Plant Cell , IF:9.618 , 2020 Jun doi: 10.1105/tpc.19.00499
The OsGSK2 Kinase Integrates Brassinosteroid and Jasmonic Acid Signaling by Interacting with OsJAZ4.
College of Agriculture and Biotechnology, Zhejiang University CITY: Hangzhou China [CN].; State Key Laboratory for Quality and Safety of Agro-products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences CITY: Hangzhou China [CN].; College of Plant Protection, Nanjing Agricultural University CITY: Nanjing China [CN].; Ningbo University CITY: Ningbo China [CN].; Institute of Virology and Biotechnology CITY: hangzhou China [CN].; Shanghai Center for Plant Stress Biology CITY: Shanghai China [CN].; Ningbo University CITY: Ningbo STATE: Zhejiang China [CN].; Institute of Virology and Biotechnology CITY: Hangzhou STATE: Zhejiang China [CN].; Institute of Plant Virology CITY: Ningbo STATE: Zhejiang China [CN].; Shanghai Center for Plant Stress Biology CITY: Songjiang STATE: Shanghai POSTAL_CODE: 201602 China [CN].; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences CITY: Beijing POSTAL_CODE: 100081 China [CN].; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences CITY: Beijing POSTAL_CODE: 100101 China [CN].; Ningbo University CITY: Ningbo STATE: Zhejiang China [CN] ztaosun@gmail.com.
The crosstalk between Brassinosteroids (BRs) and jasmonic acid (JA) signaling is crucial for plant growth and defense responses. However, the detailed interplay between BRs and JA remains obscure. Here, we found that OsGSK2, a conserved GSK3-like kinase serving as a key suppressor in BR signaling, enhanced antiviral defense and the JA response. We identified a new OsGSK2 substrate, OsJAZ4, a member of the JASMONATE ZIM-domain (JAZ) family, and confirmed that OsGSK2 interacted with and phosphorylated OsJAZ4. We demonstrated that OsGSK2 disrupted the OsJAZ4-OsNINJA complex and OsJAZ4-OsJAZ11 dimerization by competitively binding to the ZIM domain, perhaps helping to facilitate the degradation of OsJAZ4 via the 26S proteasome pathway. We also showed that OsJAZ4 negatively modulated JA signaling and antiviral defense and that the BR pathway was involved in modulating the stability of OsJAZ4 protein in an OsCOI1-dependent manner. Collectively, these results suggest that OsGSK2 enhances plant antiviral defense by activating JA signaling as it directly interacts with, phosphorylates, and destabilizes OsJAZ4. Thus, our findings provide a clear interlink between BR and JA signaling.
PMID: 32586913
Plant J , IF:6.141 , 2020 Jun doi: 10.1111/tpj.14889
Ultra-High alpha-Linolenic Acid Accumulating Developmental Defective Embryo was Rescued by Lysophosphatidic Acid Acyltransferase 2.
Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.; Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resource Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, 438000, China.
For decades, genetic engineering approaches to produce unusual fatty acids (UFAs) in crops has reached a bottleneck, including reduced seed oil production and seed vigor. Currently, plant models in the field of research are primarily used to investigate defects in oil production and seedling development, while the role of UFAs in embryonic developmental defects remains unknown. In this study, we developed a transgenic Arabidopsis plant model, in which the embryo exhibits severely wrinkled appearance owing to alpha-linolenic acid (ALA) accumulation. RNA-seq analysis in the defective embryo suggested that brassinosteroid synthesis, fatty acid (FA) synthesis, and photosynthesis were inhibited, while FA degradation, endoplasmic reticulum (ER) stress, and oxidative stress were activated. Lipidomics analysis showed that ultra-accumulated ALA is released from Phosphatidylcholine (PC) as a free fatty acid (FFA) in cell, inducing severe ER and oxidative stress. Furthermore, we identified that overexpression of lysophosphatidic acid acyltransferase 2 (LPAT2) rescued the defective phenotype. In the rescue line, the pool capacity of the Kennedy pathway was increased, and the esterification of ALA indirectly to triacylglycerol (TAG) was enhanced to avoid stress. This study provides a plant model that aids in understanding the molecular mechanism of embryonic developmental defects, and generate strategies to produce higher levels of UFAs.
PMID: 32573846
Plant J , IF:6.141 , 2020 Jun , V102 (6) : P1187-1201 doi: 10.1111/tpj.14692
GSK2 stabilizes OFP3 to suppress brassinosteroid responses in rice.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Brassinosteroids (BRs) are a class of phytohormones that modulate several important agronomic traits in rice (Oryza sativa). GSK2 is one of the critical suppressors of BR signalling and targets transcription factors such as OsBZR1 and DLT to regulate BR responses. Here, we identified OFP3 (OVATE FAMILY PROTEIN 3) as an interactor of both GSK2 and DLT by yeast-two-hybrid screening and demonstrated that OFP3 plays a distinctly negative role in BR responses. While knockout of OFP3 promoted rice seedling growth, overexpression of OFP3 led to strong BR insensitivity, which resulted in reduced plant height, leaf angle, and grain size. Interestingly, both BR biosynthetic and signalling genes had decreased expression in the overexpression plants. OFP3 overexpression also enhanced the phenotypes of BR-deficient mutants, but largely suppressed those of BR-enhanced plants. Moreover, treatment with either BR or bikinin, a GSK3-like kinase inhibitor, induced OFP3 depletion, whereas GSK2 or brassinazole, a BR synthesis inhibitor, promoted OFP3 accumulation. Furthermore, OFP3 exhibited transcription repressor activity and was able to interact with itself as well as additional BR-related components, including OFP1, OSH1, OSH15, OsBZR1, and GF14c. Importantly, GSK2 can phosphorylate OFP3 and enhance these interactions. We propose that OFP3, as a suppressor of both BR synthesis and signalling but stabilized by GSK2, incorporates into a transcription factor complex to facilitate BR signalling control, which is critical for the proper development of various tissues.
PMID: 31950543
Plant J , IF:6.141 , 2020 Jun , V102 (5) : P931-947 doi: 10.1111/tpj.14672
Brassinosteroid-mediated reactive oxygen species are essential for tapetum degradation and pollen fertility in tomato.
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, China.; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, 866 Yuhangtang Road, Hangzhou, 310058, China.; School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK.; Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Yuhangtang Road 866, Hangzhou, 310058, China.
Phytohormone brassinosteroids (BRs) are essential for plant growth and development, but the mechanisms of BR-mediated pollen development remain largely unknown. In this study, we show that pollen viability, pollen germination and seed number decreased in the BR-deficient mutant d(^im) , which has a lesion in the BR biosynthetic gene DWARF (DWF), and in the bzr1 mutant, which is deficient in BR signaling regulator BRASSINAZOLE RESISTANT 1 (BZR1), compared with those in wild-type plants, whereas plants overexpressing DWF or BZR1 exhibited the opposite effects. Loss or gain of function in the DWF or BZR1 genes altered the timing of reactive oxygen species (ROS) production and programmed cell death (PCD) in tapetal cells, resulting in delayed or premature tapetal degeneration, respectively. Further analysis revealed that BZR1 could directly bind to the promoter of RESPIRATORY BURST OXIDASE HOMOLOG 1 (RBOH1), and that RBOH1-mediated ROS promote pollen and seed development by triggering PCD and tapetal cell degradation. In contrast, the suppression of RBOH1 compromised BR signaling-mediated ROS production and pollen development. These findings provide strong evidence that BZR1-dependent ROS production plays a critical role in the BR-mediated regulation of tapetal cell degeneration and pollen development in Solanum lycopersicum (tomato) plants.
PMID: 31908046
J Integr Plant Biol , IF:4.885 , 2020 Jun , V62 (6) : P793-811 doi: 10.1111/jipb.12914
Oryza sativa mediator subunit OsMED25 interacts with OsBZR1 to regulate brassinosteroid signaling and plant architecture in rice.
Northeast Institute of Geography and Agroecology, Key Laboratory of Soybean Molecular Design Breeding, Chinese Academy of Sciences, Harbin, 150081, China.; 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, Chinese Academy of Sciences, Beijing, 100101, China.; The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
Brassinosteroids (BRs) are plant-specific steroid hormones which regulate plant growth, development, and adaptation. Transcriptional regulation plays key roles in plant hormone signaling. A mediator can serve as a bridge between gene-specific transcription factors and the RNA polymerase machinery, functioning as an essential component in regulating the transcriptional process. However, whether a mediator is involved in BR signaling is unknown. Here, we discovered that Oryza sativa mediator subunit 25 (OsMED25) is an important regulator of rice BR signaling. Phenotypic analyses showed that the OsMED25-RNAi and osmed25 mutant presented erect leaves, as observed in BR-deficient mutants. In addition, the OsMED25-RNAi and osmed25 mutant exhibited decreased BR sensitivity. Genetic analysis indicated that OsMED25-RNAi could suppress the enhanced BR signaling phenotype of Osbzr1-D. Further biochemical analysis showed that OsMED25 interacts with OsBZR1 in vivo, and OsMED25 is enriched on the promoter of OsBZR1 target genes. RNA sequencing analysis indicated that OsMED25 affects the expression of approximately 45% of OsBZR1-regulated genes and mainly functions as a corepressor of OsBZR1. Together, these findings revealed that OsMED25 regulates rice BR signaling by interacting with OsBZR1 and modulating the expression of OsBZR1 target genes, thus expanding our understanding of the roles of mediators in plant hormone signaling.
PMID: 31990125
Ecotoxicol Environ Saf , IF:4.872 , 2020 Jun , V196 : P110483 doi: 10.1016/j.ecoenv.2020.110483
The role of nitrate reductase in brassinosteroid-induced endogenous nitric oxide generation to improve cadmium stress tolerance of pepper plants by upregulating the ascorbate-glutathione cycle.
Soil Science and Plant Nutrition Department, Agriculture Faculty, Harran University, Sanliurfa, Turkey.; University of Agriculture Faisalabad, Pakistan.; Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.; Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia; Department of Botany, S.P. College Srinagar, Jammu and Kashmir, India. Electronic address: parvaizbot@yahoo.com.
A study was performed to assess if nitrate reductase (NR) participated in brassinosteroid (BR)-induced cadmium (Cd) stress tolerance primarily by accelerating the ascorbate-glutathione (AsA-GSH) cycle. Prior to initiating Cd stress (CdS), the pepper plants were sprayed with 0.5 muM 24-epibrassinolide (EBR) every other day for 10 days. Thereafter the seedlings were subjected to control or CdS (0.1 mM CdCl2) for four weeks. Cadmium stress decreased the plant growth related attributes, water relations as well as the activities of monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), but enhanced proline content, leaf Cd(2+) content, oxidative stress-related traits, activities of ascorbate peroxidase (APX) and glutathione reductase (GR), and the activities of antioxidant defence system-related enzymes as well as NR activity and endogenous nitric oxide content. EBR reduced leaf Cd(2+) content and oxidative stress-related parameters, enhanced plant growth, regulated water relations, and led to further increases in proline content, AsA-GSH cycle-related enzymes' activities, antioxidant defence system-related enzymes as well as NR activity and endogenous nitric oxide content. The EBR and the inhibitor of NR (tungstate) reversed the positive effects of EBR by reducing NO content, showing that NR could be a potential contributor of EBR-induced generation of NO which plays an effective role in tolerance to CdS in pepper plants by accelerating the AsA-GSH cycle and antioxidant enzymes.
PMID: 32247238
Ecotoxicol Environ Saf , IF:4.872 , 2020 Jun , V196 : P110528 doi: 10.1016/j.ecoenv.2020.110528
Comparative study of alleviation effects of DMTU and PCIB on root growth inhibition in two tall fescue varieties under cadmium stress.
College of Grassland Science, Beijing Forestry University, Beijing, 100083, China.; College of Grassland Science, Beijing Forestry University, Beijing, 100083, China. Electronic address: syihan@163.com.; State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry Research, Chinese Academy of Forestry, Box 1958, Beijing, 100091, China. Electronic address: shi.shengqing@caf.ac.cn.
In plants, tolerance to cadmium (Cd) stress is closely related to indole-3-acetic acid (IAA) and hydrogen peroxide (H2O2). However, it is unclear whether Cd-resistant and -sensitive varieties respond differently to Cd stress. In this study, the effects of dimethylthiourea (DMTU, a H2O2 scavenger) and p-chlorophenoxy isobutyric acid (PCIB, an IAA signaling inhibitor) on root growth, endogenous hormones and antioxidant system were investigated to decipher how DMTU and PCIB treatments alleviate the inhibition of root elongation in Cd-resistant (Commander) and -sensitive (Crossfire III) tall fescue varieties under Cd stress. Both varieties subjected to 10 muM Cd treatments for 12 h presented a substantial decrease in root elongation coupled with a reduction in brassinosteroid (BR) and zeatin riboside (ZR) contents, but the changes in IAA and abscisic acid (ABA) contents under Cd stress were opposite in the two varieties. In addition, the H2O2 content and antioxidant enzyme activities significantly increased in both varieties. However, pretreatment with PCIB or DMTU mitigated the inhibition of root elongation caused by Cd, accompanied by the significant changes of aforementioned physiological parameters. PCIB significantly reduced the IAA content in 'Commander', while DMTU significantly increased the IAA content in 'Crossfire III' and effectively relieved the inhibition of root elongation. But both treatments decreased the Cd-induced H2O2 accumulation. These results indicated that DMTU or PCIB can alleviate the Cd-inhibited root elongation in two varieties whose resistance differed under Cd stress, but they presented differences in the response of hormones, especially IAA, which may be due to the different adaptation mechanisms of two varieties in response to Cd stress.
PMID: 32240865
Int J Mol Sci , IF:4.556 , 2020 Jun , V21 (12) doi: 10.3390/ijms21124340
Regulation of Three Key Kinases of Brassinosteroid Signaling Pathway.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agriculture University, Guangzhou 510642, China.; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.; Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Brassinosteroids (BRs) are important plant growth hormones that regulate a wide range of plant growth and developmental processes. The BR signals are perceived by two cell surface-localized receptor kinases, Brassinosteroid-Insensitive1 (BRI1) and BRI1-Associated receptor Kinase (BAK1), and reach the nucleus through two master transcription factors, bri1-EMS suppressor1 (BES1) and Brassinazole-resistant1 (BZR1). The intracellular transmission of the BR signals from BRI1/BAK1 to BES1/BZR1 is inhibited by a constitutively active kinase Brassinosteroid-Insensitive2 (BIN2) that phosphorylates and negatively regulates BES1/BZR1. Since their initial discoveries, further studies have revealed a plethora of biochemical and cellular mechanisms that regulate their protein abundance, subcellular localizations, and signaling activities. In this review, we provide a critical analysis of the current literature concerning activation, inactivation, and other regulatory mechanisms of three key kinases of the BR signaling cascade, BRI1, BAK1, and BIN2, and discuss some unresolved controversies and outstanding questions that require further investigation.
PMID: 32570783
Int J Mol Sci , IF:4.556 , 2020 Jun , V21 (12) doi: 10.3390/ijms21124336
Functional Characterization of VvSK Gene Family in Grapevine (Vitis vinifera L.) Revealing their Role in Berry Ripening.
College of Horticulture, Nanjing Agricultural University, 210095 Nanjing, China.; College of Horticulture, Hunan Agricultural University, 410000 Hunan, China.; Advance innovation center for tree breeding, Beijing Forestry University, 100083 Beijing, China.
The glycogen synthase kinase 3/shaggy kinase (GSK3) is a serine/threonine kinase that plays important roles in brassinosteroid signaling, abiotic stress responses, cell division, and elongation, etc. In this study, we characterized seven grape GSK3 genes, showing high similarities with homologs from other species including Arabidopsis, white pear, apple, orange, and peach. Gene chip microarray data derived from an online database revealed very diverse developmental and tissue-specific expression patterns of VvSKs. VvSK3 and VvSK7 showed much higher expression levels in almost every tissue compared with other members. VvSK7 was highly enriched in young tissues like berries before the veraison stage, young leaves and green stems, etc., but immediately downregulated after these tissues entered maturation or senescence phases. Prediction of cis-elements in VvSK promoters indicated that VvSKs might be sensitive to light stimulation, which is further confirmed by the qPCR data. Constitutive overexpression of VvSK7 in Arabidopsis leads to dwarf plants that resembles BR-deficient mutants. The photosynthetic rate was significantly reduced in these plants, even though they accumulated more chlorophyll in leaves. Transient overexpression of VvSKs in tomatoes delayed the fruit ripening process, consistent with the observation in grapevine which blocks VvSKs by EBR- or BIKININ-promoted berry expansion and soluble solids accumulation. Data presented in the current study may serve as a theoretical basis for the future application of BRs or related compounds in quality grape production.
PMID: 32570751
J Agric Food Chem , IF:4.192 , 2020 Jun , V68 (24) : P6770-6775 doi: 10.1021/acs.jafc.0c00749
Imaging of Multiple Plant Hormones in Roots of Rice (Oryza sativa) Using Nanoparticle-Assisted Laser Desorption/Ionization Mass Spectrometry.
Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195, Japan.; Faculty of Food and Agricultural Sciences, Fukushima University, Kanayagawa, Fukushima 960-1296, Japan.
Plant hormones can act in synergistic and antagonistic ways in response to biotic and abiotic stresses and in plant growth and development. Thus, a technique is needed to simultaneously determine the distributions and concentrations of several plant hormones. Previously, we reported that localizations of two plant hormones [cytokinin (CK) and abscisic acid (ABA)] can be simultaneously visualized in a plant tissue using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). In MALDI-MS, however, self-ionization of an organic matrix occasionally interferes with ionizations of small molecules (<500 m/z) including most plant hormones. Another technique, nanoparticle-assisted laser desorption/ionization (Nano-PALDI), can avoid matrix self-ionization using nanoparticles to assist the ionization of analytes. Here, we compared the ionization efficiencies of common plant hormones by MALDI-MS and Nano-PALDI-MS. For the comparison, we prepared a standard mix of seven plant hormones [ABA, auxin (IAA), brassinosteroid (Br), two CKs (trans-zeatin, tZ, and 6-(gamma,gamma-dimethylallylamino) purine, iP), jasmonic acid, and salicylic acid (SA)], an ethylene precursor (1-aminocyclopropane-1-carboxylic acid, ACC), and a heavy hydrogen-labeled ABA (D6-ABA). Basic MALDI-MS detected all compounds except IAA, Br, and D6-ABA, while Nano-PALDI-MS detected all nine compounds. By Nano-PALDI-MS imaging (MSI), each of the abovementioned hormones and ACC were also detected in root cross sections of rice which were incubated in the hormone mix for 2 h. In the elongation zone of untreated roots, Nano-PALDI-MSI revealed high levels of ABA and CKs in the outer part of roots and much lower levels in the stele, but Br, SA, and ACC were broadly distributed in the cross section. IAA seemed to be distributed in the epidermis, cortex, and stele. Multiple-hormone imaging using Nano-PALDI-MS has great potential for investigating the roles of hormone signaling in crop development and stress responses.
PMID: 32437141
Plant Physiol Biochem , IF:3.72 , 2020 Jun , V154 : P369-378 doi: 10.1016/j.plaphy.2020.05.043
Brassinosteroid receptor mutation influences starch granule size distribution in barley grains.
Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N5A8, Canada.; Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N5A8, Canada. Electronic address: ravi.chibbar@usask.ca.
Brassinosteroids (BR) are plant-based steroids which influence several morphogenetic and developmental processes. A barley (Hordeum vulgare L.) genotype Kinai Kyoshinkai-2 (KK-2) carrying the uzu mutation exhibited altered starch granule size distribution. Hybridizing KK-2 with a barley genotype CDC Kendall with bi-modal starch granules produced progeny lines (116, 144 and 168) with almost uni-modal starch granules. Bioassays correlated uzu mutation with defective BR perception. DNA sequence analysis of the BR receptor-1 (BRI-1) gene detected a single-nucleotide A > G substitution at the position 2612 in the kinase domain which resulted in the change of His (CAC) to Arg (CGC) at residue 857 in subdomain IV of the kinase domain of the respective polypeptide. The study focused on the development of barley grain, accumulation of starch and composition influenced by defective BR perception due to the mutation detected in KK-2 and three other barley-breeding lines (116, 144 and 168). Aberrant BRI-1 delayed grain development, amylose synthesis and starch accumulation in the endosperm. The barley breeding lines 116, 144 and 168 carrying the aberrant BRI-1, exhibited altered granule size distribution with significant shift in the diameter maxima, but insignificant differences in amylose concentration. The BRI-1 mutation also altered amylopectin fine structure in both B- and C- type small starch granules, resulting in an increased fraction of short A-type glucan chains (<10 DP) and decreased fraction of B2 chains (25-36 DP) in genotypes carrying the BRI-1 mutation. The results show the influence of BR on barley grain development, starch accumulation, granule size distribution and amylopectin structure.
PMID: 32623092
Plant Physiol Biochem , IF:3.72 , 2020 Jun , V151 : P157-165 doi: 10.1016/j.plaphy.2020.03.001
Response of BpBZR genes to abiotic stress and hormone treatment in Betula platyphylla.
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China. Electronic address: gaocaiqiu@nefu.edu.cn.
Brassinazole-resistant (BZR) transcription factors have important roles in the brassinosteroid (BR) signalling pathway and are widely involved in plant growth and abiotic stress processes. However, there are few studies on the functions and regulatory mechanisms of BZR TFs in birch. In this study, 5 BZR genes were identified from birch. The qRT-PCR results showed that the expression levels of most BpBZRs were significantly downregulated and/or upregulated in at least one organ following NaCl and PEG stress or ABA, GA3 and JA treatments. In particular, BpBZR1 expression was changed in all three organs after exposure to NaCl stress at all time points, indicating that this gene may be involved in salt stress. The BpBZR1 transcription factor was shown to have transcriptional activation activity in a yeast two-hybrid assay. Through a transient transformation system, we found that overexpression of BpBZR1 in birch resulted in lower H2O2 and MDA accumulation, higher SOD and POD activities and maintained a higher photosynthetic intensity and a lower chlorophyll degradation rate than those of the control plants under salt stress. These results preliminarily showed that overexpression of the BpBZR1 gene increased the tolerance of birch to salt stress.
PMID: 32222679
Funct Integr Genomics , IF:3.058 , 2020 Jun doi: 10.1007/s10142-020-00742-z
Identification of lncRNAs involved in wheat tillering development in two pairs of near-isogenic lines.
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China.; College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China.; State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Wenjiang, Chengdu, 611130, China.; Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China. ymwei@sicau.edu.cn.; State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Wenjiang, Chengdu, 611130, China. ymwei@sicau.edu.cn.; Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China. liuyaxi@sicau.edu.cn.; State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Wenjiang, Chengdu, 611130, China. liuyaxi@sicau.edu.cn.
Emerging evidence demonstrates that lncRNAs participate in various developmental processes in plants via post-transcription regulation. However, few lncRNAs have been identified as regulators of tiller development in wheat (Triticum aestivum L.). In this study, high-throughput ribosomal depleted RNA sequencing was performed on the tillering nodes of two pairs of near-isogenic lines that differed only in the tillering trait. We identified 5399 lncRNA transcripts using bioinformational analyses. KEGG pathway analysis revealed 74 common differentially expressed lncRNAs substantially enriched in photosynthesis-related, phenylpropanoid biosynthesis, phosphatidylinositol signaling, brassinosteroid biosynthesis, zeatin biosynthesis, and carotenoid biosynthesis pathways. Detailed functional annotations of target genes were used to identify 27 tillering-associated lncRNAs. Among these, 10 were in photosynthesis-related pathways; 15 were in secondary metabolite pathways; and 8 were in plant hormone pathways, with 6 enriched in two kinds of pathways. These findings contribute to identifying tillering-associated lncRNAs in wheat and enable further investigation into the functions and roles of key candidate lncRNAs, and more experimental evidence was also needed if breeders wanted to utilize these candidate lncRNAs in wheat crop yield improvement in the future.
PMID: 32488459
Plants (Basel) , IF:2.762 , 2020 Jun , V9 (6) doi: 10.3390/plants9060780
Transcriptome Analysis of Wounding in the Model Grass Lolium temulentum.
USDA-ARS, National Forage Seed Production Research Center, 3450 SW Campus Way, Corvallis, OR 97331-7102, USA.; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA.
For forage and turf grasses, wounding is a predominant stress that often results in extensive loss of vegetative tissues followed by rapid regrowth. Currently, little is known concerning the perception, signaling, or molecular responses associated with wound stress in forage- and turf-related grasses. A transcriptome analysis of Lolium temulentum plants subjected to severe wounding revealed 9413 upregulated and 7704 downregulated, distinct, differentially expressed genes (DEGs). Categories related to signaling, transcription, and response to stimuli were enriched in the upregulated DEGs. Specifically, sequences annotated as enzymes involved in hormone biosynthesis/action and cell wall modifications, mitogen-activated protein kinases, WRKY transcription factors, proteinase inhibitors, and pathogen defense-related DEGs were identified. Surprisingly, DEGs related to heat shock and chaperones were more prevalent in the downregulated DEGs when compared with the upregulated DEGs. This wound transcriptome analysis is the first step in identifying the molecular components and pathways used by grasses in response to wounding. The information gained from the analysis will provide a valuable molecular resource that will be used to develop approaches that can improve the recovery, regrowth, and long-term fitness of forage and turf grasses before/after cutting or grazing.
PMID: 32580425
Plants (Basel) , IF:2.762 , 2020 Jun , V9 (6) doi: 10.3390/plants9060713
Transcriptome and Network Analyses of Heterostyly in Turnera subulata Provide Mechanistic Insights: Are S-Loci a Red-Light for Pistil Elongation?
School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164-4236, USA.; Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J1P3, Canada.
Heterostyly employs distinct hermaphroditic floral morphs to enforce outbreeding. Morphs differ structurally in stigma/anther positioning, promoting cross-pollination, and physiologically blocking self-fertilization. Heterostyly is controlled by a self-incompatibility (S)-locus of a small number of linked S-genes specific to short-styled morph genomes. Turnera possesses three S-genes, namely TsBAHD (controlling pistil characters), TsYUC6, and TsSPH1 (controlling stamen characters). Here, we compare pistil and stamen transcriptomes of floral morphs of T. subulata to investigate hypothesized S-gene function(s) and whether hormonal differences might contribute to physiological incompatibility. We then use network analyses to identify genetic networks underpinning heterostyly. We found a depletion of brassinosteroid-regulated genes in short styled (S)-morph pistils, consistent with hypothesized brassinosteroid-inactivating activity of TsBAHD. In S-morph anthers, auxin-regulated genes were enriched, consistent with hypothesized auxin biosynthesis activity of TsYUC6. Evidence was found for auxin elevation and brassinosteroid reduction in both pistils and stamens of S- relative to long styled (L)-morph flowers, consistent with reciprocal hormonal differences contributing to physiological incompatibility. Additional hormone pathways were also affected, however, suggesting S-gene activities intersect with a signaling hub. Interestingly, distinct S-genes controlling pistil length, from three species with independently evolved heterostyly, potentially intersect with phytochrome interacting factor (PIF) network hubs which mediate red/far-red light signaling. We propose that modification of the activities of PIF hubs by the S-locus could be a common theme in the evolution of heterostyly.
PMID: 32503265