Disruption of the Arabidopsis Defense Regulator Genes SAG101, EDS1, and PAD4 Confers Enhanced Freezing Tolerance  

作　　者：Qin-Fang Chen Le Xu Wei-Juan Tan Liang Chen Hua Qi Li-Juan Xie Mo-Xian Chen Bin-Yi Liu Lu-Jun Yu Nan Yao Jian-Hua Zhang Wensheng Shu Shi Xiao 

机构地区：[1]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 [2]State Key Laboratory of Agrobioteehnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China [3]These authors contributed equally to this article

出　　处：《Molecular Plant》2015年第10期1536-1549,共14页分子植物（英文版）

摘　　要：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, edsl, and pad4 single mutants, as well as their double mutants, exhibited similarly enhanced tolerance to freezing temperatures. Upon cold exposure, the sag101, edsl, 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, edsl, and pad4 mutants. The sag101, edsl, 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.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, edsl, and pad4 single mutants, as well as their double mutants, exhibited similarly enhanced tolerance to freezing temperatures. Upon cold exposure, the sag101, edsl, 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, edsl, and pad4 mutants. The sag101, edsl, 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.

关 键 词：cold acclimation DIACYLGLYCEROL freezing tolerance reactive oxygen species salicylic acid 

分 类 号：Q943[生物学—植物学] TU528.062[建筑科学—建筑技术科学]