香蕉枯萎病菌fgb2基因的克隆与序列分析

Cloning and Sequence Analysis of fgb2 Gene in Fusarium oxysporum f.sp.cubense

为了解fgb2基因在尖孢镰刀菌古巴专化型侵染香蕉过程中的作用,及其与尖孢镰刀菌古巴专化型1号和4号生理小种之间的致病力差异关系,采用PCR和RT-PCR方法扩增了2个生理小种的fgb2基因,并对其扩增产物进行了测序及相似序列搜索和比对,同时还对其基因编码的蛋白进行了氨基酸序列比对和功能分析。结果表明,2个生理小种fgb2基因开放阅读框分别为1466bp和1452bp,基因同源性为96.33%;其编码的氨基酸数量分别为299个和316个;从fgb2基因序列及其编码蛋白的氨基酸序列来看,2个生理小种的致病力差异与fgb2基因并无明显对应关系。

It is very important to know the roles offgb2 genes in invasion process of Fusarium oxysporum f. sp. cubense （FOC） into banana and its relationship in pathogenic difference between the races 1 and 4 of FOC attacking the same banana cuhivar. The fgb2 genes were amplified by using Polymerase Chain Reaction and Reverse Transcription Polymerase Chain Reaction, and the amplified products were then sequenced and aligned with DNAStar Meglignment software. The functions of the proteins encoded byfgb2 genes were also analyzed. The results revealed that the open reading frames offgb2 genes from races of FOC were 1 466 bp and 1 452 bp, encoding 299 and 316 amino acids. FOC race 1 showed a 96.33% similarity offgb2 gene to FOC race 4. The sequences offgb2 genes and amino acid sequences of the two FOC races showed no relationship between the pathogenic difference and the fgb2 gene. These results would help to understand the function offgb2 genes in follow- up research activities.