香蕉枯萎病菌中Hog1 MAPK同源基因FoHog1敲除突变体的生物学特性

Biological characteristics of an Hog1 MAPK homologous gene FoHog1 knock-out mutant of Fusarium oxysporum f．sp．cubense

摘要:

摘要:【目的】研究香蕉枯萎病菌4号生理小种中促分裂原活化蛋白激酶基因FoHog1的结构特点及其功能【方法】通过PCR和RT-PCR的方法获得了FoHog1基因序列并进行生物信息学分析，利用PEG介导的原生质体转化法得到了FoHog1基因缺失突变体，分析敲除突变体与野生型的生物学特性差异【结果】FoHog1基因编码一个含有357个氨基酸的蛋白，该蛋白在不同种镰刀菌中高度保守。通过对敲除突变体的研究发现，该基因缺失后菌丝密度下降，产孢量与菌丝干重明显降低，对乙酸钠和氯化铵的利用率下降，对温度、pH 及渗透压等外源胁迫更为敏感。通过致病力实验发现，基因敲除突变体的定殖能力有所降低【结论】尖孢镰刀菌古巴专化型4 号生理小种中FoHog1 基因参与调控菌丝生长、分生孢子生成、乙酸钠和氯化铵代谢、渗透压胁迫反应及致病相关过程。

Abstract:

Abstract:［Objective］This study was aimed to obtain a mitogen-activated protein kinase (MAPK) gene namely FoHog1 from Fusarium oxysporum f． sp．cubense and to verify its function．［Methods］We amplified FoHog1 gene by PCR and RT-PCR methods and analyzed it through bioinformatics method．PEG-mediated protoplast transformation was used to create the deletion mutants of FoHog1 gene．We analyzed different biological characteristics between knock-out strain and wild-type strain.［Results］FoHog1 gene encoding a putative protein of 357 amino acids and its genetic relationship with different Fusarium’s protein．Compared with the wild-type strain，FoHog1 deletion mutants have loose hyphae colony， less spores production，lower dry weight of hyphae and more sensitive to temperature，pH and osmotic stress．FoHog1 deletion mutants also have reduced colonization ability compared with the wild-type strain．［Conclusion］FoHog1 gene participated in mycelial growth，sporulation，catabolism of sodium acetate and ammonium chloride，osmotic stress response and pathogenic process with Fusarium oxysporum f. sp. cubense Ｒace 4.