玉米大斑病菌铁载体合成基因簇鉴定及表达分析  

Identification and Expression Analysis of Siderophore Synthetic Gene Cluster of Setosphaeria turcica

作　　者：岳浩峰 赵天益 李海笑 闫秋静 徐雅迪 孟亚南 曹志艳[2,3] 刘宁 董金皋[2,3] YUE Hao-Feng;ZHAO Tian-Yi;LI Hai-Xiao;YAN Qiu-Jing;XU Ya-Di;MENG Ya-Nan;CAO Zhi-Yan;LIU Ning;DONG Jin-Gao(School of Life Sciences,Hebei Agricultural University,Baoding 071001,China;College of Plant Protection,Hebei Agricultural University,Baoding 071001,China;State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology,Baoding 071000,China)

机构地区：[1]河北农业大学生命科学学院,保定071001 [2]河北农业大学植物保护学院,保定071001 [3]华北作物改良与调控国家重点实验室/河北省植物生理与分子病理学重点实验室,保定071000

出　　处：《农业生物技术学报》2024年第5期1121-1131,共11页Journal of Agricultural Biotechnology

基　　金：国家现代农业产业技术体系(CARS-02);国家自然科学基金(32072370;31901827);河北省自然科学基金(C2020204183);中央引导地方科技发展资金(226Z6502G)。

摘　　要：铁是微生物生长必需的元素,在氧代谢、电子转移以及DNA和RNA合成等过程中发挥重要作用,微生物主要依赖于铁载体吸收环境中的铁离子。铁载体作为微生物分泌的低分子量铁螯合物,协助机体运输铁离子。真菌主要利用非核糖体多肽合成酶编码基因为核心的次级代谢物生物合成基因簇合成铁载体,本研究旨在明确玉米大斑病菌(Setosphaeria turcica)铁载体的合成基因簇以及关键基因的表达。利用铬天青(chrome azurol sulphonate,CAS)鉴定玉米大斑病菌合成铁载体的类型并利用AntiSMASH网站预测其生物合成基因簇,利用玉米大斑病菌孢子不同发育时期的转录组数据及qRT-PCR分析病菌侵染过程中铁载体合成基因簇中各关键基因的表达水平以及外源铁浓度对基因表达的影响。结果表明,玉米大斑病菌产生异羟肟酸盐型铁载体,在基因组中鉴定得到1个产生异羟肟酸盐铁载体的次级代谢物生物合成基因簇,由非核糖体多肽合成酶(nonribosomal peptide synthetase,NRPS)编码基因StNPS6为核心的12个铁载体合成相关基因组成。在玉米大斑病菌孢子萌发和侵染玉米叶片的过程中,基因簇中多个基因表达显著上调。与菌丝时期相比,侵染6 d后StNPS6表达量上调5.52倍,侵染9 d时后辅助合成基因StrhbE表达量上调24.12倍,编码转运相关蛋白的基因Stpmd1上调19.95倍。同时发现富铁和贫铁均对病菌的生长具有一定的抑制作用,且富铁情况下病菌黑色素合成受阻,培养基中铁含量差异导致基因簇中多个基因表达量显著变化,尤其是转运相关蛋白基因Stpmd1在富铁条件下表达量上升73.28倍。本研究为解析玉米大斑病菌铁载体的潜在作用提供了参考。Iron is an essential element for microbial growth and plays a crucial role in processes such as oxygen metabolism,electron transfer,DNA and RNA synthesis.Microbes primarily rely on siderophores to absorb iron ions from their environment.Siderophores,as low molecular weight iron chelators secreted by microbes,assist in transporting iron ions within the organism.Fungi primarily use non-ribosomal peptide synthetase-encoded genes as the core of secondary metabolic biosynthetic gene clusters to synthesize siderophores.This study aimed to clarify the siderophore function and biosynthetic process of Setosphaeria turcica.The type of siderophores synthesized by S.turcica was identified using CAS(chrome azurol sulphonate),and its biosynthetic gene cluster was predicted using the AntiSMASH website.Transcriptional data from different developmental stages of S.turcica spores and qRT-PCR analysis of the expression levels of key genes in the siderophore biosynthetic gene cluster during pathogen infection were utilized.The results showed that S.turcica produces hydroxamate-type siderophores.One biosynthetic gene cluster responsible for hydroxamate-type siderophore production was identified in the genome.This cluster consisted of 12 genes with the core gene StNPS6 encoding non-ribosomal peptide synthetase.During spore germination and infection process of S.turcica,several genes in the cluster exhibited significant upregulation.The core gene StNPS6 had an expression level 5.52 times higher at 6 d post-infection compared to the early infection stage,and the auxiliary biosynthesis gene StrhbE showed a 24.12-fold increase in expression at 9 d post-infection.Additionally,the transport-related gene Stpmd1 increased significantly by 19.95-fold at 9 d post-infection.At the same time,it was observed that both iron-rich and iron-deficient conditions had a certain inhibitory effect on the growth of the pathogen.Moreover,under iron-rich conditions,melanin synthesis in the pathogen was hindered.The differences in iron content in the medium le

关 键 词：玉米大斑病菌 铁载体 次级代谢产物生物合成基因簇 基因表达 

分 类 号：S435.131.4[农业科学—农业昆虫与害虫防治]