马铃薯kunitz型蛋白酶抑制子基因片段的分离及表达分析

 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-like EST) 。该EST与kunitz2type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, 12 h内启动表达, 48 h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KTI2like EST也可能参与了马铃薯的抗病防御。

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

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 cDNA-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 cysteine 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.