新疆甜瓜Fom-2基因同源序列的克隆及分析

Cloning and Analysis of Gene Analogue for Fom-2 in Melon in Xinjiang

近年来甜瓜枯萎病蔓延迅速,危害严重,分离克隆甜瓜抗病基因,利用转基因技术改良甜瓜抗病品性是一种从根本上解决甜瓜枯萎病危害的新途径。根据已知Fom-2基因序列设计特异引物,采用RT-PCR技术从新疆甜瓜抗病性品种黄旦子中扩增出580bp的cDNA片段,序列分析表明它与已发表Fom-2基因具有高度同源性基因片段,命名为X-Fom-2。以X-Fom-2为探针对新疆甜瓜黄旦子、伽什瓜、红心脆、金丽-2号进行Southernblot和Northernblot,结果表明,X-Fom-2以多拷贝形式存在。X-Fom-2在抗病品种黄旦子、金丽2号有表达且在病原菌诱导后增强,而在感病品种伽什瓜、红心脆中没有表达。

Melon Fusarium wilt has been spreading rapidly and threading yield seriously these years.It is a new way to avoid lost because of melon Fusarium wilt cloning resistance genes and using these genes to inprove resistant capability.Rewerse Transcription-Polymerse Chain Reaction (RT-PCR)was performed on total RNA of resistant-line Huangdazi using specific primers designed according to known Fom-2 . A expected cDNA fragment Fom-2 was cloned , sequenced and named x-Fom-2 . It was a Open Reading Frame (ORF) comprised of 580 base pairs which encodes a Fom-2 -like protein with 193 amino acids. Fom-2 was more than one copy in melon genome based on southern blot. It expressed in high level in Huangdanzi and Jinli-2 and was enhanced by Fusarium oxysporum melonis infected. But x-Fom-2 was not transcription in susceptible-line Jiashi and Hongxincui, whether samples induced by Fusarium oxysporum melonis or not.