香蕉枯萎病菌pgx4基因的克隆与序列分析  

Cloning and Sequence Analysis of pgx4 Gene in Fusarium oxysporum f.sp.Cubense

作　　者：杨歆璇[1,2] 杨腊英[2] 羊玉花[1,2] 黄俊生[2] 

机构地区：[1]海南大学,海南儋州571737 [2]中国热带农业科学院环境与植物保护研究所海南省热带农业有害生物检测监控重点实验室,海南儋州571737

出　　处：《热带作物学报》2009年第11期1665-1670,共6页Chinese Journal of Tropical Crops

基　　金：国家科技支撑计划项目(No.2007BAD48B01);中央级公益性科研院所基本科研业务费专项(No.2008HZS1J003);2008农作物病虫害疫情监测与防控(No.ZBC200803);公益性行业(农业)科技专项经费项目(No.200903049)资助

摘　　要：为了解pgx4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生理小种1号和生理小种4号之间的致病力差异的关系,以尖孢镰刀菌古巴专化型1号生理小种和4号生理小种的基因组DNA和cDNA为材料,采用PCR和RT-PCR方法扩增了2个生理小种的pgx4基因,并对扩增产物进行克隆测序后再用生物信息学软件对序列进行比对分析。结果表明:2个生理小种pgx4基因的开放阅读框均为1395bp,编码465个氨基酸,且前17个氨基酸均构成该基因的信号肽。通过DNAStar7.1比对发现,尖孢镰刀菌古巴专化型2个生理小种pgx4基因的核苷酸序列存在25个碱基的差异,而其编码的465个氨基酸中,也有3个氨基酸不同,分析这些核苷酸序列和氨基酸序列的差异可能与尖孢镰刀菌古巴专化型1号生理小种和4号生理小种在侵染蕉类不同栽培种时的识别专性寄主机制有一定关系。In order to understand the role of pgx4 gene in the invasion process of Fusarium oxysporum f. sp. cubense （Foc） which causes Panama disease in banana, and the relation of pgx4 with the pathogenic difference between race one and race four of F. oxysporum f. sp. cubertse infecting the same banana variety. Races one and four of F. oxysporum f. sp. cubense were used as materials to extract genomic DNA and eDNA from which pathogenicity-related genes pgx4 of F. oxysporum f. sp. cubense were amplified by using Polymerase Chain Reaction and Reverse Transcription Polymerase Chain Reaction. The amplified products were cloned and sequenced, and sequence alignments were done by using the biological soflwares. The results revealed that the open reading frames of pgx4 genes from both races one and four were 1 395 bp and encoded 465 amino acids and that the first 17^Ф amino acids consisted of signal peptides of these genes. Alignment with DNAStar7.1 found that These 2 races had 25 different bases in nueleotides of the gene pgx4 between each other, and also contained 3 different amino acids among the amino acids encoded in these genes. The sequences alignment result and the amino acid sequence showed that the difference in nucleotide and amino acid sequences between races one and four might had some relationship with host specific recognition of races one and four in attacking different banana varieties.

关 键 词：尖孢镰刀菌古巴专化型 生理小种 pgx4基因 序列比对 

分 类 号：S668.1[农业科学—果树学] S432.4[农业科学—园艺学]