title: H2O2 mediates the crosstalk of brassinosteroid and abscisic acid in tomato responses to heat and oxidative stresses.
abstract: The production of H2O2 is critical for brassinosteroid (BR)- and abscisic acid (ABA)-induced stress tolerance in plants. In this study, the relationship between BR and ABA in the induction of H2O2 production and their roles in response to heat and paraquat (PQ) oxidative stresses were studied in tomato. Both BR and ABA induced increases in RBOH1 gene expression, NADPH oxidase activity, apoplastic H2O2 accumulation, and heat and PQ stress tolerance in wild-type plants. BR could only induced transient increases in these responses in the ABA biosynthetic mutant notabilis (not), whereas ABA induced strong and prolonged increases in these responses in the BR biosynthetic mutant d (^im) compared with wild-type plants. ABA levels were reduced in the BR biosynthetic mutant but could be elevated by exogenous BR. Silencing of RBOH1 compromised BR-induced apoplastic H2O2 production, ABA accumulation, and PQ stress responses; however, ABA-induced PQ stress responses were largely unchanged in the RBOH1-silenced plants. BR induces stress tolerance involving a positive feedback mechanism in which BR induces a rapid and transient H2O2 production by NADPH oxidase. The process in turn triggers increased ABA biosynthesis, leading to further increases in H2O2 production and prolonged stress tolerance. ABA induces H2O2 production in both the apoplastic and chloroplastic compartments.
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China xiaojianxia@zju.edu.cn jqyu@zju.edu.cn.
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Xia
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Zhou
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China Department of Botany & Plant Pathology, Purdue University, West Lafayette, IN 47907-2054, USA.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Zijingang Road 866, Hangzhou, 310058, PR China xiaojianxia@zju.edu.cn jqyu@zju.edu.cn.
authors.forename: Jing-Quan
authors.initials: JQ
authors.lastname: Yu
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis*; D060406:Brassinosteroids / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D006706:Homeostasis; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D013312:Stress, Physiological
chemical_list: D060406:Brassinosteroids; D000040:Abscisic Acid; D006861:Hydrogen Peroxide
keywords: Abscisic acid; NADPH oxidase; Solanum lycopersicum; VIGS.; brassinosteroid; hydrogen peroxide