香蕉枯萎病菌4号生理小种中性海藻糖酶NTH1基因敲除和功能分析

Knockout and Functional Analysis of Neutral Trehalase NTH1 Gene in Fusarium oxysporum f.sp.cubense Race 4

为了研究中性海藻糖酶在香蕉枯萎病菌4号生理小种(Foc4-37)致病和耐受不良环境中的作用,笔者构建了中性海藻糖酶编码基因敲除突变体Δnth1,并对敲除突变体的致病力、生物学特性和对氰烯菌酯的抗药性开展测定分析。结果表明:与野生型相比,Δnth1菌落生长缓慢、孢子萌发率下降,对巴西蕉苗致病力明显减弱,但产孢量没有显著差异,对氰烯菌酯的敏感性(EC50=6.07 mg·L^−1)也无明显变化。由此推断NTH1基因参与调控香蕉枯萎病菌的分生孢子萌发和生长,参与细胞壁合成和氧化应激反应的应答,不参与FOC对渗透压力、高糖和高低温胁迫的应答。

In order to study the role of neutral trehalase in the pathogenicity and intolerance environment of Fusarium oxysporum f.sp.cubense race 4(Foc4-37),a neutral trehalase-encoding gene knockout mutantΔnth1 was constructed,and its pathogenicity,biological characteristics and resistance to phenamacril were determined.The results showed the neutral trehalase-encoding gene knockout mutantΔnth1 was lower in colony growth rate and conidia germination rate,and significantly lower in pathogenicity to banana(Cavendish,AAA)than the wild-type strain.However,there was no significant difference in conidia yield and sensitivity to phenamacril(EC50=6.07 mg·L^−1)between the mutant and the wild type strain.It was inferred that NTH1 gene was involved in regulating the growth and conidia germination of Fusarium oxysporum f.sp.,and responding to the cell wall synthesis and oxidative stress,but not to the osmotic pressure,high sugar stress and temperature stress.