【摘要】 为探究转录因子TaMADS2在小麦抗叶锈病中的功能，以TaMADS2基因在亲和/非亲和小麦与叶锈菌互作过程中上调表达，且在非亲和组合中上调表达时期较亲和组合更早为依据，利用BSMV-VIGS技术沉默‘中国春’‘郑麦9023’中TaMADS2基因表达，观察TaMADS2沉默植株的表型以及病程相关基因的转录水平变化。结果表明：在接种叶锈菌后，TaMADS2基因沉默植株较对照相比叶锈菌感染加重，单侵染点处活性氧积累面积减小，菌丝长度增加，发病面积增大，促进了病原菌的生长，减弱了植物的抗性反应；通过qRT-PCR分析发现在叶锈菌侵染早期，病程相关基因TaPR1和TaPR2的表达水平下调。综上，TaMADS2基因可能通过调控抗病相关基因的表达正向调控小麦对叶锈菌的抗性。更多还原

【Abstract】 Based on the expression of TaMADS2 gene was up-regulated by the infection of leaf rust in compatible/incompatible wheat varieties and the response period was earlier in incompatible wheat than in compatible wheat, the function of TaMADS2 in wheat resistance to leaf rust was studied by using BSMV-VIGS technology. The phenotypes of TaMADS2-silenced plants(wheat cultivars ‘Chinese Spring’ and ‘Zhengmai 9023’) and the transcriptional level changes of pathogenesis-related genes were analyzed. The results showed a significant increase in disease severity of leaf rust on BSMV-infected wheat leaves, the length of infection hypha(IH) and infection area in wheat seedlings, as well as a remarkable decrease in the accumulation of reactive oxygen species(ROS) at single infection sites in TaMADS2-silenced plants, suggesting that the growth of pathogen fungus was promoted while the disease resistance response of plant was decreased in comparison to the non-silenced plants inoculated with leaf rust. Furthermore, qRT-PCR analysis showed that the expressing levels of pathogenesis-related genes TaPR1、TaPR2 and ROS-scavenging gene TaCAT were significantly down-regulated in the early stage of rust infection. In conclusion, TaMADS2 may inhibit the infection of leaf rust and positively regulate the resistance to leaf rust by regulating the expression of pathogenesis-related genes in wheat.更多还原