几丁质酶及基因参与水杨酸诱导香蕉枯萎病抗性

Chitinase and chitinase's gene involved in salicylic acid Induced resistance of fusarium wilt in banana

由尖孢镰刀菌古巴专化型真菌引起的香蕉枯萎病已成为最具毁灭性的香蕉病害,严重威胁香蕉产业的健康可持续发展。因此对香蕉枯萎病病程相关基因的研究显得尤为重要。比较了Foc4侵染下,香蕉6个病菌应答相关基因的表达;分析了Foc4处理和SA+Foc4处理的易感病巴西蕉幼苗外部形态特征、几丁质酶活性及几丁质酶基因表达的变化。结果发现Ma-14-3-3c、Ma-14-3-3d、Ma-14-3-3e、Ma-14-3-3f、Ma-Cel和MaChi 6个基因都能在转录水平响应Foc4的胁迫;与Foc4处理相比较,SA+Foc4处理的香蕉幼苗枯萎病抗性增强,根系几丁质酶活性和几丁质酶基因表达水平提高。表明几丁质酶等6个基因参与了香蕉枯萎病的生物逆境胁迫应答,同时外源水杨酸处理能够通过诱导香蕉几丁质酶的活性及几丁质酶基因的表达增强香蕉对枯萎病的抗性。

Fusarium wilt of banana is caused by Fusarium oxysporum f. sp. cubense,has become the most devastating disease of banana and is great harmful to the banana industry＇s healthy and sustainable development. So it is important to study the function of the disease resistance related gene of banana. In this study,we carried out different expression analysis of Ma-14-3-3c,Ma-14-3-3d,Ma-14-3-3e,Ma-14-3-3f,Ma-Cel and Ma-Chi,and compared the difference of the two groups（First group：Banana seedlings only infected with Foc4;Second group：Banana seedlings infected with Foc4 after salicylic acid treatment）in external morphological characteristics,roots＇ chitinase activity and chitinase gene expression. The results showed that compared with the first group,in the second group,the resistance of seedlings to fusarium wiltin creased,the activity of chitinase improved and the expression level of chitinase gene elevated in banana. Therefore,the results demonstrated that chitinase gene,and other five genes,involved in the response of Foc4,and exogenous salicylic acid treatment could enhance the resistance to fusarium wilt of banana through the induction of banana chitinase activity and the expression of chitinase gene.