马铃薯kunitz型蛋白酶抑制子基因片段的分离及表达分析

Isolation and Expression Analysis of Kunitz-type Enzyme Inhibitor Gene Fragment in Potato (Solanum tuberosum L.)

以马铃薯高抗青枯病基因型ED13为材料,利用cDNA-RGA方法获得了青枯病菌处理和水对照处理之间的差异表达片段(KTI-likeEST)。该EST与kunitz-type抑制子基因高度同源,属于kunitz-type抑制子基因家族,是马铃薯半胱氨酸蛋白酶抑制子基因家族的重要成员。半定量RT-PCR分析表明该基因受青枯病菌的诱导,12h内启动表达,48h内表达量达最高。马铃薯半胱氨酸蛋白酶抑制子基因参与马铃薯对病原的抗病防御,推测所获得的KTI-likeEST也可能参与了马铃薯的抗病防御。

The differentially expressed fragment, designated as kunitz-type enzyme inhibitor like （ KTI- like） EST, was isolated from ED13 with high resistance to Ralstonia solanacearum （Rs） using eDNA-RGA （resistance gene analogs, RGA）. Results of BLAST against NCBI database showed that the KTI-like EST shared a high similarity with kunitz-type inhibitor genes, and might be one of the important members of potato eysteine proteinase inhibitor （PCPI） gene family. Analysis of semi-quantity RT-PCR indicated that the KTI- like gene was induced by Rs and it was trigged to express before 12 h and reached the highest level at about 48 h post-inoculation, then leveled off. Results of this study combined with the fact that PCPI is involved in plant defence against insects and pathogens indicated that the KTI-like gene might play an important role in plant resistance against Rs.