拟南芥免疫相关基因启动子对免疫信号分子的响应强度分析

Analysis of the response intensity of Arabidopsis immune-related gene promoters to the immune signaling molecules

关键词:  拟南芥  植物免疫  报告基因  信号响应强度

Key words:  Arabidopsis thaliana  plant immunity  report gene  signal response intensity

摘要:

为对比不同的植物抗病相关基因对植物免疫激发子的响应强度，筛选出响应强度较高的报告基因，从拟南芥中克隆5个植物免疫相关基因（WRKY33、FRK1、WRKY29、PR2和PDF1.2）的启动子序列，构建目的基因启动子驱动的萤光素酶（Luciferase，LUC）表达载体，并将其转化到拟南芥原生质体中瞬时表达；经植物免疫激发子（FLG22与PEP1）处理后，进行LUC活性检测，判断目的基因启动子的激活情况，分析上述目的基因启动子对免疫信号分子的响应强度。结果显示：经FLG22与PEP1处理后，拟南芥原生质体细胞中WRKY33响应强度为最高，与对照相比分别上调11.2与4.5倍，WRKY29响应强度次之，分别为对照的10.0与3.1倍；与WRKY相比，FRK1响应强度明显降低，而PR2与PDF1.2均无明显响应。上述结果表明在拟南芥原生质体瞬时表达体系中WRKY33可高效响应植物免疫激发子，pWRKY33：：LUC原生质体表达体系可作为一种高效的PTI反应报告系统，用于新型植物免疫激发子的筛选鉴定。

Abstract:

In order to compare the response intensity of different plant resistance genes to plant immune elicitors and screen reporter gene with high response intensity,the promoters of 5 plant immune related genes (WRKY33,FRK1,WRKY29,PR2 and PDF1.2) were cloned from Arabidopsis thaliana in this study.Luciferase expression vectors driven by target gene promoters were constructed and transformed into Arabidopsis protoplasts for transient expression.After the treatment with plant immune elicitors (FLG22 and PEP1),LUC activity was detected to determine the activation of the target promoters,and the response intensity to immune signal molecules was analyzed.The results showed that after treatment with FLG22 and PEP1,the response intensity of WRKY33 in Arabidopsis protoplasts was the highest,which was 11.2 times and 4.5 times higher than that of control,respectively.It was followed by that of WRKY29,which was 10.0 times and 3.1 times more respectively;Compared with WRKY,the response intensity of FRK1 was significantly lower,but neither PR2 nor PDF1.2 displayed apparent response.The above results indicated that WRKY33 efficiently responded to plant immune elicitors in the protoplast transient expression system of Arabidopsis and the pWRKY33::LUC protoplast expression system could be used as a highly efficient PTI reaction reporting system for the screening and identification of novel plant immune elicitors.