拟南芥T1N6_22在抵抗Pst DC3000侵染过程中的功能分析

【目的】明确拟南芥抗灰霉病基因T1N6_22在抗Pst DC3000过程中的功能，分析T1N6_22影响拟南芥对Pst DC3000的抗性原因。【方法】对t1n6_22突变体和转基因回复突变体（t1n6_22/T1N6_22）接种Pst DC3000，检测其症状；采用间苯胺蓝染色法检测接种突变体中胼胝质的积累情况；测定接种叶片中Pst DC3000的生长量，明确T1N6_22在拟南芥抗Pst DC3000过程中的功能。利用RT-PCR技术，检测SA、JA和ET对T1N6_22表达的影响及T1N6_22对抗病防御相关基因表达的影响；利用quantitative real-time PCR技术，检测Pst DC3000对T1N6_22及抗病相关基因表达的影响，分析T1N6_22影响拟南芥对Pst DC3000的抗性原因。【结果】t1n6_22突变体接种Pst DC3000后表现明显的抗病症状，而回复突变体t1n6_22/T1N6_22和拟南芥野生型表现明显的感病症状。SA处理拟南芥野生型，T1N6_22的表达量明显增强，经JA和ACC处理，该基因的表达量无显著变化。t1n6_22突变体中，PAL、PR4、PPO、SOD和CAT的表达水平均明显高于野生型Col-0和转基因回复植株。接种Pst DC3000后，拟南芥野生型中T1N6_22及抗病相关基因PR1、PR3、PR5和PDF1.2的表达量明显增强。【结论】T1N6_22在拟南芥抗Pst DC3000过程中起负调控作用，T1N6_22的表达受SA诱导，可能主要通过调节植物的次生代谢产物的分泌影响拟南芥对Pst DC3000的抗性。

Functional Analysis of T1N6_22 in Arabidopsis thaliana Against the Infection of Pst DC3000

【Objective】 The objective of this study is to investigate the function of the T1N6_22, a resistant gene of Arabidopsis against B. cinerea, in Arabidopsis resistance to Pseudomonas syringae pv. tomato DC3000, to further analyze the mechanism of T1N6_22 genes in Arabidopsis resistance to Pst DC3000. 【Method】 The symptoms, increase of the content of callose and bacterial concentration of the t1n6_22 and t1n6_22/T1N6_22 in plants inoculated with Pst DC3000 were investigated to study the function of the T1N6_22 in Arabidopsis resistance to Pst. DC3000. RT-PCR technology was used to analyze the expression of T1N6_22 in Col-0 treatment with SA, JA, ET and the expression of defence-related genes in Col-0, the t1n6_22 and t1n6_22/T1N6_22 plants. Quantitative real-time PCR technology was used to analyze the expression of T1N6_22 and the key genes involved in the SA, JA/ET signal pathway in Col-0 inoculated with Pst DC3000. 【Result】 The t1n6_22 exhibited enhanced resistance to Pst DC3000, the Col-0 and complemental plants showed an obvious susceptibility to Pst DC3000. The expression of T1N6_22 in Col-0 treatment with SA was significantly enhanced, suggesting the expression of T1N6_22 induced by SA. Compared with the Col-0 and t1n6_22/T1N6_22 plants, the expression of PAL, PR4, PPO, SOD and CAT genes were downregulated in the t1n6_22 plants. The expression of T1N6_22 and the key genes involved in the SA, JA/ET signal pathway, such as PR1, PR3, PR5 and PDF1.2 genes, were upregulated in Col-0 after inoculation of Pst DC3000.【Conclusion】T1N6_22 gene is a negative regulatory component of Arabidopsis against Pst DC3000 and the T1N6_22 gene expression is induced by SA. T1N6_22 may be involved in the regulation of plant secondary metabolites in impact of the resistance to Pst DC3000 in Arabidopsis.