前期研究中，我们利用抑制性差减杂交技术筛选抗性相关基因，得到一个抗芜菁花叶病毒（TuMV）侵染的相关基因芥菜线粒体交替氧化酶基因(BJAOX1a)，QRT-PCR结果表明BJAOX1a高度响应TuMV侵染和外源BR的施用，且外源BR能够有效的提高芥菜系统叶片的抗病性。BR介导的芥菜BJAOX1a抗性途径的机理尚不明确，本项目拟通过构建BJAOX1a基因的过量表达株和RNAi抑制表达株，采用病毒侵染与BR合成抑制剂Brz、BR预处理结合，比较转化材料和野生型植株间的抗病性差异；分析BR对BJAOX1a基因和芥菜抗病性的影响；研究转化植株和野生型植株在不同处理下ROS含量的变化及相关基因的表达，同时结合芥菜抗病反应、抗性基因表达和外壳病毒蛋白的表达情况，阐明TuMV侵染过程中芥菜BJAOX1a介导的抗性途径与BR之间的联系；以期阐述芥菜BJAOX1a的抗病机制。

In the previous research,a poly merase chain reaction(PCR)-based suppression subtractive hybridization technique was used to isolate genes with Turnip mosaic virus (TuMV) resistance，and a mitochondrial alternative oxidase gene (BJAOX1a) was got in Brassica juncea. QRT-PCR results showed that the BJAOX1a highly responsed to TuMV infection and exogenous BR application, and the system resistance in upper leafs of mustard were enhanced by exogenous BR. In order to study the resistance pathway induced by the AOX and the relationship between BR and AOX, the BJAOX1 over-expression and RNAi transformation plants will be constructed. The BR inhibitor Brz and the BR will be applied to study the difference of virus resistance between wild type plants and transformation plants; the expression of BJAOX1a and the resistance induced by BR will be analysed in mustard; changes of ROS content, the phenotype change of mustard resistance, expression of resistant genes and virus coat proteins will also be investigated under different treatments in transgenic plants and wild type plants; The objective of this study is to elaborate the function of AOX in TuMV reistance.