镰刀菌酸在尖孢镰刀菌侵染过程中的产生规律及运输过程探究  

Study on the production and transportation of Fusaric acid during Fusarium oxy-sporum infection

作　　者：王瑞瑞 王敏 曾吉兴 朱林星 郭世伟 WANG Ruirui;WANG Min;ZENG Jixing;ZHU Linxing;GUO Shiwei(College of Resources and Environmental Sciences,Nanjing Agricultural University,Jiangsu Provincial Key Lab for Solid Organic Waste Utilization,Nanjing 210095,China)

机构地区：[1]南京农业大学资源与环境科学学院/江苏省固体有机废弃物资源化高技术研究重点实验室,南京210095

出　　处：《植物病理学报》2022年第3期465-475,共11页Acta Phytopathologica Sinica

基　　金：国家自然科学基金(32072673)。

摘　　要：镰刀菌酸(FSA)是尖孢镰刀菌产生的主要毒素之一,对病害的发展起到主导作用,但是其产生及运输机制尚不清楚,明确镰刀菌酸在寄主体内的产生过程及运输方式对防控作物枯萎病的发生具有重要的理论意义。本研究以黄瓜品种津春4号和尖孢镰刀菌黄瓜专化型菌(Fusarium oxysporum f.sp.cucumerinum)为试材,进行温室营养液培养试验,对不同侵染时期植株体内的病原菌及镰刀菌酸进行定量分析,结合韧皮部烫伤及分根根盒装置,探究镰刀菌酸的运输及分配机制。结果表明,病原菌的侵染首先从根尖或者侧根原基侵入根系,随后侵入维管组织并局限在木质部导管中,快速大量繁殖并开始产生毒素镰刀菌酸,镰刀菌酸主要通过木质部运输到叶片,发病期(11 dpi)叶片中镰刀菌酸含量是根系中镰刀菌酸含量的10倍。病原菌主要借助镰刀菌酸加速植物萎蔫死亡,并且镰刀菌酸含量与病原菌数量的相关性关系呈显著正相关。本研究进一步明确了病原菌侵染与镰刀菌酸产生的关系,病原菌在根系定殖成功后快速繁殖进入潜育期,随后产生毒素镰刀菌酸,并通过木质部运往地上部,促进叶片萎蔫,加速病原菌进入腐生阶段。在实际生产中我们可以在病害发生前期,未产生大量镰刀菌酸之前加强田间管理,以抑制或减轻枯萎病的发生。Fusaric acid(FSA),the fungal toxin produced by Fusarium oxysporum,plays a predominant role in the virulence and symptom development of Fusarium wilt disease,but its production and transport mechanism are not clear.In this study,F.oxysporum f.sp.cucumerinum was observed to invade the root system from the root tip or lateral root primordium,and then penetrated the vascular tissue.The fusaric acid began to produce when the mycelia rapidly multiplied.We quantitively evaluated the Fusarium pathogen and fusaric acid in cucumber cultivar Jinchun 4 under hydroponic condition during infection.The fusaric acid was mainly transported to the leaves through the xylem.The content of fusaric acid in the leaves at the 11 dpi was 10 times as that in the roots.The occurrence of wilt was mainly accelerated by fusaric acid and the content of fusaric acid had a significant positive correlation with the number of F.oxysporum.This study further clarified the relationship between pathogen infection and the production of fusaric acid.After successful root colonization,F.oxysporum rapidly propagates into the incubation period,and then produced fusaric acid,which was transported to the aboveground through the xylem,promoting leaf wilting and accelerating the occurrence of diseased symptoms.In agricultural production,we can strengthen the field management in the early stage of disease occurrence,before the production of a large number of fusaric acid,in order to restrain or reduce the occurrence of Fusarium wilt.

关 键 词：尖孢镰刀菌 黄瓜 镰刀菌酸 产生规律 运输过程 

分 类 号：S432.44[农业科学—植物病理学]