Nat Plants , IF:15.793 , 2021 Jul doi: 10.1038/s41477-021-00959-1
Synergistic interplay of ABA and BR signal in regulating plant growth and adaptation.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, and the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; Biogle Genome Editing Center, Changzhou, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, and the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China. ccchu@genetics.ac.cn.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China. ccchu@genetics.ac.cn.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, and the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China. jytang@genetics.ac.cn.
Complex antagonistic interactions between abscisic acid (ABA) and brassinosteroid (BR) signalling pathways have been widely documented. However, whether or how ABA interacts synergistically with BR in plants remains to be elucidated. Here, we report that low, but not high, concentration of ABA increases lamina joint inclination of rice seedling, which requires functional BR biosynthesis and signalling. Transcriptome analyses confirm that about 60% of low-concentration ABA early response genes can be regulated by BR in the same directions. ABA activates BR signal in a fast, limited and short-term manner and the BR-biosynthesis regulatory gene, OsGSR1, plays a key role during this process, whose expression is induced slightly by ABA through transcriptional factor ABI3. Moreover, the early short-term BR signal activation is also important for ABA-mediated salt stress tolerance. Intriguingly, the process and effect of short-term BR signal activation were covered by high concentration of ABA, implying adaptive mechanisms existed in plants to cope with varying degrees of stress.
PMID: 34226689
Nat Commun , IF:14.919 , 2021 Jul , V12 (1) : P4194 doi: 10.1038/s41467-021-24446-5
Chaperone-like protein DAY plays critical roles in photomorphogenesis.
Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria.; Department of Systems biology, Yonsei University, Seoul, South Korea.; The Sainsbury Laboratory, University of East Anglia, Norwich, UK.; BPMP, University of Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, France.; Sainsbury Laboratory, University of Cambridge, Cambridge, UK.; Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul, South Korea.; Plant Developmental Genetics, Department of Biological Science, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, South Korea.; Department of Life Science, Hanyang University, Seoul, South Korea.; Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria. youssef.belkhadir@gmi.oeaw.ac.at.; Department of Systems biology, Yonsei University, Seoul, South Korea. hspai@yonsei.ac.kr.
Photomorphogenesis, light-mediated development, is an essential feature of all terrestrial plants. While chloroplast development and brassinosteroid (BR) signaling are known players in photomorphogenesis, proteins that regulate both pathways have yet to be identified. Here we report that DE-ETIOLATION IN THE DARK AND YELLOWING IN THE LIGHT (DAY), a membrane protein containing DnaJ-like domain, plays a dual-role in photomorphogenesis by stabilizing the BR receptor, BRI1, as well as a key enzyme in chlorophyll biosynthesis, POR. DAY localizes to both the endomembrane and chloroplasts via its first transmembrane domain and chloroplast transit peptide, respectively, and interacts with BRI1 and POR in their respective subcellular compartments. Using genetic analysis, we show that DAY acts independently on BR signaling and chlorophyll biogenesis. Collectively, this work uncovers DAY as a factor that simultaneously regulates BR signaling and chloroplast development, revealing a key regulator of photomorphogenesis that acts across cell compartments.
PMID: 34234144
Mol Ecol Resour , IF:7.09 , 2021 Jul doi: 10.1111/1755-0998.13475
Chromosome-level genome assembly of Welwitschia mirabilis, a unique Namib Desert species.
School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710072, China.; State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, 999078, China.
Welwitschia mirabilis, which is endemic to the Namib Desert, is the only living species within the Welwitschiaceae family. This species has an extremely long lifespan of up to 2000 years and bears a single pair of opposite leaves that persist whilst alive. However, the underlying genetic mechanisms and evolution of the species remain poorly elucidated. Here, we report on a chromosome-level genome assembly for W. mirabilis, with a 6.30 Gb genome sequence and contig N50 of 27.50 Mb. In total, 39019 protein-coding genes were predicted from the genome. Two brassinosteroid-related genes (BRI1 and CYCD3), key regulators of cell division and elongation, were strongly selected in W. mirabilis and may contribute to their long ever-growing leaves. Furthermore, 29 gene families in the MAPK signaling pathway showed significant expansion, which may contribute to the desert adaptations of the plant. Three positively selected genes (EHMT1, EIF4E, SOD2) may be involved in the mechanisms leading to long lifespan. Based on molecular clock dating and fossil calibrations, the divergence time of W. mirabilis and Gnetum montanum was estimated at ~123.5 million years ago. Reconstruction of population dynamics from genome data coincided well with the aridification of the Namib Desert. The genome sequence detailed in the current study provides insight into the evolution of W. mirabilis and should be an important resource for further study on gnetophyte and gymnosperm evolution.
PMID: 34288504
Plant J , IF:6.417 , 2021 Jul doi: 10.1111/tpj.15416
Chloroplasts alter their morphology and accumulate at the pathogen interface during infection by Phytophthora infestans.
Department of Life Sciences, Imperial College London, London, UK.; INGEBI-CONICET, Ciudad Autonoma de Buenos Aires, Argentina.; Facility for Imaging by Light Microscopy, NHLI, Faculty of Medicine, Imperial College London, London, UK.; Central Laser Facility, Science and Technology Facilities Council Harwell, UK.; Centre for Process systems engineering and Centre for Environmental Policy, Imperial College London, London, UK.; The Alan Turing Institute, London, UK.; Martin-Luther-Universitat Halle-Wittenberg, Germany.; School of Biological Sciences, University of Bristol, Bristol, UK.
Upon immune activation, chloroplasts switch off photosynthesis, produce anti-microbial compounds, and associate with the nucleus through tubular extensions called stromules. Although it is well-established that chloroplasts alter their position in response to light, little is known about the dynamics of chloroplasts movement in response to pathogen attack. Here, we report that chloroplasts accumulate at the pathogen interface during infection by the Irish potato famine pathogen Phytophthora infestans, associating with the specialized membrane that engulfs the pathogen haustorium. Chemical inhibition of actin polymerization reduces the accumulation of chloroplasts at the pathogen haustoria, suggesting this process is partially dependent on the actin cytoskeleton. However, chloroplast accumulation at haustoria does not necessarily rely on movement of the nucleus to this interface and is not affected by light conditions. Stromules are typically induced during infection, embracing haustoria and facilitating chloroplast interactions, to form dynamic organelle clusters. We found that infection-triggered stromule formation relies on BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1 (BAK1) mediated surface immune signaling, whereas chloroplast repositioning towards haustoria does not. Consistent with the defense-related induction of stromules, effector mediated suppression of BAK1 mediated immune signaling reduced stromule formation during infection. On the other hand, immune recognition of the same effector stimulated stromules, presumably via a different pathway. These findings implicate chloroplasts in a polarized response upon pathogen attack and point to more complex functions of these organelles in plant-pathogen interactions.
PMID: 34250673
Plant J , IF:6.417 , 2021 Jul doi: 10.1111/tpj.15401
Robotic Assay for Drought (RoAD): An Automated Phenotyping System for Brassinosteroid and Drought Response.
Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, 50011, USA.; Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, 50011, USA.; Plant Sciences Institutes, Iowa State University, Ames, IA, 50011, USA.; Department of Biology, Duke University, USA.; Department of Biosystems Engineering, Auburn University, Auburn, AL, 36849, USA.; Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA.
Brassinosteroids (BRs) are a group of plant steroid hormones involved in regulating growth, development, and stress responses. Many components of the BR pathway have previously been identified and characterized. However, BR phenotyping experiments are typically performed in a low-throughput manner, such as on petri plates. Additionally, the BR pathway affects drought responses, but drought experiments are time-consuming and difficult to control. To mitigate these issues and increase throughput, we developed the Robotic Assay for Drought (RoAD) system to perform BR and drought response experiments in soil-grown Arabidopsis plants. RoAD is equipped with a robotic arm, a rover, a bench scale, a precisely controlled watering system, an RGB camera, and a laser profilometer. It performs daily weighing, watering, and imaging tasks and is capable of administering BR response assays by watering plants with Propiconazole (PCZ), a BR biosynthesis inhibitor. We developed image processing algorithms for both plant segmentation and phenotypic trait extraction to accurately measure traits including plant area, plant volume, leaf length, and leaf width. We then applied machine learning algorithms that utilized the extracted phenotypic parameters to identify image-derived traits that can distinguish control, drought, and PCZ-treated plants. We carried out PCZ and drought experiments on a set of BR mutants and Arabidopsis accessions with altered BR responses. Finally, we extended the RoAD assays to perform BR response assays using PCZ in Zea mays (maize) plants. This study establishes an automated and non-invasive robotic imaging system as a tool to accurately measure morphological and growth-related traits of Arabidopsis and maize plants in three dimensions (3D), providing insights into the BR-mediated control of plant growth and stress responses.
PMID: 34216161
Int J Mol Sci , IF:5.923 , 2021 Jul , V22 (14) doi: 10.3390/ijms22147673
Modification of Threonine-825 of SlBRI1 Enlarges Cell Size to Enhance Fruit Yield by Regulating the Cooperation of BR-GA Signaling in Tomato.
State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Xianyang 712100, China.
Brassinosteroids (BRs) are growth-promoting phytohormones that can efficiently function by exogenous application at micromolar concentrations or by endogenous fine-tuning of BR-related gene expression, thus, precisely controlling BR signal strength is a key factor in exploring the agricultural potential of BRs. BRASSINOSTEROID INSENSITIVE1 (BRI1), a BR receptor, is the rate-limiting enzyme in BR signal transduction, and the phosphorylation of each phosphorylation site of SlBRI1 has a distinct effect on BR signal strength and botanic characteristics. We recently demonstrated that modifying the phosphorylation sites of tomato SlBRI1 could improve the agronomic traits of tomato to different extents; however, the associated agronomic potential of SlBRI1 phosphorylation sites in tomato has not been fully exploited. In this research, the biological functions of the phosphorylation site threonine-825 (Thr-825) of SlBRI1 in tomato were investigated. Phenotypic analysis showed that, compared with a tomato line harboring SlBRI1, transgenic tomato lines expressing SlBRI1 with a nonphosphorylated Thr-825 (T825A) exhibited a larger plant size due to a larger cell size and higher yield, including a greater plant height, thicker stems, longer internodal lengths, greater plant expansion, a heavier fruit weight, and larger fruits. Molecular analyses further indicated that the autophosphorylation level of SlBRI1, BR signaling, and gibberellic acid (GA) signaling were elevated when SlBRI1 was dephosphorylated at Thr-825. Taken together, the results demonstrated that dephosphorylation of Thr-825 can enhance the functions of SlBRI1 in BR signaling, which subsequently activates and cooperates with GA signaling to stimulate cell elongation and then leads to larger plants and higher yields per plant. These results also highlight the agricultural potential of SlBRI1 phosphorylation sites for breeding high-yielding tomato varieties through precise control of BR signaling.
PMID: 34299293
Int J Mol Sci , IF:5.923 , 2021 Jul , V22 (14) doi: 10.3390/ijms22147615
Exogenous Brassinosteroid Facilitates Xylem Development in Pinus massoniana Seedlings.
Institute for Forest Resources and Environment of Guizhou, Guizhou University, Guiyang 550025, China.; Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, Guizhou University, Guiyang 550025, China.; College of Forestry, Guizhou University, Guiyang 550025, China.; Timber Forest Research Institute, Guangxi Academy of Forestry, Nanning 530009, China.
Brassinosteroids (BRs) are known to be essential regulators for wood formation in herbaceous plants and poplar, but their roles in secondary growth and xylem development are still not well-defined, especially in pines. Here, we treated Pinus massoniana seedlings with different concentrations of exogenous BRs, and assayed the effects on plant growth, xylem development, endogenous phytohormone contents and gene expression within stems. Application of exogenous BR resulted in improving development of xylem more than phloem, and promoting xylem development in a dosage-dependent manner in a certain concentration rage. Endogenous hormone determination showed that BR may interact with other phytohormones in regulating xylem development. RNA-seq analysis revealed that some conventional phenylpropanoid biosynthesis- or lignin synthesis-related genes were downregulated, but the lignin content was elevated, suggesting that new lignin synthesis pathways or other cell wall components should be activated by BR treatment in P. massoniana. The results presented here reveal the foundational role of BRs in regulating plant secondary growth, and provide the basis for understanding molecular mechanisms of xylem development in P. massoniana.
PMID: 34299234
Int J Mol Sci , IF:5.923 , 2021 Jul , V22 (14) doi: 10.3390/ijms22147313
Analysis of Phytohormone Signal Transduction in Sophora alopecuroides under Salt Stress.
College of Plant Science, Jilin University, Xi'an Road, Changchun 130062, China.
Salt stress seriously restricts crop yield and quality, leading to an urgent need to understand its effects on plants and the mechanism of plant responses. Although phytohormones are crucial for plant responses to salt stress, the role of phytohormone signal transduction in the salt stress responses of stress-resistant species such as Sophora alopecuroides has not been reported. Herein, we combined transcriptome and metabolome analyses to evaluate expression changes of key genes and metabolites associated with plant hormone signal transduction in S. alopecuroides roots under salt stress for 0 h to 72 h. Auxin, cytokinin, brassinosteroid, and gibberellin signals were predominantly involved in regulating S. alopecuroides growth and recovery under salt stress. Ethylene and jasmonic acid signals may negatively regulate the response of S. alopecuroides to salt stress. Abscisic acid and salicylic acid are significantly upregulated under salt stress, and their signals may positively regulate the plant response to salt stress. Additionally, salicylic acid (SA) might regulate the balance between plant growth and resistance by preventing reduction in growth-promoting hormones and maintaining high levels of abscisic acid (ABA). This study provides insight into the mechanism of salt stress response in S. alopecuroides and the corresponding role of plant hormones, which is beneficial for crop resistance breeding.
PMID: 34298928
Front Plant Sci , IF:5.753 , 2021 , V12 : P659645 doi: 10.3389/fpls.2021.659645
Seasonal Variation in Transcriptomic Profiling of Tetrastigma hemsleyanum Fully Developed Tuberous Roots Enriches Candidate Genes in Essential Metabolic Pathways and Phytohormone Signaling.
Department of Biotechnology, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China.; Laboratory of Plant Molecular Biology and Biotechnology, Department of Biology, The University of North Carolina at Greensboro, Greensboro, NC, United States.
Tetrastigma hemsleyanum Diels et Gilg (Sanyeqing, SYQ) is a perennial climbing liana and an endemic plant to southern China. Its tuberous roots (TRs) are used in traditional Chinese medicine for treating some diseases such as high fever, pneumonia, asthma, hepatitis, and cancers. However, the mechanisms underlying the development of TR and the content of flavonoids and phenylpropanoids (FPs) are not well-understood. In this study, we performed a transcriptomic analysis of 12 fully developed TR (FD-TR) samples harvested in four seasons [spring (Sp), summer (Su), autumn (Au), and winter (Wi)] using the RNA-Sequencing (RNA-Seq). We obtained a total of 78.54 Gb raw data and 65,578 unigenes. Then, the unigenes were annotated by using six databases such as non-redundant protein database (NR), Pfam, eggNOG, SWISSProt, Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene ontology (GO). The transcriptomic profiling showed closer relationships between the samples obtained in Su and Au than those obtained in Sp and Wi based on the results of both total unigenes and differentially expressed genes (DEGs). Three pathways, including the biosynthesis of FPs, metabolism of starch and sucrose, and signaling of phytohormones, were highly enriched, suggesting a gene-level seasonal variation. Based on the numbers of DEGs, brassinosteroid (BR) signal transduction factors appeared to play a key role in modulating the development of TRs while most of the auxin signaling genes were mainly activated in Wi and Sp FD-TRs. Most genes in the biosynthesis and biodegradation of starch and biodegradation of cellulose were activated in Wi FD-TRs. As determined by the high performance liquid chromatography (HPLC) and aluminum nitrate colorimetric method, the contents of total flavonoids and most detected FP components increased from Sp to Au but decreased in Wi. Enhanced expression levels of some genes in the biosynthetic pathways of FPs were detected in Su and Au samples, which corroborated well with metabolite content. Our findings provide the first transcriptomic and biochemical data on a seasonal variation in the composition of medically important metabolites in SYQ FD-TRs.
PMID: 34305963
Phytopathology , IF:4.025 , 2021 Jul doi: 10.1094/PHYTO-04-21-0159-R
Endophytic Bacillus subtilis TR21 Improves Banana Plant Resistance to Fusarium oxysporum f. sp. cubense and Promotes Root Growth by Upregulating the Jasmonate and Brassinosteroid Biosynthesis Pathways.
Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; sunyunhaoscope@163.com.; Institue of fruit tree research, Guangdong academy of agricultural sciences. Guangzhou 510000, People's Republic of China., Guangzhou, China; huangbingzhi@gdaas.cn.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; nkpcheng@163.com.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; 21610640@qq.com.; Zhuhai Agricultural Sciences Research Center. Guangzhou 519075, People's Republic of China., Zhuhai, China; 244324803@qq.com.; Zhuhai Agricultural Sciences Research Center. Guangzhou 519075, People's Republic of China., Zhuhai, China; 18888038@qq.com.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; 369674824@qq.com.; Laboratory & Equipment Management Department, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; 441889908@qq.com.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; dongzhangyong@hotmail.com.; College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering. Guangzhou 510225, People's Republic of China., Guangzhou, China; ygh76411@zhku.edu.cn.
The banana (Musa spp.) industry experiences dramatic annual losses from Fusarium wilt of banana (FWB) disease, which is caused by the fungus Fusarium oxysporum f. sp. cubense (FOC). Pisang Awak banana Fenza No. 1 (Musa spp. cv. Fenza No. 1), a major banana cultivar with high resistance to FOC race 4, is considered to be ideal for growth in problematic areas. However, Fenza No. 1 is still affected by FOC race 1 in the field. TR21 is an endophytic Bacillus subtilis strain isolated from orchids (Dendrobium sp.). Axillary spraying of banana plants with TR21 controls FWB, decreasing the growth period and increasing yields in the field. In this study, we established that TR21 increases root growth in different monocotyledonous plant species. By axillary inoculation, TR21 induced a similar transcriptomic change as that induced by FOC race 1 but also upregulated the biosynthetic pathways for the phytohormones brassinosteroid and jasmonate in Fenza No. 1 root tissues, indicating that TR21 increases FWB resistance, shortens growth period, and increases yield of banana by inducing specific transcriptional reprogramming and modulating phytohormone levels. These findings will contribute to the identification of candidate genes related to plant resistance against fungi in a non-model system and facilitate further study and exploitation of endophytic biocontrol agents.
PMID: 34231376
Gene , IF:3.688 , 2021 Jul , V791 : P145722 doi: 10.1016/j.gene.2021.145722
Comparative transcriptome analysis of the peanut semi-dwarf mutant 1 reveals regulatory mechanism involved in plant height.
College of Life Science, Shandong Normal University, Jinan 250014, PR China; Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan 250100, PR China.; College of Life Science, Shandong Normal University, Jinan 250014, PR China.; Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan 250100, PR China.; College of Life Science, Shandong Normal University, Jinan 250014, PR China. Electronic address: zhaoyx@sdnu.edu.cn.; College of Life Science, Shandong Normal University, Jinan 250014, PR China; Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Shandong Provincial Key Laboratory of Crop Genetic Improvement, Ecology and Physiology, Jinan 250100, PR China. Electronic address: xingjunw@hotmail.com.
Plant height is a fundamentally crucial agronomic trait to control crop growth and high yield cultivation. Several studies have been conducted on the understanding ofmolecular genetic bases of plant height in model plants and crops. However, the molecular mechanism underlying peanut plant height development is stilluncertain. In the present study, we created a peanut mutant library by fast neutron irradiation using peanut variety SH13 and identified a semi-dwarf mutant 1 (sdm1). At 84 DAP (days after planting), the main stem of sdm1 was only about 62% of SH13. The internode length of sdm1 hydroponic seedlings was found significantly shorter than that of SH13 at 14 DAP. In addition, the foliar spraying of exogenous IAA could partially restore the semi-dwarf phenotype of sdm1. Transcriptome data indicated that the differentially expressed genes (DEGs) between sdm1 and SH13 significantly enriched in diterpenoid biosynthesis, alpha-linolenic acid metabolism, brassinosteroid biosynthesis, tryptophan metabolism and plant hormone signal transduction. The expression trend of most of the genes involved in IAA and JA pathway showed significantly down- and up- regulation, which may be one of the key factors of the sdm1 semi-dwarf phenotype. Moreover, several transcription factorsand cell wall relatedgenes were expressed differentially between sdm1 and SH13. Conclusively, this research work not only provided important clues to unveil the molecular mechanism of peanut plant height regulation, but also presented basic materials for breeding peanut cultivars with ideal plant height.
PMID: 34010708