Annu Rev Plant Biol , IF:26.379 , 2021 Jun , V72 : P525-550 doi: 10.1146/annurev-arplant-080720-081920
Solving the Puzzle of Shape Regulation in Plant Epidermal Pavement Cells.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umea, Sweden; email: siamsa.doyle@slu.se, stephanie.robert@slu.se.
The plant epidermis serves many essential functions, including interactions with the environment, protection, mechanical strength, and regulation of tissue and organ growth. To achieve these functions, specialized epidermal cells develop into particular shapes. These include the intriguing interdigitated jigsaw puzzle shape of cotyledon and leaf pavement cells seen in many species, the precise functions of which remain rather obscure. Although pavement cell shape regulation is complex and still a long way from being fully understood, the roles of the cell wall, mechanical stresses, cytoskeleton, cytoskeletal regulatory proteins, and phytohormones are becoming clearer. Here, we provide a review of this current knowledge of pavement cell morphogenesis, generated from a wealth of experimental evidence and assisted by computational modeling approaches. We also discuss the evolution and potential functions of pavement cell interdigitation. Throughout the review, we highlight some of the thought-provoking controversies and creative theories surrounding the formation of the curious puzzle shape of these cells.
PMID: 34143651
Annu Rev Plant Biol , IF:26.379 , 2021 Jun , V72 : P641-676 doi: 10.1146/annurev-arplant-082520-094112
Comparative Embryogenesis in Angiosperms: Activation and Patterning of Embryonic Cell Lineages.
Department of Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany; email: thomas.dresselhaus@ur.de.; Department of Cell Biology, Max Planck Institute for Developmental Biology, D-72076 Tubingen, Germany.; Center for Plant Molecular Biology, University of Tubingen, D-72076 Tubingen, Germany; email: gerd.juergens@zmbp.uni-tuebingen.de.
Following fertilization in flowering plants (angiosperms), egg and sperm cells unite to form the zygote, which generates an entire new organism through a process called embryogenesis. In this review, we provide a comparative perspective on early zygotic embryogenesis in flowering plants by using the Poaceae maize and rice as monocot grass and crop models as well as Arabidopsis as a eudicot model of the Brassicaceae family. Beginning with the activation of the egg cell, we summarize and discuss the process of maternal-to-zygotic transition in plants, also taking recent work on parthenogenesis and haploid induction into consideration. Aspects like imprinting, which is mainly associated with endosperm development and somatic embryogenesis, are not considered. Controversial findings about the timing of zygotic genome activation as well as maternal versus paternal contribution to zygote and early embryo development are highlighted. The establishment of zygotic polarity, asymmetric division, and apical and basal cell lineages represents another chapter in which we also examine and compare the role of major signaling pathways, cell fate genes, and hormones in early embryogenesis. Except for the model Arabidopsis, little is known about embryopatterning and the establishment of the basic body plan in angiosperms. Using available in situ hybridization, RNA-sequencing, and marker data, we try to compare how and when stem cell niches are established. Finally, evolutionary aspects of plant embryo development are discussed.
PMID: 33606951
Trends Plant Sci , IF:18.313 , 2021 Jun doi: 10.1016/j.tplants.2021.06.002
Phyllotaxis development: a lesson from the Asteraceae family.
State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, the Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.; State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, the Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China. Electronic address: Yang.Dong@ibcas.ac.cn.
Phyllotaxis refers to the spatial arrangement of leaves and flowers on a stem. A recent study by Zhang et al. described the developmental process underlying phyllotaxis establishment in the capitulum of Gerbera hybrida. This work represents a cornerstone for studying the development and diversification mechanisms of capitula in the Asteraceae.
PMID: 34172385
Trends Plant Sci , IF:18.313 , 2021 Jul , V26 (7) : P665-667 doi: 10.1016/j.tplants.2021.04.003
Cell Wall and Hormone Interplay Controls Growth Asymmetry.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.; College of Life Sciences, Hebei Agriculture University, Baoding 071001, China.; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China. Electronic address: lixj@bjfu.edu.cn.
Plant cell elongation and expansion require the biosynthesis and remodeling of cell wall composition. Recently, Aryal et al. reported how feedback between the cell wall and the auxin response controls differential growth in apical hook development.
PMID: 33958277
Nat Commun , IF:14.919 , 2021 Jun , V12 (1) : P3656 doi: 10.1038/s41467-021-24018-7
Spatial regulation of thermomorphogenesis by HY5 and PIF4 in Arabidopsis.
Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA.; Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA. huq@austin.utexas.edu.
Plants respond to high ambient temperature by implementing a suite of morphological changes collectively termed thermomorphogenesis. Here we show that the above and below ground tissue-response to high ambient temperature are mediated by distinct transcription factors. While the central hub transcription factor, PHYTOCHROME INTERCTING FACTOR 4 (PIF4) regulates the above ground tissue response, the below ground root elongation is primarily regulated by ELONGATED HYPOCOTYL 5 (HY5). Plants respond to high temperature by largely expressing distinct sets of genes in a tissue-specific manner. HY5 promotes root thermomorphogenesis via directly controlling the expression of many genes including the auxin and BR pathway genes. Strikingly, the above and below ground thermomorphogenesis is impaired in spaQ. Because SPA1 directly phosphorylates PIF4 and HY5, SPAs might control the stability of PIF4 and HY5 to regulate thermomorphogenesis in both tissues. These data collectively suggest that plants employ distinct combination of SPA-PIF4-HY5 module to regulate tissue-specific thermomorphogenesis.
PMID: 34135347
Sci Adv , IF:14.136 , 2021 Jun , V7 (25) doi: 10.1126/sciadv.abg0993
Alterations in hormonal signals spatially coordinate distinct responses to DNA double-strand breaks in Arabidopsis roots.
Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama 8916-5, Ikoma, Nara 630-0192, Japan.; Plant Productivity Systems Research Group, RIKEN Center for Sustainable Resource Science, Suehiro 1-7-22, Tsurumi, Yokohama 230-0045, Japan.; Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.; Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre, Swedish University of Agricultural Sciences, 90183 Umea, Sweden.; Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama 8916-5, Ikoma, Nara 630-0192, Japan. mumeda@bs.naist.jp.
Plants have a high ability to cope with changing environments and grow continuously throughout life. However, the mechanisms by which plants strike a balance between stress response and organ growth remain elusive. Here, we found that DNA double-strand breaks enhance the accumulation of cytokinin hormones through the DNA damage signaling pathway in the Arabidopsis root tip. Our data showed that activation of cytokinin signaling suppresses the expression of some of the PIN-FORMED genes that encode efflux carriers of another hormone, auxin, thereby decreasing the auxin signals in the root tip and causing cell cycle arrest at G2 phase and stem cell death. Elevated cytokinin signaling also promotes an early transition from cell division to endoreplication in the basal part of the root apex. We propose that plant hormones spatially coordinate differential DNA damage responses, thereby maintaining genome integrity and minimizing cell death to ensure continuous root growth.
PMID: 34134976
Mol Plant , IF:13.164 , 2021 Jun doi: 10.1016/j.molp.2021.06.023
A Novel miR167a-OsARF6-OsAUX3 Module Regulates Grain Length and Weight in Rice.
Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Huhehaote 010000, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China.; Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Huhehaote 010000, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Department of Biology, University of Fribourg, Rue Albert-Gockel 3, CH-1700 Fribourg, Switzerland.; Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, Inner Mongolia Key Laboratory of Herbage & Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Huhehaote 010000, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: qyhjp@zju.edu.cn.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China. Electronic address: gaozhenyu@caas.cn.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China. Electronic address: qianqian188@hotmail.com.
Grain size is one of the most import factors of controlling rice yield, as it is associated with grain weight (GW). To date, several rice genes that regulate grain size have been isolated; however, the regulatory mechanism underlying GW control is not fully understood. Herein, a quantitative trait locus qGL5 for grain length (GL) and GW was identified in recombinant inbred lines of 9311 and Nipponbare (NPB), and fine mapped to a candidate gene, OsAUX3. Sequence variations between 9311 and NPB in the OsAUX3 promoter, and loss-of-function of OsAUX3 led to increased GL and GW. RNA-sequencing, gene expression quantification, dual-luciferase reporter assay, chromatin immunoprecipitation-quantitative polymerase chain reaction, and yeast one-hybrid assay demonstrated that OsARF6 is an upstream transcription factor of OsAUX3. OsARF6 directly binds to the auxin response elements of the OsAUX3 promoter, covering a single nucleotide polymorphism site between 9311 and NPB/Dongjin/Hwayoung, thereby controlling GL by altering longitudinal expansion and auxin distribution/content in glume cells. miR167a was also confirmed to positively regulate GL and GW by directing OsARF6 mRNA silencing. Therefore, the miR167a-OsARF6-OsAUX3 module regulates GL and GW in rice, representing a potential target for improving rice yield.
PMID: 34186219
Mol Plant , IF:13.164 , 2021 Jun , V14 (6) : P949-962 doi: 10.1016/j.molp.2021.03.011
A crosstalk between auxin and brassinosteroid regulates leaf shape by modulating growth anisotropy.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.; Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China.; Key Laboratory of Microgravity (National Microgravity Laboratory), Center of Biomechanics and Bioengineering, and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China.; Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China. Electronic address: zhangl@math.pku.edu.cn.; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yingwang@ucas.edu.cn.; State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yljiao@genetics.ac.cn.
Leaf shape is highly variable within and among plant species, ranging from slender to oval shaped. This is largely determined by the proximodistal axis of growth. However, little is known about how proximal-distal growth is controlled to determine leaf shape. Here, we show that Arabidopsis leaf and sepal proximodistal growth is tuned by two phytohormones. Two class A AUXIN RESPONSE FACTORs (ARFs), ARF6 and ARF8, activate the transcription of DWARF4, which encodes a key brassinosteroid (BR) biosynthetic enzyme. At the cellular level, the phytohormones promote more directional cell expansion along the proximodistal axis, as well as final cell sizes. BRs promote the demethyl-esterification of cell wall pectins, leading to isotropic in-plane cell wall loosening. Notably, numerical simulation showed that isotropic cell wall loosening could lead to directional cell and organ growth along the proximodistal axis. Taken together, we show that auxin acts through biosynthesis of BRs to determine cell wall mechanics and directional cell growth to generate leaves of variable roundness.
PMID: 33722761
Mol Plant , IF:13.164 , 2021 Jun , V14 (6) : P937-948 doi: 10.1016/j.molp.2021.03.008
The lncRNA APOLO interacts with the transcription factor WRKY42 to trigger root hair cell expansion in response to cold.
Instituto de Agrobiotecnologia del Litoral, Universidad Nacional del Litoral, CONICET, FBCB/FHUC, Centro Cientifico Tecnologico CONICET Santa Fe, Colectora Ruta Nacional No 168 km. 0, Paraje El Pozo, Santa Fe 3000, Argentina.; Fundacion Instituto Leloir and IIBBA-CONICET, Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina.; Instituto de Investigaciones Agrobiotecnologicas, CONICET, Universidad Nacional de Rio Cuarto, Rio Cuarto 5800, Argentina.; Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, University Paris-Saclay and University of Paris Batiment 630, 91192 Gif sur Yvette, France.; Fundacion Instituto Leloir and IIBBA-CONICET, Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida (FCsV), Universidad Andres Bello, Santiago, Chile and Millennium Institute for Integrative Biology (iBio), Santiago, Chile. Electronic address: jestevez@leloir.org.ar.; Instituto de Agrobiotecnologia del Litoral, Universidad Nacional del Litoral, CONICET, FBCB/FHUC, Centro Cientifico Tecnologico CONICET Santa Fe, Colectora Ruta Nacional No 168 km. 0, Paraje El Pozo, Santa Fe 3000, Argentina. Electronic address: fariel@santafe-conicet.gov.ar.
Plant long noncoding RNAs (lncRNAs) have emerged as important regulators of chromatin dynamics, impacting on transcriptional programs leading to different developmental outputs. The lncRNA AUXIN-REGULATED PROMOTER LOOP (APOLO) directly recognizes multiple independent loci across the Arabidopsis genome and modulates their three-dimensional chromatin conformation, leading to transcriptional shifts. Here, we show that APOLO recognizes the locus encoding the root hair (RH) master regulator ROOT HAIR DEFECTIVE 6 (RHD6) and controls RHD6 transcriptional activity, leading to cold-enhanced RH elongation through the consequent activation of the transcription factor gene RHD6-like RSL4. Furthermore, we demonstrate that APOLO interacts with the transcription factor WRKY42 and modulates its binding to the RHD6 promoter. WRKY42 is required for the activation of RHD6 by low temperatures and WRKY42 deregulation impairs cold-induced RH expansion. Collectively, our results indicate that a novel ribonucleoprotein complex with APOLO and WRKY42 forms a regulatory hub to activate RHD6 by shaping its epigenetic environment and integrate signals governing RH growth and development.
PMID: 33689931
Proc Natl Acad Sci U S A , IF:11.205 , 2021 Jun , V118 (24) doi: 10.1073/pnas.2102544118
TMK1-based auxin signaling regulates abscisic acid responses via phosphorylating ABI1/2 in Arabidopsis.
Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, People's Republic of China.; FAFU-UCR Joint Center, Horticulture and Metabolic Biology Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China.; University of Chinese Academy Sciences, Beijing 100864, People's Republic of China.; National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210, People's Republic of China.; Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin 300072, People's Republic of China.; FAFU-UCR Joint Center, Horticulture and Metabolic Biology Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China; tdxu@sibs.ac.cn.
Differential concentrations of phytohormone trigger distinct outputs, which provides a mechanism for the plasticity of plant development and an adaptation strategy among plants to changing environments. However, the underlying mechanisms of the differential responses remain unclear. Here we report that a high concentration of auxin, distinct from the effect of low auxin concentration, enhances abscisic acid (ABA) responses in Arabidopsis thaliana, which partially relies on TRANS-MEMBERANE KINASE 1 (TMK1), a key regulator in auxin signaling. We show that high auxin and TMK1 play essential and positive roles in ABA signaling through regulating ABA INSENSITIVE 1 and 2 (ABI1/2), two negative regulators of the ABA pathway. TMK1 inhibits the phosphatase activity of ABI2 by direct phosphorylation of threonine 321 (T321), a conserved phosphorylation site in ABI2 proteins, whose phosphorylation status is important for both auxin and ABA responses. This TMK1-dependent auxin signaling in the regulation of ABA responses provides a possible mechanism underlying the high auxin responses in plants and an alternative mechanism involved in the coordination between auxin and ABA signaling.
PMID: 34099554
Curr Biol , IF:10.834 , 2021 Jun doi: 10.1016/j.cub.2021.05.036
Cytokinins initiate secondary growth in the Arabidopsis root through a set of LBD genes.
Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland; Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki 00014, Finland.; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland; Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki 00014, Finland. Electronic address: xin.wang@helsinki.fi.; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki 00014, Finland; Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki 00014, Finland. Electronic address: aripekka.mahonen@helsinki.fi.
During primary growth, plant tissues increase their length, and as these tissues mature, they initiate secondary growth to increase thickness.(1) It is not known what activates this transition to secondary growth. Cytokinins are key plant hormones regulating vascular development during both primary and secondary growth. During primary growth of Arabidopsis roots, cytokinins promote procambial cell proliferation(2)(,)(3) and vascular patterning together with the hormone auxin.(4-7) In the absence of cytokinins, secondary growth fails to initiate.(8) Enhanced cytokinin levels, in turn, promote secondary growth.(8)(,)(9) Despite the importance of cytokinins, little is known about the downstream signaling events in this process. Here, we show that cytokinins and a few downstream LATERAL ORGAN BOUNDARIES DOMAIN (LBD) family of transcription factors are rate-limiting components in activating and further promoting secondary growth in Arabidopsis roots. Cytokinins directly activate transcription of two homologous LBD genes, LBD3 and LBD4. Two other homologous LBDs, LBD1 and LBD11, are induced only after prolonged cytokinin treatment. Our genetic studies revealed a two-stage mechanism downstream of cytokinin signaling: while LBD3 and LBD4 regulate activation of secondary growth, LBD1, LBD3, LBD4, and LBD11 together promote further radial growth and maintenance of cambial stem cells. LBD overexpression promoted rapid cell growth followed by accelerated cell divisions, thus leading to enhanced secondary growth. Finally, we show that LBDs rapidly inhibit cytokinin signaling. Together, our data suggest that the cambium-promoting LBDs negatively feed back into cytokinin signaling to keep root secondary growth in balance.
PMID: 34129827
J Hazard Mater , IF:10.588 , 2021 Jun , V419 : P126419 doi: 10.1016/j.jhazmat.2021.126419
Transcriptomic evaluation on methyl bromide-induced phytotoxicity in Arabidopsis thaliana and its mode of phytotoxic action via the occurrence of reactive oxygen species and uneven distribution of auxin hormones.
Department of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea.; Department of Integrative Biology, Kyungpook National University, Daegu 41566, Republic of Korea.; Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Gimcheon 39660, Republic of Korea.; Department of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea; Department of Integrative Biology, Kyungpook National University, Daegu 41566, Republic of Korea. Electronic address: selpest@knu.ac.kr.
The increase in worldwide trade has caused the quality maintenance of commercialized agriproducts to be crucial in keeping its economic value. In recent years, methyl bromide (MB) has been used dominantly during quarantine and pre-shipment, despite it being an environmental hazard with global repercussions. Through this study, it was shown that Arabidopsis thaliana's 2 h exposure to the MB treatment displayed no signs of phytotoxicity, whereas its 4 h exposure significantly interfered with growth. The transcriptomic analysis found the molecular modifications in A. thaliana after the MB fumigation with the up-regulation of genes specifically relative to the abiotic and oxidative stress, and the down-regulation of auxin transporter genes. Some important gene expressions were verified by RT-qPCR and their expression patterns were similar. Oxidative stresses via the reactive oxygen species (ROS) in relation to MB phytotoxicity were confirmed with the increased malondialdehyde in MB-4h-treated A. thaliana. Uneven distribution of auxins via lower expression of auxin transporter genes was also determined using UPLC-ESI-QqQ MS. Application of two ROS scavengers such as N-acetyl-cysteine and L-glutathione minimized MB phytotoxic effect in A. thaliana. Therefore, MB caused severe oxidative stress, and alternatives regarding the use of MB should be considered.
PMID: 34171674
New Phytol , IF:10.151 , 2021 Jun doi: 10.1111/nph.17542
MicroRNAs play important roles in regulating rapid growth of the Phyllostachys edulis culm internode.
The State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University. Guangzhou, 510642, China.; Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.; The State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, 311300, China.; Guangdong Laboratory of Lingnan Modern Agriculture, Guangzhou, 510642, China.
Moso bamboo (Phyllostachys edulis) is a fast-growing species with uneven growth and lignification from lower to upper segments within one internode. MicroRNAs (miRNAs) play a vital role in post-transcriptional regulation in plants. However, how miRNAs regulate fast growth in bamboo internodes is poorly understood. In this study, one moso bamboo internode during early rapid growth was divided into four segments regarded as F4 (bottom) to F1 (upper) and then were analyzed by transcriptomes, miRNAs and degradomes. The F4 segment possessed a higher number of actively dividing cells as well as a higher content of auxin (IAA), cytokinin (CK) and gibberellin (GA) comparing with F1 segment. RNA-seq analysis showed DNA replication and cell division associated genes highly expressed in F4 rather than that in F1. A total of 63 differentially expressed miRNAs (DEMs) were identified between F4 and F1. Degradome and transcriptome implied many downstream transcription factors and hormonal responses genes were modulated by DEMs. Several miR-targets interactions were further validated via tobacco co-infiltration. Our findings provide new insights into miRNA-mediated regulatory pathways in bamboo, which will contribute to a comprehensive understanding of the molecular mechanisms governing rapid growth.
PMID: 34101835
New Phytol , IF:10.151 , 2021 Jun doi: 10.1111/nph.17528
HSP90 affects root growth in Arabidopsis by regulating the polar distribution of PIN1.
Molecular Biology Laboratory, Department of Biotechnology, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.; Department of Chemical Biology, Faculty of Science, Palacky University, Slechtitelu 27, Olomouc, CZ-78371, Czech Republic.; Laboratory of Growth Regulators, Institute of Experimental Botany of the Czech Academy of Sciences & Faculty of Science, Palacky University, Slechtitelu 27, CZ-78371, Olomouc, Czech Republic.
Auxin homeostasis and signaling affect a broad range of developmental processes in plants. The interplay between HSP90 and auxin signaling is channeled through the chaperoning capacity of the HSP90 on the TIR1 auxin receptor. The sophisticated buffering capacity of the HSP90 system through the interaction with diverse signaling protein components drastically shapes genetic circuitries regulating various developmental aspects. However, the elegant networking capacity of HSP90 in the global regulation of auxin response and homeostasis has not been appreciated. Arabidopsis hsp90 mutants were screened for gravity response. Phenotypic analysis of root meristems and cotyledon veins was performed. PIN1 localization in hsp90 mutants was determined. Our results showed that HSP90 affected the asymmetrical distribution of PIN1 in plasma membranes and influenced its expression in prompt cell niches. Depletion of HSP90 distorted polar distribution of auxin, as the acropetal auxin transport was highly affected, leading to impaired root gravitropism and lateral root formation. The essential role of the HSP90 in auxin homeostasis was profoundly evident from early development, as HSP90 depletion affected embryo development and the pattern formation of veins in cotyledons. Our data suggest that the HSP90-mediated distribution of PIN1 modulates auxin distribution and thereby auxin signaling to properly promote plant development.
PMID: 34086995
New Phytol , IF:10.151 , 2021 Jul , V231 (1) : P8-10 doi: 10.1111/nph.17419
How plants get round problems: new insights into the root obstacle avoidance response.
Italian Space Agency, Via del Politecnico snc, Rome, 00133, Italy.; School of Biology, University of Leeds, Leeds, LS2 9JT, UK.
PMID: 34060664
New Phytol , IF:10.151 , 2021 Aug , V231 (3) : P1088-1104 doi: 10.1111/nph.17427
HEXOKINASE1 signalling promotes shoot branching and interacts with cytokinin and strigolactone pathways.
School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia.; Institut Agro, INRAE, IRHS, SFR QUASAV, Universite Angers, Angers, 49000, France.; ARC Centre for Plant Success in Nature and Agriculture, The University of Queensland, St Lucia, Qld, 4072, Australia.; Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Biocenter, Julius-Maximilians-Universitat Wurzburg, Wurzburg, 97082, Germany.
Plant architecture is controlled by several endogenous signals including hormones and sugars. However, only little information is known about the nature and roles of the sugar signalling pathways in this process. Here we test whether the sugar signalling pathway mediated by HEXOKINASE1 (HXK1) is involved in the control of shoot branching. To test the involvement of HXK1 in shoot branching and in the hormonal network controlling this process, we modulated the HXK1 pathway using physiological and genetic approaches in rose, pea and arabidopsis. Mannose-induced HXK signalling triggered bud outgrowth in rose and pea. In arabidopsis, both HXK1 deficiency and defoliation led to decreased shoot branching and conferred hypersensitivity to auxin. Complementation of the HXK1 knockout mutant gin2 with a catalytically inactive HXK1, restored shoot branching to the wild-type level. HXK1-deficient plants displayed decreased cytokinin levels and increased expression of MAX2, which is required for strigolactone signalling. The branching phenotype of HXK1-deficient plants could be partly restored by cytokinin treatment and strigolactone deficiency could override the negative impact of HXK1 deficiency on shoot branching. Our observations demonstrate that HXK1 signalling contributes to the regulation of shoot branching and interacts with hormones to modulate plant architecture.
PMID: 33909299
New Phytol , IF:10.151 , 2021 Jul , V231 (2) : P713-725 doi: 10.1111/nph.17402
NCP2/RHD4/SAC7, SAC6 and SAC8 phosphoinositide phosphatases are required for PtdIns4P and PtdIns(4,5)P2 homeostasis and Arabidopsis development.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.; Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
Phosphoinositides play important roles in plant growth and development. Several SAC domain phosphoinositide phosphatases have been reported to be important for plant development. Here, we show functional analysis of SUPPRESSOR OF ACTIN 6 (SAC6) to SAC8 in Arabidopsis, a subfamily of phosphoinositide phosphatases containing SAC-domain and two transmembrane motifs. We isolated an Arabidopsis mutant ncp2 that lacked cotyledons in seedling and embryo in pid, a background defective in auxin signaling and transport. NCP2 encodes RHD4/SAC7 phosphoinositide phosphatase. SAC6, SAC7 and SAC8 exhibit overlapping and specific expression patterns in seedling and embryo. The sac6 sac7 embryos either fail to develop into seeds, or have three or four cotyledons. The embryo development of sac7 sac8 and sac6 sac7 sac8 mutants is significantly delayed or lethal, and the seedlings are arrested at early stages. Auxin maxima are decreased in double and triple sac mutants. The contents of PtdIns4P and PtdIns(4,5)P2 in sac6 sac7 and sac7 sac8 mutants are dramatically increased. Protein trafficking of the plasma membrane (PM)-localized protein PIN1 and PIN2 from trans-Golgi network/early endosome back to PM is delayed in sac7 sac8 mutants. These results indicate that SAC6-SAC8 are essential for maintaining homeostasis of PtdIns4P and PtdIns(4,5)P2, and auxin-mediated development in Arabidopsis.
PMID: 33876422
New Phytol , IF:10.151 , 2021 Jul , V231 (2) : P726-746 doi: 10.1111/nph.17263
VviNAC33 promotes organ de-greening and represses vegetative growth during the vegetative-to-mature phase transition in grapevine.
Department of Biotechnology, University of Verona, Verona, 37134, Italy.; Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854-8020, USA.
Plants undergo several developmental transitions during their life cycle. In grapevine, a perennial woody fruit crop, the transition from vegetative/green-to-mature/woody growth involves transcriptomic reprogramming orchestrated by a small group of genes encoding regulators, but the underlying molecular mechanisms are not fully understood. We investigated the function of the transcriptional regulator VviNAC33 by generating and characterizing transgenic overexpressing grapevine lines and a chimeric repressor, and by exploring its putative targets through a DNA affinity purification sequencing (DAP-seq) approach combined with transcriptomic data. We demonstrated that VviNAC33 induces leaf de-greening, inhibits organ growth and directly activates the expression of STAY-GREEN PROTEIN 1 (SGR1), which is involved in Chl and photosystem degradation, and AUTOPHAGY 8f (ATG8f), which is involved in the maturation of autophagosomes. Furthermore, we show that VviNAC33 directly inhibits AUXIN EFFLUX FACILITATOR PIN1, RopGEF1 and ATP SYNTHASE GAMMA CHAIN 1T (ATPC1), which are involved in photosystem II integrity and activity. Our results show that VviNAC33 plays a major role in terminating photosynthetic activity and organ growth as part of a regulatory network governing the vegetative-to-mature phase transition.
PMID: 33567124
New Phytol , IF:10.151 , 2021 Jul , V231 (1) : P225-242 doi: 10.1111/nph.17180
Root growth responses to mechanical impedance are regulated by a network of ROS, ethylene and auxin signalling in Arabidopsis.
Department of Biosciences, Durham University, Durham, DH1 3LE, UK.; Department of Plant Systems Physiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg 135, Nijmegen, 6525 AJ, the Netherlands.; Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, 117543, Singapore.
The growth and development of root systems is influenced by mechanical properties of the substrate in which the plants grow. Mechanical impedance, such as by compacted soil, can reduce root elongation and limit crop productivity. To understand better the mechanisms involved in plant root responses to mechanical impedance stress, we investigated changes in the root transcriptome and hormone signalling responses of Arabidopsis to artificial root barrier systems in vitro. We demonstrate that upon encountering a barrier, reduced Arabidopsis root growth and a characteristic 'step-like' growth pattern is due to a reduction in cell elongation associated with changes in signalling gene expression. Data from RNA-sequencing combined with reporter line and mutant studies identified essential roles for reactive oxygen species, ethylene and auxin signalling during the barrier response. We propose a model in which early responses to mechanical impedance include reactive oxygen signalling integrated with ethylene and auxin responses to mediate root growth changes. Inhibition of ethylene responses allows improved growth in response to root impedance, an observation that may inform future crop breeding programmes.
PMID: 33428776
Cold Spring Harb Perspect Biol , IF:10.005 , 2021 Jun doi: 10.1101/cshperspect.a039875
Auxin Transporters-A Biochemical View.
Plant Systems Biology, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany.; Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742, USA.; Agriculture Biotechnology Center, University of Maryland, College Park, Maryland 20742, USA.
From embryogenesis to fruit formation, almost every aspect of plant development and differentiation is controlled by the cellular accumulation or depletion of auxin from cells and tissues. The respective auxin maxima and minima are generated by cell-to-cell auxin transport via transporter proteins. Differential auxin accumulation as a result of such transport processes dynamically regulates auxin distribution during differentiation. In this review, we introduce all auxin transporter (families) identified to date and discuss the knowledge on prominent family members, namely, the PIN-FORMED exporters, ATP-binding cassette B (ABCB)-type transporters, and AUX1/LAX importers. We then concentrate on the biochemical features of these transporters and their regulation by posttranslational modifications and interactors.
PMID: 34127449
Cold Spring Harb Perspect Biol , IF:10.005 , 2021 Jun doi: 10.1101/cshperspect.a040071
The Systems and Synthetic Biology of Auxin.
Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia 24061, USA.; Department of Biology, Whitman College, Walla Walla, Washington 99362, USA.; Department of Biology, University of Washington, Seattle, Washington 98195, USA.
Auxin biology as a field has been at the forefront of advances in delineating the structures, dynamics, and control of plant growth networks. Advances have been enabled by combining the complementary fields of top-down, holistic systems biology and bottom-up, build-to-understand synthetic biology. Continued collaboration between these approaches will facilitate our understanding of and ability to engineer auxin's control of plant growth, development, and physiology. There is a need for the application of similar complementary approaches to improving equity and justice through analysis and redesign of the human systems in which this research is undertaken.
PMID: 34127446
Crit Rev Biotechnol , IF:8.429 , 2021 Jun : P1-19 doi: 10.1080/07388551.2021.1924113
Plant phospholipase D: novel structure, regulatory mechanism, and multifaceted functions with biotechnological application.
National Institute of Plant Genome Research, New Delhi, India.
Phospholipases D (PLDs) are important membrane lipid-modifying enzymes in eukaryotes. Phosphatidic acid, the product of PLD activity, is a vital signaling molecule. PLD-mediated lipid signaling has been the subject of extensive research leading to discovery of its crystal structure. PLDs are involved in the pathophysiology of several human diseases, therefore, viewed as promising targets for drug design. The availability of a eukaryotic PLD crystal structure will encourage PLD targeted drug designing. PLDs have been implicated in plants response to biotic and abiotic stresses. However, the molecular mechanism of response is not clear. Recently, several novel findings have shown that PLD mediated modulation of structural and developmental processes, such as: stomata movement, root growth and microtubule organization are crucial for plants adaptation to environmental stresses. Involvement of PLDs in regulating membrane remodeling, auxin mediated alteration of root system architecture and nutrient uptake to combat nitrogen and phosphorus deficiencies and magnesium toxicity is established. PLDs via vesicle trafficking modulate cytoskeleton and exocytosis to regulate self-incompatibility (SI) signaling in flowering plants, thereby contributes to plants hybrid vigor and diversity. In addition, the important role of PLDs has been recognized in biotechnologically important functions, including oil/TAG synthesis and maintenance of seed quality. In this review, we describe the crystal structure of a plant PLD and discuss the molecular mechanism of catalysis and activity regulation. Further, the role of PLDs in regulating plant development under biotic and abiotic stresses, nitrogen and phosphorus deficiency, magnesium ion toxicity, SI signaling and pollen tube growth and in important biotechnological applications has been discussed.
PMID: 34167393
Elife , IF:8.14 , 2021 Jun , V10 doi: 10.7554/eLife.66739
Repression by the Arabidopsis TOPLESS corepressor requires association with the core mediator complex.
Department of Biology, University of Washington, Seattle, United States.; Department of Pharmacology, Seattle, United States.; Howard Hughes Medical Institute, University of Washington, Seattle, United States.
The plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli are poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle module subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.
PMID: 34075876
Curr Opin Plant Biol , IF:7.834 , 2021 Jun , V63 : P102055 doi: 10.1016/j.pbi.2021.102055
Transport mechanisms of plant hormones.
School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, 69978, Israel.; School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, 69978, Israel. Electronic address: eilonsh@tauex.tau.ac.il.
Plant growth, development, and response to the environment are mediated by a group of small signaling molecules named hormones. Plants regulate hormone response pathways at multiple levels, including biosynthesis, metabolism, perception, and signaling. In addition, plants exhibit the unique ability to spatially control hormone distribution. In recent years, multiple transporters have been identified for most of the plant hormones. Here we present an updated snapshot of the known transporters for the hormones abscisic acid, auxin, brassinosteroid, cytokinin, ethylene, gibberellin, jasmonic acid, salicylic acid, and strigolactone. We also describe new findings regarding hormone movement and elaborate on hormone substrate specificity and possible genetic redundancy in hormone transport and distribution. Finally, we discuss subcellular, cell-to-cell, and long-distance hormone movement and local hormone sinks that trigger or prevent hormone-mediated responses.
PMID: 34102450
Plant Cell Environ , IF:7.228 , 2021 Jun doi: 10.1111/pce.14141
JWB phytoplasma effectors SJP1 and SJP2 induce lateral bud outgrowth by repressing the ZjBRC1-controlled auxin efflux channel.
College of Horticulture, Anhui Agricultural University, 130 West Changjiang Road, Hefei City, Anhui Province, People's Republic of China.; Horticulture Research Institute, Anhui Academy of Agricultural Sciences, 40 South Nongke Road, Hefei City, Anhui Province, People's Republic of China.; State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 West Changjiang Road, Hefei City, Anhui Province, People's Republic of China.
Comprehensively controlling phytoplasma-associated jujube witches' broom (JWB) disease is extremely challenging for the jujube industry. Although the pathogenesis of phytoplasma disease has been highlighted in many plant species, the release of lateral buds from dormancy under JWB phytoplasma infection has not been characterized in woody perennial jujube. Here, two 16SrV-B group phytoplasma effectors, SJP1 and SJP2, were experimentally determined to induce witches' broom with increased lateral branches. In vivo interaction and subcellular localization analyses showed that both SJP1 and SJP2 were translocated from the cytoplasm to the nucleus to target the CYC/TB1-TCP transcription factor ZjBRC1. The N- and C-terminal coiled-coil domains of SJP1 and SJP2 were required for the TCP-binding ability. ZjBRC1 bound directly to the auxin efflux carrier ZjPIN1c/3 promoters and downregulated their expression to promote the accumulation of endogenous auxin indole-3-acetic acid (IAA) in jujube calli. Furthermore, JWB phytoplasma infection suppressed ZjBRC1 accumulation and induced ZjPIN1c/3 expression to stimulate lateral bud outgrowth. Therefore, SJP1 and SJP2 stimulate lateral bud outgrowth, at least partly, by repressing the ZjBRC1-controlled auxin efflux channel in jujube, representing a potential strategy for comprehensive phytoplasma-associated disease control and a resource for gene editing breeding to create new cultivars with varying degrees of shoot branching. This article is protected by copyright. All rights reserved.
PMID: 34189742
Plant Cell Environ , IF:7.228 , 2021 Jun doi: 10.1111/pce.14137
ABA regulation of root growth during soil drying and recovery can involve auxin response.
Fujian Provincial Key Laboratory of Plant Functional Biology and College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Crop and College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, China.; College of Agriculture, Yangzhou University, Yangzhou, China.; Lancaster Environment Centre, Lancaster University, Lancaster, LA14YQ, UK.
Abscisic acid (ABA) plays the important roles in plant adaptation to water deficits, but its role in regulating root growth (primary root elongation and lateral root number) during different drought-phases remains unclear. Here, we exposed wild-type (WT) and ABA-deficient (not) tomato plants to three continuous drought-phases (moderate drying: day 0-21; severe drying: day 22-47; re-watering: day 48-51). It was found that WT increased primary root growth during moderate drying; maintained more lateral roots, and greater primary root and total root length under severe drying; and produced more roots after re-watering. After RNA-Seq analysis, we found that the auxin-related genes in root showed different expression patterns between WT and not under drying or re-watering. Further, exogenous supply of IAA partially recovered the root growth of ABA-deficient not plants under three continuous drought-phases. Our results suggested that ABA regulation of tomato root growth during soil drying and recovery can involve auxin response. This article is protected by copyright. All rights reserved.
PMID: 34176142
Plant Cell Environ , IF:7.228 , 2021 Jun doi: 10.1111/pce.14133
Long noncoding RNA lncRNA354 functions as a competing endogenous RNA of miR160b to regulate ARF genes in response to salt stress in upland cotton.
State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an, Shandong, China.
Long non-coding RNAs (lncRNAs) play important roles in response to biotic and abiotic stress through acting as competing endogenous RNAs (ceRNAs) to decoy mature miRNAs. However, whether this mechanism is involved in cotton salt stress response remains unknown. We report the characterization of an endogenous lncRNA, lncRNA354, whose expression was reduced in salt-treated cotton and was localized at the nucleus and cytoplasm. Using endogenous target mimic (eTM) analysis, we predicted that lncRNA354 had a potential binding site for miR160b. Transient expression in tobacco demonstrated that lncRNA354 was a miR160b eTM and attenuated miR160b suppression of its target genes including auxin response factors (ARFs). Silencing or overexpressing lncRNA354 affected the expression of miR160b and target ARFs. Silencing lncRNA354 and targets GhARF17/18 resulted in taller cotton plants and enhanced the resistant to salt stress. Overexpression of lncRNA354 and targets GhARF17/18 in Arabidopsis led to dwarf plants, decreased root dry weight, and reduced salt tolerance. Our results show that the lncRNA354-miR160b effect on GhARF17/18 expression may modulate auxin signaling and thus affect growth. These results also shed new light on a mechanism of lncRNA-associated responses to salt stress. This article is protected by copyright. All rights reserved.
PMID: 34164822
Plant Cell Environ , IF:7.228 , 2021 Jun doi: 10.1111/pce.14125
Tomato chlorosis virus-encoded p22 suppresses auxin signalling to promote infection via interference with SKP1-Cullin-F-box(TIR1) complex assembly.
State Key Laboratory for Agro-Biotechnology, and Ministry of Agriculture and Rural Affairs, Key Laboratory for Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, China.; College of Plant Protection, Shandong Agricultural University, Taian, China.; Instituto de Hortofruticultura Subtropical y Mediterranea "La Mayora", Consejo Superior de Investigaciones Cientificas - Universidad de Malaga (IHSM-CSIC-UMA), Malaga, Spain.
Phytohormone auxin plays a fundamental role in plant growth and defense against pathogens. However, how auxin signalling is regulated during virus infection in plants remains largely unknown. Auxin/indole-3-acetic acid (Aux/IAA) is the repressor of auxin signalling and can be recognized by an F-box protein transport inhibitor response 1 (TIR1). Ubiquitination and degradation of Aux/IAA by SKP1-Cullin-F-box(TIR1) (SCF(TIR1) ) complex can trigger auxin signalling. Here, with an emerging important plant virus worldwide, we showed that tomato chlorosis virus (ToCV) infection or stable transgenic overexpression of its p22 protein does not alter auxin accumulation level but significantly decreases the expression of auxin signalling-responsive genes, suggesting that p22 can attenuate host auxin signalling. Further, p22 could bind the C-terminal of SKP1.1 and compete with TIR1 to interfere with the SCF(TIR1) complex assembly, leading to a suppression of Aux/IAA degradation. Silencing and over-expression assays suggested that both NbSKP1.1 and NbTIR1 suppress ToCV accumulation and disease symptoms. Altogether, ToCV p22 disrupts the auxin signalling through destabilizing SCF(TIR1) by interacting with the C-terminal of NbSKP1.1 to promote ToCV infection. Our findings uncovered a previously unknown molecular mechanism employed by a plant virus to manipulate SCF complex-mediated ubiquitin pathway and to reprogram auxin signalling for efficient infection.
PMID: 34105183
J Integr Plant Biol , IF:7.061 , 2021 Jun doi: 10.1111/jipb.13142
Primary root and root hair development regulation by OsAUX4 and its participation in the phosphate starvation response.
State Key Laboratory of Plant Physiology and Biochemistry, College of ZZ Sciences, Zhejiang University, Hangzhou, 310058, China.; Key Laboratory of Herbage & Endemic Crop Biotechnology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Huhehaote, 010000, China.; State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, 310006, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong, Agricultural University, Tai'an, 271018, China.; Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
Among the five members of AUX1/LAX genes coding for auxin carriers in rice, only OsAUX1 and OsAUX3 have been reported. To understand the function of the other AUX1/LAX genes, two independent alleles of osaux4 mutants, osaux4-1, and osaux4-2, were constructed using the CRISPR/Cas9 editing system. Homozygous osaux4-1 or osaux4-2 exhibited shorter primary root (PR) and longer root hair (RH) compared to the wild-type Dongjin (WT/DJ), and lost response to IAA treatment. OsAUX4 is intensively expressed in roots and localized on the plasma membrane, suggesting that OsAUX4 might function in the regulation of root development. The decreased meristem cell division activity and the downregulated expression of cell cycle genes in root apices of osaux4 mutants supported the hypothesis that OsAUX4 positively regulates PR elongation. OsAUX4 is expressed in RH, and osaux4 mutants showing longer RH compared to WT/DJ implies that OsAUX4 negatively regulates RH development. Furthermore, osaux4 mutants are insensitive to phosphate starvation (-Pi) and OsAUX4 effects on the -Pi response is associated with altered expression levels of Pi starvation regulated genes, and auxin distribution/contents. This study revealed that OsAUX4 not only regulates PR and RH development but also plays a regulatory role in crosstalk between auxin and -Pi signaling. This article is protected by copyright. All rights reserved.
PMID: 34110093
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab311
Two citrus KNAT-like genes (CsKN1 and CsKN2) are involved in the regulation of sweet orange spring shoot development.
Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China.; College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.; Institute of Pomology and Tea, Hubei Academy of Agricultural Sciences, Wuhan 430070, China.
Shoot tip abortion is a very common phenomenon in some perennial woody plants that affects the height, architecture, and branch orientation of trees. To date, little is known about the mechanism of shoot tip abortion. In this study, a sweet orange gene encoding a KNAT-like protein (CsKN1) was identified and showed high expression in the shoot apical meristem (SAM). Overexpression of CsKN1 prolonged the vegetative growth of SAM, and silencing of CsKN1 resulted in the loss or inhibition of SAM in transgenic plants. Yeast two-hybrid analysis revealed that CsKN1 interacted with another citrus KNAT-like protein (CsKN2), and overexpression of CsKN2 in lemon and tobacco caused an extremely multiple meristem phenotype. Overexpression of CsKN1 and CsKN2 resulted in the differential expression of numerous hormone biosynthesis and signaling genes in transgenic plants. Further evidence suggested that CsKN1 might prolong the vegetative growth period of SAM by inhibiting LEAFY. In addition, an ethylene responsive factor (CsERF) was found to bind to the CsKN1 promoter and suppresses its transcription. CsERF enhances ethylene and reactive oxygen species contents and may induce the occurrence of shoot tip abscission. Thus, we conclude that CsKN1 and CsKN2 may work cooperatively to regulate the shoot tip abscission process of sweet orange spring shoots.
PMID: 34185082
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab306
ABA signalling promotes cell totipotency in the shoot apex of germinating embryos.
Bioscience, Wageningen University and Research, P.O. Box 16, 6700 AA Wageningen, Netherlands.; Laboratory for Molecular Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, Netherlands.; Wageningen Seed Lab, Laboratory for Plant Physiology, Wageningen University and Research Centre, P.O. Box 16, 6700 AA, Netherlands.; Shanghai Center for Plant Stress Biology, and CAS Center of Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Somatic embryogenesis (SE) is a type of induced cell totipotency where embryos develop from vegetative tissues of the plant instead of from gamete fusion after fertilization. SE can be induced in vitro by exposing explants to growth regulators, like the auxinic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The plant hormone abscisic acid (ABA) has been proposed to be a downstream signalling component at the intersection between 2,4-D- and stress-induced SE, but it is not known how these pathways interact to induce cell totipotency. Here we show that 2,4-D-induced SE from the shoot apex of germinating Arabidopsis thaliana (arabidopsis) seeds is characterized by transcriptional maintenance of an ABA-dependent seed maturation pathway. Molecular-genetic analysis of arabidopsis mutants revealed a role for ABA in promoting SE at three different levels: ABA biosynthesis, ABA receptor complex signalling and ABA-mediated transcription, with essential roles for the ABSCISIC ACID INSENSITIVE 3 (ABI3) and ABI4 transcription factors. Our data suggest that the ability of mature arabidopsis embryos to maintain the ABA seed maturation environment is an important first step in establishing competence for auxin-induced cell totipotency. This finding provides further support for the role of ABA in directing processes other than abiotic stress response.
PMID: 34175924
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab272
Root Stem Cell Niche networks: It's complexed! A review on gene networks regulating the Arabidopsis root stem cell niche.
Wageningen University & Research, Plant Sciences department, Plant Developmental Biology group, Droevendaalsesteeg, Wageningen, Netherlands.
The presence of two meristematic cell populations in the root and shoot apex allow plants to grow indefinitely. Due to its simple and predictable tissue organisation, the Arabidopsis root apical meristem remains an ideal model to study mechanisms such as stem cell specification, asymmetric cell division and differentiation in plants. The root stem cell niche consists of a quiescent organizing center surrounded by mitotically active stem cells, that originate all root tissues. The transcription factors PLETHORA, SCARECROW and WOX5 form the signaling hubs that integrate multiple inputs from an increasing number of proteins implicated in the regulation of the stem cell niche function. Recently, locally produced auxin was added to the list of important mobile factors in stem cell niche. In addition, protein-protein interaction data elegantly demonstrated how parallel pathways can meet into a common objective. Here we discuss in a comprehensive way how multiple networks converge to specify and maintain the root stem cell niche.
PMID: 34173817
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab298
A High Concentration of Abscisic Acid Inhibits Hypocotyl Phototropism in Gossypium arboreum by Reducing the Accumulation and Asymmetric Distribution of Auxin.
Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China.
Hypocotyl phototropism is mediated by the phototropins and plays a critical role in seedling morphogenesis by optimizing growth orientation. However, the mechanisms by which phototropism influences morphogenesis require additional study, especially for polyploid crops such as cotton. Here, we found that hypocotyl phototropism was weaker in G. arboreum than in G. raimondii (two diploid cotton species), and LC-MS analysis indicated that G. arboreum hypocotyls had a higher content of ABA and a lower content of IAA and bioactive GAs. Consistently, the expression of ABA2, AAO3 and GA2OX1 was higher in G. arboreum than in G. raimondii, and that of GA3OX was lower; these changes promoted ABA synthesis and the transformation of active GA to inactive GA. Higher concentrations of ABA inhibited the asymmetric distribution of IAA across the hypocotyl and blocked the phototropic curvature of G. raimondii. Application of IAA or GA3 to the shaded and illuminated sides of the hypocotyl enhanced and inhibited phototropic curvature, respectively, in G. arboreum. The application of IAA but not GA to one side of the hypocotyl caused hypocotyl curvature in the dark. These results indicate that the asymmetric distribution of IAA promotes phototropic growth, and the weakened phototropic curvature of G. arboreum may be attributed to its higher ABA levels that inhibit the action of auxin, which is regulated by GA signaling.
PMID: 34145440
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab287
The CaM1-Associated CCaMK-MKK1/6 cascade positively affects the lateral root growth through auxin signaling under salt stress in rice.
MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Huazhong Agricultural University, Wuhan, China.; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning, China.
CCaMKs and MAPKKs are two kinases that regulate salt stress response in plants. It remains unclear, however, how they cooperatively affect the lateral root growth under salt stress. Here, two conserved phosphorylation sites (S102 and T118) of OsCaM1 were identified, and affected the capability of binding to Ca 2+ in vitro and kinase activity of OsCCaMK in vivo. OsCCaMK specifically interacted with OsMKK1/6 in a Ca 2+/CaM-dependent manner. The in vitro kinase and in vivo dual-luciferase assays revealed that OsCCaMK phosphorylated OsMKK6 while OsMKK1 phosphorylated OsCCaMK. Overexpression and antisense-RNA repression expression of OsCaM1-1 and CRISPR/Cas9-mediated gene edition mutations of OsMKK1, OsMKK6 and OsMKK1/6 proved that OsCaM1-1, OsMKK1 and OsMKK6 enhanced the auxin content in roots and lateral root growth under salt stress. Consistently, OsCaM1-1, OsMKK1 and OsMKK6 regulated the transcript levels of the genes of this cascade, salt stress-related and lateral root growth-related auxin signaling under salt stress in rice roots. These findings demonstrate that the OsCaM1-associated OsCCaMK-OsMKK1/6 cascade plays a critical role in recruiting auxin signaling in rice roots. These results also provide new insight into the regulatory mechanism of the CaM-mediated phosphorylation relay cascade to auxin signalling in lateral root growth under salt stress in plants.
PMID: 34129028
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab274
Mechanisms of stress response in the root stem cell niche.
Institute of Cytology and Genetics, Novosibirsk, Russia.; Novosibirsk State University, LCT&EB, Novosibirsk, Russia.; Department of Plant Systems Physiology, Institute for Water and Wetland Research, Radboud University, Heyendaalseweg, Nijmegen, The Netherlands.
As plants are sessile organisms unable to escape from environmental hazards, they need to adapt for survival. The stem cell niche in the root apical meristem is particularly sensitive to DNA damage induced by environmental stresses such as chilling, flooding, wounding, UV, and irradiation. DNA damage has been proven to cause stem cell death, with stele stem cells being the most vulnerable. Stress also induces the division of quiescent center cells. Both reactions disturb the structure and activity of the root stem cell niche temporally; however, this preserves root meristem integrity and functioning long-term. Plants have evolved many mechanisms that ensure stem cell niche maintenance, recovery, and acclimation, allowing them to survive in a changing environment. Here, we give an overview of the cellular and molecular aspects of stress responses in the root stem cell niche.
PMID: 34111279
J Exp Bot , IF:6.992 , 2021 Jun doi: 10.1093/jxb/erab224
A C-Terminal Encoded Peptide, ZmCEP1, is essential for kernel development in maize (Zea mays L.).
State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Heterosis and Utilization (MOE), Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.; National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
C-Terminal Encoded Peptides (CEPs) are peptide hormones which act as mobile signals coordinating important developmental program. Previous studies have unraveled that CEPs are able to regulate plant growth and abiotic stress via cell-to-cell communications in Arabidopsis and rice, however, little is known about their roles in maize. Here, we examined the spatiotemporal expression patterns of ZmCEP1 and clarified that ZmCEP1 is highly expressed in young ears and tassels, particularly in the vascular bundles of ear. Heterogeneous expression of ZmCEP1 in Arabidopsis results in smaller plant and seed size. Similarly, overexpression of ZmCEP1 in maize decreased the plant and ear height, ear length, kernel size and 100-kernel weight. Consistently, exogenous application of the synthesized ZmCEP1 peptide to the roots of Arabidopsis and maize elicited the same response in the light of root elongation. Knockout of ZmCEP1 through CRISPR/Cas9 significantly increased plant and ear height, kernel size and 100-kernel weight. Transcriptomic analysis revealed that knockout of ZmCEP1 upregulated a subset of genes involved in the nitrogen metabolism, nitrate transport, sugar transport and auxin response. Thus, these results provided an insight into the genetic and molecular function of ZmCEP1 in regulating kernel development and plant growth, and guidance for maize breeding.
PMID: 34104938
J Exp Bot , IF:6.992 , 2021 Jun , V72 (13) : P4773-4795 doi: 10.1093/jxb/erab177
Integrating transcriptome, co-expression and QTL-seq analysis reveals that primary root growth in maize is regulated via flavonoid biosynthesis and auxin signal transduction.
Jiangsu Key Laboratory of Crop Genetics and Physiology/ Key Laboratory of Plant Functional Genomics of the Ministry of Education/ Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College of Yangzhou University, Yangzhou, China.; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, China.
The primary root is critical for early seedling growth and survival. To understand the molecular mechanisms governing primary root development, we performed a dynamic transcriptome analysis of two maize (Zea mays) inbred lines with contrasting primary root length at nine time points over a 12-day period. A total of 18 702 genes were differentially expressed between two lines or different time points. Gene enrichment, phytohormone content determination, and metabolomics analysis showed that auxin biosynthesis and signal transduction, as well as the phenylpropanoid and flavonoid biosynthesis pathways, were associated with root development. Co-expression network analysis revealed that eight modules were associated with lines/stages, as well as primary or lateral root length. In root-related modules, flavonoid metabolism accompanied by auxin biosynthesis and signal transduction constituted a complex gene regulatory network during primary root development. Two candidate genes (rootless concerning crown and seminal roots, rtcs and Zm00001d012781) involved in auxin signaling and flavonoid biosynthesis were identified by co-expression network analysis, QTL-seq and functional annotation. These results increase our understanding of the regulatory network controlling the development of primary and lateral root length, and provide a valuable genetic resource for improvement of root performance in maize.
PMID: 33909071
Int J Biol Macromol , IF:6.953 , 2021 Jun , V185 : P277-286 doi: 10.1016/j.ijbiomac.2021.06.097
Auxin transport mechanism of membrane transporter encoded by AEC gene of Bacillus licheniformis isolated from metagenome of Tapta Kund Hotspring of Uttrakhand, India.
Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India.; Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India. Electronic address: monashimla@gmail.com.; Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow 226025, India. Electronic address: yusuf@daad-alumni.de.
Members of group Bacillus are most widely occurring microbes in agricultural soil and they affect crop health in various ways. They directly stimulate plant growth either by augmenting nutrients availability, invigorating plants' defence mechanisms; repressing soil-borne phytopathogens or by producing growth-regulating hormones like auxins and cytokinins. It is a well known fact that indole-3- acetic acid (a type of auxin) is a vital biologically active phytohormone excreted by certain Bacillus species, but its molecular mechanism has not yet been described. In this study, the auxin efflux carrier gene is isolated from the metagenome of the Tapta Kund hot spring, Uttrakhand, India. In addition, auxin efflux carrier (AEC) transporter protein of Bacillus licheniformis is modeled and the 318 amino acid residues long protein was found homologous to the apical sodium-dependent bile acid transporter (ASBT) of Yersinia frederiksnii, with 10 transmembrane segments (TM1-10) split into different domains: a panel domain defined by TM1, 2, 6 and 7; and a core domain defined by TM3-5 and 8-10. Finally, the predicted Bacillus licheniformis AEC protein has also been phylogenetically evaluated and its detailed molecular transport mechanism was worked out using molecular dynamics simulation analysis. Conclusively, this study demonstrates the efflux mechanism of the substrate, Indole 3- acetic acid by AEC transporter protein.
PMID: 34147526
Development , IF:6.868 , 2021 Jun doi: 10.1242/dev.197210
Arabidopsis vascular complexity and connectivity controls PIN-FORMED1 dynamics and lateral vein patterning during embryogenesis.
Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA.; Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA.; Biochemistry and Plant Molecular Physiology, University of Montpellier, CNRS, INRA, SupAgro, Montpellier, France.
Arabidopsis VASCULATURE COMPLEXITY AND CONNECTIVITY (VCC) is a plant-specific transmembrane protein that controls the development of veins in cotyledons. Here we show that the expression and localization of the auxin efflux carrier PIN-FORMED1 (PIN1) is altered in vcc developing cotyledons and that overexpression of PIN1-GFP partially rescues vascular defects of vcc in a dosage-dependent manner. Genetic analyses suggest that VCC and PINOID (PID), a kinase that regulates PIN1 polarity, are both required for PIN1-mediated control of vasculature development. VCC expression is upregulated by auxin, likely as part of a positive feedback loop for the progression of vascular development. VCC and PIN1 localized to the plasma membrane in pre-procambial cells but are actively redirected to vacuoles in procambial cells for degradation. In the vcc mutant, PIN1 failed to properly polarize in pre-procambial cells during the formation of basal strands and instead, it is prematurely degraded in vacuoles. VCC plays a role in localization and stability of PIN1, which is critical for the transition of pre-procambial into procambial cells involved in the formation of basal lateral strands in embryonic cotyledons.
PMID: 34137447
Front Plant Sci , IF:5.753 , 2021 , V12 : P656642 doi: 10.3389/fpls.2021.656642
Baseline Sensitivity of Echinochloa crus-gall and E. oryzicola to Florpyrauxifen-Benzyl, a New Synthetic Auxin Herbicide, in Korea.
Department of Plant Science, Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea.; Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea.; Integrated Field Science, Corteva Agriscience, Indianapolis, IN, United States.
Echinochloa species is one of the most problematic weed species due to its high competitiveness and increasing herbicide resistance. Florpyrauxifen-benzyl, a new auxin herbicide, was recently introduced for Echinochloa management; however, the potential risk for the development of herbicide resistance in Echinochloa species has not been well-investigated. Thus, this study was conducted to evaluate the baseline sensitivity of Echinochloa species to florpyrauxifen-benzyl to estimate the risk of future resistance development. A total of 70 and 71 accessions of Echinochloa crus-galli and Echinochloa oryzicola were collected from paddy fields in Korea, respectively. These two Echinochloa species were grown in plastic pots up to the 5-leaf stage, and treated with florpyrauxifen-benzyl at a range of doses from 2.2 g to 70.0 g a.i. ha(-1). Nonlinear regression analyses revealed that GR50 values for E. oryzicola ranged from 4.54 g to 29.66 g a.i. ha(-1), giving a baseline sensitivity index (BSI) of 6.53, while those for E. crus-galli ranged from 6.15 g to 16.06 g a.i. ha(-1), giving a BSI of 2.61. Our findings suggest that E. oryzicola has a greater potential risk than E. crus-galli for the development of metabolism-based resistance to florpyrauxifen-benzyl.
PMID: 34177979
Front Plant Sci , IF:5.753 , 2021 , V12 : P669143 doi: 10.3389/fpls.2021.669143
PagERF16 of Populus Promotes Lateral Root Proliferation and Sensitizes to Salt Stress.
College of Forestry, Shanxi Agricultural University, Jinzhong, China.; College of Forestry, Hebei Agricultural University, Baoding, China.
The aggravation of soil salinization limits the growth and development of plants. The AP2/ERF transcription factors (TFs) have been identified and play essential roles in plant development and stress response processes. In this study, the function of PagERF16 was detected using the overexpressing (OX) and RNAi transgenic poplar 84K hybrids. Plant growth, stomatal conductance, antioxidant enzymes activity, and PagERF16 co-expressed TFs were analyzed using morphological, physiological, and molecular methods. OX showed a more robust lateral root system with a bigger diameter and volume compared to the wild-type plants (WT). Physiological parameters indicated the bigger stomatal aperture and lower stomatal density of OX along with the lower Catalase (CAT) activity and higher malondialdehyde (MDA) content contributed to the salt sensitivity. The plant height and rooting rate of OX and RNAi were significantly worse compared to WT. Other than that, the morphology and physiology of RNAi plants were similar to WTs, suggesting that the function of PagERF16 may be redundant with other TFs. Our results indicate that when PagERF16 expression is either too high or too low, poplar growth and rooting is negatively affected. In addition, a downstream target TF, NAC45, involved in Auxin biosynthesis, was identified and PagERF16 could directly bind to its promoter to negatively regulate its expression. These results shed new light on the function of ERF TFs in plant root growth and salt stress tolerance.
PMID: 34149765
Cell Commun Signal , IF:5.712 , 2021 Jun , V19 (1) : P65 doi: 10.1186/s12964-021-00744-9
Sequence determinants of in cell condensate morphology, dynamics, and oligomerization as measured by number and brightness analysis.
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA.; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO, 63130, USA.; Center for Engineering Mechanobiology, Washington University, St. Louis, MO, 63130, USA.; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, 63110, USA. alex.holehouse@wustl.edu.; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO, 63130, USA. alex.holehouse@wustl.edu.; Center for Science and Engineering Living Systems (CSELS), Washington University, St. Louis, MO, 63130, USA. lucia.strader@duke.edu.; Center for Engineering Mechanobiology, Washington University, St. Louis, MO, 63130, USA. lucia.strader@duke.edu.; Department of Biology, Duke University, Durham, NC, 27708, USA. lucia.strader@duke.edu.
BACKGROUND: Biomolecular condensates are non-stoichiometric assemblies that are characterized by their capacity to spatially concentrate biomolecules and play a key role in cellular organization. Proteins that drive the formation of biomolecular condensates frequently contain oligomerization domains and intrinsically disordered regions (IDRs), both of which can contribute multivalent interactions that drive higher-order assembly. Our understanding of the relative and temporal contribution of oligomerization domains and IDRs to the material properties of in vivo biomolecular condensates is limited. Similarly, the spatial and temporal dependence of protein oligomeric state inside condensates has been largely unexplored in vivo. METHODS: In this study, we combined quantitative microscopy with number and brightness analysis to investigate the aging, material properties, and protein oligomeric state of biomolecular condensates in vivo. Our work is focused on condensates formed by AUXIN RESPONSE FACTOR 19 (ARF19), a transcription factor integral to the auxin signaling pathway in plants. ARF19 contains a large central glutamine-rich IDR and a C-terminal Phox Bem1 (PB1) oligomerization domain and forms cytoplasmic condensates. RESULTS: Our results reveal that the IDR amino acid composition can influence the morphology and material properties of ARF19 condensates. In contrast the distribution of oligomeric species within condensates appears insensitive to the IDR composition. In addition, we identified a relationship between the abundance of higher- and lower-order oligomers within individual condensates and their apparent fluidity. CONCLUSIONS: IDR amino acid composition affects condensate morphology and material properties. In ARF condensates, altering the amino acid composition of the IDR did not greatly affect the oligomeric state of proteins within the condensate. Video Abstract.
PMID: 34090478
Microbiol Res , IF:5.415 , 2021 Jul , V248 : P126767 doi: 10.1016/j.micres.2021.126767
Trichoderma asperellum xylanases promote growth and induce resistance in poplar.
School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.; College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China. Electronic address: jsdwangyi@126.com.; College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China.; College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China.; College of Forestry, Shenyang Agricultural University, Shenyang, 110866, China; School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. Electronic address: LiuZH789@syau.edu.cn.
Xylanase secreted by Trichoderma asperellum ACCC30536 can stimulate the systemic resistance of host plants against pathogenic fungi. Following T. asperellum conidia co-culture with Populus davidiana x P. alba var. pyramidalis Louche (PdPap) seedlings, the expression of xylanases TasXyn29.4 and TasXyn24.2 in T. asperellum were upregulated, peaking at 12 h, by 106 (2(6.74)) and 10.1 (2(3.34))-fold compared with the control, respectively. However, the expression of TasXyn24.4 and TasXyn24.0 was not detected. When recombinant xylanases rTasXyn29.4 and rTasXyn24.2 were heterologously expressed in Pichia pastoris GS115, their activities reached 18.9 IU/mL and 20.4 IU/mL, respectively. In PdPap seedlings induced by rTasXyn29.4 and rTasXyn24.2, the auxin and jasmonic acid signaling pathways were activated to promote growth and enhance resistance against pathogens. PdPap seedlings treated with both xylanases showed increased methyl jasmonate contents at 12 hpi, reaching 122 % (127 mug/g) compared with the control. However, neither of the xylanases could induce the salicylic acid signaling pathway in PdPap seedlings. Meanwhile, both xylanases could enhance the antioxidant ability of PdPap seedlings by improving their catalase activity. Both xylanases significantly induced systemic resistance of PdPap seedlings against Alternaria alternata, Rhizoctonia solani, and Fusarium oxysporum. However, the xylanases could only be sensed by the roots of the PdPap seedlings, not the leaves. In summary, rTasXyn29.4 and rTasXyn24.2 from T. asperellum ACCC30536 promoted growth and induced systemic resistance of PdPap seedlings, which endowed the PdPap seedlings broad-spectrum resistance to phytopathogens.
PMID: 33873138
Microbiol Res , IF:5.415 , 2021 Jul , V248 : P126754 doi: 10.1016/j.micres.2021.126754
Antifungal potential against Sclerotinia sclerotiorum (Lib.) de Bary and plant growth promoting abilities of Bacillus isolates from canola (Brassica napus L.) roots.
Departamento de Genetica, Instituto de Biociencias, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncalves, 9500, Caixa Postal 15.053, 91501-970, Porto Alegre, RS, Brazil.; LABRESIS - Laboratorio de Pesquisa em Resistencia Bacteriana, Centro de Pesquisa Experimental, Hospital de Clinicas de Porto Alegre (HCPA), Rua Ramiro Barcelos 2350, Porto Alegre, RS, 90.035-903, Brazil.; Departamento de Genetica, Instituto de Biociencias, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncalves, 9500, Caixa Postal 15.053, 91501-970, Porto Alegre, RS, Brazil. Electronic address: luciane.passaglia@ufrgs.br.
Endophytic bacteria show important abilities in promoting plant growth and suppressing phytopathogens, being largely explored in agriculture as biofertilizers or biocontrol agents. Bacteria from canola roots were isolated and screened for different plant growth promotion (PGP) traits and biocontrol of Sclerotinia sclerotiorum. Thirty isolates belonging to Bacillus, Paenibacillus, Lysinibacillus, and Microbacterium genera were obtained. Several isolates produced auxin, siderophores, hydrolytic enzymes, fixed nitrogen and solubilized phosphate. Five isolates presented antifungal activity against S. sclerotiorum by the dual culture assay and four of them also inhibited fungal growth by volatile organic compounds production. All antagonistic isolates belonged to the Bacillus genus, and had their genomes sequenced for the search of biosynthetic gene clusters (BGC) related to antimicrobial metabolites. These isolates were identified as Bacillus safensis (3), Bacillus pumilus (1), and Bacillus megaterium (1), using the genomic metrics ANI and dDDH. Most strains showed several common BGCs, including bacteriocin, polyketide synthase (PKS), and non-ribosomal peptide synthetase (NRPS), related to pumilacidin, bacillibactin, bacilysin, and other antimicrobial compounds. Pumilacidin-related mass peaks were detected in acid precipitation extracts through MALDI-TOF analysis. The genomic features demonstrated the potential of these isolates in the suppression of plant pathogens; however, some aspects of plant-bacterial interactions remain to be elucidated.
PMID: 33848783
J Agric Food Chem , IF:5.279 , 2021 Jun , V69 (24) : P6779-6790 doi: 10.1021/acs.jafc.1c02275
Plant Hormones and Volatiles Response to Temperature Stress in Sweet Corn (Zea mays L.) Seedlings.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.; Key Laboratory of Crops Genetics Improvement of Guangdong Province, Crop Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.; Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
This work aims to emphasize on disclosing the regulative mechanism of sweet corn seedlings response to extreme temperature stress; transcriptomics and metabolomics for volatiles and plant hormones were integrated in this study. Results showed that low-temperature stress significantly impressed 20 volatiles; abscisic acid and salicylic acid accumulated, while auxin and jasmonic acid decreased. The regulatory patterns of vp14 and ABF for abscisic acid accumulation and signal transduction were elucidated in low-temperature stress. High-temperature stress influenced 31 volatiles and caused the reductions on zeatin, salicylic acid, jasmonic acid, and auxin. The up-regulation of an ARR-B gene emphasized its function on zeatin signal transduction under high-temperature stress. Correlations among gene modules, phytohormones, and volatiles were analyzed for building the regulative network of sweet corn seedlings under temperature stress. The attained result might build foundations for improving early development of sweet corn by biological intervention or genomic-level modulation.
PMID: 34115469
J Agric Food Chem , IF:5.279 , 2021 Jun , V69 (21) : P5858-5870 doi: 10.1021/acs.jafc.1c01100
Hormone Orchestrates a Hierarchical Transcriptional Cascade That Regulates Al-Induced De Novo Root Regeneration in Tea Nodal Cutting.
College of Horticulture, Northwest A&F University, Yangling, 712100 Shaanxi, China.
The aluminum in acid soils is very rhizotoxic to most plant species, but it is essential for root growth and development in Camellia sinensis. However, the molecular basis of Al-mediated signaling pathways in root regeneration of tea plants is largely unclear. In this study, we profiled the physiological phenotype, transcriptome, and phytohormones in the process using stems treated with Al (0.3 mM) and control (0.02 mM). The anatomical analysis showed that the 0.3 mM Al-treated stem began to develop adventitious root (AR) primordia within 7 days, ARs occurred after 21 days, while the control showed a significant delay. We further found that the expression patterns of many genes involved in the biosynthesis of ZT, ACC, and JA were stimulated by Al on day 3; also, the expression profiles of auxin transporter-related genes were markedly increased under Al during the whole rooting process. Moreover, the expression of these genes was strongly correlated with the accumulation of ZT, ACC, JA, and IAA. CsERFs, CsMYBs, and CsWRKYs transcription factor genes with possible crucial roles in regulating AR regeneration were also uncovered. Our findings suggest that multiple phytohormones and genes related to their biosynthesis form a hierarchical transcriptional cascade during Al-induced de novo root regeneration in tea nodal cuttings.
PMID: 34018729
Plant Methods , IF:4.993 , 2021 Jun , V17 (1) : P63 doi: 10.1186/s13007-021-00763-0
Protocol: analytical methods for visualizing the indolic precursor network leading to auxin biosynthesis.
Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, St. Paul, MN, USA. mkreiser@umn.edu.; Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, St. Paul, MN, USA.
BACKGROUND: The plant hormone auxin plays a central role in regulation of plant growth and response to environmental stimuli. Multiple pathways have been proposed for biosynthesis of indole-3-acetic acid (IAA), the primary auxin in a number of plant species. However, utilization of these different pathways under various environmental conditions and developmental time points remains largely unknown. RESULTS: Monitoring incorporation of stable isotopes from labeled precursors into proposed intermediates provides a method to trace pathway utilization and characterize new biosynthetic routes to auxin. These techniques can be aided by addition of chemical inhibitors to target specific steps or entire pathways of auxin synthesis. CONCLUSIONS: Here we describe techniques for pathway analysis in Arabidopsis thaliana seedlings using multiple stable isotope-labeled precursors and chemical inhibitors coupled with highly sensitive liquid chromatography-mass spectrometry (LC-MS) methods. These methods should prove to be useful to researchers studying routes of IAA biosynthesis in vivo in a variety of plant tissues.
PMID: 34158074
Plant Sci , IF:4.729 , 2021 Jul , V308 : P110909 doi: 10.1016/j.plantsci.2021.110909
Mdm-MIR393b-mediated adventitious root formation by targeted regulation of MdTIR1A expression and weakened sensitivity to auxin in apple rootstock.
College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: keli505@163.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: 1551882256@qq.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: wrhrose@163.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: mjp588@163.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: 2826267803@qq.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: 835734450@qq.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: 3361604145@qq.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: 2987827737@qq.com.; College of Horticulture, Yangling Subsidiary Center Project of the National Apple Improvement Center, Northwest Agriculture & Forestry University, Yangling, 712100, China. Electronic address: afant@nwsuaf.edu.cn.
Adventitious root (AR) formation is of great significance for apple rootstock breeding. It is widely accepted that miR393 influences AR formation in many plant species; however, the molecular mechanism by which factors regulate AR formation remains insufficient. In this study, the evolutionary relationship of mdm-miR393 and candidate target genes MdTIR1/AFB was systematically identified, and the expression patterns were analysed. Multisequence alignment analysis of miR393 family members suggests that miR393 conservatively evolved between different species. The evolutionary relationship of the TIR1/AFBs can be divided into G1, G2 and G3 subgroups. During AR formation, the expression level of mdm-miR393a/b/c was significantly upregulated at 1 d and 7 d by exogenous auxin treatment. Furthermore, the expression levels of MdTIR1A, MdTIR1D, MdAFB1, MdAFB2, MdAFB3, MdAFB4 and MdAFB8 also appeared to be significantly changed by exogenous auxin induction. Subsequently, tissue-specific expression analysis showed that the expression levels of mdm-miR393 and MdTIR1/AFBs in different tissues exhibited significant differences. The promoter of mdm-miR393 contains multiple elements that respond to ABA, adversity and light signals; auxin treatment can activate the mdm-MIR393b promoter but is obviously inhibited by NPA treatment. The targeting relationship between mdm-MIR393b and MdTIR1A was verified by expression patterns, degradation group data, transient tobacco conversion results, and genes functions experiments. Heterologous overexpression of mdm-MIR393b (35S::mdm-MIR393b) decreased the number of ARs in the phenotype and reduced the expression level of the target gene NtTIR1 in tobacco. Compared to the wild type, the 35S::mdm-MIR393b transgenic plants demonstrated insensitivity to auxin. Furthermore, tir1 mutant exhibited reduced root system structure relative to the control. The above results illustrated that mdm-MIR393b is involved in mediating AR formation by targeted regulation of MdTIR1A expression in apple rootstock.
PMID: 34034866
Plant Sci , IF:4.729 , 2021 Jul , V308 : P110903 doi: 10.1016/j.plantsci.2021.110903
OsIAA20, an Aux/IAA protein, mediates abiotic stress tolerance in rice through an ABA pathway.
College of Life Science, Hebei Normal University, No.20 Road East. 2nd Ring South, Yuhua District, Shijiazhuang 050024, Hebei, China.; College of Life Science, Hebei Normal University, No.20 Road East. 2nd Ring South, Yuhua District, Shijiazhuang 050024, Hebei, China; Boustead College, Tianjin University of Commerce, Jinjing Road 28, 300384, Tianjin, China.; College of Life Science, Hebei Normal University, No.20 Road East. 2nd Ring South, Yuhua District, Shijiazhuang 050024, Hebei, China. Electronic address: zhaobaocun@hebtu.edu.cn.
In plants, auxin and ABA play significant roles in conferring tolerance to environmental abiotic stresses. Earlier studies have been shown that some Aux/IAA genes, with important signaling factors in the auxin pathway, were induced in response to drought and other abiotic stresses. However, the mechanistic links between Aux/IAA expression and general drought response remain largely unknown. In this study, OsIAA20, a rice Aux/IAA protein, shown with important roles in abiotic stress. Phenotypic analyses revealed that OsIAA20 RNAi transgenic rice reduced drought and salt tolerance; whereas, OsIAA20 overexpression plants displayed the opposite phenotype. Physiological analyses of OsIAA20 RNAi rice grown under drought or salt stress showed that proline and chlorophyll content significantly decreased, while malondialdehyde content and the ratio of Na(+)/ K(+) significantly increased. In addition, OsIAA20down-regulation reduced stomatal closure and increased the rate of water loss, while transgenic plants overexpressing OsIAA20 exhibited the opposite physiological responses. Furthermore, an ABA-responsive gene, OsRab21, was down-regulated in OsIAA20 RNAi rice lines and upregulated in OsIAA20 overexpression plants. Those results means OsIAA20 played an important role in plant drought and salt stress responses, by an ABA dependent mechanism, and it will be a candidate target gene used to breed abiotic stress tolerance.
PMID: 34034863
Plant Cell Rep , IF:4.57 , 2021 Jun doi: 10.1007/s00299-021-02721-5
Expression dynamics indicate the role of Jasmonic acid biosynthesis pathway in regulating macronutrient (N, P and K(+)) deficiency tolerance in rice (Oryza sativa L.).
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.; National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India. amarjeet.singh@nipgr.ac.in.
KEY MESSAGE: Expression pattern indicates that JA biosynthesis pathway via regulating JA levels might control root system architecture to improve nutrient use efficiency (NUE) and N, P, K(+) deficiency tolerance in rice. Deficiencies of macronutrients (N, P and K(+)) and consequent excessive use of fertilizers have dramatically reduced soil fertility. It calls for development of nutrient use efficient plants. Plants combat nutrient deficiencies by altering their root system architecture (RSA) to enhance the acquisition of nutrients from the soil. Amongst various phytohormones, Jasmonic acid (JA) is known to regulate plant root growth and modulate RSA. Therefore, to understand the role of JA in macronutrient deficiency in rice, expression pattern of JA biosynthesis genes was analyzed under N, P and K(+) deficiencies. Several members belonging to different families of JA biosynthesis genes (PLA1, LOX, AOS, AOC, OPR, ACX and JAR1) showed differential expression exclusively in one nutrient deficiency or in multiple nutrient deficiencies. Expression analysis during developmental stages showed that several genes expressed significantly in vegetative tissues, particularly in root. In addition, JA biosynthesis genes were found to have significant expression under the treatment of different phytohormones, including Auxin, cytokinin, gibberellic acid (GA), abscisic acid (ABA), JA and abiotic stresses, such as drought, salinity and cold. Analysis of promoters of these genes revealed various cis-regulatory elements associated with hormone response, plant development and abiotic stresses. These findings suggest that JA biosynthesis pathway by regulating the level of JA might control the RSA thus, it may help rice plant in combating macronutrient deficiency.
PMID: 34089089
Plant Cell Rep , IF:4.57 , 2021 Jun doi: 10.1007/s00299-021-02724-2
Phytohormone signalling and cross-talk to alleviate aluminium toxicity in plants.
School of Genetic Engineering, ICAR-Indian Institute of Agricultural Biotechnology, Ranchi, 834 003, India. alok_ranjan84@yahoo.com.; School of Genetic Engineering, ICAR-Indian Institute of Agricultural Biotechnology, Ranchi, 834 003, India.; School of Genomics and Molecular Breeding, ICAR-Indian Institute of Agricultural Biotechnology, Ranchi, 834 003, India.; School of Genetic Engineering, ICAR-Indian Institute of Agricultural Biotechnology, Ranchi, 834 003, India. anils13@gmail.com.
Aluminium (Al) is one of the most abundant metals in earth crust, which becomes toxic to the plants growing in acidic soil. Phytohormones like ethylene, auxin, cytokinin, abscisic acid, jasmonic acid and gibberellic acid are known to play important role in regulating Al toxicity tolerance in plants. Exogenous applications of auxin, cytokinin and abscisic acid have shown significant effect on Al-induced root growth inhibition. Moreover, ethylene and cytokinin act synergistically with auxin in responding against Al toxicity. A number of studies showed that phytohormones play vital roles in controlling root responses to Al toxicity by modulating reactive oxygen species (ROS) signalling, cell wall modifications, organic acid exudation from roots and expression of Al responsive genes and transcription factors. This review provides a summary of recent studies related to involvement of phytohormone signalling and cross-talk with other pathways in regulating response against Al toxicity in plants.
PMID: 34086069
Plant Cell Rep , IF:4.57 , 2021 Jul , V40 (7) : P1269-1284 doi: 10.1007/s00299-021-02709-1
Genome-wide analysis of ARF transcription factors reveals HcARF5 expression profile associated with the biosynthesis of beta-ocimene synthase in Hedychium coronarium.
The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China.; College of Economics and Management, Kunming University, Kunming, 650214, China.; College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.; Department of Botany, Division of Science and Technology, University of Education, Lahore, 54770, Punjab, Pakistan.; College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.; The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, 510642, China. fanyanping@scau.edu.cn.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangzhou, 510642, China. fanyanping@scau.edu.cn.
KEY MESSAGE: Herein, 37 ARF genes were identified and analyzed in Hedychium coronarium and HcARF5 showed a potential role in the regulation of HcTPS3. Auxin is an important plant hormone, implicated in various aspects of plant growth and development processes especially in the biosynthesis of various secondary metabolites. Auxin response factors (ARF) belong to the transcription factors (TFs) gene family and play a crucial role in transcriptional activation/repression of auxin-responsive genes by directly binding to their promoter region. Nevertheless, whether ARF genes are involved in the regulatory mechanism of volatile compounds in flowering plants is largely unknown. beta-ocimene is a key floral volatile compound synthesized by terpene synthase 3 (HcTPS3) in Hedychium coronarium. A comprehensive analysis of H. coronarium genome reveals 37 candidate ARF genes in the whole genome. Tissue-specific expression patterns of HcARFs family members were assessed using available transcriptome data. Among them, HcARF5 showed a higher expression level in flowers, and significantly correlated with the key structural beta-ocimene synthesis gene (HcTPS3). Furthermore, transcript levels of both genes were associated with the flower development. Under hormone treatments, the response of HcARF5 and HcTPS3, and the emission level of beta-ocimene contents were evaluated. Subcellular and transcriptional activity assay showed that HcARF5 localizes to the nucleus and possesses transcriptional activity. Yeast one-hybrid (Y1H) and dual-luciferase assays revealed that HcARF5 directly regulates the transcriptional activity of HcTPS3. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that HcARF5 interacts with scent-related HcIAA4, HcIAA6, and HcMYB1 in vivo. Overall, these results indicate that HcARF5 is potentially involved in the regulation of beta-ocimene synthesis in H. coronarium.
PMID: 34052884
Plant Cell Rep , IF:4.57 , 2021 Jul , V40 (7) : P1115-1126 doi: 10.1007/s00299-021-02680-x
The SlTCP26 promoting lateral branches development in tomato.
Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China.; Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China. zoujian@cwnu.edu.cn.
KEY MESSAGE: The SlTCP26 negatively regulated auxin signal to relieve the apical dominance and suppressed abscisic acid signal to remove the lateral bud dormancy, promoting lateral branches development. Lateral branches formation from lateral buds is a complex regulatory process in higher plants, and the interaction between transcription factors and hormones is indispensable during this process. TCP transcription factors have been reported to regulate lateral branches development, while the detailed function, especially interacting with auxin and ABA during this process, was still ambiguous in tomato. In this study, a branch regulatory gene, SlTCP26, was identified in tomato, and its role along with its interaction to hormones during branch development, as investigated. The results indicated that overexpression of SlTCP26 would promote lateral branches development, and could suppress the expressing of the genes associated with IAA signaling, presenting similar effects in decapitated plants. Conversely, the exogenous IAA application could inhibit the expression of SlTCP26. Furthermore, the expressing of the ABA signaling-related genes was inhibited in SlTCP26 overexpressed tomato, similar to that in decapitated tomato. Our findings suggested that SlTCP26 may be a crucial adjuster for synergistic action between ABA and IAA signals during the development of lateral branches, and it could promote the lateral buds grow into lateral shoots, via inhibiting IAA signal to relieve the apical dominance and suppressing ABA signal to remove the lateral bud dormancy. Our study provided some insights for the development of tomato lateral branches to understand the apical dominance regulatory network.
PMID: 33758995
Sci Rep , IF:4.379 , 2021 Jun , V11 (1) : P13094 doi: 10.1038/s41598-021-92305-w
Large scale production of indole-3-acetic acid and evaluation of the inhibitory effect of indole-3-acetic acid on weed growth.
Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.; Academy of Science, Royal Society of Thailand, Bangkok, 10300, Thailand.; Department of Microbiology, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand. fscints@ku.ac.th.
Indole-3-acetic acid (IAA) is the most common plant hormone of the auxin class and regulates various plant growth processes. The present study investigated IAA production by the basidiomycetous yeast Rhodosporidiobolus fluvialis DMKU-CP293 using the one-factor-at-a-time (OFAT) method and response surface methodology (RSM). IAA production was optimized in shake-flask culture using a cost-effective medium containing 4.5% crude glycerol, 2% CSL and 0.55% feed-grade L-tryptophan. The optimized medium resulted in a 3.3-fold improvement in IAA production and a 3.6-fold reduction in cost compared with those obtained with a non-optimized medium. Production was then scaled up to a 15-L bioreactor and to a pilot-scale (100-L) bioreactor based on the constant impeller tip speed (Vtip) strategy. By doing so, IAA was successfully produced at a concentration of 3569.32 mg/L at the pilot scale. To the best of our knowledge, this is the first report of pilot-scale IAA production by microorganisms. In addition, we evaluated the effect of crude IAA on weed growth. The results showed that weed (Cyperus rotundus L.) growth could be inhibited by 50 mg/L of crude IAA. IAA therefore has the potential to be developed as a herbicidal bioproduct to replace the chemical herbicides that have been banned in various countries, including Thailand.
PMID: 34158557
Sci Rep , IF:4.379 , 2021 Jun , V11 (1) : P12381 doi: 10.1038/s41598-021-91931-8
Melatonin influences the early growth stage in Zoysia japonica Steud. by regulating plant oxidation and genes of hormones.
College of Grassland Science, Beijing Forestry University, Beijing, 100083, China.; College of Grassland Science, Beijing Forestry University, Beijing, 100083, China. caoyuehui@163.com.; College of Grassland Science, Beijing Forestry University, Beijing, 100083, China. hanliebao@163.com.
Zoysia japonica is a commonly used turfgrass species around the world. Seed germination is a crucial stage in the plant life cycle and is particularly important for turf establishment and management. Experiments have confirmed that melatonin can be a potential regulator signal in seeds. To determine the effect of exogenous melatonin administration and explore the its potential in regulating seed growth, we studied the concentrations of several hormones and performed a transcriptome analysis of zoysia seeds after the application of melatonin. The total antioxidant capacity determination results showed that melatonin treatment could significantly improve the antioxidant capacity of zoysia seeds. The transcriptome analysis indicated that several of the regulatory pathways were involved in antioxidant activity and hormone activity. The hormones concentrations determination results showed that melatonin treatment contributed to decreased levels of cytokinin, abscisic acid and gibberellin in seeds, but had no significant effect on the secretion of auxin in early stages. Melatonin is able to affect the expression of IAA (indoleacetic acid) response genes. In addition, melatonin influences the other hormones by its synergy with other hormones. Transcriptome research in zoysia is helpful for understanding the regulation of melatonin and mechanisms underlying melatonin-mediated developmental processes in zoysia seeds.
PMID: 34117332
Plant Physiol Biochem , IF:4.27 , 2021 Jun , V166 : P540-548 doi: 10.1016/j.plaphy.2021.06.036
PopW enhances drought stress tolerance of alfalfa via activating antioxidative enzymes, endogenous hormones, drought related genes and inhibiting senescence genes.
Faculty of Agriculture, Department of Field Crops, Ordu University, 52200, Ordu, Turkey. Electronic address: gurkandemirkol@odu.edu.tr.
Alfalfa (Medicago sativa L.) has the advantages of high yield and nutritional value as a perennial forage. However, one of the drawbacks of alfalfa is its susceptibility to drought conditions, which is a global problem in agriculture. The purpose of this study was to reveal the effects of exogenous PopW, a harpin protein from Ralstonia solanacearum, treatment on growth parameters, physiological and biochemical mechanism of alfalfa under drought-stress conditions. Growth parameters, relative water content, free proline, leaf area, total chlorophyll, antioxidative enzymes, endogenous hormones including ABA, CTK, GA, JA, SA and IAA were determined in response to exogenous PopW treatment under drought stress in alfalfa cultivar (Victoria). Moreover, relative gene expressions of drought-related and leaf senescence genes were determined. Under drought stress, alfalfa plants had lower shoot dry weight, shoot length, relative water content, leaf area, and total chlorophyll content, compared to control (non-stressed). However, Exogenous PopW treatment significantly increased growth values, relative water content, free proline, leaf area, total chlorophyll content, catalase, glutathione reductase and superoxide dismutase under drought conditions, compared to control and drought stress alone. Moreover, exogenous PopW treatment significantly increased ABA, GA, JA, SA, IAA contents, up-regulated auxin- and drought-responsive genes, down-regulated leaf senescence genes. Exogenous PopW treatment enhanced drought stress tolerance of alfalfa due to changes of endogenous hormone contents and expression levels of drought stress and leaf senescence genes. The results of the study show that PopW treatment could be used to increase the forage yield of alfalfa on areas having drought problem.
PMID: 34174659
Plant Physiol Biochem , IF:4.27 , 2021 Jun , V166 : P512-521 doi: 10.1016/j.plaphy.2021.06.007
Physiological impact of flavonoids on nodulation and ureide metabolism in legume plants.
Sao Paulo State University (UNESP), Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP, Postal Code 14884-900, Brazil.; Sao Paulo State University (UNESP), Postal Code 15385-000, Ilha Solteira, SP, Brazil.; Sao Paulo State University (UNESP), Rua Domingos da Costa Lopes 780, Postal Code 17602-496, Tupa, SP, Brazil. Electronic address: andre.reis@unesp.br.
Legume plants from Fabaceae family (phylogenetic group composed by three subfamilies: Caesalpinioideae, Mimosoideae, and Papilionoideae) can fix atmospheric nitrogen (N2) into ammonia (NH3) by the symbiotic relationship with rhizobia bacteria. These bacteria respond chemotactically to certain compounds released by plants such as sugars, amino acids and organic acids. Root secretion of isoflavonoids acts as inducers for nod genes in rhizobia and ABC transporters and ICHG (isoflavone conjugates hydrolyzing beta-glucosidase) at apoplast are related to the exudation of genistein and daidzein in soybean roots. Biological nitrogen fixation (BNF) occurs inside the nodule by the action of nitrogenase enzyme, which fixes N2 into NH3, which is converted into ureides (allantoin and allantoic acid). In this review, we bring together the latest findings on flavonoids biosynthesis and ureide metabolism in several legume plant species. We emphasize how flavonoids induce nod genes in rhizobia, affecting chemotaxis, nodulation, ureide production, growth and yield of legume plants. Mainly, isoflavonoids daidzein and genistein are responsible for nod genes activation in the rhizobia bacteria. Flavonoids also play an important role during nodule organogenesis by acting as auxin transporter inhibitors in root cells, especially in indeterminate nodules. The ureides are the main N transport form in tropical legumes and they are catabolized in leaves and other sink tissues to produce amino acids and proteins needed for plant growth and yield.
PMID: 34171572
Plant Physiol Biochem , IF:4.27 , 2021 Jun , V166 : P477-484 doi: 10.1016/j.plaphy.2021.06.023
Comparative transcriptomic pro fi ling reveals the regulation of terpenoid biosynthesis in Sinocalycanthus chinensis.
Institute of Biopharmaceuticals, Taizhou University, Taizhou, 318000, China. Electronic address: qiao1605@126.com.; Institute of Biopharmaceuticals, Taizhou University, Taizhou, 318000, China.
Sinocalycanthus chinensis, a diploid (2n = 22) deciduous shrub, belongs to the Calycanthaceae family of magnoliids and is rich secondary metabolites, such as terpenoids. However, the regulation of terpenoid biosynthesis in S. chinensis is largely unknown. In this study, comparative transcriptome analyses were performed in the bark, branches, leaves, and flowers. KEGG enrichment analysis revealed that the terpenoid biosynthesis and cytochrome P450 pathways were significantly enriched in the four tissues. Twelve terpenoid backbone biosynthesis-related genes were identified, and eight terpene synthases (TPSs) were reassembled based on independent transcriptomes from the four tissues. Phylogenetic analysis of the TPSs showed high sequence similarity between S. chinensis and Arabidopsis, and these TPSs were classified into three subfamilies. Moreover, 39 phytohormone response-related genes, including 5 abscisic acid (ABA) receptors, 25 auxin response factors, 3 gibberellin (GA) response genes, 5 ethylene response genes, and 1 jasmonic acid (JA) response gene were analyzed. Most phytohormone pathway-related genes were upregulated in the flowers and downregulated in the leaves. The endogenous indole acetic acid (IAA) content was higher in the flowers than in the other comparisons. Our results provide an opportunity to reveal the regulation of terpenoid biosynthesis in S. chinensis.
PMID: 34166974
Plant Physiol Biochem , IF:4.27 , 2021 Jul , V164 : P1-9 doi: 10.1016/j.plaphy.2021.04.008
Auxin alters sodium ion accumulation and nutrient accumulation by playing protective role in salinity challenged strawberry.
College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China; State Key Laboratory of Crop Biology, Taian, Shandong, 271018, China.; College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China. Electronic address: ileman@sdau.edu.cn.; College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China; State Key Laboratory of Crop Biology, Taian, Shandong, 271018, China. Electronic address: liling217@sdau.edu.cn.
High salinity in soil affects the strawberry production and fruit quality. Auxin-primed plants have enhanced responses to soil salinization. In this study, we report that exogenous application of IAA can partially relieve stress responses of strawberry seedlings. Cytological analysis showed that the ultrastructure of root tip and leaf cells in strawberry seedlings were altered under high salinity condition, which was partially recovered after the application of IAA. The study showed that the ultrastructure of root tip and leaf cells in strawberry seedlings were altered under salt stress condition, which was partially recovered after the application of IAA. Exogenous IAA ameliorated deleterious effects on seedling growth under salinity were attributed to accelerated Na(+) fluxes, decreased the contents of Na(+) to maintain the ion homeostasis, protect root growth, and promote the absorption of nutrients for improved photosynthetic efficiency in strawberry.
PMID: 33932693
BMC Plant Biol , IF:4.215 , 2021 Jun , V21 (1) : P274 doi: 10.1186/s12870-021-03060-z
An NADPH oxidase regulates carbon metabolism and the cell cycle during root nodule symbiosis in common bean (Phaseolus vulgaris).
Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Avenida Universidad, Cuernavaca, Morelos, Colonia Chamilpa, Mexico.; Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Avenida Universidad, Cuernavaca, Morelos, Colonia Chamilpa, Mexico. carmen.quinto@ibt.unam.mx.
BACKGROUND: Rhizobium-legume symbiosis is a specific, coordinated interaction that results in the formation of a root nodule, where biological nitrogen fixation occurs. NADPH oxidases, or Respiratory Burst Oxidase Homologs (RBOHs) in plants, are enzymes that generate superoxide (O2 (*-)). Superoxide produces other reactive oxygen species (ROS); these ROS regulate different stages of mutualistic interactions. For example, changes in ROS levels are thought to induce ROS scavenging, cell wall remodeling, and changes in phytohormone homeostasis during symbiotic interactions. In common bean (Phaseolus vulgaris), PvRbohB plays a key role in the early stages of nodulation. RESULTS: In this study, to explore the role of PvRbohB in root nodule symbiosis, we analyzed transcriptomic data from the roots of common bean under control conditions (transgenic roots without construction) and roots with downregulated expression of PvRbohB (by RNA interference) non-inoculated and inoculated with R. tropici. Our results suggest that ROS produced by PvRBOHB play a central role in infection thread formation and nodule organogenesis through crosstalk with flavonoids, carbon metabolism, cell cycle regulation, and the plant hormones auxin and cytokinin during the early stages of this process. CONCLUSIONS: Our findings provide important insight into the multiple roles of ROS in regulating rhizobia-legume symbiosis.
PMID: 34130630
BMC Plant Biol , IF:4.215 , 2021 Jun , V21 (1) : P261 doi: 10.1186/s12870-021-03013-6
Differential transcription pathways associated with rootstock-induced dwarfing in breadfruit (Artocarpus altilis) scions.
Australian Centre for Pacific Islands Research, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia. yzhou1@usc.edu.au.; Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, 4072, Australia. yzhou1@usc.edu.au.; Australian Centre for Pacific Islands Research, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia.; Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, 4072, Australia.
BACKGROUND: Breadfruit (Artocarpus altilis) is a traditional staple tree crop throughout the tropics. Through interspecific grafting, a dwarf phenotype with over 50% reduction in plant height was identified when marang (Artocarpus odoratissimus) rootstocks were used. However, the molecular mechanism underlying the rootstock-induced breadfruit dwarfing is poorly understood. RESULTS: An RNA-sequencing study of breadfruit scions at 22 months after grafting identified 5409 differentially expressed genes (DEGs) of which 2069 were upregulated and 3339 were downregulated in scion stems on marang rootstocks compared to those on self-graft. The DEGs were predominantly enriched for biological processes involved in carbon metabolism, cell wall organization, plant hormone signal transduction and redox homeostasis. The down-regulation of genes encoding vacuolar acid invertases and alkaline/neutral invertases, was consistent with the decreased activity of both enzymes, accompanying with a higher sucrose but lower glucose and fructose levels in the tissues. Key genes of biosynthetic pathways for amino acids, lipids and cell wall were down regulated, reflecting reduction of sucrose utilisation for stem growth on dwarfing rootstocks. Genes encoding sugar transporters, amino acid transporters, choline transporters, along with large number of potassium channels and aquaporin family members were down-regulated in scion stems on marang rootstocks. Lower activity of plasma membrane H(+)-ATPase, together with the predominance of genes encoding expansins, wall-associated receptor kinases and key enzymes for biosynthesis and re-modelling of cellulose, xyloglucans and pectins in down-regulated DGEs suggested impairment of cell expansion. Signalling pathways of auxin and gibberellin, along with strigolacton and brassinosteroid biosynthetic genes dominated the down-regulated DEGs. Phenylpropanoid pathway was enriched, with key lignin biosynthetic genes down-regulated, and flavonoid biosynthetic genes upregulated in scions on marang rootstocks. Signalling pathways of salicylic acid, jasmonic acid, ethylene and MAPK cascade were significantly enriched in the upregulated DEGs. CONCLUSIONS: Rootstock-induced disruption in pathways regulating nutrient transport, sucrose utilisation, cell wall biosynthesis and networks of hormone transduction are proposed to impair cell expansion and stem elongation, leading to dwarf phenotype in breadfruit scions. The information provides opportunity to develop screening strategy for rootstock breeding and selection for breadfruit dwarfing.
PMID: 34090350
Planta , IF:4.116 , 2021 Jun , V254 (1) : P7 doi: 10.1007/s00425-021-03597-1
Correlation analysis of the transcriptome and metabolome reveals the role of the flavonoid biosynthesis pathway in regulating axillary buds in upland cotton (Gossypium hirsutum L.).
State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, 455000, China.; Xinjiang Qianhai Seed Industry Limited Liability Company, Tumsuk, 843901, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, 455000, China. yangentu@caas.cn.
MAIN CONCLUSION: Flavonoids are involved in axillary bud development in upland cotton. The phenylpropanoid and flavonoid biosynthesis pathways regulate axillary bud growth by promoting the transport of auxin in upland cotton. In cotton production, simplified cultivation and mechanical harvesting are emerging trends that depend on whether the cotton plant type meets production requirements. The axillary bud is an important index of cotton plant-type traits, and the molecular mechanism of axillary bud development in upland cotton has not yet been completely studied. Here, a combined investigation of transcriptome and metabolome analyses in G. hirsutum CCRI 117 at the fourth week (stage 1), fifth week (stage 2) and sixth week (stage 3) after seedling emergence was performed. The metabolome results showed that the total lipid, amino acid and organic acid contents in the first stalk node decreased during axillary bud development. The abundance of 71 metabolites was altered between stage 2 and stage 1, and 32 metabolites exhibited significantly altered abundance between stage 3 and stage 2. According to the correlation analysis of metabolome and transcriptome profiles, we found that phenylpropanoid and flavonoid biosynthesis pathways exhibit high enrichment degrees of both differential metabolites and differential genes in three stages. Based on the verification of hormone, soluble sugar and flavonoid detection, we propose a model for flavonoid-mediated regulation of axillary bud development in upland cotton, revealing that the decrease in secondary metabolites of phenylpropanoid and flavonoid biosynthesis is an essential factor to promote the transport of auxin and subsequently promote the growth of axillary buds. Our findings provide novel insights into the regulation of phenylpropanoid and flavonoid biosynthesis in axillary bud development and could prove useful for cultivating machine-harvested cotton varieties with low axillary buds.
PMID: 34142246
Planta , IF:4.116 , 2021 Jun , V254 (1) : P4 doi: 10.1007/s00425-021-03656-7
Differential responses of anthers of stress tolerant and sensitive wheat cultivars to high temperature stress.
AgriBio, Centre for Agribioscience, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia.; Melbourne Polytechnic, Epping, VIC, Australia.; CSIRO Agriculture and Food, Canberra, ACT, Australia.; AgriBio, Centre for Agribioscience, Department of Animal, Plant and Soil Sciences, La Trobe University, Bundoora, VIC, Australia. r.parish@latrobe.edu.au.
MAIN CONCLUSION: Transcriptomic analyses identified anther-expressed genes in wheat likely to contribute to heat tolerance and hence provide useful genetic markers. The genes included those involved in hormone biosynthesis, signal transduction, the heat shock response and anther development. Pollen development is particularly sensitive to high temperature heat stress. In wheat, heat-tolerant and heat-sensitive cultivars have been identified, although the underlying genetic causes for these differences are largely unknown. The effects of heat stress on the developing anthers of two heat-tolerant and two heat-sensitive wheat cultivars were examined in this study. Heat stress (35 degrees C) was found to disrupt pollen development in the two heat-sensitive wheat cultivars but had no visible effect on pollen or anther development in the two heat-tolerant cultivars. The sensitive anthers exhibited a range of developmental abnormalities including an increase in unfilled and clumped pollen grains, abnormal pollen walls and a decrease in pollen viability. This subsequently led to a greater reduction in grain yield in the sensitive cultivars following heat stress. Transcriptomic analyses of heat-stressed developing wheat anthers of the four cultivars identified a number of key genes which may contribute to heat stress tolerance during pollen development. Orthologs of some of these genes in Arabidopsis and rice are involved in regulation of the heat stress response and the synthesis of auxin, ethylene and gibberellin. These genes constitute candidate molecular markers for the breeding of heat-tolerant wheat lines.
PMID: 34131818
BMC Genomics , IF:3.969 , 2021 Jun , V22 (1) : P467 doi: 10.1186/s12864-021-07796-8
RNA sequencing reveals transcriptomic changes in tobacco (Nicotiana tabacum) following NtCPS2 knockdown.
College of Tobacco Science, Henan Agricultural University, National Tobacco Cultivation & Physiology & Biochemistry Research Centre, Scientific Observation and Experiment Station of Henan, Ministry of Agriculture, Zhengzhou, 450002, China.; Technology Center, China Tobacco Zhejiang Industry Co, Ltd., Hangzhou, 310008, China.; China National Tobacco Corporation Henan company, Zhengzhou, 450002, Henan, China.; Hunan Tobacco Corporation Changsha Company, Changsha, 410007, Hunan, China.; Guangxi Zhuang Autonomous Region Tobacco Corporation Baise Company, Baise, 533000, Guangxi, China.; College of Tobacco Science, Henan Agricultural University, National Tobacco Cultivation & Physiology & Biochemistry Research Centre, Scientific Observation and Experiment Station of Henan, Ministry of Agriculture, Zhengzhou, 450002, China. xushixiao@henau.edu.cn.
BACKGROUND: Amber-like compounds form in tobacco (Nicotiana tabacum) during leaf curing and impact aromatic quality. In particular, cis-abienol, a polycyclic labdane-related diterpenoid, is of research interest as a precursor of these compounds. Glandular trichome cells specifically express copalyl diphosphate synthase (NtCPS2) at high levels in tobacco, which, together with NtABS, are major regulators of cis-abienol biosynthesis in tobacco. RESULTS: To identify the genes involved in the biosynthesis of cis-abienol in tobacco, we constructed transgenic tobacco lines based on an NtCPS2 gene-knockdown model using CRISPR/Cas9 genome-editing technology to inhibit NtCPS2 function in vitro. In mutant plants, cis-abienol and labdene diol contents decreased, whereas the gibberellin and abscisic acid (ABA) contents increased compared with those in wild-type tobacco plants. RNA sequencing analysis revealed the presence of 9514 differentially expressed genes (DEGs; 4279 upregulated, 5235 downregulated) when the leaves of wild-type and NtCPS2-knockdown tobacco plants were screened. Among these DEGs, the genes encoding cis-abienol synthase, ent-kaurene oxidase, auxin/ABA-related proteins, and transcription factors were found to be involved in various biological and physiochemical processes, including diterpenoid biosynthesis, plant hormone signal transduction, and plant-pathogen interactions. CONCLUSIONS: The present study provides insight into the unique transcriptome profile of NtCPS2 knockdown tobacco, allowing for a better understanding of the biosynthesis of cis-abienol in tobacco.
PMID: 34162328
BMC Genomics , IF:3.969 , 2021 Jun , V22 (1) : P463 doi: 10.1186/s12864-021-07765-1
Identification, systematic evolution and expression analyses of the AAAP gene family in Capsicum annuum.
Biotechnology Research Center, Chongqing Academy of Agricultural Sciences/Chongqing Key Laboratory of Adversity Agriculture Research, Chongqing, 401329, China.; Biotechnology Research Center, Chongqing Academy of Agricultural Sciences/Chongqing Key Laboratory of Adversity Agriculture Research, Chongqing, 401329, China. leikairong@126.com.
BACKGROUND: The amino acid/auxin permease (AAAP) family represents a class of proteins that transport amino acids across cell membranes. Members of this family are widely distributed in different organisms and participate in processes such as growth and development and the stress response in plants. However, a systematic comprehensive analysis of AAAP genes of the pepper (Capsicum annuum) genome has not been reported. RESULTS: In this study, we performed systematic bioinformatics analyses to identify AAAP family genes in the C. annuum 'Zunla-1' genome to determine gene number, distribution, structure, duplications and expression patterns in different tissues and stress. A total of 53 CaAAAP genes were identified in the 'Zunla-1' pepper genome and could be divided into eight subgroups. Significant differences in gene structure and protein conserved domains were observed among the subgroups. In addition to CaGAT1, CaATL4, and CaVAAT1, the remaining CaAAAP genes were unevenly distributed on 11 of 12 chromosomes. In total, 33.96% (18/53) of the CaAAAP genes were a result of duplication events, including three pairs of genes due to segmental duplication and 12 tandem duplication events. Analyses of evolutionary patterns showed that segmental duplication of AAAPs in pepper occurred before tandem duplication. The expression profiling of the CaAAAP by transcriptomic data analysis showed distinct expression patterns in various tissues and response to different stress treatment, which further suggest that the function of CaAAAP genes has been differentiated. CONCLUSIONS: This study of CaAAAP genes provides a theoretical basis for exploring the roles of AAAP family members in C. annuum.
PMID: 34157978
Plant Reprod , IF:3.767 , 2021 Jun doi: 10.1007/s00497-021-00423-2
Characterization of transcriptomic response in ovules derived from inter-subgeneric hybridization in Prunus (Rosaceae) species.
Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, 619-0244, Japan. morimoto@kpu.ac.jp.; Japanese Apricot Laboratory, Wakayama Fruit Tree Experiment Station, Wakayama, 645-0021, Japan.; Faculty of Agriculture, Setsunan University, Osaka, 573-0101, Japan.; Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, 619-0244, Japan.
KEY MESSAGE: Characterization of hybrid seed failure in Prunus provides insight into conserved or lineage-specific hybrid incompatibility mechanisms in plant species. Postzygotic hybrid incompatibility resulting from a cross between different species involves complex mechanisms occurring at various developmental stages. Embryo arrest, followed by seed abortion, is the first stage of such incompatibility reactions and inhibits hybrid seed development. In Prunus, a rosaceous woody species, some interspecific crosses result in fruit drop during the early stage of fruit development, in which inferior seed development may be accounted for the observed hybrid incompatibility. In this study, we investigated ovule development and the transcriptomes of developing ovules in inter-subgeneric crosses of Prunus. We conducted a cross of Prunus mume (subgenus Prunus), pollinated by P. persica (subgenus Amygdalus), and found that ovule and seed coat degeneration occurs before fruit drop. Transcriptome analysis identified differentially expressed genes enriched in several GO pathways, including organelle development, stimulus response, and signaling. Among these pathways, the organelle-related genes were actively regulated during ovule development, as they showed higher expression in the early stage of interspecific crosses and declined in the later stage, suggesting that the differential regulation of organelle function may induce the degeneration of hybrid ovules. Additionally, genes related to ovule and seed coat development, such as genes encoding AGL-like and auxin response, were differentially regulated in Prunus interspecific crosses. Our results provide histological and molecular information on hybrid seed abortion in Prunus that could be utilized to develop new hybrid crops. Additionally, we compared and discussed transcriptome responses to hybrid seed failure in Prunus and other plant species, which provides insight into conserved or lineage-specific hybrid incompatibility mechanisms in some plant species.
PMID: 34165636
Gene , IF:3.688 , 2021 Jun : P145782 doi: 10.1016/j.gene.2021.145782
Genome-wide identification of AUX/IAA in radish and functional characterization of RsIAA33 gene during taproot thickening.
National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOA, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China; Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization, College of Horticulture Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China.; National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOA, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.; National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOA, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China. Electronic address: nauxuliang@njau.edu.cn.; Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization, College of Horticulture Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao 066004, China.; National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOA, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China. Electronic address: nauliulw@njau.edu.cn.
Auxin/indole-3-acetic acid (Aux/IAA) genes encode short lived nuclear proteins that cooperated with auxin or auxin response factor (ARF), which are involved in plant growth and developmental processes. However, it's still ambiguous how the Aux/IAA genes regulate the process governing taproot thickening in radish. Herein, 65 Aux/IAA genes were identified from the radish genome. Gene duplication analysis showed that two pairs of tandem duplication and 17 (27%) segmental duplication events were identified among Aux/IAA family genes in radish. Transcriptomic analysis revealed that most of Aux/IAA genes (52/65) exhibited differential expression pattern in root different tissues, and six root-specific genes were high abundance expression in root cortex, cambium, xylem, and root tip in radish. RT-qPCR analysis showed that the expression level of RsIAA33 was the highest at cortex splitting stage (CSS), and early expanding stage (ES). Furthermore, amiRNA-mediated gene silencing of RsIAA33 indicated it could inhibit the reproductive growth, thus promoting taproot thickening and development. These results would provide valuable information for elucidating the molecular mechanisms of Aux/IAA genes involved in taproot thickening in radish.
PMID: 34146634
Biochem Biophys Res Commun , IF:3.575 , 2021 Jun , V558 : P196-201 doi: 10.1016/j.bbrc.2020.09.039
Overexpression of a phosphate transporter gene ZmPt9 from maize influences growth of transgenic Arabidopsis thaliana.
School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, China; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China.; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China.; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China. Electronic address: lixiaoyu@ahau.edu.cn.; School of Agriculture, Yunnan University, Kunming, 650504, China; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, 230036, China. Electronic address: liufang0019@ynu.edu.cn.
Phosphate transporters (PHTs) are well-known for their roles in phosphate uptake in plants. However, their actions in imparting plant growth in plants are still not so clear. In our previous study, we observed that maize PHT1 gene ZmPt9 plays a significant role in phosphate uptake. In this study, we further characterized ZmPt9 in response to low phosphate condition through ZmPt9 promoter inductive analysis by GUS staining and quantification. To elucidate the function of ZmPt9, we generated overexpression plant in Arabidopsis. ZmPt9 overexpressing Arabidopsis plants conferred small leaves and early flowering compared with the wild-type plants. In addition, ZmPt9 can complement the late flowering phenotype of Arabidopsis mutant pht1;2. The qRT-PCR analysis revealed that overexpression of ZmPt9 in Arabidopsis changed expression levels of some flowering-related genes. Further expressed detection of hormone related genes revealed that GA and auxin maybe the main determinant for growth influences of ZmPt9. In conclusion, these results suggest that apart from phosphate transport activity, ZmPt9 can be further exploited for improving crops growth.
PMID: 32962860
J Plant Physiol , IF:3.549 , 2021 Jul , V262 : P153437 doi: 10.1016/j.jplph.2021.153437
Interactive effects of plant growth-promoting rhizobacteria and a seaweed extract on the growth and physiology of Allium cepa L. (onion).
Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa.; Laboratory of Growth Regulators, Faculty of Science, Palacky University & Institute of Experimental Botany AS CR, v.v.i., Slechtitelu 11, 78371, Olomouc, Czech Republic.; Laboratory of Growth Regulators, Faculty of Science, Palacky University & Institute of Experimental Botany AS CR, v.v.i., Slechtitelu 11, 78371, Olomouc, Czech Republic; Department of Chemical Biology, Faculty of Science, Palacky University, Slechtitelu 11, 78371, Olomouc, Czech Republic.; Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa. Electronic address: rcpgd@ukzn.ac.za.
Detrimental effects caused by the overuse of synthetic agrochemicals have led to the development of natural biostimulants such as seaweed extracts and plant growth-promoting rhizobacteria (PGPR) being used as an alternative, environmentally-friendly technology to improve crop growth and increase agricultural yields. The present study aimed to investigate the interactions between PGPR and a commercial seaweed extract on the growth and biochemical composition of onion (Allium cepa). A pot trial was conducted under greenhouse conditions where onion plants were treated individually with the two PGPR, namely Bacillus licheniformis (BL) and Pseudomonas fluorescens (PF) and a seaweed extract Kelpak(R) (KEL) and combinations of KEL+BL and KEL+PF. Growth and yield parameters were measured after 12 weeks. KEL-treated plants showed the best growth response and overcame the inhibitory effects of BL treatment. KEL-treated plants also had the highest chlorophyll content. PGPR application improved the mineral nutrition of onion with these plants having the highest mineral content in the leaves and bulb. All biostimulant treatments increased the endogenous cytokinin and auxin content with the highest concentrations generally detected in the PF-treated plants. These results suggest that co-application of different biostimulant classes with different modes of action could further increase crop productivity with an improvement in both growth and nutrition content being achieved in onion with the co-application of a seaweed extract and PGPR.
PMID: 34034041
J Plant Physiol , IF:3.549 , 2021 Jul , V262 : P153436 doi: 10.1016/j.jplph.2021.153436
Extracting relevant physiological information from polar auxin transport data in Panax ginseng.
Plant Biodynamics Laboratory, Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands; Fytagoras, 2333 BE, Leiden, the Netherlands.; Plant Biodynamics Laboratory, Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands; Mathematical Institute, Leiden University, 2333 CA, Leiden, the Netherlands.; Fytagoras, 2333 BE, Leiden, the Netherlands.; Plant Biodynamics Laboratory, Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands.; Plant Biodynamics Laboratory, Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands; Fytagoras, 2333 BE, Leiden, the Netherlands. Electronic address: bert.vanduijn@fytagoras.com.
BACKGROUND: Measuring polar auxin transport (PAT) in plants and drawing conclusions from the observed transport data is only meaningful if these data are being analysed with a mathematical model which describes PAT. In this report we studied the polar auxin transport in Panax ginseng stems of different age and grown on different substrates. METHODS: We measured polar IAA transport in stems using a radio labelled IAA and analysed the transport data with a mathematical model we developed for Arabidopsis. RESULTS: We found that PAT in ginseng stems, as compared to Arabidopsis inflorescence stems, has a 2-fold lower transport velocity and a 3-fold lower steady state auxin flux. CONCLUSION: We were able to pinpoint two physiological parameters that influenced the observed transport characteristics in ginseng which differ from Arabidopsis, namely an increase in immobilization together with a reduced reflux of IAA from the surrounding tissue back to the transporting cells.
PMID: 34029983
Mol Genet Genomics , IF:3.291 , 2021 Jul , V296 (4) : P985-1003 doi: 10.1007/s00438-021-01797-8
A prescient evolutionary model for genesis, duplication and differentiation of MIR160 homologs in Brassicaceae.
Department of Biotechnology, TERI School of Advanced Studies, 10 Institutional Area, Vasant Kunj, New Delhi, 110070, India.; Department of Life Sciences, School of Basic Sciences and Research, Sharda University, Plot no. 32-34, Knowledge Park III, Greater Noida, Uttar Pradesh, 201310, India.; Department of Biotechnology, TERI School of Advanced Studies, 10 Institutional Area, Vasant Kunj, New Delhi, 110070, India. asingh@terisas.ac.in.
MicroRNA160 is a class of nitrogen-starvation responsive genes which governs establishment of root system architecture by down-regulating AUXIN RESPONSE FACTOR genes (ARF10, ARF16 and ARF17) in plants. The high copy number of MIR160 variants discovered by us from land plants, especially polyploid crop Brassicas, posed questions regarding genesis, duplication, evolution and function. Absence of studies on impact of whole genome and segmental duplication on retention and evolution of MIR160 homologs in descendent plant lineages prompted us to undertake the current study. Herein, we describe ancestry and fate of MIR160 homologs in Brassicaceae in context of polyploidy driven genome re-organization, copy number and differentiation. Paralogy amongst Brassicaceae MIR160a, MIR160b and MIR160c was inferred using phylogenetic analysis of 468 MIR160 homologs from land plants. The evolutionarily distinct MIR160a was found to represent ancestral form and progenitor of MIR160b and MIR160c. Chronology of evolutionary events resulting in origin and diversification of genomic loci containing MIR160 homologs was delineated using derivatives of comparative synteny. A prescient model for causality of segmental duplications in establishment of paralogy in Brassicaceae MIR160, with whole genome duplication accentuating the copy number increase, is being posited in which post-segmental duplication events viz. differential gene fractionation, gene duplications and inversions are shown to drive divergence of chromosome segments. While mutations caused the diversification of MIR160a, MIR160b and MIR160c, duplicated segments containing these diversified genes suffered gene rearrangements via gene loss, duplications and inversions. Yet the topology of phylogenetic and phenetic trees were found congruent suggesting similar evolutionary trajectory. Over 80% of Brassicaceae genomes and subgenomes showed a preferential retention of single copy each of MIR160a, MIR160b and MIR160c suggesting functional relevance. Thus, our study provides a blue-print for reconstructing ancestry and phylogeny of MIRNA gene families at genomics level and analyzing the impact of polyploidy on organismal complexity. Such studies are critical for understanding the molecular basis of agronomic traits and deploying appropriate candidates for crop improvement.
PMID: 34052911
Plant Biol (Stuttg) , IF:3.081 , 2021 Jul , V23 (4) : P636-642 doi: 10.1111/plb.13252
Abscisic acid crosstalk with auxin and ethylene in biosynthesis and degradation of inulin-type fructans in chicory.
Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran.; Evidence-Based Phytotherapy & Complementary Medicine Research Center, Alborz University of Medical Sciences, Karaj, Iran.; Department of Pharmacognosy, School of Pharmacy, Alborz University of Medical Sciences, Karaj, Iran.; Department of Agricultural, Food and Environmental Science, University of Perugia, Perugia, Italy.
The effect of different hormones on fructan accumulation and the genes regulating biosynthesis and degradation is known; however, information on hormonal interaction mechanisms for fructan content and mean degree of polymerization (mDP) is limited. Cell suspension cultures of chicory were prepared and treated with abscisic acid (ABA), auxin (AUX), ethylene (ETH), ABA + AUX or ABA + ETH, then inulin concentration, mDP of inulin and expression of FAZY genes was determined. A low concentration of AUX and ETH increased fructan content, while a high concentration of AUX and ETH decreased it. Exogenous ABA increased mDP of inulin and this coincided with the low expression of 1-FEHII. In hormone interactions, ABA changed and adjusted the effect of both AUX and ETH. ABA, together with a low level of AUX and ETH, resulted in a decrease in inulin content and increase in mDP, which coincided with low expression of FEHII. ABA together with a high level of AUX and ETH caused an increase in inulin content with a lower mDP, which coincided with high expression of biosynthesis (1-FFT) and degradation (1-FEHII) genes. The effect of both AUX and ETH was almost the same, although the effect of ETH was more severe. ABA had a modulating role in combinations with AUX and ETH. Among biosynthesis and degradation genes, the expression of 1-FEHII was more affected by these hormones.
PMID: 33710751
Plant Direct , IF:3.038 , 2021 Jun , V5 (6) : Pe00328 doi: 10.1002/pld3.328
Targeted mutation of transcription factor genes alters metaxylem vessel size and number in rice roots.
Intercollege Graduate Degree Program in Plant Biology Huck Institutes of the Life Sciences Penn State University University Park PA USA.; Department of Plant Pathology and Environmental Microbiology Huck Institute of the Life Sciences The Pennsylvania State University University Park PA USA.; Department of Plant Science The Pennsylvania State University University Park PA USA.
Root metaxylem vessels are responsible for axial water transport and contribute to hydraulic architecture. Variation in metaxylem vessel size and number can impact drought tolerance in crop plants, including rice, a crop that is particularly sensitive to drought. Identifying and validating candidate genes for metaxylem development would aid breeding efforts for improved varieties for drought tolerance. We identified three transcription factor candidate genes that potentially regulate metaxylem vessel size and number in rice based on orthologous annotations, published expression data, and available root and drought-related QTL data. Single gene knockout mutants were generated for each candidate using CRISPR-Cas9 genome editing. Root metaxylem vessel area and number were analyzed in 6-week-old knockout mutants and wild-type plants under well-watered and drought conditions in the greenhouse. Compared with wild type, LONESOME HIGHWAY (OsLHW) mutants had fewer, smaller metaxylem vessels in shallow roots and more, larger vessels in deep roots in drought conditions, indicating that OsLHW may be a repressor of drought-induced metaxylem plasticity. The AUXIN RESPONSE FACTOR 15 mutants showed fewer but larger metaxylem vessel area in well-watered conditions, but phenotypes were inconsistent under drought treatment. ORYZA SATIVA HOMEBOX 6 (OSH6) mutants had fewer, smaller metaxylem vessels in well-watered conditions with greater effects on xylem number than size. OSH6 mutants had larger shoots and more, deeper roots than the wild type in well-watered conditions, but there were no differences in performance under drought between mutants and wild type. Though these candidate gene mutants did not exhibit large phenotypic effects, the identification and investigation of candidate genes related to metaxylem traits in rice deepen our understanding of metaxylem development and are needed to facilitate incorporation of favorable alleles into breeding populations to improve drought stress tolerance.
PMID: 34142002
Plant Direct , IF:3.038 , 2021 Jun , V5 (6) : Pe00326 doi: 10.1002/pld3.326
slim shady is a novel allele of PHYTOCHROME B present in the T-DNA line SALK_015201.
Department of Genetics Development and Cell Biology Iowa State University Ames IA USA.; Center for Plant Biology Purdue University West Lafayett IN USA.; Department of Horticulture and Landscape Architecture Purdue University West Lafayett IN USA.; Department of Plant Pathology and Microbiology Iowa State University Ames IA USA.; Department of Biochemistry Purdue University West Lafayett IN USA.
Auxin is a hormone that is required for hypocotyl elongation during seedling development. In response to auxin, rapid changes in transcript and protein abundance occur in hypocotyls, and some auxin responsive gene expression is linked to hypocotyl growth. To functionally validate proteomic studies, a reverse genetics screen was performed on mutants in auxin-regulated proteins to identify novel regulators of plant growth. This uncovered a long hypocotyl mutant, which we called slim shady, in an annotated insertion line in IMMUNOREGULATORY RNA-BINDING PROTEIN (IRR). Overexpression of the IRR gene failed to rescue the slim shady phenotype and characterization of a second T-DNA allele of IRR found that it had a wild-type (WT) hypocotyl length. The slim shady mutant has an elevated expression of numerous genes associated with the brassinosteroid-auxin-phytochrome (BAP) regulatory module compared to WT, including transcription factors that regulate brassinosteroid, auxin, and phytochrome pathways. Additionally, slim shady seedlings fail to exhibit a strong transcriptional response to auxin. Using whole genome sequence data and genetic complementation analysis with SALK_015201C, we determined that a novel single nucleotide polymorphism in PHYTOCHROME B was responsible for the slim shady phenotype. This is predicted to induce a frameshift and premature stop codon at leucine 1125, within the histidine kinase-related domain of the carboxy terminus of PHYB, which is required for phytochrome signaling and function. Genetic complementation analyses with phyb-9 confirmed that slim shady is a mutant allele of PHYB. This study advances our understanding of the molecular mechanisms in seedling development, by furthering our understanding of how light signaling is linked to auxin-dependent cell elongation. Furthermore, this study highlights the importance of confirming the genetic identity of research material before attributing phenotypes to known mutations sourced from T-DNA stocks.
PMID: 34136747
Bioorg Med Chem Lett , IF:2.823 , 2021 Jul , V43 : P128085 doi: 10.1016/j.bmcl.2021.128085
Tryptophan derivatives regulate the seed germination and radicle growth of a root parasitic plant, Orobanche minor.
Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki-shi, Kanagawa 214-8571, Japan.; Department of Agricultural Chemistry, School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki-shi, Kanagawa 214-8571, Japan. Electronic address: yoshiya@meiji.ac.jp.
Root parasitic plant germination is induced by the host-derived chemical, strigolactone (SL). We found that a major microbial culture broth component, tryptone, inhibits the SL-inducible germination of a root parasitic plant, Orobanche minor. l-tryptophan (l-Trp) was isolated as the active compound from tryptone. We further found that l-Trp related compounds (1b-11), such as a major plant hormone auxin (8, indole-3-acetic acid; IAA), also inhibit the germination and post-radicle growth of O. minor. We designed a hybrid chemical (13), in which IAA is attached to a part of SL, and found that this synthetic analog induced the germination of O. minor, and also inhibited post-radicle growth. Moreover, contrary to our expectations, we found that N-acetyl Trp (9) showed germination stimulating activity, and introduction of a substitution at C-5 position increased its activity (12a-12f). Our data, in particular, the discovery of a structurally hybrid compound that has two activities that induce spontaneous germination and inhibit subsequent radical growth, would provide new types of germination regulators for root parasitic plants.
PMID: 33964445
Physiol Mol Biol Plants , IF:2.391 , 2021 Jun , V27 (6) : P1173-1189 doi: 10.1007/s12298-021-01015-0
Identification of tomato root growth regulatory genes and transcription factors through comparative transcriptomic profiling of different tissues.
Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India.grid.417642.20000 0000 9068 0476; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India.grid.469887.c; Integral University, Lucknow, 226026 India.grid.411723.20000 0004 1756 4240
Tomato is an economically important vegetable crop and a model for development and stress response studies. Although studied extensively for understanding fruit ripening and pathogen responses, its role as a model for root development remains less explored. In this study, an Illumina-based comparative differential transcriptomic analysis of tomato root with different aerial tissues was carried out to identify genes that are predominantly expressed during root growth. Sequential comparisons revealed ~ 15,000 commonly expressed genes and ~ 3000 genes of several classes that were mainly expressed or regulated in roots. These included 1069 transcription factors (TFs) of which 100 were differentially regulated. Prominent amongst these were members of families encoding Zn finger, MYB, ARM, bHLH, AP2/ERF, WRKY and NAC proteins. A large number of kinases, phosphatases and F-box proteins were also expressed in the root transcriptome. The major hormones regulating root growth were represented by the auxin, ethylene, JA, ABA and GA pathways with root-specific expression of certain components. Genes encoding carbon metabolism and photosynthetic components showed reduced expression while several protease inhibitors were amongst the most highly expressed. Overall, the study sheds light on genes governing root growth in tomato and provides a resource for manipulation of root growth for plant improvement. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-021-01015-0.
PMID: 34177143
Plant Signal Behav , IF:2.247 , 2021 Jun , V16 (6) : P1907043 doi: 10.1080/15592324.2021.1907043
Exogenously-supplied trehalose inhibits the growth of wheat seedlings under high temperature by affecting plant hormone levels and cell cycle processes.
Instruments Sharing Platform of School of Life Sciences, East China Normal University, Shanghai, China.; Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China.; Stress Adaptation Research Unit, RIKEN Center for Sustainable Resource Science, Yokohama, Japan.
High temperature reduces the yield of crops, and exogenous trehalose can improve the stress resistance of plants. However, the mechanism by which trehalose causes phenotypic changes in plants is still unknown. Here we investigated the effects of exogenously supplied trehalose (1.5 mM) during high-temperature stress and subsequent recovery on plant hormones and cell cycle in wheat seedlings. Our results showed that after high-temperature stress, exogenously supplied trehalose reduced the root length, vertical height, leaf area, and leaf length of wheat seedlings, thereby reducing their growth. However, the content of hormones, such as abscisic acid, auxin (IAA), gibberellin (GA3), and cytokinin in seedlings pretreated with trehalose and high-temperature stress was lower than that under high-temperature stress alone. Our further experiments showed that the levels of these hormones were affected by genes involved in hormone biosynthesis and decomposition pathways in trehalose-pretreated seedlings. Compared with control plants, the activity of IAA oxidase is also higher. In addition, exogenous trehalose decreased the transcriptional levels of CycD2 and CDC2 (two genes regulating cell cycle progression) under heat stress, and reduced the activity of vacuolar invertase after recovery from heat stress, thereby shortening the cell length. These results indicate that trehalose inhibits wheat growth at high temperature by affecting plant hormone levels and the cell cycle process.AbbreviationsABA, abscisic acid; CDK, cyclin-dependent kinase; CycD, D-type cyclins; GA3, gibberellin; IAA, auxin; KRP, KIP-related protein; T6P, trehalsoe-6-phosphate; VIN, vacuolar invertase.
PMID: 33960273
Plant Signal Behav , IF:2.247 , 2021 Jun , V16 (6) : P1911400 doi: 10.1080/15592324.2021.1911400
Barbara G. Pickard - Queen of Plant Electrophysiology.
IZMB, University of Bonn, Bonn, Germany.; Department of Agrifood Production and Environmental Sciences, University of Florence, Florence, Italy.; Biology Department, University of Washington, Seattle, WA, USA.
Barbara Gillespie Pickard (1936-2019) studied plant electrophysiology and mechanosensory biology for more than 50 y. Her first papers on the roles of auxin in plant tropisms were coauthored with Kenneth V. Thimann. Later, she studied plant electrophysiology. She made it clear that plant action potentials are not a peculiar feature of so-called sensitive plants, but that all plants exhibit these fast electric signals. Barbara Gillespie Pickard proposed a neuronal model for the spreading of electric signals induced by mechanical stimuli across plant tissues. In later years, she studied the stretch-activated plasma membrane channels of plants and formulated the plasma-membrane control center model. Barbara Pickard summarized all her findings in a new model of phyllotaxis involving waves of auxin fluxes and mechano-sensory signaling.
PMID: 33853497
Plant Signal Behav , IF:2.247 , 2021 Jun , V16 (6) : P1906574 doi: 10.1080/15592324.2021.1906574
The potential roles of different metacaspases in maize defense response.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, PR China.
Metacaspases (MCs), a class of cysteine-dependent proteases, act as important regulators in plant defense response. In maize genome, there are 11 ZmMCs which have been categorized into two types (type I and II) based on their structural differences. In this study, we investigated the different transcript patterns of 11 ZmMCs in maize defense response mediated by the nucleotide-binding, leucine-rich-repeat protein Rp1-D21. We further predicted that many cis-elements responsive to salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA) and auxin were identified in the promoter regions of ZmMCs, and several different transcription factors were predicted to bind to their promoters. We analyzed the localization of ZmMCs with previously identified quantitative trait loci (QTLs) in maize disease resistance, and found that all other ZmMCs, except for ZmMC6-8, are co-located with at least one QTL associated with disease resistance to southern leaf blight, northern leaf blight, gray leaf spot or Fusarium ear rot. Based on previous RNA-seq analysis, different ZmMCs display different transcript levels in response to Cochliobolous heterostrophus and Fusarium verticillioides. All the results imply that the members of ZmMCs might have differential functions to different maize diseases. This study lays the basis for further investigating the roles of ZmMCs in maize disease resistance.
PMID: 33843433
Biochem Genet , IF:1.89 , 2021 Jun doi: 10.1007/s10528-021-10093-4
Identification and Expression Analysis of miR160 and Their Target Genes in Cucumber.
School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang, 453003, China.; Henan Province Engineering Research Center of Horticultural Plant Resource Utilization and Germplasm Enhancement, Xinxiang, 453003, China.; School of Horticulture and Landscape Architecture, Henan Institute of Science and Technology, Xinxiang, 453003, China. sunyd2001@163.com.; Henan Province Engineering Research Center of Horticultural Plant Resource Utilization and Germplasm Enhancement, Xinxiang, 453003, China. sunyd2001@163.com.; Institute of Horticulture, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China.
miR160 plays a crucial role in various biological processes by regulating their target gene auxin response factor (ARF) in plants. However, little is known about miR160 and ARF in cucumber fruit expansion. Here, 4 Csa-MIR160 family members and 17 CsARFs were identified through a genome-wide search. Csa-miR160 showed a closer relationship with those in melon. Phylogenetic analysis revealed that CsARFs were divided into four classes and most of CsARFs presented a closer evolutionary relationship with those from tomato. Putative cis-elements analysis predicted that Csa-MIR160 and CsARFs were involved in light, phytohormone and stress response, which proved that they might take part in light, phytohormone and stress signaling pathway by the miR160-ARF module. In addition, CsARF5, CsARF11, CsARF13 and CsARF14 were predicted as the target genes of Csa-miR160. qRT-PCR revealed that Csa-miR160 and their target gene CsARFs were differentially expressed in differential cucumber tissues and developmental stages. Csa-miR160d was only expressed in the expanded cucumber fruit. CsARF5, CsARF11 and CsARF13 exhibited the lower expression in the expanded fruit than those in the ovary, while, CsARF14 showed the reverse trend. Our results suggested that Csa-miR160d might play a crucial role in cucumber fruit expansion by negatively targeting CsARF5, CsARF11 and CsARF13. This is the first genome-wide analysis of miR160 in cucumber. These findings provide useful information and resources for further studying the role of miR160 and ARF in cucumber fruit expansion.
PMID: 34117971
J Genet Eng Biotechnol , 2021 Jun , V19 (1) : P89 doi: 10.1186/s43141-021-00192-5
Phytohormones: plant switchers in developmental and growth stages in potato.
Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran. abbas.saidi@gmail.com.; Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
BACKGROUND: Potato is one of the most important food crops worldwide, contributing key nutrients to the human diet. Plant hormones act as vital switchers in the regulation of various aspects of developmental and growth stages in potato. Due to the broad impacts of hormones on many developmental processes, their role in potato growth and developmental stages has been investigated. This review presents a description of hormonal basic pathways, various interconnections between hormonal network and reciprocal relationships, and clarification of molecular events underlying potato growth. In the last decade, new findings have emerged regarding their function during sprout development, vegetative growth, tuber initiation, tuber development, and maturation in potato. Hormones can control the regulation of various aspects of growth and development in potato, either individually or in combination with other hormones. The molecular characterization of interplay between cytokinins (CKs), abscisic acid (ABA), and auxin and/or gibberellins (GAs) during tuber formation requires further undertaking. Recently, new evidences regarding the relative functions of hormones during various stages and an intricate network of several hormones controlling potato tuber formation are emerging. Although some aspects of their functions are widely covered, remarkable breaks in our knowledge and insights yet exist in the regulation of hormonal networks and their interactions during different stages of growth and various aspects of tuber formation. SHORT CONCLUSION: The present review focuses on the relative roles of hormones during various developmental stages with a view to recognize their mechanisms of function in potato tuber development. For better insight, relevant evidences available on hormonal interaction during tuber development in other species are also described. We predict that the present review highlights some of the conceptual developments in the interplay of hormones and their associated downstream events influencing tuber formation.
PMID: 34142228