Trends Plant Sci , IF:14.416 , 2019 Mar , V24 (3) : P220-236 doi: 10.1016/j.tplants.2018.12.001
An Update on the Signals Controlling Shoot Branching.
The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia.; The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia; These authors contributed equally to this publication.; The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia. Electronic address: c.beveridge@uq.edu.au.
Many new questions on the regulation of shoot branching have been raised in recent years, prompting a review and reassessment of the role of each signal involved. Sugars and their signaling networks have been attributed a major role in the early events of axillary bud outgrowth, whereas cytokinin appears to play a critical role in the modulation of this process in response to the environment. Perception of the recently discovered hormone strigolactone is now quite well understood, while the downstream targets remain largely unknown. Recent literature has highlighted that auxin export from a bud is important for its subsequent growth.
PMID: 30797425
Trends Plant Sci , IF:14.416 , 2019 Mar , V24 (3) : P250-262 doi: 10.1016/j.tplants.2018.11.005
In Silico Roots: Room for Growth.
Computational Developmental Biology Group, Faculty of Science, Utrecht University, Utrecht, The Netherlands.; Computational Developmental Biology Group, Faculty of Science, Utrecht University, Utrecht, The Netherlands. Electronic address: k.h.w.j.tentusscher@uu.nl.
Computational models are invaluable tools for understanding the hormonal and genetic control of root development. Thus far, models have focused on the crucial roles that auxin transport and metabolism play in determining the auxin signaling gradient that controls the root meristem. Other hormones such as cytokinins, gibberellins, and ethylene have predominantly been considered as modulators of auxin dynamics, but their underlying patterning mechanisms are currently unresolved. In addition, the effects of cell- and tissue-level growth dynamics, which induce dilution and displacement of signaling molecules, have remained unexplored. Elucidating these additional mechanisms will be essential to unravel how root growth is patterned in a robust and self-organized manner. Models incorporating growth will thus be crucial in unraveling the underlying logic of root developmental decision making.
PMID: 30665820
Nat Plants , IF:13.256 , 2019 Mar , V5 (3) : P316-327 doi: 10.1038/s41477-019-0378-z
Capturing the phosphorylation and protein interaction landscape of the plant TOR kinase.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB Center for Plant Systems Biology, Ghent, Belgium.; The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, College of Life Sciences, Shandong University, Jinan, China.; Bioinformatics Institute Ghent, Ghent University, Ghent, Belgium.; Department of Biochemistry, Ghent University, Ghent, Belgium.; VIB Center for Medical Biotechnology, Ghent, Belgium.; VIB Proteomics Core, Ghent, Belgium.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. geert.dejaeger@psb.vib-ugent.be.; VIB Center for Plant Systems Biology, Ghent, Belgium. geert.dejaeger@psb.vib-ugent.be.
The target of rapamycin (TOR) kinase is a conserved regulatory hub that translates environmental and nutritional information into permissive or restrictive growth decisions. Despite the increased appreciation of the essential role of the TOR complex in plants, no large-scale phosphoproteomics or interactomics studies have been performed to map TOR signalling events in plants. To fill this gap, we combined a systematic phosphoproteomics screen with a targeted protein complex analysis in the model plant Arabidopsis thaliana. Integration of the phosphoproteome and protein complex data on the one hand shows that both methods reveal complementary subspaces of the plant TOR signalling network, enabling proteome-wide discovery of both upstream and downstream network components. On the other hand, the overlap between both data sets reveals a set of candidate direct TOR substrates. The integrated network embeds both evolutionarily-conserved and plant-specific TOR signalling components, uncovering an intriguing complex interplay with protein synthesis. Overall, the network provides a rich data set to start addressing fundamental questions about how TOR controls key processes in plants, such as autophagy, auxin signalling, chloroplast development, lipid metabolism, nucleotide biosynthesis, protein translation or senescence.
PMID: 30833711
Mol Plant , IF:12.084 , 2019 Mar , V12 (3) : P360-373 doi: 10.1016/j.molp.2018.10.005
The Auxin-Regulated Protein ZmAuxRP1 Coordinates the Balance between Root Growth and Stalk Rot Disease Resistance in Maize.
State Key Laboratory of Plant Physiology and Biochemistry/National Maize Improvement Center/College of Agronomy and Biotechnology/Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100193, P. R. China.; State Key Laboratory of Plant Physiology and Biochemistry/National Maize Improvement Center/College of Agronomy and Biotechnology/Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100193, P. R. China. Electronic address: mxu@cau.edu.cn.
To optimize fitness, plants must efficiently allocate their resources between growth and defense. Although phytohormone crosstalk has emerged as a major player in balancing growth and defense, the genetic basis by which plants manage this balance remains elusive. We previously identified a quantitative disease-resistance locus, qRfg2, in maize (Zea mays) that protects against the fungal disease Gibberella stalk rot. Here, through map-based cloning, we demonstrate that the causal gene at qRfg2 is ZmAuxRP1, which encodes a plastid stroma-localized auxin-regulated protein. ZmAuxRP1 responded quickly to pathogen challenge with a rapid yet transient reduction in expression that led to arrested root growth but enhanced resistance to Gibberella stalk rot and Fusarium ear rot. ZmAuxRP1 was shown to promote the biosynthesis of indole-3-acetic acid (IAA), while suppressing the formation of benzoxazinoid defense compounds. ZmAuxRP1 presumably acts as a resource regulator modulating indole-3-glycerol phosphate and/or indole flux at the branch point between the IAA and benzoxazinoid biosynthetic pathways. The concerted interplay between IAA and benzoxazinoids can regulate the growth-defense balance in a timely and efficient manner to optimize plant fitness.
PMID: 30853061
Mol Plant , IF:12.084 , 2019 Mar , V12 (3) : P374-389 doi: 10.1016/j.molp.2018.12.024
The barren stalk2 Gene Is Required for Axillary Meristem Development in Maize.
Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.; Department of Biology, Penn State University, University Park, PA 16802, USA.; Department of Biological Sciences, California State University, Long Beach, CA 90840, USA.; Division of Biological Sciences, Interdisciplinary Plant Group, Columbia, MO 65211, USA.; Division of Biological Sciences, Interdisciplinary Plant Group, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA. Electronic address: mcsteenp@missouri.edu.
The diversity of plant architecture is determined by axillary meristems (AMs). AMs are produced from small groups of stem cells in the axils of leaf primordia and generate vegetative branches and reproductive inflorescences. Previous studies identified genes critical for AM development that function in auxin biosynthesis, transport, and signaling. barren stalk1 (ba1), a basic helix-loop-helix transcription factor, acts downstream of auxin to control AM formation. Here, we report the cloning and characterization of barren stalk2 (ba2), a mutant that fails to produce ears and has fewer branches and spikelets in the tassel, indicating that ba2 functions in reproductive AM development. Furthermore, the ba2 mutation suppresses tiller growth in the teosinte branched1 mutant, indicating that ba2 also plays an essential role in vegetative AM development. The ba2 gene encodes a protein that co-localizes and heterodimerizes with BA1 in the nucleus. Characterization of the genetic interaction between ba2 and ba1 demonstrates that ba1 shows a gene dosage effect in ba2 mutants, providing further evidence that BA1 and BA2 act together in the same pathway. Characterization of the molecular and genetic interaction between ba2 and additional genes required for the regulation of ba1 further supports this finding. The ba1 and ba2 genes are orthologs of rice genes, LAX PANICLE1 (LAX1) and LAX2, respectively, hence providing insights into pathways controlling AMs development in grasses.
PMID: 30690173
Mol Plant , IF:12.084 , 2019 Mar , V12 (3) : P298-320 doi: 10.1016/j.molp.2018.12.012
Auxin EvoDevo: Conservation and Diversification of Genes Regulating Auxin Biosynthesis, Transport, and Signaling.
Division of Biological Sciences, Interdisciplinary Plant Group and Missouri Maize Center, University of Missouri-Columbia, 301 Christopher Bond Life Sciences Center, Columbia, MO 65211, USA.; Department of Biological Sciences, California State University, Long Beach, CA 90840, USA.; Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854-8020, USA; Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.; Division of Biological Sciences, Interdisciplinary Plant Group and Missouri Maize Center, University of Missouri-Columbia, 301 Christopher Bond Life Sciences Center, Columbia, MO 65211, USA. Electronic address: mcsteenp@missouri.edu.
The phytohormone auxin has been shown to be of pivotal importance in growth and development of land plants. The underlying molecular players involved in auxin biosynthesis, transport, and signaling are quite well understood in Arabidopsis. However, functional characterizations of auxin-related genes in economically important crops, specifically maize and rice, are still limited. In this article, we comprehensively review recent functional studies on auxin-related genes in both maize and rice, compared with what is known in Arabidopsis, and highlight conservation and diversification of their functions. Our analysis is illustrated by phylogenetic analysis and publicly available gene expression data for each gene family, which will aid in the identification of auxin-related genes for future research. Current challenges and future directions for auxin research in maize and rice are discussed. Developments in gene editing techniques provide powerful tools for overcoming the issue of redundancy in these gene families and will undoubtedly advance auxin research in crops.
PMID: 30590136
Autophagy , IF:9.77 , 2019 Mar , V15 (3) : P407-422 doi: 10.1080/15548627.2018.1520547
Autophagy regulates glucose-mediated root meristem activity by modulating ROS production in Arabidopsis.
a State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences , Sun Yat-sen University , Guangzhou , China.
Glucose produced from photosynthesis is a key nutrient signal regulating root meristem activity in plants; however, the underlying mechanisms remain poorly understood. Here, we show that, by modulating reactive oxygen species (ROS) levels, the conserved macroautophagy/autophagy degradation pathway contributes to glucose-regulated root meristem maintenance. In Arabidopsis thaliana roots, a short exposure to elevated glucose temporarily suppresses constitutive autophagosome formation. The autophagy-defective autophagy-related gene (atg) mutants have enhanced tolerance to glucose, established downstream of the glucose sensors, and accumulate less glucose-induced ROS in the root tips. Moreover, the enhanced root meristem activities in the atg mutants are associated with improved auxin gradients and auxin responses. By acting with AT4G39850/ABCD1 (ATP-binding cassette D1; Formerly PXA1/peroxisomal ABC transporter 1), autophagy plays an indispensable role in the glucose-promoted degradation of root peroxisomes, and the atg mutant phenotype is partially rescued by the overexpression of ABCD1. Together, our findings suggest that autophagy is an essential mechanism for glucose-mediated maintenance of the root meristem. Abbreviation: ABA: abscisic acid; ABCD1: ATP-binding cassette D1; ABO: ABA overly sensitive; AsA: ascorbic acid; ATG: autophagy related; CFP: cyan fluorescent protein; Co-IP: co-immunoprecipitation; DAB: 3',3'-diaininobenzidine; DCFH-DA: 2',7'-dichlorodihydrofluorescin diacetate; DR5: a synthetic auxin response element consists of tandem direct repeats of 11 bp that included the auxin-responsive TGTCTC element; DZ: differentiation zone; EZ, elongation zone; GFP, green fluorescent protein; GSH, glutathione; GUS: beta-glucuronidase; HXK1: hexokinase 1; H2O2: hydrogen peroxide; IAA: indole-3-acetic acid; IBA: indole-3-butyric acid; KIN10/11: SNF1 kinase homolog 10/11; MDC: monodansylcadaverine; MS: Murashige and Skoog; MZ: meristem zone; NBT: nitroblue tetrazolium; NPA: 1-N-naphtylphthalamic acid; OxIAA: 2-oxindole-3-acetic acid; PIN: PIN-FORMED; PLT: PLETHORA; QC: quiescent center; RGS1: Regulator of G-protein signaling 1; ROS: reactive oxygen species; SCR: SCARECROW; SHR, SHORT-ROOT; SKL: Ser-Lys-Leu; SnRK1: SNF1-related kinase 1; TOR: target of rapamycin; UPB1: UPBEAT1; WOX5: WUSCHEL related homeobox 5; Y2H: yeast two-hybrid; YFP: yellow fluorescent protein.
PMID: 30208757
Curr Biol , IF:9.601 , 2019 Mar , V29 (6) : P1038-1046.e4 doi: 10.1016/j.cub.2019.01.057
Regulatory Diversification of INDEHISCENT in the Capsella Genus Directs Variation in Fruit Morphology.
Crop Genetics Department, John Innes Centre, Norwich NR4 7UH, UK.; Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden.; Crop Genetics Department, John Innes Centre, Norwich NR4 7UH, UK. Electronic address: lars.ostergaard@jic.ac.uk.
Evolution of gene-regulatory sequences is considered the primary driver of morphological variation [1-3]. In animals, the diversity of body plans between distantly related phyla is due to the differential expression patterns of conserved "toolkit" genes [4]. In plants, variation in expression domains similarly underlie most of the reported diversity of organ shape both in natural evolution and in the domestication of crops [5-9]. The heart-shaped fruit from members of the Capsella genus is a morphological novelty that has evolved after Capsella diverged from Arabidopsis approximately 8 mya [10]. Comparative studies of fruit growth in Capsella and Arabidopsis revealed that the difference in shape is caused by local control of anisotropic growth [11]. Here, we show that sequence variation in regulatory domains of the fruit-tissue identity gene, INDEHISCENT (IND), is responsible for expansion of its expression domain in the heart-shaped fruits from Capsella rubella. We demonstrate that expression of this CrIND gene in the apical part of the valves in Capsella contributes to the heart-shaped appearance. While studies on morphological diversity have revealed the importance of cis-regulatory sequence evolution, few examples exist where the downstream effects of such variation have been characterized in detail. We describe here how CrIND exerts its function on Capsella fruit shape by binding sequence elements of auxin biosynthesis genes to activate their expression and ensure auxin accumulation into highly localized maxima in the fruit valves. Thus, our data provide a direct link between changes in expression pattern and altered hormone homeostasis in the evolution of morphological novelty.
PMID: 30827915
Proc Natl Acad Sci U S A , IF:9.412 , 2019 Mar , V116 (13) : P6451-6456 doi: 10.1073/pnas.1900084116
Processing bodies control the selective translation for optimal development of Arabidopsis young seedlings.
Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan.; Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.; Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan.; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan; shuwu@gate.sinica.edu.tw.
Germinated plant seeds buried in soil undergo skotomorphogenic development before emergence to reach the light environment. Young seedlings transitioning from dark to light undergo photomorphogenic development. During photomorphogenesis, light alters the transcriptome and enhances the translation of thousands of mRNAs during the dark-to-light transition in Arabidopsis young seedlings. About 1,500 of these mRNAs have comparable abundance before and after light treatment, which implies widespread translational repression in dark-grown seedlings. Processing bodies (p-bodies), the cytoplasmic granules found in diverse organisms, can balance the storage, degradation, and translation of mRNAs. However, the function of p-bodies in translation control remains largely unknown in plants. Here we found that an Arabidopsis mutant defective in p-body formation (Decapping 5; dcp5-1) showed reduced fitness under both dark and light conditions. Comparative transcriptome and translatome analyses of wild-type and dcp5-1 seedlings revealed that p-bodies can attenuate the premature translation of specific mRNAs in the dark, including those encoding enzymes for protochlorophyllide synthesis and PIN-LIKES3 for auxin-dependent apical hook opening. When the seedlings protrude from soil, light perception by photoreceptors triggers a reduced accumulation of p-bodies to release the translationally stalled mRNAs for active translation of mRNAs encoding proteins needed for photomorphogenesis. Our data support a key role for p-bodies in translation repression, an essential mechanism for proper skotomorphogenesis and timely photomorphogenesis in seedlings.
PMID: 30850529
Proc Natl Acad Sci U S A , IF:9.412 , 2019 Mar , V116 (13) : P6463-6472 doi: 10.1073/pnas.1809037116
Selective auxin agonists induce specific AUX/IAA protein degradation to modulate plant development.
Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden.; Institute of Physical and Theoretical Chemistry, University of Bonn, 53121 Bonn, Germany.; Laboratories for Chemical Biology Umea, Chemical Biology Consortium Sweden, Department of Chemistry, Umea University, SE-901 87 Umea, Sweden.; Centre for Plant Sciences, University of Leeds, LS2 9JT Leeds, United Kingdom.; Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre for Plant Biology in Uppsala, SE-75007 Uppsala, Sweden.; Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences, CZ-78371 Olomouc, Czech Republic.; Laboratory of Growth Regulators, Faculty of Science, Palacky University, CZ-78371 Olomouc, Czech Republic.; Sup'Biotech, IONIS Education Group, 94800 Villejuif, France.; Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0116.; Department of Molecular and Cellular Biology, University of California, Davis, CA 95616.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, Vlaams Instituut voor Biotechnologie, 9052 Ghent, Belgium.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden; Stephanie.Robert@slu.se.
Auxin phytohormones control most aspects of plant development through a complex and interconnected signaling network. In the presence of auxin, AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors are targeted for degradation by the SKP1-CULLIN1-F-BOX (SCF) ubiquitin-protein ligases containing TRANSPORT INHIBITOR RESISTANT 1/AUXIN SIGNALING F-BOX (TIR1/AFB). CULLIN1-neddylation is required for SCF(TIR1/AFB) functionality, as exemplified by mutants deficient in the NEDD8-activating enzyme subunit AUXIN-RESISTANT 1 (AXR1). Here, we report a chemical biology screen that identifies small molecules requiring AXR1 to modulate plant development. We selected four molecules of interest, RubNeddin 1 to 4 (RN1 to -4), among which RN3 and RN4 trigger selective auxin responses at transcriptional, biochemical, and morphological levels. This selective activity is explained by their ability to consistently promote the interaction between TIR1 and a specific subset of AUX/IAA proteins, stimulating the degradation of particular AUX/IAA combinations. Finally, we performed a genetic screen using RN4, the RN with the greatest potential for dissecting auxin perception, which revealed that the chromatin remodeling ATPase BRAHMA is implicated in auxin-mediated apical hook development. These results demonstrate the power of selective auxin agonists to dissect auxin perception for plant developmental functions, as well as offering opportunities to discover new molecular players involved in auxin responses.
PMID: 30850516
ISME J , IF:9.18 , 2019 Mar , V13 (3) : P738-751 doi: 10.1038/s41396-018-0300-0
Legacy of land use history determines reprogramming of plant physiology by soil microbiome.
CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.; Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands.; Institute for Environmental Biology, Ecology & Biodiversity, Utrecht University, Utrecht, 3584 CH, The Netherlands.; Soil Biology Group, Wageningen University, Wageningen, 6708 PB, The Netherlands.; CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. xxwang@issas.ac.cn.; Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan, 335211, China. xxwang@issas.ac.cn.
Microorganisms associated with roots are thought to be part of the so-called extended plant phenotypes with roles in the acquisition of nutrients, production of growth hormones, and defense against diseases. Since the crops selectively enrich most rhizosphere microbes out of the bulk soil, we hypothesized that changes in the composition of bulk soil communities caused by agricultural management affect the extended plant phenotype. In the current study, we performed shotgun metagenome sequencing of the rhizosphere microbiome of the peanut (Arachis hypogaea) and metatranscriptome analysis of the roots of peanut plants grown in the soil with different management histories, peanut monocropping and crop rotation. We found that the past planting record had a significant effect on the assembly of the microbial community in the peanut rhizosphere, indicating a soil memory effect. Monocropping resulted in a reduction of the rhizosphere microbial diversity, an enrichment of several rare species, and a reduced representation of traits related to plant performance, such as nutrients metabolism and phytohormone biosynthesis. Furthermore, peanut plants in monocropped soil exhibited a significant reduction in growth coinciding with a down-regulation of genes related to hormone production, mainly auxin and cytokinin, and up-regulation of genes related to the abscisic acid, salicylic acid, jasmonic acid, and ethylene pathways. These findings suggest that land use history affects crop rhizosphere microbiomes and plant physiology.
PMID: 30368524
New Phytol , IF:8.512 , 2019 Mar , V221 (4) : P2190-2202 doi: 10.1111/nph.15551
Lipo-chitooligosaccharides promote lateral root formation and modify auxin homeostasis in Brachypodium distachyon.
LIPM, Universite de Toulouse, INRA, CNRS, 31326, Castanet-Tolosan, France.; Sainsbury Laboratory, Cambridge University, 47 Bateman Street, Cambridge, CB2 1LR, UK.; Laboratoire de Recherche en Sciences Vegetales, Universite de Toulouse, UPS, CNRS, 24 chemin de Borde Rouge-Auzeville, 31326, Castanet-Tolosan, France.
Lipo-chitooligosaccharides (LCOs) are microbial symbiotic signals that also influence root growth. In Medicago truncatula, LCOs stimulate lateral root formation (LRF) synergistically with auxin. However, the molecular mechanisms of this phenomenon and whether it is restricted to legume plants are not known. We have addressed the capacity of the model monocot Brachypodium distachyon (Brachypodium) to respond to LCOs and auxin for LRF. For this, we used a combination of root phenotyping assays, live-imaging and auxin quantification, and analysed the regulation of auxin homeostasis genes. We show that LCOs and a low dose of the auxin precursor indole-3-butyric acid (IBA) stimulated LRF in Brachypodium, while a combination of LCOs and IBA led to different regulations. Both LCO and IBA treatments locally increased endogenous indole-3-acetic acid (IAA) content, whereas the combination of LCO and IBA locally increased the endogenous concentration of a conjugated form of IAA (IAA-Ala). LCOs, IBA and the combination differentially controlled expression of auxin homeostasis genes. These results demonstrate that LCOs are active on Brachypodium roots and stimulate LRF probably through regulation of auxin homeostasis. The interaction between LCO and auxin treatments observed in Brachypodium on root architecture opens interesting avenues regarding their possible combined effects during the arbuscular mycorrhizal symbiosis.
PMID: 30347445
New Phytol , IF:8.512 , 2019 Mar , V221 (4) : P1906-1918 doi: 10.1111/nph.15496
TGACG-BINDING FACTORs (TGAs) and TGA-interacting CC-type glutaredoxins modulate hyponastic growth in Arabidopsis thaliana.
Albrecht-von-Haller-Institut fur Pflanzenwissenschaften, Georg-August-Universitat Gottingen, Julia-Lermontowa-Weg 3, D-37077, Gottingen, Germany.; Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
TGACG-BINDING FACTORs (TGAs) control the developmental or defense-related processes. In Arabidopsis thaliana, the functions of at least TGA2 and PERIANTHIA (PAN) can be repressed by interacting with CC-type glutaredoxins, which have the potential to control the redox state of target proteins. As TGA1 can be redox modulated in planta, we analyzed whether some of the 21 CC-type glutaredoxins (ROXYs) encoded in the Arabidopsis genome can influence TGA1 activity in planta and whether the redox active cysteines of TGA1 are functionally important. We show that the tga1 tga4 mutant and plants ectopically expressing ROXY8 or ROXY9 are impaired in hyponastic growth. As expression of ROXY8 and ROXY9 is activated upon transfer of plants from hyponasty-inducing low light to normal light, they might interfere with the growth-promoting function of TGA1/TGA4 to facilitate reversal of hyponastic growth. The redox-sensitive cysteines of TGA1 are not required for induction or reversal of hyponastic growth. TGA1 and TGA4 interact with ROXYs 8, 9, 18, and 19/GRX480, but ectopically expressed ROXY18 and ROXY19/GRX480 do not interfere with hyponastic growth. Our results therefore demonstrate functional specificities of individual ROXYs for distinct TGAs despite promiscuous protein-protein interactions and point to different repression mechanisms, depending on the TGA/ROXY combination.
PMID: 30252136
J Exp Bot , IF:5.908 , 2019 Mar , V70 (6) : P1711-1718 doi: 10.1093/jxb/erz048
When to stop: an update on molecular mechanisms of floral meristem termination.
College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China.; Nara Institute of Science and Technology, Biological Sciences, Plant Stem Cell Regulation and Floral Patterning Laboratory, Takayama, Ikoma, Nara, Japan.; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Honcho, Kawaguchi-shi, Saitama, Japan.; Archisen, Singapore, Singapore.
Flowers have fascinated humans for millennia, not only because of their beauty, but also because they give rise to fruits, from which most agricultural products are derived. In most angiosperms, the number and position of floral organs are morphologically and genetically defined, and their development is tightly controlled by complex regulatory networks to ensure reproductive success. How flower development is temporally initiated and spatially maintained has been widely researched. As the flower develops, the balance between proliferation and differentiation dynamically shifts towards organogenesis and termination of floral stem cell maintenance. In this review, we focus on recent findings that further reveal the intricate molecular mechanisms for precise timing of floral meristem termination.
PMID: 30916342
J Exp Bot , IF:5.908 , 2019 Mar , V70 (6) : P1955-1967 doi: 10.1093/jxb/erz027
Revealing the hierarchy of processes and time-scales that control the tropic response of shoots to gravi-stimulations.
Universite Clermont Auvergne, INRA, PIAF, Clermont-Ferrand, France.; Aix Marseille University, CNRS, IUSTI, Marseille, France.
Gravity is a major abiotic cue for plant growth. However, little is known about the responses of plants to various patterns of gravi-stimulation, with apparent contradictions being observed between the dose-like responses recorded under transient stimuli in microgravity environments and the responses under steady-state inclinations recorded on earth. Of particular importance is how the gravitropic response of an organ is affected by the temporal dynamics of downstream processes in the signalling pathway, such as statolith motion in statocytes or the redistribution of auxin transporters. Here, we used a combination of experiments on the whole-plant scale and live-cell imaging techniques on wheat coleoptiles in centrifuge devices to investigate both the kinematics of shoot-bending induced by transient inclination, and the motion of the statoliths in response to cell inclination. Unlike previous observations in microgravity, the response of shoots to transient inclinations appears to be independent of the level of gravity, with a response time much longer than the duration of statolith sedimentation. This reveals the existence of a memory process in the gravitropic signalling pathway, independent of statolith dynamics. By combining this memory process with statolith motion, a mathematical model is built that unifies the different laws found in the literature and that predicts the early bending response of shoots to arbitrary gravi-stimulations.
PMID: 30916341
J Exp Bot , IF:5.908 , 2019 Mar , V70 (6) : P1859-1873 doi: 10.1093/jxb/erz047
Increased biomass accumulation in maize grown in mixed nitrogen supply is mediated by auxin synthesis.
Department of Plant Nutrition, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
The use of mixed nitrate and ammonium as a nitrogen source can improve plant growth. Here, we used metabolomics and transcriptomics to study the underlying mechanisms. Maize plants were grown hydroponically in the presence of three forms of nitrogen (nitrate alone, 75%/25% nitrate/ammonium, and ammonium alone). Plants grown with mixed nitrogen had a higher photosynthetic rate than those supplied only with nitrate, and had the highest leaf area and shoot and root biomass among the three nitrogen treatments. In shoot and root, the concentration of nitrogenous compounds (ammonium, glutamine, and asparagine) and carbohydrates (sucrose, glucose, and fructose) in plants with a mixed nitrogen supply was higher than that with nitrate supply, but lower than that with ammonium supply. The activity of the related enzymes (glutamate synthase, asparagine synthase, phosphoenolpyruvate carboxylase, invertase, and ADP-glucose pyrophosphorylase) changed accordingly. Specifically, the mixed nitrogen source enhanced auxin synthesis via the shikimic acid pathway, as indicated by the higher levels of phosphoenolpyruvate and tryptophan compared with the other two treatments. The expression of corresponding genes involving auxin synthesis and response was up-regulated. Supply of only ammonium resulted in high levels of glutamine and asparagine, starch, and trehalose hexaphosphate. We conclude that, in addition to increased photosynthesis, mixed nitrogen supply enhances leaf growth via increasing auxin synthesis to build a large sink for carbon and nitrogen utilization, which, in turn, facilitates further carbon assimilation and nitrogen uptake.
PMID: 30759246
J Exp Bot , IF:5.908 , 2019 Mar , V70 (5) : P1461-1467 doi: 10.1093/jxb/erz038
Re-evaluation of the ethylene-dependent and -independent pathways in the regulation of floral and organ abscission.
Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), The Volcani Center, Rishon LeZion, Israel.; The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.; Soybean Genomics and Improvement Lab, Agricultural Research Service, United States Department of Agriculture, BARC-West, Beltsville, MD, USA.; Department of Horticulture, University of Wisconsin-Madison, Madison, WI, USA.; Office of the Vice-Chancellor, Drake Circus, Plymouth, Devon, UK.
Abscission is a developmental process with important implications for agricultural practices. Ethylene has long been considered as a key regulator of the abscission process. The existence of an ethylene-independent abscission pathway, controlled by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide and the HAESA (HAE) and HAESA-like2 (HSL2) kinases, has been proposed, based mainly on observations that organ abscission in ethylene-insensitive mutants was delayed but not inhibited. A recent review on plant organ abscission signaling highlighted the IDA-HAE-HSL2 components as the regulators of organ abscission, while the role of auxin and ethylene in this process was hardly addressed. After a careful analysis of the relevant abscission literature, we propose that the IDA-HAE-HSL2 pathway is essential for the final stages of organ abscission, while ethylene plays a major role in its initiation and progression. We discuss the view that the IDA-HAE-HSL2 pathway is ethylene independent, and present recent evidence showing that ethylene activates the IDA-HAE-HSL2 complex. We conclude that the ability of an organ to abscise is tightly linked to cell turgidity in the abscission zone, and suggest that lack of cell turgidity might contribute to the failure of floral organ abscission in the ida mutants.
PMID: 30726930
J Exp Bot , IF:5.908 , 2019 Mar , V70 (5) : P1447-1460 doi: 10.1093/jxb/erz026
Gynoecium development: networks in Arabidopsis and beyond.
Unidad de Genomica Avanzada (LANGEBIO), Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico.
Life has always found a way to preserve itself. One strategy that has been developed for this purpose is sexual reproduction. In land plants, the gynoecium is considered to be at the top of evolutionary innovation, since it has been a key factor in the success of the angiosperms. The gynoecium is composed of carpels with different tissues that need to develop and differentiate in the correct way. In order to control and guide gynoecium development, plants have adapted elements of pre-existing gene regulatory networks (GRNs) but new ones have also evolved. The GRNs can interact with internal factors (e.g. hormones and other metabolites) and external factors (e.g. mechanical signals and temperature) at different levels, giving robustness and flexibility to gynoecium development. Here, we review recent findings regarding the role of cytokinin-auxin crosstalk and the genes that connect these hormonal pathways during early gynoecium development. We also discuss some examples of internal and external factors that can modify GRNs. Finally, we make a journey through the flowering plant lineage to determine how conserved are these GRNs that regulate gynoecium and fruit development.
PMID: 30715461
J Exp Bot , IF:5.908 , 2019 Mar , V70 (5) : P1469-1482 doi: 10.1093/jxb/erz003
Ethylene and hydrogen peroxide regulate formation of a sterol-enriched domain essential for wall labyrinth assembly in transfer cells.
School of Environmental and Life Sciences, University of Newcastle, Newcastle NSW, Australia.
Transfer cells (TCs) facilitate high rates of nutrient transport into, and within, the plant body. Their transport function is conferred by polarized wall ingrowth papillae, deposited upon a specialized uniform wall layer, that form a scaffold supporting an amplified area of plasma membrane enriched in nutrient transporters. We explored the question of whether lipid-enriched domains of the TC plasma membrane could serve as organizational platforms for proteins regulating the construction of the intricate TC wall labyrinth using developing Vicia faba cotyledons. When these cotyledons are placed in culture, their adaxial epidermal cells trans-differentiate to a TC phenotype regulated by auxin, ethylene, extracellular hydrogen peroxide (apoH2O2), and cytosolic Ca2+ ([Ca2+]cyt) arranged in series. Staining cultured cotyledons with the sterol-specific dye, Filipin III, detected a polarized sterol-enriched domain in the plasma membrane of their trans-differentiating epidermal transfer cells (ETCs). Ethylene activated sterol biosynthesis while extracellular apoH2O2 directed sterol-enriched vesicles to fuse with the outer periclinal region of the ETC plasma membrane. The sterol-enriched domain was essential for generating the [Ca2+]cyt signal and orchestrating construction of both the uniform wall layer and wall ingrowth papillae. A model is presented outlining how the sterol-enriched plasma membrane domain forms and functions to regulate wall labyrinth assembly.
PMID: 30649402
Development , IF:5.611 , 2019 Mar , V146 (6) doi: 10.1242/dev.172411
A core mechanism for specifying root vascular patterning can replicate the anatomical variation seen in diverse plant species.
Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.; Institute of Biotechnology, HiLIFE/Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland.; Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan.; Research Center in Biodiversity and Genetic Resources, Department of Biology, Faculty of Sciences, University of Porto, 4485-661 Vairao, Portugal.; School of Mathematical Sciences/Centre for Plant Integrative Biology, University of Nottingham, University Park, Nottingham NG7 2RD, UK.; Centre for Plant Integrative Biology/School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK anthony.bishopp@nottingham.ac.uk.
Pattern formation is typically controlled through the interaction between molecular signals within a given tissue. During early embryonic development, roots of the model plant Arabidopsis thaliana have a radially symmetric pattern, but a heterogeneous input of the hormone auxin from the two cotyledons forces the vascular cylinder to develop a diarch pattern with two xylem poles. Molecular analyses and mathematical approaches have uncovered the regulatory circuit that propagates this initial auxin signal into a stable cellular pattern. The diarch pattern seen in Arabidopsis is relatively uncommon among flowering plants, with most species having between three and eight xylem poles. Here, we have used multiscale mathematical modelling to demonstrate that this regulatory module does not require a heterogeneous auxin input to specify the vascular pattern. Instead, the pattern can emerge dynamically, with its final form dependent upon spatial constraints and growth. The predictions of our simulations compare to experimental observations of xylem pole number across a range of species, as well as in transgenic systems in Arabidopsis in which we manipulate the size of the vascular cylinder. By considering the spatial constraints, our model is able to explain much of the diversity seen in different flowering plant species.
PMID: 30858228
PLoS Genet , IF:5.174 , 2019 Mar , V15 (3) : Pe1008023 doi: 10.1371/journal.pgen.1008023
Connective auxin transport contributes to strigolactone-mediated shoot branching control independent of the transcription factor BRC1.
Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.
The shoot systems of plants are built by the action of the primary shoot apical meristem, established during embryogenesis. In the axil of each leaf produced by the primary meristem, secondary axillary shoot apical meristems are established. The dynamic regulation of the activity of these axillary meristems gives shoot systems their extraordinary plasticity of form. The ability of plants to activate or repress these axillary meristems appropriately requires communication between meristems that is environmentally sensitive. The transport network of the plant hormone auxin has long been implicated as a central player in this tuneable communication system, with other systemically mobile hormones, such as strigolactone and cytokinin, acting in part by modulating auxin transport. Until recently, the polar auxin transport stream, which provides a high conductance auxin transport route down stems dominated by the auxin export protein PIN-FORMED1 (PIN1), has been the focus for understanding long range auxin transport in the shoot. However, recently additional auxin exporters with important roles in the shoot have been identified, including PIN3, PIN4 and PIN7. These proteins contribute to a wider less polar stem auxin transport regime, which we have termed connective auxin transport (CAT), because of its role in communication across the shoot system. Here we present a genetic analysis of the role of CAT in shoot branching. We demonstrate that in Arabidopsis, CAT plays an important role in strigolactone-mediated shoot branching control, with the triple pin3pin4pin7 mutant able to suppress partially the highly branched phenotype of strigolactone deficient mutants. In contrast, the branchy phenotype of mutants lacking the axillary meristem-expressed transcription factor, BRANCHED1 (BRC1) is unaffected by pin3pin4pin7. We further demonstrate that mutation in the ABCB19 auxin export protein, which like PIN3 PIN4 and PIN7 is widely expressed in stems, has very different effects, implicating ABCB19 in auxin loading at axillary bud apices.
PMID: 30865619
J Integr Plant Biol , IF:4.885 , 2019 Mar , V61 (3) : P310-336 doi: 10.1111/jipb.12747
Translating auxin responses into ovules, seeds and yield: Insight from Arabidopsis and the cereals.
School of Agriculture, Food and Wine, Waite Research Institute, The University of Adelaide, Glen Osmond, SA, Australia.
Grain production in cereal crops depends on the stable formation of male and female gametes in the flower. In most angiosperms, the female gamete is produced from a germline located deep within the ovary, protected by several layers of maternal tissue, including the ovary wall, ovule integuments and nucellus. In the field, germline formation and floret fertility are major determinants of yield potential, contributing to traits such as seed number, weight and size. As such, stimuli affecting the timing and duration of reproductive phases, as well as the viability, size and number of cells within reproductive organs can significantly impact yield. One key stimulant is the phytohormone auxin, which influences growth and morphogenesis of female tissues during gynoecium development, gametophyte formation, and endosperm cellularization. In this review we consider the role of the auxin signaling pathway during ovule and seed development, first in the context of Arabidopsis and then in the cereals. We summarize the gene families involved and highlight distinct expression patterns that suggest a range of roles in reproductive cell specification and fate. This is discussed in terms of seed production and how targeted modification of different tissues might facilitate improvements.
PMID: 30474296
Int J Mol Sci , IF:4.556 , 2019 Mar , V20 (7) doi: 10.3390/ijms20071550
Crop Pollen Development under Drought: From the Phenotype to the Mechanism.
State Key Laboratory of Subtropical Silviculture, School of Agriculture and Food Sciences, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China. yujing2009@zafu.edu.cn.; State Key Laboratory of Subtropical Silviculture, School of Agriculture and Food Sciences, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China. jiangmengyuan1234567@126.com.; State Key Laboratory of Subtropical Silviculture, School of Agriculture and Food Sciences, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China. guock@zafu.edu.cn.
Drought stress induced pollen sterility is a harmful factor that reduces crop yield worldwide. During the reproductive process, the meiotic stage and the mitotic stage in anthers are both highly vulnerable to water deficiency. Drought at these stages causes pollen sterility by affecting the nature and structure of the anthers, including the degeneration of some meiocytes, disorientated microspores, an expanded middle layer and abnormal vacuolizated tapeta. The homeostasis of the internal environment is imbalanced in drought-treated anthers, involving the decreases of gibberellic acid (GA) and auxin, and the increases of abscisic acid (ABA), jasmonic acid (JA) and reactive oxygen species (ROS). Changes in carbohydrate availability, metabolism and distribution may be involved in the effects of drought stress at the reproductive stages. Here, we summarize the molecular regulatory mechanism of crop pollen development under drought stresses. The meiosis-related genes, sugar transporter genes, GA and ABA pathway genes and ROS-related genes may be altered in their expression in anthers to repair the drought-induced injures. It could also be that some drought-responsive genes, mainly expressed in the anther, regulate the expression of anther-related genes to improve both drought tolerance and anther development. A deepened understanding of the molecular regulatory mechanism of pollen development under stress will be beneficial for breeding drought-tolerant crops with high and stable yield under drought conditions.
PMID: 30925673
Int J Mol Sci , IF:4.556 , 2019 Mar , V20 (5) doi: 10.3390/ijms20051126
Effects of 2,4-Dichlorophenoxyacetic Acid on Cucumber Fruit Development and Metabolism.
Key Laboratory of Marine Biotechnology of Zhejiang Province, Key Laboratory of Applied Marine Biotechnology of Department of Education, School of Marine Sciences, Ningbo University, Ningbo 315211, China. huchaoyang@nbu.edu.cn.; Lab (Hangzhou) for Risk Assessment of Agricultural Products of Ministry of Agriculture, Institute of Quality and Standard for Agricultural Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. zhaohuiyu64@163.com.; Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. jianxin.shi@sjtu.edu.cn.; Lab (Hangzhou) for Risk Assessment of Agricultural Products of Ministry of Agriculture, Institute of Quality and Standard for Agricultural Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. 13003619086@163.com.; Shaoxing Jin Shuo Agricultural Technology Co., Ltd., Shaoxing 312000, China. xbnie@126.com.; Lab (Hangzhou) for Risk Assessment of Agricultural Products of Ministry of Agriculture, Institute of Quality and Standard for Agricultural Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China. guilingchina2008@163.com.
The auxin-like compound 2,4-dichlorophenoxyacetic acid (2,4-D) has been widely used as a plant growth regulator in cucumber fruit production; however, its influence on fruit development and metabolism has not been evaluated. In this study, the phenotype of cucumber fruits in both 2,4-D treatment and non-treatment control groups were recorded, and the metabolome of different segments of cucumber fruit at various sampling time points were profiled by a standardized non-targeted metabolomics method based on UPLC-qTOF-MS. The application of 2,4-D increased the early growth rate of the fruit length but had no significant effect on the final fruit length, and produced cucumber fruits with fresh flowers at the top. The 2,4-D treatment also affected the cucumber fruit metabolome, causing significant changes in the stylar end at 4 days after flowering (DAF). The significantly changed metabolites were mainly involved in methionine metabolism, the citric acid cycle and flavonoid metabolism pathways. At the harvest stage, 2,4(-)D treatment significantly decreased the levels of flavonoids and cinnamic acid derivatives while increased the levels of some of the amino acids. In summary, exogenous application of 2,4-D can greatly alter the phenotype and metabolism of cucumber fruit. These findings will assist in exploring the mechanisms of how 2,4-D treatment changes the fruit phenotype and evaluating the influence of 2,4-D treatment on the nutritional qualities of cucumber fruit.
PMID: 30841619
Int J Mol Sci , IF:4.556 , 2019 Mar , V20 (5) doi: 10.3390/ijms20051098
Physiological and Transcriptome Analyses of Early Leaf Senescence for ospls1 Mutant Rice (Oryza sativa L.) during the Grain-Filling Stage.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China. zhaoweili@fafu.edu.cn.; Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou 350002, China. zhaoweili@fafu.edu.cn.; Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou 350002, China. 3165006035@m.fafu.edu.cn.; College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. 3165006035@m.fafu.edu.cn.; Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou 350002, China. 3157614046@m.fafu.edu.cn.; College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. 3157614046@m.fafu.edu.cn.; Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou 350002, China. fankai@fafu.edu.cn.; College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. fankai@fafu.edu.cn.; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China. lwx@fafu.edu.cn.; Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, Fujian Agriculture and Forestry University, Fuzhou 350002, China. lwx@fafu.edu.cn.
Early leaf senescence is an important agronomic trait that affects crop yield and quality. To understand the molecular mechanism of early leaf senescence, Oryza sativa premature leaf senescence 1 (ospls1) mutant rice with a deletion of OsVHA-A and its wild type were employed in this study. The genotype-dependent differences in photosynthetic indexes, senescence-related physiological parameters, and yield characters were investigated during the grain-filling stage. Moreover, RNA sequencing (RNA-seq) was performed to determine the genotype differences in transcriptome during the grain-filling stage. Results showed that the ospls1 mutant underwent significant decreases in the maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), net photosynthesis rate (Pn), and soluble sugar and protein, followed by the decreases in OsVHA-A transcript and vacuolar H(+)-ATPase activity. Finally, yield traits were severely suppressed in the ospls1 mutant. RNA-seq results showed that 4827 differentially expressed genes (DEGs) were identified in ospls1 mutant between 0 day and 14 days, and the pathways of biosynthesis of secondary metabolites, carbon fixation in photosynthetic organisms, and photosynthesis were downregulated in the senescing leaves of ospls1 mutant during the grain-filling stage. In addition, 81 differentially expressed TFs were identified to be involved in leaf senescence. Eleven DEGs related to hormone signaling pathways were significantly enriched in auxin, cytokinins, brassinosteroids, and abscisic acid pathways, indicating that hormone signaling pathways participated in leaf senescence. Some antioxidative and carbohydrate metabolism-related genes were detected to be differentially expressed in the senescing leaves of ospls1 mutant, suggesting that these genes probably play response and regulatory roles in leaf senescence.
PMID: 30836615
J Agric Food Chem , IF:4.192 , 2019 Mar , V67 (10) : P2811-2817 doi: 10.1021/acs.jafc.8b04996
New Alkylitaconic Acid Derivatives from Nodulisporium sp. A21 and Their Auxin Herbicidal Activities on Weed Seeds.
College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application , Nanjing Agricultural University , Nanjing 210095 , P. R. China.; Key Laboratory of Integrated Management of Crop Diseases and Pests , Ministry of Education , Nanjing 210095 , P. R. China.; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences , Nanjing University , Nanjing 210023 , P. R. China.
Five alkylitaconic acid (AA) derivatives, including two novel compounds, epideoxysporothric acid (2) and sporochartine F (5), and three known compounds, deoxysporothric acid (1), deoxyisosporothric acid (3), and 1-undecen-2,3-dicarboxylic acid (4), were obtained from the fermentation culture of the endophytic fungus Nodulisporium sp. A21. The auxin herbicidal activities of compounds 1-4 against weed seeds were investigated under laboratory conditions. In general, the tested compounds displayed radicle growth promoting activity at low doses and inhibitory activity at higher doses. Compounds 1 and 2 could significantly inhibit the radicle growth of dicotyledon weeds, Eclipta prostrata and Veronica persica, at a concentration range from 50 to 200 mug mL(-1), while 3 notably stimulated radicle growth at the same concentration range. The results suggested that these AA derivatives have the potential to be used as the lead scaffold for novel auxin herbicide development. In addition, the biosynthetic pathways of 1-4 were deduced based on (13)C labeling experiment.
PMID: 30789727
Sci Rep , IF:3.998 , 2019 Mar , V9 (1) : P3983 doi: 10.1038/s41598-019-40657-9
Transcriptomics of cytokinin and auxin metabolism and signaling genes during seed maturation in dormant and non-dormant wheat genotypes.
Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.; Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada. belay.ayele@umanitoba.ca.
To gain insights into the roles of cytokinin (CK) and auxin in regulating dormancy during seed maturation in wheat, we examined changes in the levels of CK and indole-3-acetic acid (IAA) and expression patterns of their metabolism and signaling genes in embryonic and endospermic tissues of dormant and non-dormant genotypes. Seed maturation was associated with a decrease in the levels of isopentenyladenine in both tissues mainly via repression of the CK biosynthetic TaLOG genes. Differential embryonic trans-zeatin content and expression patterns of the CK related genes including TacZOG, TaGLU and TaARR12 between maturing seeds of the two genotypes implicate CK in the control of seed dormancy induction and maintenance. Seed maturation induced a decrease of IAA level in both tissues irrespective of genotype, and this appeared to be mediated by repression of specific IAA biosynthesis, transport and IAA-conjugate hydrolysis genes. The differential embryonic IAA content and expression pattern of the IAA biosynthetic gene TaAO during the early stage of seed maturation between the two genotypes imply the role of IAA in dormancy induction. It appears from our data that the expression of specific auxin signaling genes including TaRUB, TaAXR and TaARF mediate the role of auxin signaling in dormancy induction and maintenance during seed maturation in wheat.
PMID: 30850728
Plant Cell Rep , IF:3.825 , 2019 Mar , V38 (3) : P279-293 doi: 10.1007/s00299-018-2361-y
Transcriptome analysis revealed the interaction among strigolactones, auxin, and cytokinin in controlling the shoot branching of rice.
Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China.; College of Biology and Environmental Sciences, Jishou University, Jishou, 416000, People's Republic of China.; Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha, 40100, Pakistan.; Forest and Fruit Tree Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, People's Republic of China.; Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, People's Republic of China.; Agronomy College, Nanjing Agricultural University, Nanjing, People's Republic of China. wangsh@njau.edu.cn.; Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, 210095, People's Republic of China. wangsh@njau.edu.cn.
KEY MESSAGE: Strigolactones inhibit bud growth by negatively regulating the auxin transport without changing the auxin biosynthesis and suppressing the expression of A-ARR in buds. Strigolactones (SLs) are important phytohormones associated with regulation of shoot branching in rice. Rice shoot branching is persuasively mediated by plant hormones like auxin, cytokinins (CKs) and SLs. The interactions among these hormones were diversely investigated by many researchers but remained a subject of debate. In the present study, the removal of panicle and application of subsequent synthetic SLs were used to regulate rice bud growth on node 2 (the second node from panicle) at full heading stage. The bud growth was significantly induced after panicle removal but GR24 (synthetic SLs) application inhibited it, along with variations in endogenous hormone contents in bud. RNA samples from buds were subjected to RNA sequencing through Illumina HiSeq 2000 (RNA-seq). Comparison of transcript expression levels among three treatments, viz. (1) intact (Co), (2) removed panicle (RP) and (3) RP combined with synthetic SL GR24 (GR) revealed the involvement of numerous genes associated with hormone signal transduction. GR24 supply minimized the RP-induced enhancement of auxin early response genes, independent of ARF. CK signal transduction was also induced by RP, but type-A ARR were the only genes responding to GR without any other CK signal associated genes. Additionally, RP and GR can also modulate auxin transport and CK degradation by regulating the genes' expression involved in the biosynthesis of flavonoid, phenylpropanoid and benzoxazinoid. Contemplating the results obtained so far, it is possible to open new vistas of research to reveal the interactions among SLs, auxin and CK in controlling the shoot branching of rice.
PMID: 30689021
Genes (Basel) , IF:3.759 , 2019 Mar , V10 (3) doi: 10.3390/genes10030213
RNA-Seq Transcriptome Analysis of Rice Primary Roots Reveals the Role of Flavonoids in Regulating the Rice Primary Root Growth.
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China. xy13101391509@163.com.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. xy13101391509@163.com.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. zoujunjie@caas.cn.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. zhenghongyan@caas.cn.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. xumiaoyun@caas.cn.; College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China. zxfeng@swu.edu.cn.; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. wanglei01@caas.cn.
Flavonoids play important roles in root development and in its tropic responses, whereas the flavonoids-mediated changes of the global transcription levels during root growth remain unclear. Here, the global transcription changes in quercetin-treated rice primary roots were analyzed. Quercetin treatment significantly induced the inhibition of root growth and the reduction of H(2)O(2) and O(2)(-) levels. In addition, the RNA-seq analysis revealed that there are 1243 differentially expressed genes (DEGs) identified in quercetin-treated roots, including 1032 up-regulated and 211 down-regulated genes. A gene ontology (GO) enrichment analysis showed that the enriched GO terms are mainly associated with the cell wall organization, response to oxidative stress, and response to hormone stimulus. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis showed that the enriched DEGs are involved in phenylpropanoid biosynthesis, glutathione metabolism, and plant hormone signal transduction. Moreover, the quercetin treatment led to an increase of the antioxidant enzyme activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in rice roots. Also, the quercetin treatment altered the DR5:GUS expression pattern in the root tips. All of these data indicated that the flavonoids-mediated transcription changes of genes are related to the genes involved in cell wall remodeling, redox homeostasis, and auxin signaling, leading to a reduced cell division in the meristem zone and cell elongation in the elongation zone of roots.
PMID: 30871177
BMC Genomics , IF:3.594 , 2019 Mar , V20 (1) : P237 doi: 10.1186/s12864-019-5599-z
RNA-Seq analysis reveals transcript diversity and active genes after common cutworm (Spodoptera litura Fabricius) attack in resistant and susceptible wild soybean lines.
National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, 210095, China.; Jiangsu Academy of Agricultural Sciences, Provincial Key Laboratory of Agrobiology, Institute of Germplasm Resources and Biotechnology, Nanjing, 210014, China.; College of Chemistry and Chemical Engineering, Key Laboratory of Ecological Restoration in Hilly Area, PingDingshan University, Pingdingshan, 467000, China.; National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, 210095, China. wanghui0@njau.edu.cn.; National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, 210095, China. dyyu@njau.edu.cn.
BACKGROUND: Common cutworm (CCW) is highly responsible for destabilizing soybean productivity. Wild soybean is a resource used by breeders to discover elite defensive genes. RESULTS: The transcriptomes of two wild accessions (W11 and W99) with different resistance to CCW were analyzed at early- and late-induction time points. After induction, the susceptible accession W11 differentially expressed 1268 and 508 genes at the early and late time points, respectively. Compared with W11, the resistant accession W99 differentially expressed 1270 genes at the early time point and many more genes (2308) at the late time point. In total, 3836 non-redundant genes were identified in both lines. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the differentially expressed genes (DEGs) in W99 at the late time point were mostly associated with specific processes and pathways. Among the non-redundant genes, 146 genes were commonly up-regulated in the treatment condition compared with the control condition at the early- and late-induction time points in both accessions used in this experiment. Approximately 40% of the common DEGs were related to secondary metabolism, disease resistance, and signal transduction based on their putative function. Excluding the common DEGs, W99 expressed more unique DEGs than W11. Further analysis of the 3836 DEGs revealed that the induction of CCW not only up-regulated defense-related genes, including 37 jasmonic acid (JA)-related genes, 171 plant-pathogen-related genes, and 17 genes encoding protease inhibitors, but also down-regulated growth-related genes, including 35 photosynthesis-related genes, 48 nutrition metabolism genes, and 28 auxin metabolism genes. Therefore, representative defense-related and growth-related genes were chosen for binding site prediction via co-expression of transcription factors (TFs) and spatial expression pattern analyses. In total, 53 binding sites of 28 TFs were identified based on 3 defense-related genes and 3 growth-related genes. Phosphate transporter PT1, which is a representative growth-related gene, was transformed into soybean, and the transgenic soybean plants were susceptible to CCW. CONCLUSIONS: In summary, we described transcriptome reprograming after herbivore induction in wild soybean, identified the susceptibility of growth-related genes, and provided new resources for the breeding of herbivore-resistant cultivated soybeans.
PMID: 30902045
Plant Sci , IF:3.591 , 2019 Mar , V280 : P51-65 doi: 10.1016/j.plantsci.2018.11.001
Hormone balance in a climacteric plum fruit and its non-climacteric bud mutant during ripening.
Department of Plant Sciences, University of California, Davis CA 95616, USA.; Department of Plant Sciences, University of California, Davis CA 95616, USA; Department of Molecular Biology & Ecology of Plants, Tel Aviv University, Tel Aviv, 69978 Israel.; CEBAS, CSIC, Murcia, Spain.; Department of Fruit Tree Sciences, ARO, The Volcani Center, Rishon LeZion, Israel.; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S3B2, Canada.; Department of Plant Sciences, University of California, Davis CA 95616, USA. Electronic address: eblumwald@ucdavis.edu.
Hormone balance plays a crucial role in the control of fruit ripening. We characterized and compared hormone balance in two Japanese plum cultivars (Prunus salicina Lindl.), namely Santa Rosa, a climacteric type, and Sweet Miriam, its non-climacteric bud-sport mutant. We assessed hormonal changes in gene expression associated with hormone biosynthesis, perception and signaling during ripening on-the tree and throughout postharvest storage and in response to ethylene treatments. Non-climacteric fruit displayed lower ethylene levels than climacteric fruit at all stages and lower auxin levels during the initiation of ripening on-the-tree and during most of post-harvest storage. Moreover, 1-MCP-induced ethylene decrease also resulted in low auxin contents in Santa Rosa, supporting the role of auxin in climacteric fruit ripening. The differences in auxin contents between Santa Rosa and Sweet Miriam fruit could be the consequence of different routed auxin biosynthesis pathways as indicated by the significant negative correlations between clusters of auxin metabolism-associated genes. Ethylene induced increased ABA levels throughout postharvest storage in both ripening types. Overall, ripening of Santa Rosa and Sweet Miriam fruit are characterized by distinct hormone accumulation pathways and interactions.
PMID: 30824029
Plant Sci , IF:3.591 , 2019 Mar , V280 : P383-396 doi: 10.1016/j.plantsci.2018.12.029
Hypomethylated drm1 drm2 cmt3 mutant phenotype of Arabidopsis thaliana is related to auxin pathway impairment.
Dipartimento di Biologia, Ecologia e Scienze della Terra, Universita della Calabria, Arcavacata di Rende (CS), 87036 Arcavacata di Rende, CS, Italy; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium; Center Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Dipartimento di Biologia, Ecologia e Scienze della Terra, Universita della Calabria, Arcavacata di Rende (CS), 87036 Arcavacata di Rende, CS, Italy.; Dipartimento di Biologia, Ecologia e Scienze della Terra, Universita della Calabria, Arcavacata di Rende (CS), 87036 Arcavacata di Rende, CS, Italy; The Francis Crick Institute, London NW1 1AT, United Kingdom.; Dipartimento di Agraria, Universita Mediterranea di Reggio Calabria, 89124 Reggio Calabria, Italy.; Dipartimento di Biologia, Ecologia e Scienze della Terra, Universita della Calabria, Arcavacata di Rende (CS), 87036 Arcavacata di Rende, CS, Italy. Electronic address: leonardo.bruno@unical.it.
DNA methylation carried out by different methyltransferase classes is a relevant epigenetic modification of DNA which plays a relevant role in the development of eukaryotic organisms. Accordingly, in Arabidopsis thaliana loss of DNA methylation due to combined mutations in genes encoding for DNA methyltransferases causes several developmental abnormalities. The present study describes novel growth disorders in the drm1 drm2 cmt3 triple mutant of Arabidopsis thaliana, defective both in maintenance and de novo DNA methylation, and highlights the correlation between DNA methylation and the auxin hormone pathway. By using an auxin responsive reporter gene, we discovered that auxin accumulation and distribution were affected in the mutant compared to the wild type, from embryo to adult plant stage. In addition, we demonstrated that the defective methylation status also affected the expression of genes that regulate auxin hormone pathways from synthesis to transport and signalling and a direct relationship between differentially expressed auxin-related genes and altered auxin accumulation and distribution in embryo, leaf and root was observed. Finally, we provided evidence of the direct and organ-specific modulation of auxin-related genes through the DNA methylation process.
PMID: 30824017
Plant Sci , IF:3.591 , 2019 Mar , V280 : P355-366 doi: 10.1016/j.plantsci.2018.12.023
Genetic engineering of the biosynthesis of glycinebetaine enhances the fruit development and size of tomato.
College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China.; Department of Horticulture, ALS 4017, Oregon State University, Corvallis, OR, 97331, USA.; College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China. Electronic address: xhyang@sdau.edu.cn.
Glycinebetaine has been widely considered as an effective protectant against abiotic stress in plants, and also found to promote plant growth under normal growing conditions, especially during the reproductive stage. Betaine aldehyde dehydrogenase (BADH) and choline oxidase (COD) are two key enzymes which have been used to confer glycinebetaine synthesis in plant which normally does not synthesis glycinebetaine. In this study, we used the tomato (Solanum lycopersicum, cv 'Moneymaker') plants of wild-type and the transgenic lines codA (L1, L2) and BADH (2, 46), which were transformed with codA and BADH, respectively, to study the impact of glycinebetaine on tomato fruit development. Our results showed that the codA and BADH transgenes induced the formation of enlarged flowers and fruits in transgenic tomato plants. In addition, the transgenic tomato plants had a higher photosynthetic rate, higher assimilates content, and higher leaf chlorophyll content than the wild-type plants. We also found that the enlargement of fruit size was related to the contents of phytohormones, such as auxin, brassinolide, gibberellin, and cytokinin. Additionally, qPCR results indicated that the expressions levels of certain genes related to fruit growth and development were also elevated in transgenic plants. Finally, transcriptome sequencing results revealed that the differences in the levels of gene expression in tomato fruit between the transgenic and wild-type plants were observed in multiple pathways, predominantly those of photosynthesis, DNA replication, plant hormone signal transduction, and biosynthesis. Taken together, our results suggest that glycinebetaine promotes tomato fruit development via multiple pathways. We propose that genetic engineering of glycinebetaine synthesis offers a novel approach to enhance the productivity of tomato and other crop plants.
PMID: 30824015
Plant Sci , IF:3.591 , 2019 Mar , V280 : P31-40 doi: 10.1016/j.plantsci.2018.11.009
Integration of RACK1 and ethylene signaling regulates plant growth and development in Arabidopsis.
Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: 838438746@qq.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: wangxutong0019@163.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: wangxp439@nenu.edu.cn.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: botanist1@yahoo.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: botanistonline@yahoo.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: zhangna-0452@qq.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China. Electronic address: xym.candy@foxmail.com.; Key Laboratory of Molecular Epigenetics of MOE, Northeast Normal University, Changchun, China; College of Life Science, Linyi University, Linyi, China. Electronic address: wangsc550@nenu.edu.cn.
Arabidopsis RACK1 (Receptors for Activated C Kinase 1) are versatile scaffold proteins that have been shown to be involved in the regulation of plant response to plant hormones including auxin, ABA, gibberellin and brassinosteroid, but not ethylene. By characterizing the double and triple mutants of RACK1 genes, we found that rack1 mutants showed reduced sensitivity to ethylene. By characterizing double and high order mutants generated between ein2, a loss-of-function mutant of the key ethylene signaling regulator gene EIN2 (Ethylene INsensitive 2), and rack1 mutants, we found that loss-of-function of EIN2 partially recovered some phenotypes observed in the rack1 mutants, such as low-fertility and reduced root length and rosette size. On the other hand, the ein2 rack1 mutants produced more rosette leaves, and flowered late when compared with ein2 and the corresponding rack1 mutants. We also found that the curled leaves and twisted petioles phenotypes observed in the ein2 mutants were enhanced in the ein2 rack1 mutants. However, assays in yeast indicated that EIN2 may not physically interact with RACK1. On the other hand, RT-PCR results showed that the expression level of EIN2 was reduced in the rack1 mutants. Taken together, our results suggest that RACKl may integrate ethylene signaling to regulate plant growth and development in Arabidopsis.
PMID: 30824009
Plant Sci , IF:3.591 , 2019 Mar , V280 : P175-186 doi: 10.1016/j.plantsci.2018.11.019
CONSTITUTIVE TRIPLE RESPONSE1 and PIN2 act in a coordinate manner to support the indeterminate root growth and meristem cell proliferating activity in Arabidopsis seedlings.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Molecular and Developmental Complexity Group, Unidad de Genomica Avanzada, Laboratorio Nacional de Genomica para la Biodiversidad, Centro de Investigacion y de Estudios Avanzados del IPN, Campus Irapuato, Guanajuato, Mexico.; Departamento de Ingenieria Genetica, Centro de Investigacion y de Estudios Avanzados del IPN, Campus Irapuato, Guanajuato, Mexico.; Facultad de Biologia, Universidad Michoacana de San Nicolas de Hidalgo, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Red de estudios moleculares avanzados, Instituto de Ecologia A. C., Carretera Antigua a Coatepec 351, El Haya, C. P. 91070, Xalapa, Veracruz, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico. Electronic address: jbucio@umich.mx.
The plant hormone ethylene induces auxin biosynthesis and transport and modulates root growth and branching. However, its function on root stem cells and the identity of interacting factors for the control of meristem activity remains unclear. Genetic analysis for primary root growth in wild-type (WT) Arabidopsis thaliana seedlings and ethylene-related mutants showed that the loss-of-function of CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) inhibits cell division and elongation. This phenotype is associated with an increase in the expression of the auxin transporter PIN2 and a drastic decrease in the expression of key factors for stem cell niche maintenance such as PLETHORA1, SHORT ROOT and SCARECROW. While the root stem cell niche is affected in ctr1 mutants, its maintenance is severely compromised in the ctr1-1eir1-1(pin2) double mutant, in which an evident loss of proliferative capacity of the meristematic cells leads to a fully differentiated root meristem shortly after germination. Root traits affected in ctr1-1 mutants could be restored in ctr1-1ein2-1 double mutants. These results reveal that ethylene perception via CTR1 and EIN2 in the root modulates the proliferative capacity of root stem cells via affecting the expression of genes involved in the two major pathways, AUX-PIN-PLT and SCR-SHR, which are key factors for proper root stem cell niche maintenance.
PMID: 30823995
Plant Sci , IF:3.591 , 2019 Mar , V280 : P1-11 doi: 10.1016/j.plantsci.2018.11.004
The moss jasmonate ZIM-domain protein PnJAZ1 confers salinity tolerance via crosstalk with the abscisic acid signalling pathway.
Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266000, People's Republic of China; Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, People's Republic of China.; Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266000, People's Republic of China.; Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266000, People's Republic of China. Electronic address: xiagm@sdu.edu.cn.
Abscisic acid (ABA) and jasmonates (JAs) are the primary plant hormones involved in mediating salt tolerance. In addition, these two plant hormones exert a synergistic effect to inhibit seed germination. However, the molecular mechanism of the interaction between ABA signalling and JA signalling is still not well documented. Here, a moss jasmonate ZIM-domain gene (PnJAZ1), which encodes a nucleus-localized protein with conserved ZIM and Jas domains, was cloned from Pohlia nutans. PnJAZ1 expression was rapidly induced by various abiotic stresses. The PnJAZ1 protein physically interacted with MYC2 and was degraded by exogenous 12-oxo-phytodienoic acid (OPDA) treatment, implying that the JAZ protein-mediated signalling pathway is conserved in plants. Transgenic Arabidopsis and Physcomitrella plants overexpressing PnJAZ1 showed increased tolerance to salt stress and decreased ABA sensitivity during seed germination and early development. The overexpression of PnJAZ1 inhibited the expression of ABA pathway genes related to seed germination and seedling growth. Moreover, the transgenic Arabidopsis lines exhibited enhanced tolerance to auxin (IAA) and glucose, mimicking the phenotypes of abi4 or abi5 mutants. These results suggest that PnJAZ1 acts as a repressor, mediates JA-ABA synergistic crosstalk and enhances plant growth under salt stress.
PMID: 30823987
BMC Plant Biol , IF:3.497 , 2019 Mar , V19 (1) : P112 doi: 10.1186/s12870-019-1709-y
Mal de Rio Cuarto virus infection causes hormone imbalance and sugar accumulation in wheat leaves.
Instituto de Biotecnologia, CICVyA, INTA, CONICET, Hurlingham, Buenos Aires, Argentina.; Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany Czech Academy of Sciences, Slechtitelu 27, CZ-78371, Olomouc, Czech Republic.; Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.; Instituto de Patologia Vegetal, CIAP, INTA, Cordoba, Argentina.; Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA.; Instituto de Agrobiotecnologia del Litoral, UNL, CONICET, FBCB, Santa Fe, Argentina.; Instituto de Biotecnologia, CICVyA, INTA, CONICET, Hurlingham, Buenos Aires, Argentina. delvas.mariana@inta.gob.ar.
BACKGROUND: Mal de Rio Cuarto virus (MRCV) infects several monocotyledonous species including maize and wheat. Infected plants show shortened internodes, partial sterility, increased tillering and reduced root length. To better understand the molecular basis of the plant-virus interactions leading to these symptoms, we combined RNA sequencing with metabolite and hormone measurements. RESULTS: More than 3000 differentially accumulated transcripts (DATs) were detected in MRCV-infected wheat plants at 21 days post inoculation compared to mock-inoculated plants. Infected plants exhibited decreased levels of TaSWEET13 transcripts, which are involved in sucrose phloem loading. Soluble sugars, starch, trehalose 6-phosphate (Tre6P), and organic and amino acids were all higher in MRCV-infected plants. In addition, several transcripts related to plant hormone metabolism, transport and signalling were increased upon MRCV infection. Transcripts coding for GA20ox, D14, MAX2 and SMAX1-like proteins involved in gibberellin biosynthesis and strigolactone signalling, were reduced. Transcripts involved in jasmonic acid, ethylene and brassinosteroid biosynthesis, perception and signalling and in auxin transport were also altered. Hormone measurements showed that jasmonic acid, brassinosteroids, abscisic acid and indole-3-acetic acid were significantly higher in infected leaves. CONCLUSIONS: Our results indicate that MRCV causes a profound hormonal imbalance that, together with alterations in sugar partitioning, could account for the symptoms observed in MRCV-infected plants.
PMID: 30902042
BMC Plant Biol , IF:3.497 , 2019 Mar , V19 (1) : P111 doi: 10.1186/s12870-019-1719-9
VvmiR160s/VvARFs interaction and their spatio-temporal expression/cleavage products during GA-induced grape parthenocarpy.
College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; Department of Botany, Faculty of Sciences, Aswan University, Aswan, 81528, Egypt.; Arid Land Research Center, Tottori University, Tottori, 680-001, Japan.; Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.; College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. wangchen@njau.edu.cn.
BACKGROUND: Grape (Vitis vinifera) is highly sensitive to gibberellin (GA), which effectively induce grape parthenocarpy. Studies showed that miR160s and their target AUXIN RESPONSIVE FACTOR (ARF) responding hormones are indispensable for various aspects of plant growth and development, but their functions in GA-induced grape parthenocarpy remain elusive. RESULTS: In this study, the morphological changes during flower development in response to GA treatments were examined in the 'Rosario Bianco' cultivar. The precise sequences of VvmiR160a/b/c/d/e and their VvARF10/16/17 target genes were cloned, sequenced and characterized. The phylogenetic relationship and intron-exon structure of VvARFs and other ARF family members derived from different species were investigated. All VvmiR160s (except VvmiR160b) and VvARF10/16/17 had the common cis-elements responsive to GA, which support their function in GA-mediated grape parthenocarpy. The cleavage role of VvmiR160s-mediated VvARF10/16/17 was verified in grape flowers. Moreover, spatio-temporal expression analysis demonstrated that among VvmiR160 family, VvmiR160a/b/c highly expressed at late stage of flower/berry development, while VvARF10/16/17showed a reverse expression trend. Interestingly, GA exhibited a long-term effect through inducing the expression of VvmiR160a/b/c/e to increase their cleavage product accumulations from 5 to 9 days after treatment, but GA enhanced the expressions of VvARF10/16/17 only at short term. Pearson correlation analysis based on expression data revealed a negative correlation between VvmiR160a/b/c and VvARF10/16/17 in flowers not berries during GA-induced grape parthenocarpy. CONCLUSIONS: This work demonstrated that the negative regulation of VvARF10/16/17 expression by VvmiR160a/b/c as key regulatory factors is critical for GA-mediated grape parthenocarpy, and provide significant implications for molecular breeding of high-quality seedless berry.
PMID: 30898085
BMC Plant Biol , IF:3.497 , 2019 Mar , V19 (1) : P100 doi: 10.1186/s12870-019-1698-x
Identification and analysis of oxygen responsive microRNAs in the root of wild tomato (S. habrochaites).
College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; College of Horticulture, Henan Agricultural University, Zhengzhou, 450002, China.; College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. zpzxyy@163.com.
BACKGROUND: MicroRNA (miRNA) are key players in regulating expression of target genes at post-transcriptional level. A number of miRNAs are implicated in modulating tolerance to various abiotic stresses. Waterlogging is an abiotic stress that deters plant growth and productivity by hypoxia. Dozens of reports mention about the miRNAs expressed in response to waterlogging and hypoxia. Despite the fact that tomato is a model vegetable but waterlogging sensitive crop, the role of miRNAs in hypoxia tolerance is poorly understood in tomato. RESULTS: In this study, we investigated the differentially expressed miRNAs between hypoxia-treated and untreated wild tomato root by using high-throughput sequencing technology. A total of 33 known miRNAs were lowly expressed, whereas only 3 miRNAs showed higher expression in hypoxia-treated wild tomato root compared with untreated wild tomato root. Then two conserved and lowly expressed miRNAs, miR171 and miR390, were deactivated by Short Tandem Target Mimic (STTM) technology in Arabidopsis. As the results, the number and length of lateral roots were more in STTM171 and STTM390 transgenic lines compared with that of wild type plant, which partly phenocopy the increase root number and shortening the root length in hypoxia-treated wild tomato root. CONCLUSIONS: The differentially expressed miRNAs between hypoxia-treated wild tomato and control root, which contribute to the auxin homeostasis, morphologic change, and stress response, might result in reduction in the biomass and length of the root in hypoxiated conditions.
PMID: 30866807
Planta , IF:3.39 , 2019 Mar , V249 (3) : P693-707 doi: 10.1007/s00425-018-3027-2
Characterization of genome-wide microRNAs and their roles in development and biotic stress in pear.
Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193, China.; Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193, China. jiangfeng@cau.edu.cn.; Laboratory of Fruit Cell and Molecular Breeding, China Agricultural University, Beijing, 100193, China. litianzhong1535@163.com.
MAIN CONCLUSION: Using a genome-wide analysis of miRNAs in 'Yali' pear (Pyrus bretschneideri) via the next-generation high-throughput sequencing of small RNAs with a bioinformatics analysis, we found that pbr-miR156, pbr-miR164, pbr-miR399, and pbr-miR482 and their target genes function in viral defense in 'Duli' and 'Hongbaoshi'. pbr-miR160, pbr-miR168, pbr-miR171, and pbr-miR319 and their targets function in auxin signaling pathways in 'Zhongai 4' and 'Zhongai 5'. Successful fruit production in pear (Pyrus spp.) depends on the use of optimal combinations of rootstocks and scions. Deciphering plant-pathogen defense mechanisms and hormone signaling pathways is an important step towards developing pear rootstocks and varieties with improved qualities. In the current study, we combined next-generation sequencing of small RNAs with a bioinformatics analysis to systematically identify and characterize 298 miRNAs in the pear scion cultivar 'Yali' (Pyrus bretschneideri). We also analyzed miRNAs in three rootstock varieties ('Duli', 'Zhongai 4', and 'Zhongai 5') and one scion cultivar ('Hongbaoshi'). We found that pbr-miR156, pbr-miR164, pbr-miR399, and pbr-miR482 are induced following infection with the pear virus Apple stem pitting virus (ASPV), and identified their target genes (pbRPS6, pbNAC, pbTLR, and pbRX-CC, respectively), which participate in viral defense pathways in 'Duli' and 'Hongbaoshi'. Furthermore, we identified pbr-miR160, pbr-miR168, pbr-miR171, and pbr-miR319, and found that the production of these miRNAs was suppressed under low levels of synthetic auxin. The targets of these miRNAs (pbARF, pbAEC, pbSCL, and pbTCP4) respond to auxin signaling pathways in 'Zhongai 4' and 'Zhongai 5'. Our results lay the foundation for breeding improved pear cultivars.
PMID: 30368557
Planta , IF:3.39 , 2019 Mar , V249 (3) : P635-646 doi: 10.1007/s00425-018-3029-0
Ploidy and hybridity effects on leaf size, cell size and related genes expression in triploids, diploids and their parents in Populus.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Key Laboratory of Forest Trees and Ornamental Plants Biological Engineering of State Forestry Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.; Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA.; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Key Laboratory of Forest Trees and Ornamental Plants Biological Engineering of State Forestry Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China. zjf@bjfu.edu.cn.
MAIN CONCLUSION: Cell-size enlargement plays a pivotal role in increasing the leaf size of triploid poplar, and polyploidization could change leaf shape. ABP1 was highly expressed in triploid plants and positively related to cell size. In the plant kingdom, the leaf is the most important energy production organ, and polyploidy often exhibits a "Gigas" effect on leaf size, which benefits agriculture and forestry. However, little is known regarding the cellular and molecular mechanisms underlying the leaf size superiority of polyploid woody plants. In the present study, the leaf area and abaxial epidermal cells of diploid and triploid full-sib groups and their parents were measured at three different positions. We measured the expression of several genes related to cell division and cell expansion. The results showed that the leaf area of triploids was significantly larger than that of diploids, and the triploid group showed transgressive variation compared to their full-sib diploid group. Cell size but not cell number was the main reason for leaf size variation. Cell expansion was in accordance with leaf enlargement. In addition, the leaf shape changes in triploids primarily resulted from a significant decrease in the leaf ratio of length to -width. Auxin-binding protein 1 (ABP1) was highly expressed in triploids and positively related to leaf size. These results enhanced the current understanding that giant leaf is affected by polyploidy vigor. However, significant heterosis is not exhibited in diploid offspring. Overall, polyploid breeding is an effective strategy to enhance leaf size, and Populus, as an ideal material, plays an important role in studying the leaf morphological variations of polyploid woody plants.
PMID: 30327883
Gene , IF:2.984 , 2019 Mar , V690 : P90-98 doi: 10.1016/j.gene.2018.12.049
Isolation and characterization of larch BABY BOOM2 and its regulation of adventitious root development.
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Xiangshan Rd., Beijing 100091, PR China; Research Institute of Forestry, Chinese Academy of Forestry, Xiangshan Rd., Beijing 100091, PR China.; Guangxi Forestry Research Institute, No.23, Yongwu Road, Xixiangtang District, Nanning, Guangxi Province, PR China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Xiangshan Rd., Beijing 100091, PR China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Xiangshan Rd., Beijing 100091, PR China; Research Institute of Forestry, Chinese Academy of Forestry, Xiangshan Rd., Beijing 100091, PR China. Electronic address: shougong.zhang@caf.ac.cn.
The BABY BOOM2 gene, designated LkBBM2, and its promoter were isolated from hybrid larch (Larix kaempferixL. olgensis). The open reading frame of LkBBM2 was 2574bp, encoding 857 amino acids. The LkBBM2 protein contains two AP2 DNA binding domains and a BBM specific motif, but lacks the euANT5 motif common to AP2 family members. The LkBBM2 promoter contains several hormone response and root-specific expression elements. LkBBM2 expression was significantly higher in larch adventitious roots (ARs) than in stems, leaves or stem tips, and increased after auxin treatment. The fused protein LkBBM2-GFP was localized in both the nucleus and cytoplasm whereas LkBBM1-GFP was only localized in the nucleus. Over-expression of LkBBM2 and LkBBM1 in Arabidopsis significantly elongated the roots. Furthermore, over-expression those two genes in the hybrid poplar (Populus albaxP. glandulosa) significantly increased ARs number. We speculated that these two genes regulate AR development.
PMID: 30597235
Funct Plant Biol , IF:2.617 , 2019 Mar , V46 (4) : P360-375 doi: 10.1071/FP18076
Hydroponic grown tobacco plants respond to zinc oxide nanoparticles and bulk exposures by morphological, physiological and anatomical adjustments.
Department of Biology, Plant Physiology, Faculty of Science, Lorestan University, Khoramabad-Tehran Road (5th K), Iran.; Department of Biology, Plant Physiology, Faculty of Science, Lorestan University, Khoramabad-Tehran Road (5th K), Iran; and Corresponding author. Emails: madadkar.m@lu.ac.ir; m_madadkar@yahoo.com.; Department of Agronomy and Plant Breeding, Faculty of Agriculture, Lorestan University, Iran.
Zinc oxide nanoparticles (NPs) are the third highest in terms of global production among the various inorganic nanoparticles, and there are concerns because of their worldwide availability and accumulation in the environment. In contrast, zinc is an essential element in plant growth and metabolism, and ZnO NPs (nano-ZnO) may have unknown interactions with plants due to their small sizes as well as their particular chemical and physical characteristics. The present study examined the effect of nano-ZnO (25nm) and bulk or natural form (<1000nm, bulk-ZnO), compared with zinc in the ionic form (ZnSO4) on Nicotiana tabacum seedlings in a nutrient solution supplemented with either nano-ZnO, bulk-ZnO (0.2, 1, 5 and 25microM) or ZnSO4 (control) for 21 days. Results showed that nano-ZnO at most of the levels and 1microM bulk-ZnO positively affected growth (root and shoot length/dry weight), leaf surface area and its metabolites (auxin, phenolic compounds, flavonoids), leaf enzymatic activities (CAT, APX, SOD, POX, GPX, PPO and PAL) and anatomical properties (root, stem, cortex and central cylinder diameters), while bulk-ZnO caused decreases at other levels. The activities of enzymes were induced to a greater extent by intermediate nano-ZnO levels than by extreme concentrations, and were higher in nano-ZnO treated than in bulk treated tobacco. As the ZnO level increased, the vascular expansion and cell wall thickening of the collenchyma/parenchyma cells occurred, which was more pronounced when treated by NPs than by its counterpart. The Zn content of root and leaf increased in most of ZnO treatments, whereas the Fe content of leaves decreased. Our findings indicate that tobacco responded positively to 1microM bulk-ZnO and to nearly all nano-ZnO levels (with the best levels being at 0.2microM and 1microM) by morphological, physiological and anatomical adjustments.
PMID: 32172745
Plant Biol (Stuttg) , IF:2.167 , 2019 Mar , V21 (2) : P326-335 doi: 10.1111/plb.12927
Responses of the weed Bidens pilosa L. to exogenous application of the steroidal saponin protodioscin and plant growth regulators 24-epibrassinolide, indol-3-acetic acid and abscisic acid.
Department of Biochemistry, University of Maringa, Maringa, Brazil.; Department of Sciences of Nature, Federal University of Acre, Rio Branco, Brazil.; Department of Agronomy, University of Londrina, Londrina, Brazil.
The exogenous application of plant hormones and their analogues has been exploited to improve crop performance in the field. Protodioscin is a saponin whose steroidal moiety has some similarities to plant steroidal hormones, brassinosteroids. To test the possibility that protodioscin acts as an agonist or antagonist of brassinosteroids or other plant growth regulators, we compared responses of the weed species Bidens pilosa L. to treatment with protodioscin, brassinosteroids, auxins (IAA) and abscisic acid (ABA). Seeds were germinated and grown in agar containing protodioscin, dioscin, brassinolides, IAA and ABA. Root apex respiratory activity was measured with an oxygen electrode. Malondialdehyde (MDA) and antioxidant enzymes activities were assessed. Protodioscin at 48-240 mum inhibited growth of B. pilosa seedlings. The steroidal hormone 24-epibrassinolide (0.1-5 mum) also inhibited growth of primary roots, but brassicasterol was inactive. IAA at higher concentrations (0.5-10.0 mum) strongly inhibited primary root length and fresh weight of stems. ABA inhibited all parameters of seedling growth and also seed germination. Respiratory activity of primary roots (KCN-sensitive and KCN-insensitive) was activated by protodioscin. IAA and ABA reduced KCN-insensitive respiration. The content of MDA in primary roots increased only after protodioscin treatment. All assayed compounds increased APx and POD activity, with 24-epibrassinolide being most active. The activity of CAT was stimulated by protodioscin and 24-epibrassinolide. The results revealed that protodioscin was toxic to B. pilosa through a mechanism not related to plant growth regulator signalling. Protodioscin caused a disturbance in mitochondrial respiratory activity, which could be related to overproduction of ROS and consequent cell membrane damage.
PMID: 30341820
Biol Open , IF:2.029 , 2019 Mar , V8 (3) doi: 10.1242/bio.039677
Reprogramming of the cambium regulators during adventitious root development upon wounding of storage tap roots in radish (Raphanus sativus L.).
School of Biological Sciences, College of Natural Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.; Department of Behavioural Biology, University Utrecht, Padualaan 8, Utrecht 3584CH, The Netherlands.; School of Biological Sciences, College of Natural Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea jl924@snu.ac.kr.; Plant Genomics and Breeding Institute, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Cambium contains a stem cell population that produces xylem and phloem tissues in a radial direction during the secondary growth stage. The growth of many storage roots, including in the radish, Raphanus sativus L., also depends on cambium. Interestingly, we observed numerous adventitious roots (ARs) emerging from the cambia of cut surfaces when the bases of radish storage tap roots were removed. Previous studies in Arabidopsis showed that the WOX11/12 pathway regulates AR initiation and meristem establishment in an auxin-dependent manner. Here, we provide evidence indicating the evolutionary conservation of the WOX11/12 pathway during the AR development in radishes. Additionally, we found that expression of two cambium regulators, PXY and WOX4, is induced in the cambium regions that are connected to emerging ARs via vascularization. Both AR formation and genes associated with this were induced by exogenous auxin. Our research suggests that some key cambium regulators might be reprogrammed to aid in the AR development in concert with the WOX11/12 pathway.This article has an associated First Person interview with the first author of the paper.
PMID: 30787007
Physiol Mol Biol Plants , IF:2.005 , 2019 Mar , V25 (2) : P533-548 doi: 10.1007/s12298-018-0619-z
Role of activated charcoal and amino acids in developing an efficient regeneration system for foxtail millet (Setaria italica (L.) Beauv.) using leaf base segments.
1Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu 630 003 India.0000 0001 0363 9238grid.411312.4; 2Department of Biotechnology Engineering, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of Negev, 84105 Beer Sheva, Israel.0000 0004 1937 0511grid.7489.2
An efficacious, reproducible direct in vitro regeneration system has been developed from leaf base segments (LBs) of six high yielding genotypes of foxtail millet (Setaria italica (L.) Beauv.). LBs excised from 4-day-old seedling were inoculated on Murashige and Skoog (MS) medium supplemented with different types and concentrations of cytokinins. The shoots induced per explant significantly increased with the supplementation of BAP to auxin containing medium. The results showed that a maximum shoot induction, 58.8% was obtained on MS medium incorporated with 8.9 microM BAP and 2.7 microM NAA in 'CO5' genotype. Further, the highest frequency of multiple shoots was produced on MS(I) medium containing 8.9 microM BAP, 2.7 microM NAA, 700 mg L(-1) proline, 0.5 mg L(-1) cysteine, 2.0 mg L(-1) glycine and 150 mg L(-1) arginine. MS(I) medium additionally fortified with 5.0 g L(-1) activated charcoal (AC) was found to achieve the best precocious plant regeneration. Elongated shoots were rooted on half-strength MS medium amended with 2.9 microM IAA and achieved maximum root number (8.7) within 10 days. Rooted plantlets were acclimated in soil with 92% survival rate. Molecular marker analysis of in vitro regenerated and field grown plants revealed no somaclonal variations. Briefly, amino acids and activated charcoal could significantly enhance the foxtail millet direct multiple shoot proliferation and plant regeneration. Here we report, a short-term, genotype independent, direct plant regeneration protocol for future genetic transformation studies in foxtail millet genotypes.
PMID: 30956434
3 Biotech , IF:1.798 , 2019 Mar , V9 (3) : P109 doi: 10.1007/s13205-019-1638-3
A novel function of N-signaling in plants with special reference to Trichoderma interaction influencing plant growth, nitrogen use efficiency, and cross talk with plant hormones.
1Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Utter Pradesh 221 005 India.0000 0001 2287 8816grid.411507.6; 2Institute of Environmental and Sustainable Development, Banaras Hindu University, Varanasi, Utter Pradesh 221 005 India.0000 0001 2287 8816grid.411507.6; 3Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Utter Pradesh 221005 India.0000 0001 2287 8816grid.411507.6
Trichoderma spp. is considered as a plant growth promoter and biocontrol fungal agents. They colonize on the surface of root in most of the agriculture crops. They secrete different secondary metabolites and enzymes which promote different physiological processes as well as protect plants from various environmental stresses. This is part of their vital functions. They are widely exploited as a biocontrol agent and plant growth promoter in agricultural fields. Colonization of Trichoderma with roots can enhance nutrient acquisition from surrounding soil to root and can substantially increase nitrogen use efficiency (NUE) in crops and linked with activation of plant signaling cascade. Among Trichoderma species, only some Trichoderma species were well characterized which help in the uptake of nitrogen-containing compound (especially nitrate form) and induced nitric oxide (NO) in plants. Both nitrate and NO are known as a signaling agent, involved in plant growth and development and disease resistance. Activation of these signaling molecules may crosstalk with other signaling molecule (Ca(2+)) and phytohormone (auxin, gibberellins, cytokinin and ethylene). This ability of Trichoderma is important to agriculture not only for increased plant growth but also to control plant diseases. Recently, Trichoderma strains have been shown to encompass the ability to regulate transcripts level of high-affinity nitrate transporters and probably it was positively regulated by NO. This review aims to focus the usage of Trichoderma strains on crops by their abilities to regulate transcript levels, probably through activation of plant N signaling transduction that improve plant health.
PMID: 30863693
J Biosci , IF:1.645 , 2019 Mar , V44 (1)
Light and auxin signaling cross-talk programme root development in plants.
School of Biological Sciences, National Institute of Science Education and Research (NISER), HBNI, P.O. Bhimpur-Padanpur, Via Jatni, Dist. Khurda, Odisha 752 050, India.
Root development in plants is affected by light and phytohormones. Different ranges of light wavelength influence root patterning in a particular manner. Red and white light promote overall root development, whereas blue light has both positive as well as negative role in these processes. Light-mediated root development primarily occurs through modulation of synthesis, signaling and transport of the phytohormone auxin. Auxin has been shown to play a critical role in root development. It is being well-understood that components of light and auxin signaling cross-talk with each other. However, the signaling network that can modulate the root development is an intense area of research. Currently, limited information is available about the interaction of these two signaling pathways. This review not only summarizes the current findings on how different quality and quantity of light affect various aspects of root development but also present the role of auxin in these developmental aspects starting from lower to higher plants.
PMID: 30837377
J Genet Genomics , 2019 Mar , V46 (3) : P133-140 doi: 10.1016/j.jgg.2019.03.001
Control of de novo root regeneration efficiency by developmental status of Arabidopsis leaf explants.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China.; School of Life Sciences, Nantong University, Nantong, 226019, China.; School of Public Health, Nantong University, Nantong, 226019, China.; Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China. Electronic address: yujie2016@sibs.ac.cn.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China. Electronic address: zhangyijing@sibs.ac.cn.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China. Electronic address: xulin01@sibs.ac.cn.
De novo root regeneration (DNRR) has wide applications in agriculture such as those related to cutting technology. Detached Arabidopsis thaliana leaf explants can regenerate adventitious roots without added hormones. The regenerative ability is highly dependent on the developmental status of the leaf. An immature leaf has a higher regenerative ability, while a mature leaf is difficult to regenerate. Using RNA-Seq analysis, we showed that the expression levels of many genes, including those in the auxin network, changed during leaf maturation. Particularly, the expression levels of many YUCCA (YUC) genes in the auxin biosynthesis pathway are responsive to leaf maturation. Overexpression of YUC1 in the yuc-1D dominant mutant rescued the rooting defects caused by leaf maturation. In addition, YUC4 expression levels were also affected by circadian rhythms. The regenerative ability was reduced in both immature and mature mutant leaf explants from the new wuschel-related homeobox 11-3 (wox11-3) and wox12-3 mutant alleles created by the CRISPR/Cas9 method. Overall, the transcriptome and genetic data, together with the auxin concentration analysis, indicate that the ability to upregulate auxin levels upon detachment may be reduced during leaf maturation. Thus, multiple developmental and environmental signals may converge to control auxin accumulation, which affects the efficiency of the WOX11/12-mediated DNRR from leaf explants.
PMID: 30928533