Plant Cell , IF:9.618 , 2019 Apr , V31 (4) : P791-808 doi: 10.1105/tpc.18.00941
Plant U-Box40 Mediates Degradation of the Brassinosteroid-Responsive Transcription Factor BZR1 in Arabidopsis Roots.
Department of Life Science, Hanyang University, Seoul 04763, South Korea.; Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305.; Department of Life Science, Chung-Ang University, Seoul 06974, South Korea.; Department of Life Science, Hanyang University, Seoul 04763, South Korea twgibio@hanyang.ac.kr.; Research Institute for Natural Sciences, Hanyang University, Seoul 04763, South Korea.
Brassinosteroid (BR) regulates a wide range of physiological responses through the activation of BRASSINAZOLE RESISTANT1 (BZR1), whose activity is tightly controlled by its phosphorylation status and degradation. Although BZR1 appears to be degraded in distinct ways in response to different hormonal or environmental cues, little is known about how BR signaling regulates its degradation. Here we show that the BR-regulated U-box protein PUB40 mediates the proteasomal degradation of BZR1 in a root-specific manner in Arabidopsis (Arabidopsis thaliana). BZR1 levels were strongly reduced by plant U-box40 (PUB40) overexpression, whereas the pub39 pub40 pub41 mutant accumulated much more BZR1 than wild type in roots. The bzr1-1D gain-of-function mutation reduced the interaction with PUB40, which suppressed PUB40-mediated BZR1 degradation in roots. The cell layer-specific expression of PUB40 in roots helps induce selective BZR1 accumulation in the epidermal layer. Both BR treatment and loss-of-function of PUB40 expanded BZR1 accumulation to most cell layers. In addition, BZR1 accumulation increased the resistance of pub39 pub40 pub41 to low inorganic phosphate availability, as observed in bzr1-1D BRASSINOSTEROID-INSENSITIVE2-induced phosphorylation of PUB40, which mainly occurs in roots, gives rise to BZR1 degradation through enhanced binding of PUB40 to BZR1 and PUB40's stability. Our results suggest a molecular mechanism of root-specific BZR1 degradation regulated by BR signaling.
PMID: 30814258
Sci Total Environ , IF:6.551 , 2019 Apr , V662 : P805-815 doi: 10.1016/j.scitotenv.2019.01.258
Exogenous 24-epibrassinolide enhanced benzene detoxification in Chlorophytum comosum via overexpression and conjugation by glutathione.
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.; Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.; School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand. Electronic address: paitip.thi@kmutt.ac.th.
Benzene, a hydrophobic xenobiotic, induces cell damage in both humans and plants. Due to its volatilization, benzene is an airborne environmental problem. The potential of an exogenous bioactive brassinosteroid phytohormone to enhance benzene removal for phytoremediation was investigated. Chlorophytum comosum had higher brassinosteroids content under benzene stress. Plant treated with 24-epibrassinolide (EBR) removed significantly more gaseous benzene than untreated plants under both light and dark conditions at an initial benzene of 12.75mumol in the systematic chambers (P<0.05). Although benzene increased malondialdehyde in plant tissue, EBR-treated plants lowered this lipid peroxidation by enhancing their antioxidant content and increasing benzene detoxification-related genes expression, including ascorbic acid (AsA), homogentisate phytyltransferase (HPT), and glutathione synthethase (GS). This contributed to maintaining higher photosynthetic performances. Moreover, EBR-treated plants had higher gene expression of ferredoxin-NADP reductase (FNR) and glucose-6-phosphate 1-dehydrogenase (G6PDH), thus promoting NADPH biosynthesis to cope with benzene under light and dark conditions, respectively. Further, higher glutathione biosynthesis promoted more glutathione conjugate of benzene products including S-phenylcysteine (SPC) in EBR-treated plants. Hence, application of exogenous EBR as foliar spray provided for enhanced benzene detoxification via antioxidant content, benzene detoxification-related genes and benzene conjugation products with glutathione (GSH) and consequently greater gaseous benzene removal.
PMID: 30708296
Viruses , IF:3.816 , 2019 Apr , V11 (4) doi: 10.3390/v11040368
Nitric Oxide as a Downstream Signaling Molecule in Brassinosteroid-Mediated Virus Susceptibility to Maize Chlorotic Mottle Virus in Maize.
State Key Laboratory for Biology of Plant Disease and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. cang327@126.com.; State Key Laboratory for Biology of Plant Disease and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. binhuizhan@126.com.; State Key Laboratory for Biology of Plant Disease and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. zzhou@zju.edu.cn.; State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China. zzhou@zju.edu.cn.
Maize chlorotic mottle virus (MCMV) infection causes growth abnormalities in maize. Transcriptome sequencing was conducted to compare the global gene expression of MCMV-inoculated plants with that of mock-inoculated plants. Data analyses showed that brassinosteroid (BR)-associated genes were upregulated after MCMV infection. Exogenous 2,4-epibrassinolide (BL) or brassinazole (BRZ) applications indicated that BR pathway was involved in the susceptibility to MCMV infection. In addition, treatment of BL on maize induced the accumulation of nitric oxide (NO), and the changes of NO content played positive roles in the disease incidence of MCMV. Moreover, MCMV infection was delayed when the BL-treated plants were applied with NO scavenger, which suggested that BR induced the susceptibility of maize to MCMV infection in a NO-dependent manner. Further investigation showed the maize plants with knock-down of DWARF4 (ZmDWF4, a key gene of BR synthesis) and nitrate reductase (ZmNR, a key gene of NO synthesis) by virus-induced gene silencing displayed higher resistance to MCMV than control plants. Taken together, our results suggest that BR pathway promotes the susceptibility of maize to MCMV in a NO-dependent manner.
PMID: 31013593
Plant Physiol Biochem , IF:3.72 , 2019 Apr , V137 : P84-92 doi: 10.1016/j.plaphy.2019.01.030
The role of chloroplasts in the oxidative stress that is induced by zearalenone in wheat plants - The functions of 24-epibrassinolide and selenium in the protective mechanisms.
Polish Academy of Sciences, The Franciszek Gorski Institute of Plant Physiology, Niezapominajek 21, 30-239, Krakow, Poland; Institute of Biology, Pedagogical University, Podchorazych 2, 30-084, Krakow, Poland.; Institute of Biology, Pedagogical University, Podchorazych 2, 30-084, Krakow, Poland.; Faculty of Agriculture and Economics, University of Agriculture in Krakow, Podluzna 3, 30-239, Krakow, Poland.; Laboratory of Growth Regulators, Centre of the Region Hana for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacky University, Slechtitelu 27, 78371, Olomouc, Czech Republic.; Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Krakow, Poland.; Polish Academy of Sciences, The Franciszek Gorski Institute of Plant Physiology, Niezapominajek 21, 30-239, Krakow, Poland.; Polish Academy of Sciences, The Franciszek Gorski Institute of Plant Physiology, Niezapominajek 21, 30-239, Krakow, Poland. Electronic address: ania@belanna.strefa.pl.
This study focused on the idea that the toxic effect of zearalenone (ZEA) and the protective actions of the brassinosteroid - 24-epibrassinolide (EBR) as well as selenium are dependent on its accumulation in chloroplasts to a high degree. These organelles were isolated from the leaves of oxidative stress-sensitive and stress-tolerant wheat cultivars that had been grown from grains that had been incubated in a solution of ZEA (30muM), Na2SeO4 (Se, 10muM), EBR (0.1muM) or in a mixture of ZEA with Se or EBR. Ultra-high performance liquid chromatography techniques indicated that ZEA was adsorbed in higher amounts in the chloroplasts in the sensitive rather than tolerant cultivar. Although the brassinosteroids and Se were also accumulated in the chloroplasts, higher levels were only found in the tolerant cultivar. The application of EBR increased the homocastasterone content, especially in the chloroplasts of the tolerant plant and after the addition of ZEA. The presence of both protectants caused a decrease in the ZEA content in studied organelles and resulted in diminishing of the oxidative stress (i.e. changes in the activity of the antioxidative enzymes). Moreover, a recovery of photosystem II and decrease in the negative impact of ZEN on Hsp90 transcript accumulation was observed in plants.
PMID: 30769236
Mol Plant Microbe Interact , IF:3.696 , 2019 Apr , V32 (4) : P452-463 doi: 10.1094/MPMI-10-18-0275-R
An Effector, BxSapB1, Induces Cell Death and Contributes to Virulence in the Pine Wood Nematode Bursaphelenchus xylophilus.
1 Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.; 2 Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University; and.; 3 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
The pine wood nematode (PWN) Bursaphelenchus xylophilus has caused serious damage to pine forests in China. Effectors secreted by phytonematodes play a role in host infection. We identified and characterized an effector, BxSapB1, based on the B. xylophilus transcriptome at the early stages of infection and the transient expression of proteins in Nicotiana benthamiana. BxSapB1 triggered cell death in N. benthamiana when secreted into the apoplast, and this effect was independent of N. benthamiana brassinosteroid-insensitive 1-associated kinase 1 (NbBAK1) and suppressor of BIR1-1 (NbSOBIR1). The signal peptide of BxSapB1 was proven to be functional in yeast using the yeast signal sequence trap system and BxSapB1 was strongly expressed in the subventral gland cells of B. xylophilus, as revealed by in-situ hybridization. In addition, based on local BLAST analysis, the BxSapB1 showed 100% identity to BUX.s00139.62, which was identified from the B. xylophilus secretome during Pinus thunbergii infection. BxSapB1 was upregulated in a highly virulent strain and downregulated in a weakly virulent strain of PWN at the early stages of infection. RNA interference assays showed that silencing BxSapB1 resulted in decreased expression of pathogenesis-related genes (PtPR-1b, PtPR-3, and PtPR-5) as well as delayed onset of symptoms in P. thunbergii infected by B. xylophilus. The combined data suggest that BxSapB1 can trigger cell death in N. benthamiana and that it contributes to the virulence in B. xylophilus during parasitic interaction.
PMID: 30351223
BMC Plant Biol , IF:3.497 , 2019 Apr , V19 (1) : P141 doi: 10.1186/s12870-019-1735-9
Phenotypic and genetic characterization of tomato mutants provides new insights into leaf development and its relationship to agronomic traits.
Instituto de Biologia Molecular y Celular de Plantas (IBMCP), Universitat Politecnica de Valencia - Consejo Superior de Investigaciones Cientificas, Ingeniero Fausto Elio s/n, 46022, Valencia, Spain.; Facultad Ciencias de la Salud, Universidad Cooperativa de Colombia, Carrera 35#36-99, Barrio Barzal, Villavicencio, Colombia.; Facultad de Agronomia, Universidad Autonoma de Sinaloa, Km 17.5 Carretera Culiacan-El Dorado, C.P 80000, Culiacan, Sinaloa, Mexico.; Centro de Investigacion en Biotecnologia Agroalimentaria (BITAL), Universidad de Almeria, 04120, Almeria, Spain.; Instituto de Biologia Molecular y Celular de Plantas (IBMCP), Universitat Politecnica de Valencia - Consejo Superior de Investigaciones Cientificas, Ingeniero Fausto Elio s/n, 46022, Valencia, Spain. vmoreno@ibmcp.upv.es.
BACKGROUND: Tomato mutants altered in leaf morphology are usually identified in the greenhouse, which demands considerable time and space and can only be performed in adequate periods. For a faster but equally reliable scrutiny method we addressed the screening in vitro of 971 T-DNA lines. Leaf development was evaluated in vitro in seedlings and shoot-derived axenic plants. New mutants were characterized in the greenhouse to establish the relationship between in vitro and in vivo leaf morphology, and to shed light on possible links between leaf development and agronomic traits, a promising field in which much remains to be discovered. RESULTS: Following the screening in vitro of tomato T-DNA lines, putative mutants altered in leaf morphology were evaluated in the greenhouse. The comparison of results in both conditions indicated a general phenotypic correspondence, showing that in vitro culture is a reliable system for finding mutants altered in leaf development. Apart from providing homogeneous conditions, the main advantage of screening in vitro lies in the enormous time and space saving. Studies on the association between phenotype and nptII gene expression showed co-segregation in two lines (P > 99%). The use of an enhancer trap also allowed identifying gain-of-function mutants through reporter expression analysis. These studies suggested that genes altered in three other mutants were T-DNA tagged. New mutants putatively altered in brassinosteroid synthesis or perception, mutations determining multiple pleiotropic effects, lines affected in organ curvature, and the first tomato mutant with helical growth were discovered. Results also revealed new possible links between leaf development and agronomic traits, such as axillary branching, flower abscission, fruit development and fruit cracking. Furthermore, we found that the gene tagged in mutant 2635-MM encodes a Sterol 3-beta-glucosyltransferase. Expression analysis suggested that abnormal leaf development might be due to the lack-off-function of this gene. CONCLUSION: In vitro culture is a quick, efficient and reliable tool for identifying tomato mutants altered in leaf morphology. The characterization of new mutants in vivo revealed new links between leaf development and some agronomic traits. Moreover, the possible implication of a gene encoding a Sterol 3-beta-glucosyltransferase in tomato leaf development is reported.
PMID: 30987599
Mol Biol Rep , IF:1.402 , 2019 Apr , V46 (2) : P1909-1930 doi: 10.1007/s11033-019-04642-9
Genome-wide identification and expression analysis of brassinosteroid action-related genes during the shoot growth of moso bamboo.
State Forestry Administration Key Open Laboratory on the Science and Technology of Bamboo and Rattan, Institute of Gene Science for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing, 100102, China.; Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT, 06269, USA.; State Forestry Administration Key Open Laboratory on the Science and Technology of Bamboo and Rattan, Institute of Gene Science for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing, 100102, China. lixp@icbr.ac.cn.; State Forestry Administration Key Open Laboratory on the Science and Technology of Bamboo and Rattan, Institute of Gene Science for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing, 100102, China. gaozhimin@icbr.ac.cn.
Brassinosteroids (BRs) are a group of plant steroid hormones that play crucial roles in a range of plant growth and development processes. BR action includes active BR formation by a complex biosynthesis process and driving BR biological function through signal transduction. Although the characterization of several BR action-related genes has been conducted in a few model plants, systematic information about these genes in bamboo is still lacking. We identified 64 genes related to BR action from the genome of moso bamboo (Phyllostachys edulis), including twenty that participated in BR biosynthesis and forty-four involved in BR signal transduction. The characteristics of all these candidate genes were identified by bioinformatics methods, including the gene structures, basic physical and chemical properties of proteins, conserved domains and evolutionary relationships. Based on the transcriptome data, the candidate genes demonstrated different expression patterns, which were further validated by qRT-PCR using templates from bamboo shoots with different heights. Thirty-four positive and three negative co-expression modules were identified by 44 candidate genes in the newly emerging bamboo shoot. The gene expression patterns and co-expression modules of BR action-related genes in bamboo shoots indicated that they might function to promote bamboo growth through BR biosynthesis and signal transduction processes. This study provides the first step towards the cloning and functional dissection of the role of BR action-related genes in moso bamboo, which also presents an excellent opportunity for genetic engineering using the candidate genes to improve bamboo quantity and quality.
PMID: 30721422