不同致病力棉花黄萎病菌乙烯含量及相关基因表达量的测定

Determination of ethylene and transcript levels of genes involved in ethylene biosynthesis by different virulent Verticillim dahliae from cotton

为了分析大丽轮枝菌(Verticillium dahliae Kleb.)乙烯合成与致病力的关系,本研究以棉花黄萎病菌落叶型强致病力菌株V592和非落叶型弱致病力菌株V774为研究对象,分别将2个菌株于非诱导查氏培养液中和添加棉花根提取物的诱导查氏培养液中进行培养,对其乙烯含量进行测定,并通过qRT-PCR分析大丽轮枝菌中6个与乙烯合成相关基因的表达量。结果表明:强、弱致病力菌株均能产生乙烯,强致病力菌株产生的乙烯含量明显高于弱致病力菌株,且强致病力菌株合成乙烯的能力受寄主根诱导后明显加强。非诱导条件下4个基因在强、弱致病力菌株中的表达量存在差异;在诱导条件下6个基因在强、弱致病力菌株中的表达量存在明显差异(P<0.05)。这些基因的差异表达可能是造成强、弱致病力菌株乙烯含量不同的主要因素。

This research aimed to analyze the correlation between ethylene biosynthesis produced by Verticillim dahliae and its virulence.Ethylene production by a highly virulent V.dahliae cotton defoliating strain V592 and a less virulent non-defoliating strain V774 were measured when the two strains were cultured in liquid Czapek-Dox medium and in Czapek-Dox medium contained with cotton root extract.The transcript levels of six genes involved in ethylene biosynthesis in the two V.dahliae strains were determined by quantitative real-time RT-PCR(qRT-PCR) method.The results showed that both V.dahliae strains were capable of synthesizing ethylene in culture;V592 produced more ethylene than V774 and ethylene production by V592 was stimulated by cotton root extract.Of the six genes,the transcript levels of four genes displayed differences between the two strains in Czapek-Dox medium,whereas six genes displayed significant differences between the two strains in Czapek-Dox medium with cotton root extract.The results suggested that virulence variation of V.dahliae might result from the significandy different transcript level of genes involved in ethylene biosynthesis.