title: Disruption of the Arabidopsis Defense Regulator Genes SAG101, EDS1, and PAD4 Confers Enhanced Freezing Tolerance.
abstract: In Arabidopsis, three lipase-like regulators, SAG101, EDS1, and PAD4, act downstream of resistance protein-associated defense signaling. Although the roles of SAG101, EDS1, and PAD4 in biotic stress have been extensively studied, little is known about their functions in plant responses to abiotic stresses. Here, we show that SAG101, EDS1, and PAD4 are involved in the regulation of freezing tolerance in Arabidopsis. With or without cold acclimation, the sag101, eds1, and pad4 single mutants, as well as their double mutants, exhibited similarly enhanced tolerance to freezing temperatures. Upon cold exposure, the sag101, eds1, and pad4 mutants showed increased transcript levels of C-REPEAT/DRE BINDING FACTORs and their regulons compared with the wild type. Moreover, freezing-induced cell death and accumulation of hydrogen peroxide were ameliorated in sag101, eds1, and pad4 mutants. The sag101, eds1, and pad4 mutants had much lower salicylic acid (SA) and diacylglycerol (DAG) contents than the wild type, and exogenous application of SA and DAG compromised the freezing tolerance of the mutants. Furthermore, SA suppressed the cold-induced expression of DGATs and DGKs in the wild-type leaves. These findings indicate that SAG101, EDS1, and PAD4 are involved in the freezing response in Arabidopsis, at least in part, by modulating the homeostasis of SA and DAG.
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Qin-Fang
authors.initials: QF
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Le
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Wei-Juan
authors.initials: WJ
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Mo-Xian
authors.initials: MX
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Bin-Yi
authors.initials: BY
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Lu-Jun
authors.initials: LJ
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Wensheng
authors.initials: W
authors.lastname: Shu
authors.affiliation: State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China. Electronic address: xiaoshi3@mail.sysu.edu.cn.
authors.forename: Shi
authors.initials: S
authors.lastname: Xiao
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism; D005615:Freezing; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D010935:Plant Diseases; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D004075:Diglycerides; C118837:EDS1 protein, Arabidopsis; D002265:Carboxylic Ester Hydrolases; C400766:PAD4 protein, Arabidopsis; C460108:SAG101 protein, Arabidopsis; D020156:Salicylic Acid
keywords: cold acclimation; diacylglycerol; freezing tolerance; reactive oxygen species; salicylic acid