霜霉菌或水分胁迫诱导的黄瓜叶片胞间隙27kD蛋白为几丁质酶  

Intercellular 27 kD Protein Is a Chitinase Induced by Water Stress or Pseudoperonospora cubensis in Cucumber Leaves

作　　者：陈鹏[1] 李玉红[2] 程智慧[2] 陈涛[3] 

机构地区：[1]西北农林科技大学 生命科学学院,陕西杨凌712100 [2]西北农林科技大学 园艺学院,陕西杨凌712100 [3]西北农林科技大学 资环学院,陕西杨凌712100

出　　处：《植物生理与分子生物学学报》2007年第6期581-588,共8页Journal Of Plant Physiology and Molecular Biology

基　　金：西北农林科技大学青年学术骨干支持计划项目;国家自然科学基金(No.30400282)资助。

摘　　要：蛋白含量测定和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析结果表明,水分胁迫或霜霉菌接种处理均使黄瓜(Cucumis sativus L.)叶片胞间隙总蛋白含量升高,27kD蛋白积累。通过基体辅助激光解析电离飞行时间质谱(MALDI-TOF MS)分析纯化的27 kD蛋白,将所得的PMF(肽指纹图谱)在NCBInr蛋白质数据库中比对,发现水分胁迫和霜霉菌接种所诱导的27kD蛋白是同一种蛋白,均为一种酸性的几丁质酶。其酶活性测定结果表明,水分胁迫或霜霉菌接种处理的叶片胞间隙液几丁质酶活性均高于对照。Cucumber seedlings were droughtstressed or inoculated with Pseudoperonospora cubensis. After 3 or 6 d the intercellular fluids of treated cucumber leaves were extracted and analyzed. Protein contents increased after pathogen inoculation and a 27-kD protein was found in intercellular fluids （Figs. 1, 7）. Both 27 kD proteins were purified from the intercellular fluids of cucumber leaves after drought stress or pathogen inoculation by SDS-PAGE and electro-elution protocol respectively （Figs.2, 3）. Purified proteins from drought-stressed and P. cubensis infected seedlings were analyzed by MALDI-TOF MS and their peptide mass fingerprinting （PMF） results were obtained （Figs.4, 5）. The PMF results were compared with protein database using the software Profound. The results show that the 27 kD proteins from seedlings after drought stress and after P. cubensis infection were the same protein, i.e. an acidic chitinase （Tables 1, 2; Fig.6）. The activities of chitinase in the intercellular fluids of cucumber leaves after pathogen inoculation and in those drought stress were also analyzed. Results showed that both treatments induced the increase in chitinase activity （Fig.8）, which indicated that chitinase may be involved in the protection of cucumber plant against both pathogen attack and water stress.

关 键 词：黄瓜 霜霉菌 水分胁迫 基体辅助激光解析 电离飞行时间质谱 几丁质酶 

分 类 号：S436.421[农业科学—农业昆虫与害虫防治]