Early ETI and PTI responses in Arabidopsis thaliana camta3-D (sr1-4d) mutant

Innate immune responses of plant cells confer the first line of defence against pathogens. Signals generated by activated receptors are integrated inside the cell and converge on transcriptional programmes in the nucleus. In Arabidopsis, the CAMTA family of transcription factors plays a pivotal function in immunity. CAMTA binding motifs are highly enriched in the genes quickly induced during ETI and PTI. Using RNA-seq, we investigated the role of CAMTA TFs during the early ETI and PTI transcriptional responses. Overall design: We compared the expression changes between an Arabidopsis mutant line carrying the camta3-D (sr1-4d) dominant negative mutation and Col-0 wild-type plants following treatment with the PAMP flg22 (100 nM), and the avirulent bacterial strains Pst DC3000 AvrRpm1 (OD600=0.001) and Pst DC3000 AvrRps4 (OD600=0.001). The expression changes were analysed at one time point after each treatment (1 hour for flg22 and 4 hours for Pst DC3000 AvrRpm1 and Pst DC3000 AvrRps4 treatments).植物细胞的先天免疫应答是抵御病原菌的第一道防线。激活的受体所产生的信号在细胞内整合，并汇聚至细胞核内的转录程序。在拟南芥（Arabidopsis）中，CAMTA家族转录因子在免疫过程中发挥关键性作用。CAMTA结合基序在效应子触发的免疫（Effector-Triggered Immunity, ETI）和模式触发的免疫（Pattern-Triggered Immunity, PTI）期间快速诱导的基因中高度富集。本研究通过RNA测序（RNA-seq）探究了CAMTA转录因子在早期ETI和PTI转录应答中的功能。整体实验设计：本研究比较了携带camta3-D（sr1-4d）显性负突变的拟南芥突变株与Col-0野生型植株，分别经病原相关分子模式（Pathogen-Associated Molecular Pattern, PAMP）flg22（100 nM）、无毒细菌菌株丁香假单胞菌番茄致病变种DC3000 AvrRpm1（Pseudomonas syringae pv. tomato DC3000, Pst DC3000 AvrRpm1，OD600=0.001）以及Pst DC3000 AvrRps4（OD600=0.001）处理后的基因表达变化。每种处理仅在一个时间点分析表达变化：flg22处理后1小时，Pst DC3000 AvrRpm1与Pst DC3000 AvrRps4处理后4小时。