基于LC-MS技术的代谢组学方法研究根肿菌对拟南芥代谢的影响

Metabolic changes of Arabidopsis thalianainfected with Plasmodiophora brassicae based on LC-MS analysis

为探寻根肿菌侵染拟南芥后期寄主代谢的生物标志物,将罹患根肿病的油菜根切块进行组织培养,获得较为纯化的、单一的根肿菌接种体,与拟南芥种子在1/2MS培养基上共培养,利用液相色谱-质谱联用(LCMS)技术的非靶向代谢组学方法分析根肿菌侵染后期拟南芥根部代谢物差异。组织培养结果表明,根肿菌可以在愈伤组织中生长和繁殖;共培养结果显示45d后拟南芥侧根尖端肿大,显微观察显示根肿菌能完成侵染循环;代谢组数据PCA和PLS-DA分析结果显示试验组(接种根肿菌)和对照组(未接种根肿菌)明显分离;OPLSDA分析和t检验结果表明重要的差异代谢物包括油菜素内酯、类黄酮、木质素、萜类、甾体皂苷和磷脂等物质。提示这些物质可能在根肿菌侵染后期时拟南芥与根肿菌的相互作用中起重要作用。

The aim of the present study was to find some important metabolic biomarkers of Arabi dopsisthalianaroots infected with Plasmodiophora brassicae at the late infection stage.P.brassicae spores were extracted from callus cultures of clubroot gall sections,co-cultured with A.thaliana seeds on 1/2 MS medium and then after 45 dmetabolic changes of the A.thalianaroots were analyzed by liquid chromatography-mass spectrometry(LC-MS)technique.The results showed that P.brassicae could grow and develop in callus,and after co-cultured with A.thaliana for 45 d,microscopic observation showed that the pathogens had a complete life cycle on the medium.Multivariate statistical methods of PCA and PLS-DA suggested that the metabolities of experimental group(inoculated with P.brassicae)and control group(uninoculated with P.brassicae)differentially expressed.The results of OPLSDA and t-test showed that the metabolites of flavonoids,lignans,terpenoids,steroidal glycosides,brassinosteroids and phospholipids were significantly increased during P.brassicae infection,suggesting their potential important roles in interaction between A.thaliana and P.brassicae at the late stage of infection.