1. Pepper CabZIP63 acts as a positive regulator duringRalstonia solanacearumor high temperature–high humidity challenge in a positive feedback loop with CaWRKY40
- Author
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Jiazhi Li, Zhiqin Liu, Li He, Cailing Liu, Wei Lin, Wei Cheng, Shuilin He, Shaoliang Mou, Yanyan Liu, Rongzhang Wang, Tong Yang, Jiong Hu, Qian Tang, Yang Wu, Jiaqi Liang, Hanyang Cai, Ansar Hussain, Huanxin Yu, Yangwen Zhang, Lei Shen, Wei Shi, Jiayu Wen, Deyi Guan, Sheng Yang, and Lanping Shi
- Subjects
0106 biological sciences ,0301 basic medicine ,Hot Temperature ,Transcription, Genetic ,transcription factors ,Physiology ,Regulator ,Plant Science ,Acetates ,Bioinformatics ,01 natural sciences ,CabZIP63 ,pepper ,Gene Expression Regulation, Plant ,Sequence Analysis, Protein ,Plant Immunity ,Cloning, Molecular ,Promoter Regions, Genetic ,Plant Proteins ,Feedback, Physiological ,Ralstonia solanacearum ,Cell Death ,food and beverages ,Adaptation, Physiological ,Cell biology ,Protein Transport ,Crosstalk (biology) ,CaWRKY40 ,Capsicum ,Research Paper ,Protein Binding ,Programmed cell death ,Cyclopentanes ,Biology ,Genes, Plant ,03 medical and health sciences ,high temperature–high humidity ,Pepper ,Gene silencing ,Gene Silencing ,Oxylipins ,Gene ,Cell Nucleus ,Base Sequence ,Humidity ,Promoter ,biochemical phenomena, metabolism, and nutrition ,Ethylenes ,biology.organism_classification ,030104 developmental biology ,Biomarkers ,Abscisic Acid ,010606 plant biology & botany - Abstract
Highlight CabZIP63, indirectly activated by CaWRKY40, positively modulates transcription of CabZIP63 and CaWRKY40, enhances the binding of CaWRKY40 to its target promoters, and, therefore, increases resistance to Ralstonia solanacearum and thermotolerance., CaWRKY40 is known to act as a positive regulator in the response of pepper (Capsicum annuum) to Ralstonia solanacearum inoculation (RSI) or high temperature–high humidity (HTHH), but the underlying mechanism remains elusive. Herein, we report that CabZIP63, a pepper bZIP family member, participates in this process by regulating the expression of CaWRKY40. CabZIP63 was found to localize in the nuclei, be up-regulated by RSI or HTHH, bind to promoters of both CabZIP63 (pCabZIP63) and CaWRKY40 (pCaWRKY40), and activate pCabZIP63- and pCaWRKY40-driven β-glucuronidase expression in a C- or G-box-dependent manner. Silencing of CabZIP63 by virus-induced gene silencing (VIGS) in pepper plants significantly attenuated their resistance to RSI and tolerance to HTHH, accompanied by down-regulation of immunity- or thermotolerance-associated CaPR1, CaNPR1, CaDEF1, and CaHSP24. Hypersensitive response-mediated cell death and expression of the tested immunity- and thermotolerance-associated marker genes were induced by transient overexpression (TOE) of CabZIP63, but decreased by that of CabZIP63-SRDX. Additionally, binding of CabZIP63 to pCaWRKY40 was up-regulated by RSI or HTHH, and the transcript level of CaWRKY40 and binding of CaWRKY40 to the promoters of CaPR1, CaNPR1, CaDEF1 and CaHSP24 were up-regulated by TOE of CabZIP63. On the other hand, CabZIP63 was also up-regulated transcriptionally by TOE of CaWRKY40. The data suggest collectively that CabZIP63 directly or indirectly regulates the expression of CaWRKY40 at both the transcriptional and post-transcriptional level, forming a positive feedback loop with CaWRKY40 during pepper’s response to RSI or HTHH. Altogether, our data will help to elucidate the underlying mechanism of crosstalk between pepper’s response to RSI and HTHH.
- Published
- 2016