CaAIL1 Acts Positively in Pepper Immunity against Ralstonia solanacearum by Repressing Negative Regulators
CaAIL1 Acts Positively in Pepper Immunity against Ralstonia solanacearum by Repressing Negative Regulators
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CaAIL1 通过抑制负调节因子在辣椒对青枯菌的免疫中发挥积极作用
DOI：
10.1093/pcp/pcab125
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Xueying Huang
中科院分区：
文献类型：
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作者：
Weiwei Cai;Shicong He;Yutong Zheng;Lei Shen;Xueying Huang
aptala2 （AP2）亚家族转录因子参与植物生长发育，但其在植物免疫中的作用尚不清楚。本研究发现AP2转录因子CaAIL1在辣椒抗茄白僵菌感染（RSI）免疫中起作用。RSI上调了CaAIL1的表达，病毒诱导基因沉默和瞬时过表达的功能缺失和功能获得实验分别表明，CaAIL1在辣椒对RSI的免疫中起积极作用。染色质免疫沉淀测序（ChIP-seq）揭示了CaAIL1通过其顺式元件（如GT或AGGCA基序）直接靶向的转录因子编码基因子集，包括carap2 -7、CaGATA17、cagtf3a和catcf25。ChIP-qPCR和电泳迁移迁移实验证实了这些发现。这些编码负向免疫转录因子的基因在辣椒对RSI的反应中被CaAIL1抑制，而编码正向免疫调节因子的基因如caeas1则被CaAIL1抑制。重要的是，我们发现CaAIL1中的非典型EAR基序（LXXLXXLXX）在其免疫功能中是不可或缺的。这些发现表明，CaAIL1通过与启动子中的几个顺式元件结合，在RSI反应中抑制一组负性免疫调节因子，从而增强辣椒对RSI的免疫力。
APETALA2 (AP2) subfamily transcription factors participate in plant growth and development, but their roles in plant immunity remain unclear. Here, we discovered that the AP2 transcription factor CaAIL1 functions in immunity againstRalstonia solanacearuminfection (RSI) in pepper (Capsicum annuum).CaAIL1expression was upregulated by RSI, and loss- and gain-of-function assays using virus-induced gene silencing and transient overexpression, respectively, revealed that CaAIL1 plays a positive role in immunity to RSI in pepper. Chromatin immunoprecipitation sequencing (ChIP-seq) uncovered a subset of transcription-factor-encoding genes, includingCaRAP2-7, CaGATA17, CaGtf3aandCaTCF25, that were directly targeted by CaAIL1 via theircis-elements, such as GT or AGGCA motifs. ChIP-qPCR and electrophoretic mobility shift assays confirmed these findings. These genes, encoding transcription factors with negative roles in immunity, were repressed by CaAIL1 during pepper response to RSI, whereas genes encoding positive immune regulators such asCaEASwere derepressed by CaAIL1. Importantly, we showed that the atypical EAR motif (LXXLXXLXX) in CaAIL1 is indispensable for its function in immunity. These findings indicate that CaAIL1 enhances the immunity of pepper against RSI by repressing a subset of negative immune regulators during the RSI response through its binding to severalcis-elements in their promoters.