants against various abiotic stresses, including heavy metals. Previous research has shown that Se can alleviate Cd toxicity, but the molecular mechanism is still not clear. In this study, we explore the function of auxin and phosphate (P) in tobacco (Nicotiana tabacum), with particular focus on their interaction with Se and Cd. Under Cd stress conditions, low Se (10 muM) significantly increased the biomass and antioxidant capacity of tobacco plants and reduced uptake of Cd. We also measured the auxin concentration and expression of auxin-relative genes in tobacco and found that plants treated with low Se (10 muM) had higher auxin concentrations at different Cd supply levels (0 muM, 20 muM, 50 muM) compared with no Se treatment, probably due to increased expression of auxin synthesis genes and auxin efflux carriers. Overexpression of a high affinity phosphate transporter NtPT2 enhanced the tolerance of tobacco to Cd stress, possibly by increasing the total P and Se content and decreasing Cd accumulation compared to that in the wild type (WT). Our results show that there is an interactive mechanism among P, Se, Cd, and auxin that affects plant growth and may provide a new approach for relieving Cd toxicity in plants.
PMID: 31374993
Mol Plant Pathol , IF:4.326 , 2019 Aug , V20 (8) : P1093-1104 doi: 10.1111/mpp.12814
Suppression of auxin signalling promotes rice susceptibility to Rice black streaked dwarf virus infection.
The State Key Laboratory Breeding Base for Sustainable Control of Pest and Disease, Institute of Plant Virology, Ningbo University, Ningbo, 315211, China.; Key Laboratory of Biotechnology in Plant Protection of MOA and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
Auxin plays a fundamental role in plant growth and development, and also influences plant defence against various pathogens. Previous studies have examined the different roles of the auxin pathway during infection by biotrophic bacteria and necrotrophic fungi. We now show that the auxin signalling pathway was markedly down-regulated following infection of rice by Rice black streaked dwarf virus (RBSDV), a dsRNA virus. Repression of the auxin receptor TIR1 by a mutant overexpressing miR393 increased rice susceptibility to RBSDV. Mutants overexpressing the auxin signalling repressors OsIAA20 and OsIAA31 were also more susceptible to RBSDV. The induction of jasmonic acid (JA) pathway genes in response to RBSDV was supressed in auxin signalling mutants, suggesting that activation of the JA pathway may be part of the auxin signalling-mediated rice defence against RBSDV. More importantly, our results also revealed that OsRboh-mediated reactive oxygen species levels played important roles in this defence. The results offer novel insights into the regulatory mechanisms of auxin signalling in the rice-RBSDV interaction.
PMID: 31250531
Biochem J , IF:4.097 , 2019 Aug , V476 (16) : P2393-2409 doi: 10.1042/BCJ20190435
Rhizobacteria AK1 remediates the toxic effects of salinity stress via regulation of endogenous phytohormones and gene expression in soybean.
School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea.; Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman.; School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea ijlee@knu.ac.kr.; Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, South Korea.
Salinity stress adversely affects the growth and productivity of different crops. In the present study, we isolated the rhizospheric bacteria Arthrobacter woluwensis AK1 from Pohang beach, South Korea and determined its plant growth-promoting potential under NaCl salt stress (0, 100, and 200 mM). AK1 has phosphate-solubilizing activity and produce siderophores, organic acids, and phytohormones such as gibberellic acid (GA) and indole-3-acetic acid (IAA) that significantly alleviate sodium chloride (NaCl) stress and increase all plant growth attributes. Furthermore, inoculation of AK1 significantly decreased endogenous abscisic acid (ABA) content, extensively regulated the antioxidant activities and mitigated NaCl stress. Similarly, inductively coupled plasma mass spectrometry results showed that soybean plants inoculated with AK1 significantly decreased the amount of sodium (Na(+)) uptake during NaCl stress after 6 and 12 days. Four genes, auxin resistant 1 (GmLAX1), potassium channel AKT2 (GmAKT2), soybean salt tolerance 1 (GmST1), and salt tolerance-associated gene on chromosome 3 (GmSALT3) were up-regulated, while two genes chloride channel gene (GmNHX1) and Na(+)/H(+) antiporter (GmCLC1) were down-regulated in soybean AK1treated plants. In conclusion, AK1 can mitigate salinity stress, increase plant growth and could be utilized as an eco-friendly bio-fertilizer under salinity stress.
PMID: 31375565
Biomolecules , IF:4.082 , 2019 Aug , V9 (9) doi: 10.3390/biom9090420
Roles of Small-Molecule Compounds in Plant Adventitious Root Development.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.; College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China. liaowb@gsau.edu.cn.
Adventitious root (AR) is a kind of later root, which derives from stems and leaf petioles of plants. Many different kinds of small signaling molecules can transmit information between cells of multicellular organisms. It has been found that small molecules can be involved in many growth and development processes of plants, including stomatal movement, flowering, fruit ripening and developing, and AR formation. Therefore, this review focuses on discussing the functions and mechanisms of small signaling molecules in the adventitious rooting process. These compounds, such as nitric oxide (NO), hydrogen gas (H2), hydrogen sulfide (H2S), carbon monoxide (CO), methane (CH4), ethylene (ETH), and hydrogen peroxide (H2O2), can be involved in the induction of AR formation or development. This review also sums the crosstalk between these compounds. Besides, those signaling molecules can regulate the expressions of some genes during AR development, including cell division genes, auxin-related genes, and adventitious rooting-related genes. We conclude that these small-molecule compounds enhance adventitious rooting by regulating antioxidant, water balance, and photosynthetic systems as well as affecting transportation and distribution of auxin, and these compounds further conduct positive effects on horticultural plants under environmental stresses. Hence, the effect of these molecules in plant AR formation and development is definitely a hot issue to explore in the horticultural study now and in the future.
PMID: 31466349
Plant Cell Physiol , IF:4.062 , 2019 Aug , V60 (8) : P1633-1645 doi: 10.1093/pcp/pcz137
Class I TCP Transcription Factors Target the Gibberellin Biosynthesis Gene GA20ox1 and the Growth-Promoting Genes HBI1 and PRE6 during Thermomorphogenic Growth in Arabidopsis.
Instituto de Agrobiotecnologi inverted question mark(1/2)a del Litoral (CONICET-UNL), Ci inverted question mark(1/2)tedra de Biologi inverted question mark(1/2)a Celular y Molecular, Facultad de Bioqui inverted question mark(1/2)mica y Ciencias Bioli inverted question mark(1/2)gicas, Universidad Nacional del Litoral, Santa Fe, Argentina.
Plants respond to a rise in ambient temperature by increasing the growth of petioles and hypocotyls. In this work, we show that Arabidopsis thaliana class I TEOSINTE BRANCHED 1, CYCLOIDEA, PCF (TCP) transcription factors TCP14 and TCP15 are required for optimal petiole and hypocotyl elongation under high ambient temperature. These TCPs influence the levels of the DELLA protein RGA and the expression of growth-related genes, which are induced in response to an increase in temperature. However, the class I TCPs are not required for the induction of the auxin biosynthesis gene YUCCA8 or for auxin-dependent gene expression responses. TCP15 directly targets the gibberellin biosynthesis gene GA20ox1 and the growth regulatory genes HBI1 and PRE6. Several of the genes regulated by TCP15 are also targets of the growth regulator PIF4 and show an enrichment of PIF4- and TCP-binding motifs in their promoters. PIF4 binding to GA20ox1 and HBI1 is enhanced in the presence of the TCPs, indicating that TCP14 and TCP15 directly participate in the induction of genes involved in gibberellin biosynthesis and cell expansion by high temperature functionally interacting with PIF4. In addition, overexpression of HBI1 rescues the growth defects of tcp14 tcp15 double mutants, suggesting that this gene is a major outcome of regulation by both class I TCPs during thermomorphogenesis.
PMID: 31292642
Sci Rep , IF:3.998 , 2019 Aug , V9 (1) : P12109 doi: 10.1038/s41598-019-48601-7
Genome-wide analysis of the Dof gene family in durian reveals fruit ripening-associated and cultivar-dependent Dof transcription factors.
Molecular Crop Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand.; Molecular Crop Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand. supaart.s@chula.ac.th.; Omics Sciences and Bioinformatics Center, Chulalongkorn University, 254 Phayathai Road, Bangkok, 10330, Thailand. supaart.s@chula.ac.th.
DNA binding with one finger (Dof) proteins constitute a ubiquitous plant-specific transcription factor (TF) family associated with diverse biological processes, including ripening. We conducted a genome-wide analysis of durian (Durio zibethinus Murr.) and identified 24 durian Dofs (DzDofs), 15 of which were expressed in fruit pulp. Gene expression analysis revealed differential expression of DzDofs during ripening in two commercial durian cultivars from Thailand, Monthong and Chanee. Comparing the expression levels of fruit pulp-expressed DzDofs between cultivars revealed ten potential cultivar-dependent Dofs, among which DzDof2.2 showed a significantly greater fold increase at every ripening stage in Chanee than in Monthong. The prediction of DzDof2.2's function based on its orthologue in Arabidopsis revealed its possible role in regulating auxin biosynthesis. We observed significantly higher auxin levels during ripening of Chanee than Monthong which concurred with the greater expression of auxin biosynthetic genes. Transient expression of DzDof2.2 in Nicotiana benthamiana significantly upregulated the expression levels of auxin biosynthetic genes. Higher expression levels of DzDof2.2 in Chanee would enhance auxin levels through transcriptional regulation of auxin biosynthetic genes. Higher auxin levels in Chanee could activate auxin-mediated transcription, contributing to its faster ripening compared to Monthong through earlier initiation of the ethylene response (auxin-ethylene crosstalk).
PMID: 31431665
Plant Cell Rep , IF:3.825 , 2019 Aug , V38 (8) : P1013-1016 doi: 10.1007/s00299-019-02430-0
Crosstalk among hormones in barley spike contributes to the yield.
Faculty of Agriculture, Cairo University, Giza, 12613, Egypt. helmy.youssef@biol.lu.se.; Department of Biology, Lund University, Solvegatan 35B, 22362, Lund, Sweden. helmy.youssef@biol.lu.se.; Department of Biology, Lund University, Solvegatan 35B, 22362, Lund, Sweden.
KEY MESSAGE: The hormonal ratios along the barley spike regulate the development, atrophy and abortion of the spikelets and could be the mechanism by which the barley spike adapts its yield potential. Barley (Hordeum vulgare L.) is one of the oldest cereal crops known to be cultivated since about 10,000 years. The inflorescence of cultivated barley is an indeterminate spike that produces three single-flowered spikelets at each rachis node which make it unique among the grasses. The yield production in barley is predominantly controlled by very important parameters such as number of tillers and number of spikelets per spike. These two parameters are negatively correlated. Therefore, studying the biological and genetics of the spikelet development during the spike developmental stages is essential for breeding programs. Here we summarize our current understanding of the crosstalk between hormones such as auxin, cytokinin, gibberellin and abscisic acid along the spike and what is their role in regulating spike and spikelet development in barley. We conclude that the hormonal ratios at the apical, central, and basal sections of the spike not only regulate the spike developmental stages, but also the development, atrophy, and abortion of the spikelets. This hormonal dependent modification of the grain number along the spike could be the mechanism by which the barley spike adapts its yield potential.
PMID: 31139893
Plant Cell Rep , IF:3.825 , 2019 Aug , V38 (8) : P951-963 doi: 10.1007/s00299-019-02417-x
The tomato MADS-box gene SlMBP9 negatively regulates lateral root formation and apical dominance by reducing auxin biosynthesis and transport.
Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Room 523-1, Campus B, 174 Shapingba Main Street, Chongqing, 400044, People's Republic of China.; Laboratory of Molecular Biology of Tomato, Bioengineering College, Chongqing University, Room 523-1, Campus B, 174 Shapingba Main Street, Chongqing, 400044, People's Republic of China. huzongli71@163.com.
KEY MESSAGE: Overexpression of SlMBP9 reduced auxin biosynthesis and transport, and negatively regulated lateral root formation and apical dominance. MADS-box transcription factors play a critical role in plant development. In this study, we describe SlMBP9, a novel MADS-box gene that is expressed in the roots of tomato plants. Tomato lines that over- or under-expressed SlMBP9 were generated using a transgenic approach. The number of lateral roots (LRs) were reduced in SlMBP9-overexpressing lines but slightly increased in SlMBP9-silenced lines. A physiological index revealed that the auxin content significantly decreased in the root maturation zone of the overexpression lines. In addition, gene expression analysis revealed that the expression of the polar auxin transporter genes PIN1 and ABCB19/MDR1 and genes involved in auxin biosynthesis was downregulated in the stems of overexpression lines, which is consistent with the reduced accumulation of auxin in the root maturation zone. Exogenous indole-3-acetic acid (auximone) rescued the lateral root phenotypes of the SlMBP9-overexpressing lines. Overexpression of SlMBP9 resulted in dwarf plants, enhanced lateral buds and reduced the gibberellin content in the stems. Together, these results suggest that SlMBP9 plays a negative role in the process of auxin biosynthesis and transport.
PMID: 31062133
Plant Cell Rep , IF:3.825 , 2019 Aug , V38 (8) : P883-897 doi: 10.1007/s00299-019-02410-4
Three BnaIAA7 homologs are involved in auxin/brassinosteroid-mediated plant morphogenesis in rapeseed (Brassica napus L.).
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China.; Key Laboratory of Cotton and Rapeseed, Ministry of Agriculture, Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.; Department of Biology, Wilkes University, Wilkes-Barre, PA, 18766, USA.; Key Laboratory of Cotton and Rapeseed, Ministry of Agriculture, Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China. puhuiming@126.com.; Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China. huawei@oilcrops.cn.
KEY MESSAGE: BnaIAA7 crosstalk with BR signaling is mediated by the interaction between BnaARF8 and BnaBZR1 to regulate rapeseed plant morphogenesis. Auxin (indole-3-acetic acid, IAA) and brassinosteroids (BRs) are essential regulators of plant morphogenesis. However, their roles in rapeseed have not been reported. Here, we identified an extremely dwarf1 (ed1) mutant of rapeseed that displays reduced stature, short hypocotyls, as well as wavy and curled leaves. We isolated ED1 by map-based cloning, and found that it encodes a protein homologous to AtIAA7. ED1 acts as a repressor of IAA signaling, and IAA induces its degradation through its degron motif. A genomic-synteny analysis revealed that ED1 has four homologs in rapeseed, but two were not expressed. Analyses of transcriptomes and of various mutant BnaIAA7s in transgenic plants revealed that the three expressed BnaIAA7 homologs had diverse expression patterns. ED1/BnaC05.IAA7 predominantly functioned in stem elongation, BnaA05.IAA7 was essential for reproduction, while BnaA03.IAA7 had the potential to reduce plant height. Physical interaction assays revealed that the three BnaIAA7 homologs interacted in different ways with BnaTIRs/AFBs and BnaARFs, which may regulate the development of specific organs. Furthermore, BnaARF8 could directly interact with the BnaIAA7s and BnaBZR1. We propose that BnaIAA7s interact with BR signaling via BnaARF8 and BnaBZR1 to regulate stem elongation in rapeseed.
PMID: 31011789
Genes (Basel) , IF:3.759 , 2019 Aug , V10 (9) doi: 10.3390/genes10090664
Natural Variation and Domestication Selection of ZmPGP1 Affects Plant Architecture and Yield-Related Traits in Maize.
Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou 225009, China.; Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou 225009, China. qtls@yzu.edu.cn.
ZmPGP1, involved in the polar auxin transport, has been shown to be associated with plant height, leaf angle, yield traits, and root development in maize. To explore natural variation and domestication selection of ZmPGP1, we re-sequenced the ZmPGP1 gene in 349 inbred lines, 68 landraces, and 32 teosintes. Sequence polymorphisms, nucleotide diversity, and neutral tests revealed that ZmPGP1 might be selected during domestication and improvement processes. Marker-trait association analysis in inbred lines identified 11 variants significantly associated with 4 plant architecture and 5 ear traits. SNP1473 was the most significant variant for kernel length and ear grain weight. The frequency of an increased allele T was 40.6% in teosintes, and it was enriched to 60.3% and 89.1% during maize domestication and improvement. This result revealed that ZmPGP1 may be selected in the domestication and improvement process, and significant variants could be used to develop functional markers to improve plant architecture and ear traits in maize.
PMID: 31480272
Pest Manag Sci , IF:3.75 , 2019 Aug , V75 (8) : P2086-2094 doi: 10.1002/ps.5393
Development of enzymes for robust aryloxyphenoxypropionate and synthetic auxin herbicide tolerance traits in maize and soybean crops.
Bayer Crop Science, Plant Biotechnology, Chesterfield, MO, USA.; Bayer Crop Science, Plant Biotechnology, Cambridge, MA, USA.
BACKGROUND: Effective management of weedy species in agricultural fields is essential for maintaining favorable growing conditions and crop yields. The introduction of genetically modified crops containing herbicide tolerance traits has been a successful additional tool available to farmers to better control weeds. However, weed resistance challenges present a need for additional herbicide tolerance trait options. RESULTS: To help meet this challenge, a new trait that provides tolerance to an aryloxyphenoxypropionate (FOP) herbicide and members of the synthetic auxin herbicide family, such as 2,4-dichlorophenoxyacetic acid (2,4-D), was developed. Development of this herbicide tolerance trait employed an enzyme engineered with robust and specific enzymatic activity for these two herbicide families. This engineering effort utilized a microbial-sourced dioxygenase scaffold to generate variants with improved enzymatic parameters. Additional optimization to enhance in-plant stability of the enzyme enabled an efficacious trait that can withstand the higher temperature conditions often found in field environments. CONCLUSION: Optimized herbicide tolerance enzyme variants with enhanced enzymatic and temperature stability parameters enabled robust herbicide tolerance for two herbicide families in transgenic maize and soybeans. This herbicide tolerance trait for FOP and synthetic auxin herbicides such as 2,4-D could be useful in weed management systems, providing additional tools for farmers to control weeds. (c) 2019 Society of Chemical Industry.
PMID: 30828945
Plant Physiol Biochem , IF:3.72 , 2019 Aug , V141 : P122-132 doi: 10.1016/j.plaphy.2019.05.018
The interaction of genes controlling root traits is required for the developmental acquisition of deep and thick root traits and improving root architecture in response to low water or nitrogen content in rice (Oryza sativa L.) cultivars.
Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517, Egypt. Electronic address: rnada@du.edu.eg.; Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517, Egypt.
Most of the hot spots about rice research are related to roots; increasing rice yield is mainly associated with improving root traits. Understanding phenotype-gene regulation relationship in different rice cultivars can contribute to the genetic improvement of root system. The expression pattern of root genes in moroberekan (deep and thick roots and high root/shoot ratio "R/S") was compared to that in Giza178 and PM12 (numerous but shallow roots) and IR64 (fewer but deeper roots than the latter ones). In contrast to the other genotypes, moroberekan did not cease developing deep and thick roots even after 60 days from sowing, perhaps because of not only the consistent upregulation but also the interaction of root genes. Xylem sap flow was significantly higher even under drought (low water content) in moroberekan. Auxin signaling-related ARF12 and PIN1 genes could play key roles in improving root traits in response to low water or nitrogen content. Their concurrent upregulation was coincided with developing 1) deeper roots in moroberekan under drought, 2) thicker and deeper roots in PM12 under low nitrogen content (LN) and 3) new roots with thicker and deeper characteristics in the four genotypes after root trimming. The upregulation of PIN1 or ARF12 in Giza178 at LN, PM12 at drought or in IR64 under drought or LN did not greatly change the root traits. Hierarchical analysis showed that ARF12 and PIN1 were distantly related, but overlapped with other genes controlling root traits. Overexpression of ARF12 and PIN1 could improve root traits in rice cultivars.
PMID: 31151078
BMC Genomics , IF:3.594 , 2019 Aug , V20 (1) : P644 doi: 10.1186/s12864-019-6008-3
Transcriptomic analysis reveals the mechanism of thermosensitive genic male sterility (TGMS) of Brassica napus under the high temperature inducement.
College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.; College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China. zht2188@126.com.
BACKGROUND: The thermo-sensitive genic male sterility (TGMS) of Brassica napus facilitates reproductive researches and hybrid seed production. Considering the complexity and little information about the molecular mechanism involved in B. napus TGMS, comparative transcriptomic analyses were peroformed for the sterile (160S-MS) and fertile (160S-MF) flowers to identify potential crucial genes and pathways associated with TGMS. RESULTS: In total, RNA-seq analysis showed that 2202 genes (561 up-regulated and 1641 down-regulated) were significantly differentially expressed in the fertile flowers of 160S-MF at 25 degrees C when compared the sterile flower of 160S-MS at 15 degrees C. Detailed analysis revealed that expression changes in genes encoding heat shock proteins, antioxidant, skeleton protein, GTPase and calmodulin might be involved in TGMS of B. napus. Moreover, gene expression of some key members in plant hormone signaling pathways, such as auxin, gibberellins, jasmonic acid, abscisic acid, brassinosteroid signalings, were significantly surppressed in the flowers of 160S, suggesting that these genes might be involved in the regulation in B. napus TGMS. Here, we also found that transcription factor MADS, NFY, HSF, MYB/C and WRKY might play a crucial role in male fertility under the high temperature condition. CONCLUSION: High temperature can significant affect gene expression in the flowers. The findings in the current study improve our understanding of B. napus TGMS at the molecular level and also provide an effective foundation for male fertility researches in other important economic crops.
PMID: 31409283
Plant Sci , IF:3.591 , 2019 Aug , V285 : P99-109 doi: 10.1016/j.plantsci.2019.04.007
Arabidopsis EMSY-like (EML) histone readers are necessary for post-fertilization seed development, but prevent fertilization-independent seed formation.
Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA.; Department of Molecular Genetics, Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA.; Department of Molecular Genetics, Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA. Electronic address: grotewol@msu.edu.; Arabidopsis Biological Resource Center, The Ohio State University, Columbus, OH, 43210, USA. Electronic address: brkljacic.1@osu.edu.
Seed development is a complex regulatory process that includes a transition from gametophytic to sporophytic program. The synchronized development of different seed compartments (seed coat, endosperm and embryo) depends on a balance in parental genome contributions. In the most severe cases, the disruption of the balance leads to seed abortion. This represents one of the main obstacles for the engineering of asexual reproduction through seeds (apomixis), and for generating new interspecies hybrids. The repression of auxin synthesis by the Polycomb Repressive Complex 2 (PRC2) is a major mechanism contributing to sensing genome balance. However, current efforts focusing on decreasing PRC2 or elevating auxin levels have not yet resulted in the production of apomictic seed. Here, we show that EMSY-Like Tudor/Agenet H3K36me3 histone readers EML1 and EML3 are necessary for early stages of seed development to proceed at a normal rate in Arabidopsis. We further demonstrate that both EML1 and EML3 are required to prevent the initiation of seed development in the absence of fertilization. Based on the whole genome expression analysis, we identify auxin transport and signaling genes as the most enriched downstream targets of EML1 and EML3. We hypothesize that EML1 and EML3 function to repress and soften paternal gene expression by fine-tuning auxin responses. Discovery of this pathway may contribute to the engineering of apomixis and interspecies hybrids.
PMID: 31203898
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P377 doi: 10.1186/s12870-019-1982-9
Physiological analysis and transcriptome sequencing reveal the effects of combined cold and drought on tomato leaf.
Department of Food Science, Aarhus University, Arslev, Denmark. rong.zhou@food.au.dk.; Laboratory for Genetic Improvement of High Efficiency Horticultural Crops in Jiangsu Province, Institute of Vegetable Crop, Jiangsu Province Academy of Agricultural Sciences, Nanjing, Jiangsu, China. rong.zhou@food.au.dk.; National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, China.; Laboratory for Genetic Improvement of High Efficiency Horticultural Crops in Jiangsu Province, Institute of Vegetable Crop, Jiangsu Province Academy of Agricultural Sciences, Nanjing, Jiangsu, China.; Department of Food Science, Aarhus University, Arslev, Denmark. coo@food.au.dk.; Department of Plant and Environmental Sciences, University of Copenhagen, Taastrup, Denmark.
BACKGROUND: Co-occurrence of cold and drought stress can alter the response of plants at morphological, physiological and molecular levels, which finally affect crop production, more than individual stress. Understanding the responses of crop to combined stress is necessary to improve tolerance and maintain crop production especially in the field where combined stress frequently occurs. We aimed to clarify the underlying leaf physiological and molecular mechanisms of tomato by imposing combining cold and drought on one popular tomato cultivar 'Jinlingmeiyu' as an example. RESULTS: The physiological and genetic responses were identified in tomatoes after 42 h exposure to control, cold, drought and combined treatments. As compared with control, water loss rate at the three stresses including cold, drought and combined stress significantly decreased until 40 min after taking samples from the plants. The content of H2O2, zeatin riboside (ZR) and melatonin in all stress treatments were significantly higher than the control. Drought stress alone and combined stress induced the accumulation of abscisic acid (ABA) and auxin (IAA) as compared with control. The individual cold and combined stress significantly decreased the maximum quantum efficiency of PSII (Fv/Fm), quantum yield of PSII (Fq(')/Fm(')) and electron transport rate (ETR). In total, 7141, 1850 and 7841 genes were involved in the stress response to cold, drought and their combination. Functional analysis of the stress-inducible genes provided more insights concerning the complex regulatory mechanisms that were involved in combined stress. The expression level of 12 genes were validated by quantitative real-time PCR (qRT-PCR). CONCLUSIONS: We found that the expression of stress-specific genes changed with physiological variation, indicating the close crosstalk between physiological and genetic response especially under combined stress. This study provides new knowledge on the complex regulatory mechanism genes in tomato ('Jinlingmeiyu') leaf to abiotic stresses.
PMID: 31455231
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P373 doi: 10.1186/s12870-019-1976-7
Gene co-expression network analysis reveals pathways associated with graft healing by asymmetric profiling in tomato.
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. shanglab211@126.com.
BACKGROUND: The ability of severed rootstocks and shoots to re-establish vascular connections is used to generate grafted plants that combine desirable traits from both scions and rootstocks. Clarifying the mechanisms of graft healing is essential for its further application. We performed RNA sequencing of internodes near the cut position, making a distinction between separated or grafted tissues above and below the cut, in order to obtain a genetic description of graft union formation. RESULTS: Using weighted gene co-expression analysis, variable transcripts were clustered into 10 distinct co-expression networks (modules) based on expression profiles, and genes with the most "hubness" ("hub" genes show the most connections in a network) within each module were predicted. A large proportion of modules were related to Position, and represent asymmetric expression networks from different pathways. Expression of genes involved in auxin and sugar transport and signaling, and brassinosteroid biosynthesis was increased above the cut, while stress response genes were up-regulated below the cut. Some modules were related to graft union formation, among which oxidative detoxification genes were co-expressed along with both wounding response and cell wall organization genes. CONCLUSIONS: The present work provides a comprehensive understanding of graft healing-related gene networks in tomato. Also, the candidate pathways and hub genes identified here will be valuable for future studies of grafting in tomato.
PMID: 31445524
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P369 doi: 10.1186/s12870-019-1942-4
Genome-wide identification and characterization of long non-coding RNAs involved in fruit ripening and the climacteric in Cucumis melo.
Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, Inner Mongolia, People's Republic of China.; Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau & Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, People's Republic of China.; Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, Inner Mongolia, People's Republic of China. zhangjin593@163.com.; Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, Inner Mongolia, People's Republic of China. lshasi@imu.edu.cn.
BACKGROUND: Cucumis melo is a suitable study material for investigation of fruit ripening owing to its climacteric nature. Long non-coding RNAs have been linked to many important biological processes, such as fruit ripening, flowering time regulation, and abiotic stress responses in plants. However, knowledge of the regulatory roles of lncRNAs underlying the ripening process in C. melo are largely unknown. In this study the complete transcriptome of Cucumis melo L. cv. Hetao fruit at four developmental stages was sequenced and analyzed. The potential role of lncRNAs was predicted based on the function of differentially expressed target genes and correlated genes. RESULTS: In total, 3857 lncRNAs were assembled and annotated, of which 1601 were differentially expressed between developmental stages. The target genes of these lncRNAs and the regulatory relationship (cis- or trans-acting) were predicted. The target genes were enriched with GO terms for biological process, such as response to auxin stimulus and hormone biosynthetic process. Enriched KEGG pathways included plant hormone signal transduction and carotenoid biosynthesis. Co-expression network construction showed that LNC_002345 and LNC_000154, which were highly expressed, might co-regulate with mutiple genes associated with auxin signal transduction and acted in the same pathways. We identified lncRNAs (LNC_000987, LNC_000693, LNC_001323, LNC_003610, LNC_001263 and LNC_003380) that were correlated with fruit ripening and the climacteric, and may participate in the regulation of ethylene biosynthesis and metabolism and the ABA signaling pathway. A number of crucial transcription factors, such as ERFs, WRKY70, NAC56, and NAC72, may also play important roles in the regulation of fruit ripening in C. melo. CONCLUSIONS: Our results predict the regulatory functions of the lncRNAs during melon fruit development and ripening, and 142 highly expressed lncRNAs (average FPKM > 100) were identified. These lncRNAs participate in the regulation of auxin signal transduction, ethylene, sucrose biosynthesis and metabolism, the ABA signaling pathway, and transcription factors, thus regulating fruit development and ripening.
PMID: 31438855
BMC Plant Biol , IF:3.497 , 2019 Aug , V19 (1) : P335 doi: 10.1186/s12870-019-1941-5
Effects of maize organ-specific drought stress response on yields from transcriptome analysis.
Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Qingdao, 266237, Shandong, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, 250100, Shandong, China.; Key Laboratory of Plant Cell Engineering and Germplasm Innovation, School of Life Sciences, Shandong University, Qingdao, 266237, Shandong, China. zhaoxia_1019@126.com.
BACKGROUND: Drought is a serious causal factor of reduced crop yields than any other abiotic stresses. As one of the most widely distributed crops, maize plants frequently suffer from drought stress, which causes great losses in the final kernel yield. Drought stress response in plants showed tissue- and developmental stage-specific characteristics. RESULTS: In this study, the ears at the V9 stage, kernels and ear leaf at the 5DAP (days after pollination) stage of maize were used for morphological, physiological and comparative transcriptomics analysis to understand the different features of "sink" or "source" organs and the effects on kernel yield under drought stress conditions. The ABA-, NAC-mediate signaling pathway, osmotic protective substance synthesis and protein folding response were identified as common drought stress response in the three organs. Tissue-specific drought stress responses and the regulators were identified, they were highly correlated with growth, physiological adaptation and yield loss under drought stress. For ears, drought stress inhibited ear elongation, led to the abnormal differentiation of the paired spikelet, and auxin signaling involved in the regulation of cell division and growth and primordium development changes. In the kernels, reduced kernel size caused by drought stress was observed, and the obvious differences of auxin, BR and cytokine signaling transduction appeared, which indicated the modification in carbohydrate metabolism, cell differentiation and growth retardation. For the ear leaf, dramatically and synergistically reduced the expression of photosynthesis genes were observed when suffered from drought stress, the ABA- and NAC- mediate signaling pathway played important roles in the regulation of photosynthesis. CONCLUSIONS: Transcriptomic changes caused by drought were highly correlated with developmental and physiological adaptation, which was closely related to the final yield of maize, and a sketch of tissue- and developmental stage-specific responses to drought stress in maize was drafted.
PMID: 31370805
Molecules , IF:3.267 , 2019 Aug , V24 (17) doi: 10.3390/molecules24173146
Identification of Potential Auxin-Responsive Small Signaling Peptides through a Peptidomics Approach in Arabidopsis thaliana.
Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China.; School of Life Sciences, Tsinghua University, Beijing 100084, China.; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China. yisu@hunau.edu.cn.; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, China. ltxiao@hunau.edu.cn.
Small signaling peptides (SSPs) are a class of short peptides playing critical roles in plant growth and development. SSPs are also involved in the phytohormone signaling pathway. However, identification of mature SSPs is still a technical challenge because of their extremely low concentrations in plant tissue and complicated interference by many other metabolites. Here, we report an optimized protocol to extract SSPs based on protoplast extraction and to analyze SSPs based on tandem mass spectrometry peptidomics. Using plant protoplasts as the material, soluble peptides were directly extracted into phosphate buffer. The interference of non-signaling peptides was significantly decreased. Moreover, we applied the protocol to identify potential SSPs in auxin treated wild type and auxin biosynthesis defective mutant yuc2yuc6. Over 100 potential SSPs showed a response to auxin in Arabidopsis thaliana.
PMID: 31470600
Environ Sci Pollut Res Int , IF:3.056 , 2019 Aug , V26 (23) : P23571-23582 doi: 10.1007/s11356-019-05629-6
The impact of humic acid on toxicity of individual herbicides and their mixtures to aquatic macrophytes.
Faculty of Sciences, Department of Biology and Ecology, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21 000, Serbia. varja.knezevic@dbe.uns.ac.rs.; Faculty of Sciences, Department of Biology and Ecology, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21 000, Serbia.; Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21 000, Serbia.; Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovica 8, Novi Sad, 21 000, Serbia.
This study investigates the impact of humic acid (HA) on the toxicity of selected herbicides and their binary mixtures to aquatic plants. The focus was on two auxin simulators (2,4-D and dicamba) and two photosynthetic inhibitors (atrazine and isoproturon). The results suggested that the addition of HA to the standard synthetic medium does not affect Lemna minor growth nor the toxicity of atrazine, but increases the toxicity of 2,4-D and the binary mixture of atrazine and 2,4-D. The addition of HA to the standard synthetic medium reversibly decreased the growth (biomass) of Myriophyllum aquaticum and enhanced the toxicity of individually tested herbicides (isoproturon and dicamba) as well as their binary mixture. The results showed delayed toxic effects of auxin simulators, especially 2,4-D in the Lemna test. The recovery after the exposure to individual photosystem II inhibitors (atrazine and isoproturon) is fast in both plant species, regardless of the presence of HA. In the case of selected mixtures (atrazine + 2,4-D and isoproturon + dicamba), recovery of both plant species was noted, while the efficiency depended on the herbicide concentration in the mixture rather than the presence or absence of HA.
PMID: 31203541
J Plant Physiol , IF:3.013 , 2019 Aug , V239 : P10-17 doi: 10.1016/j.jplph.2019.04.004
The effects of IBA on the composition of maize root cell walls.
Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, 845 23 Bratislava, Slovakia.; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 38 Bratislava, Slovakia.; Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 38 Bratislava, Slovakia. Electronic address: Zuzana.Vivodova@savba.sk.
Auxin is one of the crucial plant hormones which stimulates and controls cell and plant growth. The effects of auxin IBA (indole-3-butyric acid) during 10-days on maize plants growth in controlled conditions (hydroponic, 16-h photoperiod, 70% humidity, 25/20 degrees C temperature), depended on its concentration in the substrate. A high concentration (10(-7) M) of IBA inhibited root growth, evoked the development of apoplasmic barriers (Casparian bands and suberin lamellae) closer to the root apex, and elevated the amount of lignin in roots. A low concentration (10(-11) M) of IBA stimulated root growth but affected neither the development of apoplasmic barriers, nor the amount of lignin. Auxin in a 10(-8) M concentration influenced the root growth to a minimal extent compare to the control, and it was the non-effective concentration. Plant cell walls as cell structures ensure cell enlargement and plant growth, and have to react to auxin stimulus by modification of their components. We found the most significant changes in the composition of the PF III fraction (lignocellulosic complex) of the cell wall. The presence of auxin in the substrate affected all three components of this fraction - Klason lignin and both the by acid (2M TFA) non-hydrolysable and the hydrolysable parts of this complex. The ratio of the non-hydrolysable part to the Klason lignin increased from 1.3 to 3.3 with increasing auxin concentrations in the substrate. This may be related to the deposition of polysaccharides and lignin in the cell wall, which help maintain the specific tensile stress of, and turgor pressure on, the cell walls.
PMID: 31177026
Biochem Biophys Res Commun , IF:2.985 , 2019 Aug , V516 (3) : P957-962 doi: 10.1016/j.bbrc.2019.06.142
Narrow leaf 1 (NAL1) regulates leaf shape by affecting cell expansion in rice (Oryza sativa L.).
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi, Xinjiang, 832003, China.; State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong, 271018, China.; State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong, 271018, China. Electronic address: chenqiangenetics@163.com.; The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi, Xinjiang, 832003, China. Electronic address: qjc_agr@shzu.edu.cn.
The narrow leaf1 (nal1) mutant of rice (Oryza sativa L.) exhibits a narrow leaf phenotype. Previous studies have shown that NAL1 modulates leaf size by affecting vein patterning and cell division; however, the underlying mechanism remains unclear. Here, we report that the nal1 mutant shows reduced size of the leaf abaxial epidermal cells and culm parenchyma cells compared with the wild type (WT), indicating that NAL1 also regulates cell expansion. To understand the molecular mechanism of the reduced cell size phenotype, leaves of 40-day-old nal1 mutant and WT seedlings were subjected to RNA-Seq analysis, which has identified 4277 differentially expressed genes (DEGs) between WT and the nal1 mutant. Gene ontology (GO) enrichment analysis revealed a large number of genes down-regulated in the nal1 mutant were involved in cell wall formation. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that NAL1-regulated DEGs, such as ARFs and SAURs, were mapped in auxin signal transduction and auxin-regulated cell expansion pathways. A combination of RNA-Seq analysis and gene expression validation using RT-qPCR suggested that NAL1 is involved in the regulation of auxin-mediated acid growth in rice. These results indicate that, in addition to controlling cell division, NAL1 controls leaf width, at least partially, through its effect on cell expansion, probably via the acid growth mechanism.
PMID: 31272720
Biochem Biophys Res Commun , IF:2.985 , 2019 Aug , V516 (1) : P112-119 doi: 10.1016/j.bbrc.2019.05.142
Molecular mechanisms governing shade responses in maize.
College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, 271018, China.; College of Life Science, Qilu Normal University, Jinan, 250013, China.; College of Agronomy, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, 271018, China.; College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong, 271018, China. Electronic address: gangli@sdau.edu.cn.
Light is one of the most important environmental factors affecting plant growth and development. Plants use shade avoidance or tolerance strategies to adjust their growth and development thus increase their success in the competition for incoming light. To investigate the mechanism of shade responses in maize (Zea mays), we examined the anatomical and transcriptional dynamics of the early shade response in seedlings of the B73 inbred line. Transcriptome analysis identified 912 differentially expressed genes, including genes involved in light signaling, auxin responses, and cell elongation pathways. Grouping transcription factor family genes and performing enrichment analysis identified multiple types of transcription factors that are differentially regulated by shade and predicted putative core genes responsible for regulating shade avoidance syndrome. For functional analyses, we ectopically over-expressed ZmHB53, a type II HD-ZIP transcription factor gene significantly induced by shade, in Arabidopsis thaliana. Transgenic Arabidopsis plants overexpressing ZmHB53 exhibited narrower leaves, earlier flowering, and enhanced expression of shade-responsive genes, suggesting that ZmHB53 might participates in the regulation of shade responses in maize. This study increases our understanding of the regulatory network of the shade response in maize and provides a useful resource for maize genetics and breeding.
PMID: 31200955
J Sep Sci , IF:2.878 , 2019 Aug , V42 (16) : P2687-2695 doi: 10.1002/jssc.201900265
Preparation and application of molecularly imprinted polymer solid-phase microextraction fiber for the selective analysis of auxins in tobacco.
The Guangxi Key Laboratory of Theory & Technology for Environmental Pollution Control, College of Environmental Science & Engineering, Guilin University of Technology, Guilin, P. R. China.; College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, P. R. China.; College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, P. R. China.
As signal molecules, auxins play an important role in mediating plant growth. Due to serious interfering substances in plants, it is difficult to accurately detect auxins with traditional solid-phase extraction methods. To improve the selectivity of sample pretreatment, a novel molecularly imprinted polymer -coated solid-phase microextraction fiber, which could be coupled directly to high-performance liquid chromatography, was prepared with indole acetic acid as template molecule for the selective extraction of auxins. The factors influencing the polymer formation, such as polymerization solvent, cross-linker, and polymerization time, were investigated in detail to enhance the performance of indole acetic acid-molecularly imprinted polymer coating. The morphological and chemical stability of this molecularly imprinted polymer-coated fiber was characterized by scanning electron microscopy, infrared spectrometry, and thermal analysis. The extraction capacity of the molecularly imprinted polymer-coated solid-phase microextraction fiber was evaluated for the selective extraction of indole acetic acid and indole-3-pyruvic acid followed by high-performance liquid chromatography analysis. The linear range for indole acetic acid and indole-3-pyruvic acid was 1-100 microg/L and their detection limit was 0.5 microg/L. The method was applied to the simultaneous determination of two auxins in two kinds of tobacco (Nicotiana tabacum L and Nicotiana rustica L) samples, with recoveries range from 82.1 to 120.6%.
PMID: 31161698
Plants (Basel) , IF:2.762 , 2019 Aug , V8 (8) doi: 10.3390/plants8080264
Comparative Transcriptome Analysis of Waterlogging-Sensitive and Tolerant Zombi Pea (Vigna Vexillata) Reveals Energy Conservation and Root Plasticity Controlling Waterlogging Tolerance.
Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.; Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand. fscipdj@ku.ac.th.; Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok 10900, Thailand. fscipdj@ku.ac.th.; Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand. fscipdj@ku.ac.th.; Department of Botany, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.; Department of Agronomy, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom 73140, Thailand.
Vigna vexillata (zombi pea) is an underutilized legume crop considered to be a potential gene source in breeding for abiotic stress tolerance. This study focuses on the molecular characterization of mechanisms controlling waterlogging tolerance using two zombi pea varieties with contrasting waterlogging tolerance. Morphological examination revealed that in contrast to the sensitive variety, the tolerant variety was able to grow, maintain chlorophyll, form lateral roots, and develop aerenchyma in hypocotyl and taproots under waterlogging. To find the mechanism controlling waterlogging tolerance in zombi pea, comparative transcriptome analysis was performed using roots subjected to short-term waterlogging. Functional analysis indicated that glycolysis and fermentative genes were strongly upregulated in the sensitive variety, but not in the tolerant one. In contrast, the genes involved in auxin-regulated lateral root initiation and formation were expressed only in the tolerant variety. In addition, cell wall modification, aquaporin, and peroxidase genes were highly induced in the tolerant variety under waterlogging. Our findings suggest that energy management and root plasticity play important roles in mitigating the impact of waterlogging in zombi pea. The basic knowledge obtained from this study can be used in the molecular breeding of waterlogging-tolerant legume crops in the future.
PMID: 31382508
Oecologia , IF:2.654 , 2019 Aug , V190 (4) : P847-856 doi: 10.1007/s00442-019-04458-1
Individual and interactive effects of herbivory on plant fitness: endopolyploidy as a driver of genetic variation in tolerance and resistance.
School of Integrative Biology, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL, 61801, USA.; Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1201 West Gregory Drive, Urbana, IL, 61801, USA.; School of Integrative Biology, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL, 61801, USA. k-paige@illinois.edu.
Previous studies have shown a causal link between mammalian herbivory, tolerance, and chemical defense in Arabidopsis thaliana, driven by the process of endoreduplication (replication of the genome without mitosis). Removal of the apical meristem by mammalian herbivores lowers auxin, which triggers entry into the endocycle. Increasing chromosome number through endoreduplication, and therefore gene copy number, provides a means of increasing gene expression promoting rapid regrowth rates, higher defensive chemistry and enhanced fitness. Here, we assess whether insect leaf-feeding elicits the same compensatory response as the removal of apical dominance. Insect feeding has been shown to downregulate auxin production, which should trigger endoreduplication. Results here support this contention; insect leaf-feeding by Trichoplusia ni elicited a compensatory response similar to that of mammalian herbivores-an ecotype-specific response consistent with the level of endoreduplication. The interactive effects of mammalian and insect herbivory were also assessed to determine whether interactions were additive (pairwise) or non-additive (diffuse) on tolerance (fitness). Specifically, results indicate that herbivory is either diffuse (a significant clipping x T. ni interaction) or pairwise (no significant interaction between clipping and T. ni herbivory), dependent upon plant genotype and compensatory ability. In general, herbivore-induced changes in plant quality appear to be responsible for the observed differences in herbivory and fitness compensation. We discuss the importance of evaluating endoreduplication among plants within a population to avoid masking the association between tolerance and resistance and the fitness consequences of multi-herbivore interactions.
PMID: 31273517
Life Sci Space Res (Amst) , IF:2.453 , 2019 Aug , V22 : P29-37 doi: 10.1016/j.lssr.2019.07.001
Gravity-regulated localization of PsPIN1 is important for polar auxin transport in etiolated pea seedlings: Relevance to the International Space Station experiment.
Future Development Division, Advanced Engineering Services Co., Ltd., 1-6-1 Takezono, Tsukuba, Ibaraki 305-0032, Japan. Electronic address: kamada.motoshi@jaxa.jp.; Faculty of Agriculture, Tottori University, 4-101 Koyamacho-minami, Tottori 680-8553, Japan.; Future Development Division, Advanced Engineering Services Co., Ltd., 1-6-1 Takezono, Tsukuba, Ibaraki 305-0032, Japan.; Faculty of Liberal Arts and Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.; Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.; Technology and Research Promotion Department, Japan Space Forum, Shin-Otemachi Bldg., 2-2-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.; Utilization Engineering Department, Japan Manned Space System Corporation, Space Station Test Building, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.; Kibo Utilization Center, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan.; Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. Electronic address: ueda@b.s.osakafu-u.ac.jp.
To clarify the mechanism of gravity-controlled polar auxin transport, we conducted the International Space Station (ISS) experiment "Auxin Transport" (identified by NASA's operation nomenclature) in 2016 and 2017, focusing on the expression of genes related to auxin efflux carrier protein PsPIN1 and its localization in the hook and epicotyl cells of etiolated Alaska pea seedlings grown for three days in the dark under microgravity (mug) and artificial 1g conditions on a centrifuge in the Cell Biology Experiment Facility (CBEF) in the ISS, and under 1g conditions on Earth. Regardless of gravity conditions, the accumulation of PsPIN1 mRNA in the proximal side of epicotyls of the seedlings was not different, but tended to be slightly higher as compared with that in the distal side. 2,3,5-Triiodobenzoic acid (TIBA) also did not affect the accumulation of PsPIN1 mRNA in the proximal and distal sides of epicotyls. However, in the apical hook region, TIBA increased the accumulation of PsPIN1 mRNA under mug conditions as compared with that under artificial 1g conditions in the ISS. The accumulation of PsPIN1 proteins in epicotyls determined by western blotting was almost parallel to that of mRNA of PsPIN1. Immunohistochemical analysis with a specific polyclonal antibody of PsPIN1 revealed that a majority of PsPIN1 in the apical hook and subapical regions of the seedlings grown under artificial 1g conditions in the ISS localized in the basal side (rootward) of the plasma membrane of the endodermal tissues. Conversely, in the seedlings grown under mug conditions, localization of PsPIN1 was greatly disarrayed. TIBA substantially altered the cellular localization pattern of PsPIN1, especially under mug conditions. These results strongly suggest that the mechanisms by which gravity controls polar auxin transport are more likely to be due to the membrane localization of PsPIN1. This physiologically valuable report describes a close relationship between gravity-controlled polar auxin transport and the localization of auxin efflux carrier PsPIN1 in etiolated pea seedlings based on the mug experiment conducted in space.
PMID: 31421846
Bull Math Biol , IF:1.812 , 2019 Aug , V81 (8) : P3342-3361 doi: 10.1007/s11538-019-00600-5
Strain- or Stress-Sensing in Mechanochemical Patterning by the Phytohormone Auxin.
Reproduction et Developpement des Plantes, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Universite de Lyon, Lyon Cedex 07, France.; Laboratoire de Physique, ENS de Lyon, UCB Lyon 1, CNRS, Universite de Lyon, Lyon Cedex 07, France.; Max-Planck Institute for Dynamics and Self-Organization, 37077, Gottingen, Germany.; Reproduction et Developpement des Plantes, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Universite de Lyon, Lyon Cedex 07, France. arezki.boudaoud@ens-lyon.fr.
Both chemical and mechanical fields are known to play a major role in morphogenesis. In plants, the phytohormone auxin and its directional transport are essential for the formation of robust patterns of organs, such as flowers or leaves, known as phyllotactic patterns. The transport of auxin was recently shown to be affected by mechanical signals, and conversely, auxin accumulation in incipient organs affects the mechanical properties of the cells. The precise interaction between mechanical fields and auxin transport, however, is poorly understood. In particular, it is unknown whether transport is sensitive to the strain or to the stress exerted on a given cell. Here, we investigate the nature of this coupling with the help of theoretical models. Namely, we introduce the effects of either mechanical stress or mechanical strain in a model of auxin transport and compare the patterns predicted with available experimental results, in which the tissue is perturbed by ablations, chemical treatments, or genetic manipulations. We also study the robustness of the patterning mechanism to noise and investigate the effect of a shock that changes abruptly its parameters. Although the model predictions with the two different feedbacks are often indistinguishable, the strain feedback seems to better agree with some of the experiments. The computational modeling approach used here, which enables us to distinguish between several possible mechanical feedbacks, offers promising perspectives to elucidate the role of mechanics in tissue development, and may help providing insight into the underlying molecular mechanisms.
PMID: 30903593
Plant Direct , IF:1.725 , 2019 Aug , V3 (8) : Pe00157 doi: 10.1002/pld3.157
A tetraspanin gene regulating auxin response and affecting orchid perianth size and various plant developmental processes.
Institute of Biotechnology National Chung Hsing University Taichung Taiwan, ROC.; Advanced Plant Biotechnology Center National Chung Hsing University Taichung Taiwan, ROC.
The competition between L (lip) and SP (sepal/petal) complexes in P-code model determines the identity of complex perianth patterns in orchids. Orchid tetraspanin gene Auxin Activation Factor (AAF) orthologs, whose expression strongly correlated with the expansion and size of the perianth after P code established, were identified. Virus-induced gene silencing (VIGS) of OAGL6-2 in L complex resulted in smaller lips and the down-regulation of Oncidium OnAAF. VIGS of PeMADS9 in L complex resulted in the enlarged lips and up-regulation of Phalaenopsis PaAAF. Furthermore, the larger size of Phalaenopsis variety flowers was associated with higher PaAAF expression, larger and more cells in the perianth. Thus, a rule is established that whenever bigger perianth organs are made in orchids, higher OnAAF/PaAAF expression is observed after their identities are determined by P-code complexes. Ectopic expression Arabidopsis AtAAF significantly increased the size of flower organs by promoting cell expansion in transgenic Arabidopsis due to the enhancement of the efficiency of the auxin response and the subsequent suppression of the jasmonic acid (JA) biosynthesis genes (DAD1/OPR3) and BIGPETAL gene during late flower development. In addition, auxin-controlled phenotypes, such as indehiscent anthers, enhanced drought tolerance, and increased lateral root formation, were also observed in 35S::AtAAF plants. Furthermore, 35S::AtAAF root tips maintained gravitropism during auxin treatment. In contrast, the opposite phenotype was observed in palmitoylation-deficient AtAAF mutants. Our data demonstrate an interaction between the tetraspanin AAF and auxin/JA that regulates the size of flower organs and impacts various developmental processes.
PMID: 31406958
Mol Biol Rep , IF:1.402 , 2019 Aug , V46 (4) : P4409-4421 doi: 10.1007/s11033-019-04896-3
Maize transcriptomic repertoires respond to gibberellin stimulation.
Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou, 225009, China.; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China.; College of Agriculture, Anhui Science and Technology University, Fengyang, 233100, China.; Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou, 225009, China. wyj@yzu.edu.cn.; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China. wyj@yzu.edu.cn.
Phytohormone gibberellin (GA) serves as hub modulator of diverse biological events. Understanding the transcriptomic features of GA-mediated processes has scientific significance. The transcriptomic landscapes of cereal crops upon GA stimulation remains largely unknown. Herein, to reveal the transcriptomic changes in cereal crop maize under GA treatment, we first selected normal height and GA-sensitive maize dwarf plants from advanced backcross population for GA treatment. RNA-seq analysis discovered multiple protein-coding transcripts that were differentially expressed in GA-treated samples compared to distilled water-treated ones. Some differentially expressed transcripts, namely GA-responsive transcripts in this study, encoded the components of GA pathway, including CPS, KS, and KO enzymes for GA biosynthesis, GA2ox enzymes for GA degradation, DELLA repressors and GID1 receptor for GA signaling. A total of 214 shared GA-responsive transcripts were identified both in GA3-treated normal height and GA-sensitive dwarf samples. Shared GA-responsive transcripts were involved in GA signaling, auxin biosynthesis, ethylene response, the composition and structure of cell wall, chlorophyll biogenesis, and sugar homeostasis. In addition, the convergence and divergence in expression of shared GA-responsive transcripts were observed in GA3-treated normal height and GA-sensitive dwarf plants. Interaction network modeling indicated that some shared GA-responsive transcripts tended to be co-regulated, which increases the complexity of GA-triggered regulation at transcriptomic layer. Results presented here will extend our knowledge of GA-mediated regulatory cascade, and enhance our ability to apply hormone GA knowledge in agricultural practice.
PMID: 31144186
Mol Biol Rep , IF:1.402 , 2019 Aug , V46 (4) : P4235-4244 doi: 10.1007/s11033-019-04878-5
Genetic analyses of nitrogen assimilation enzymes in Brassica juncea (L.) Czern & Coss.
Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141001, India.; Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141001, India. nppbg@pau.edu.
Nitrogen (N) is a critical input for plant growth and development. A better understanding of N uptake and utilization is important to develop plant breeding strategies for improving nitrogen use efficiency (NUE). With that objective in mind, we assayed a SNP-genotyped association panel comprising 92 inbred lines for the activities of nitrate reductase (NR), nitrite reductase (NIR), glutamine synthetase (GS) and glutamate synthase (GOGAT). All these enzymes are associated with N assimilation. The experiments were carried out at two levels of N application: no added N (N0) and agrnomically recommened dose (100 kg/ha) of N application (N100). Genome wide association studies (GWAS) helped to identify several marker-trait associations (MTAs), involving chromosomes A01, A06, A08, B02, B04, B05 and B08. These explained high phenotypic variation (up to 32%). Annotation of the genomic region(s) in or around significant SNPs allowed prediction of genes encoding high affinity nitrate transporters, glutamine synthetase 1.3, myb-like transcription factor family protein, bidirectional amino acid transporter 1, auxin signaling F-box 3 and oxidoreductases. This is the first attempt to use GWAS for identification of enzyme QTLs to explain variation for nitrogen assimilation enzymes in Brassica juncea.
PMID: 31115836
Sheng Wu Gong Cheng Xue Bao , 2019 Aug , V35 (8) : P1424-1432 doi: 10.13345/j.cjb.180537
[Progress in endosomal Na(+),K(+)/H(+) antiporter in Arabidopsis thaliana].
Biotechnology Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou 730070, Gansu, China.
Important progress has been made in the interpretation of subcellular location, ion transport characteristics and biological functions of endosomal Na(+),K(+)/H(+) antiporter in Arabidopsis thaliana. The endosomal Na(+),K(+)/H(+) antiporter contain two members, AtNHX5 and AtNHX6, whose amino acid sequence similarity is 78.7%. Studies have shown that AtNHX5 and AtNHX6 are functionally redundant, and they are all located in Golgi, trans-Golgi network (TGN), endoplasmic reticulum (ER) and prevacuolar compartment (PVC). AtNHX5 and AtNHX6 are critical for salt tolerance stress and the homeostasis of pH and K(+). It has been reported that there are conservative acidic amino acid residues that can regulate their ion activity in the endosomal NHXs transmembrane domain, which plays a decisive role in their own functions. The results of the latest research indicate that endosomal NHXs affect vacuolar transport and protein storage, and participate in the growth of auxin-mediated development in A. thaliana. In this paper, the progress of subcellular localization, ion transport, function and application of endosomal NHXs in A. thaliana was summarized.
PMID: 31441613