蛹虫草原基分化的差异蛋白质组学研究

蛹虫草子实体形成及发育的蛋白分子机制尚不清楚,本研究引入SWATH非标记定量蛋白质组学技术,对蛹虫草Cordyceps militaris 905菌株的菌丝体（mycelium,My）、原基（primordium,Po）、生长期子实体（developmental fruiting body,DF）和成熟期子实体（mature fruiting body,MF）进行了比较蛋白质组学分析。经搜库比对,从蛹虫草的My、Po、DF和MF中依次鉴定蛋白1 136个、1 090个、1 018个和997个（global FDR 1%）,经维恩分析后获得C. militaris 905蛹虫草表达蛋白1 578个。在此基础上,SWATH非标记技术定量蛋白1 109个。本研究获得了蛹虫草Po期与My期、DF期与Po期、MF期与DF期的差异表达蛋白,依次为115个、352个和104个,并对菌丝体分化形成原基的差异表达蛋白进行了重点解析。GO注释结果表明,Po期与My期差异表达蛋白以有机含氮类化合物代谢为主,其中AMP（活性成分虫草素合成的中间产物）从头生物合成途径富集最为显著。约1/5的差异表达蛋白参与氧化还原反应,还原酶活性的蛋白在原基中几乎都上调表达,而氧化功能的蛋白受到抑制,表明蛹虫草原基分化可能受到氧化应激的诱导。蛋白互作网络分析结果进一步表明,氧化还原反应与核苷类物质代谢相关联,可能通过影响AMP从头生物合成途径来调控虫草素的生物合成。对蛹虫草子实体系统的蛋白质组学研究和解析有利于揭示子实体形成的蛋白分子机制,为蛹虫草的基础和栽培研究提供了理论支撑。

Differential proteomic analysis of Cordyceps militaris in association with primordium differentiation

The protein molecular mechanism of fruiting body formation and development of Cordyceps militaris is still unclear. SWATH MS ^ALL label-free quantitative proteomic technology was introduced to analyse the proteomics of mycelium (My), primordium (Po), developmental fruiting body (DF) and mature fruiting body (MF) of C. militaris 905. Respectively, 1 136, 1 090, 1 018 and 997 expressed proteins (global FDR 1%) were obtained. In total, 1 578 proteins were identified by Venn analysis and 1 109 proteins were quantified by SWATH. In addition, 115, 352 and 104 differentially expressed proteins (DEPs) were respectively obtained between Po and My, DF and Po, and MF and DF. Mechanism of primordium formation from mycelium differentiation was dissected based on bioinformatics’ analysis results. GO analytic results showed that most of DEPs involved in organonitrogen compound metabolic process, and the enrichment factor of de novo AMP biosynthetic process was the highest where AMP was the important intermediate products for cordycepin biosynthesis in C. militaris. More importantly, nearly one fifth of DEPs between Po vs. My took part in oxidation-reduction process, and DEPs with reductase activity expressed up while ones with oxidase activity down-regulated in Po. The results indicated that primordia might be induced by oxidative stress. The results of protein-protein interaction analysis further showed that nucleoside metabolism was associated with redox reaction, and cordycepin biosynthesis might be regulated via de novo AMP biosynthesis pathway. This study provides new insights into the formation mechanism of fruiting body and may be useful to strengthen the knowledge of C. militaris.