利用VIGS技术研究马铃薯抗晚疫病基因R3a和RB的信号传导

 利用VIGS技术，在烟草中沉默已知的抗病信号传导关键基因SIPK、NDR1、SGT1、HSP90、NPR1、Rar1、EDS1、WRKY1，再瞬时表达马铃薯抗病基因和其相应的无毒基因RB-Avrblb1和R3a-Avr3a，根据过敏反应（Hypersensitive Response，HR）反应是否被阻断来研究RB和R3a介导的抗病信号传导。结果发现SGT1和HSP90基因沉默阻断了HR反应的发生，表明SGT1和HSP90是参与RB和R3a抗病信号传导途径过程中的关键基因。该技术体系的建立，为以后发现新的晚疫病抗病相关基因的功能验证提供了一个高效的技术平台。

Studies on Signal Pathways of The Potato Late Blight Resistance Gene R3a,RB Using VIGS

R3a and RB confer resistance to potato late blight by recognizing the effector protein Avr3a and Avrblb1 of Phytophthora infestans. R gene mediated resistance requires multiple signal transduction pathways. Virus-induced gene silencing (VIGS) is a powerful tool for studying genes participation in signal pathways. Eight genes, SIPK, NDR1, SGT1, HSP90, NPR1, Rar1, EDS1 and WRKY1 from other species are known to be involved in defence-related signal pathway. Expression of each gene was suppressed by VIGS in Nicotiana benthamiana and the effect was determined on Hypersensitive Response symptoms induced by RB-Avrblb1 and R3a-Avr3a. R3a- and RB-mediated resistance was compromised by the silencing of HSP90 and SGT1, suggesting that the RB-Avrblb1 and R3a-Avr3a interaction are dependent on ubiquitin ligase-associated protein SGT1 and heat-shock protein HSP90. The establishment of this system will identify new genes involved in resistance to late blight.