ABI5 promotes heat stress-induced chlorophyll degradation by modulating the stability of MYB44 in cucumber  

作　　者：Weikang Liu Guangling Chen Mingming He Jianqiang Wu Wenxu Wen Qinsheng Gu Shirong Guo Yu Wang Jin Sun 

机构地区：[1]College of Horticulture,Nanjing Agricultural University,Nanjing 210095,China [2]Zhengzhou Fruit Research Institute,Chinese Academy of Agricultural Sciences,Zhengzhou 450009,China

出　　处：《Horticulture Research》2023年第6期250-262,共13页园艺研究（英文）

基　　金：This work was funded by the National Natural Science Foundation of China(31872152);the Open Fundation of the Key Laboratory of Horticulture for Southern Mountainous Regions,Ministry of Education,Southwest University,the China Agriculture Research System(CARS-23);the Postdoctoral Research Funding Scheme of Jiangsu Province(2019 K071).

摘　　要：The yellowing of leaves caused by the decomposition of chlorophyll(Chl)is a characteristic event during senescence,which can be induced by various environmental stresses.However,the molecular mechanisms of high temperature-induced Chl degradation in horticultural plants remain poorly understood.Here,we found that heat stress induced Chl degradation and the expression of ABI5 and MYB44 in cucumber.Silencing of ABI5 compromised heat stress-induced Chl degradation,and the transcription of pheophytinase(PPH)and pheophorbide a oxygenase(PAO),two key genes in Chl catabolic pathway,but silencing of MYB44 exhibited the opposite results.Furthermore,ABI5 interacted with MYB44 in vitro and in vivo.ABI5 positively regulated heat stress-induced Chl degradation through two pathways.ABI5 directly bound to PPH and PAO promoters to promote their expression,leading to accelerating Chl degradation.On the other hand,the interaction between ABI5 and MYB44 reduced the binding of MYB44 to PPH and PAO promoters and led to the ubiquitination-depended protein degradation of MYB44,thereby alleviating the transcription inhibitory effect of MYB44 on PPH and PAO.Taken together,our findings propose a new regulatory network for ABI5 in regulating heat stress-induced Chl degradation.

关 键 词：STRESS thereby STABILITY 

分 类 号：S642.2[农业科学—蔬菜学]