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The Arabidopsis J‐protein AtDjB1 facilitates thermotolerance by protecting cells against heat‐induced oxidative damage
Author(s) -
Zhou Wei,
Zhou Ting,
Li MiXin,
Zhao ChunLan,
Jia Ning,
Wang XingXing,
Sun YongZhen,
Li GuoLiang,
Xu Meng,
Zhou RenGang,
Li Bing
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2012.04070.x
Subject(s) - arabidopsis thaliana , oxidative phosphorylation , arabidopsis , mitochondrion , heat shock protein , oxidative stress , microbiology and biotechnology , biology , wild type , atpase , reactive oxygen species , biochemistry , hydrogen peroxide , chemistry , mutant , enzyme , gene
Summary• 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.