title: The Arabidopsis J-protein AtDjB1 facilitates thermotolerance by protecting cells against heat-induced oxidative damage.
abstract: AtDjB1 belongs to the J-protein family in Arabidopsis thaliana. Its biological functions in plants are largely unknown. In this study, we examined the roles of AtDjB1 in resisting heat and oxidative stresses in A. thaliana using reverse genetic analysis. AtDjB1 knockout plants (atj1-1) were more sensitive to heat stress than wildtype plants, and displayed decreased concentrations of ascorbate (ASC), and increased concentrations of hydrogen peroxide (H(2)O(2)) and oxidative products after heat shock. Application of H(2)O(2) accelerated cell death and decreased seedling viability in atj1-1. Exogenous ASC conferred much greater thermotolerance in atj1-1 than in wildtype plants, suggesting that a lower concentration of ASC in atj1-1 could be responsible for the increased concentration of H(2)O(2) and decreased thermotolerance. Furthermore, AtDjB1 was found to localize to mitochondria, directly interact with a mitochondrial heat-shock protein 70 (mtHSC70-1), and stimulate ATPase activity of mtHSC70-1. AtDjB1 knockout led to the accumulation of cellular ATP and decreased seedling respiration, indicating that AtDjB1 modulated the ASC concentration probably through affecting the function of mitochondria. Taken together, these results suggest that AtDjB1 plays a crucial role in maintaining redox homeostasis, and facilitates thermotolerance by protecting cells against heat-induced oxidative damage.
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.|Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.|College of Biology and Engineering, Hebei University of Economics and Business, Shijiazhuang 050061, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Mi-Xin
authors.initials: MX
authors.lastname: Li
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Chun-Lan
authors.initials: CL
authors.lastname: Zhao
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Jia
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Xing-Xing
authors.initials: XX
authors.lastname: Wang
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Sun
authors.affiliation: Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Li
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.
authors.forename: Ren-Gang
authors.initials: RG
authors.lastname: Zhou
authors.affiliation: Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Science, Hebei Normal University, Shijiazhuang 050024, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000255:Adenosine Triphosphate / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001205:Ascorbic Acid / Q000494:pharmacology; D019069:Cell Respiration / Q000187:drug effects; D019610:Cytoprotection / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000187:drug effects; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D024101:Mitochondrial Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects; D010641:Phenotype; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
chemical_list: C494632:ATJ1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D024101:Mitochondrial Proteins; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid