禾谷镰孢菌bZIP转录因子FgMetR的生物学功能  

Biological functions of the bZIP transcription factor FgMetR in Fusarium graminearum

作　　者：马浩 张丽敏 赵彦翔 黄金光 MA Hao;ZHANG Limin;ZHAO Yanxiang;HUANG Jinguang(College of Plant Health and Medicine,Qingdao Agricultural University,Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management,Qingdao 266109,Shandong,China)

机构地区：[1]青岛农业大学植物医学学院,山东省高校植物病虫害绿色防控工程研究中心,山东青岛266109

出　　处：《菌物学报》2025年第4期29-43,共15页Mycosystema

基　　金：国家重点研发计划(2023YFD2303200,2022YFD1400104);山东省自然科学基金(ZR2022QC152)。

摘　　要：由禾谷镰孢菌Fusarium graminearum引起的小麦赤霉病是小麦最主要的真菌病害之一,对小麦的产量和食用安全均造成了巨大的威胁。bZIP转录因子是硫同化的核心正调控因子,能够影响病原菌的无性生殖及对植物寄主的致病力。为全面揭示bZIP转录因子在禾谷镰孢菌中的生物学功能,本研究鉴定了禾谷镰孢菌中的同源蛋白FgMetR,并获得禾谷镰孢菌的FgMetR敲除突变体ΔFgMetR,对其进行生物学表型测定,结果表明:ΔFgMetR在PDA上呈透明状,菌丝稀疏分散,很少产生气生菌丝,在PDB培养基中不形成红色素;菌落径向生长速率、菌丝高度、分生孢子产量与野生型菌株存在显著差异;在不含任何硫元素的基础培养基中添加有机态硫能够部分恢复FgMetR缺失导致的生长缺陷表型;在有性生殖时期不能形成子囊壳及子囊孢子;对小麦穗和小麦胚芽鞘的致病力显著降低;相比野生型和互补体菌株,对戊唑醇和咪鲜胺更加敏感。综上所述,bZIP转录因子FgMetR是禾谷镰孢菌营养生长、色素沉着、无性和有性生殖、致病力所必需的,并参与调节禾谷镰孢菌硫同化和对唑类杀菌剂的敏感性。Fusarium head blight(FHB)caused by Fusarium graminearum is one of the most important fungal diseases of wheat,posing a serious threat to wheat production and food safety.bZIP transcription factors are core positive regulators of sulfur assimilation and involved in the regulation of fungal asexual reproduction and pathogenicity.In order to further reveal the biological function of the bZIP transcription factors in F.graminearum,in this study,the authors identified a bZIP transcription factor FgMetR in F.graminearum and obtained the deletion mutant ΔFgMetR.The effect of FgMetR deletion on various phenotype was evaluated.The results showed that the colony of ΔFgMetR appeared transparent on PDA plates and the mycelia were sparsely dispersed with few aerial hyphae.No red pigment was observed either on PDA plates or in PDB broth.The radial growth rate of colonies,mycelial height,and conidial production ofΔFgMetR were significantly reduced as compared with those of the wild-type strain.The growth defect phenotype ofΔFgMetR on minimal medium without any sulfur element can be partially restored by supplementing organic but not inorganic sulfur sources.ΔFgMetR mutant failed to form perithecia and ascospores on carrot culture medium.Deletion of FgMetR significantly reduced the pathogenicity of F.graminearum invading both wheat coleoptiles and heads.In addition,ΔFgMetR mutant was more sensitive to tebuconazole and prochloraz.The facts prove that bZIP transcription factor FgMetR is essential for the vegetative growth,pigmentation,asexual and sexual reproduction,pathogenicity and involvement in the regulation of sulfur assimilation and sensitivity to azole fungicides of F.graminearum.

关 键 词：赤霉病 转录调控 硫同化 致病力 唑类杀菌剂 

分 类 号：S435.121[农业科学—农业昆虫与害虫防治]