苹果壳囊孢Cytospora mali分泌蛋白组学分析

Secretome analysis of apple canker pathogen Cytospora mali

野苹果腐烂病是一种严重的苹果病害,主要由苹果壳囊孢Cytospora mali(EGI-1)引起。本研究在全基因组水平进行预测并且与胞外分泌蛋白组分析相结合,对Cytosporamali分泌蛋白进行定量和定性分析。信号肽预测结果显示,共有956个蛋白具有分泌信号肽,信号肽平均长度为26 bp。LC-MS质谱组学分析结果显示在苹果枝条、叶片以及PDA培养基中分别检测到1789、2199和439个蛋白,其中141个分泌蛋白在所有样品中均有分布。GO分析结果显示,枝条、叶片以及PDA培养基中代谢过程和细胞过程相关的蛋白富集数量最多。此外,共同存在的141个分泌蛋白中24个具有信号肽,其中12个蛋白具有碳水化合物酶类(carbohydrate active-enzymes,CAZymes)功能区域。通过酵母分泌性实验,我们验证了5个候选分泌蛋白均可外泌。本研究利用生物信息学、LC-MS质谱以及酵母分泌性实验,初步建立了从新疆野苹果中分离鉴定的Cytosporamali(EGI-1)分泌蛋白数据库,为解析新疆野苹果树腐烂病菌致病分子机理提供基础。

Apple canker is a severe disease mainly caused by Cytospora mali(EGI-1).In this study,a quantitative and qualitative analysis of the secreted proteins of Cytospora mali was conducted through a combination of whole-genome prediction and extracellular secretome analysis.The signal peptide prediction results indicate that 956 proteins possess secretory signal peptides,with an average signal peptide length of 26 bp.The LC-MS analysis revealed the presence of 1789,2199,and 439 proteins in apple twigs,leaves,and PDA medium,respectively,with 141 secreted proteins common to all three samples.The results of GO analysis showed that the number of proteins related to metabolic processes and cellular processes in branches,leaves and PDA medium was maximum.Furthermore,among the 141 common proteins,24 possessed signal peptides,and 12 had functional domains of CAZymes(carbohydrate-active enzymes).Yeast secretion experiments confirmed the extracellular secretion of five candidate secreted proteins.Using bioinformatics,LC-MS analysis and yeast secretion experiments,a database of Cytospora mali(EGI-1)secreted proteins isolated and identified from Xinjiang wild apple Malus sieversii was preliminarily established.This study provides the basis for further investigation of molecular mechanism of apple canker pathogens.