Vegetative Storage Protein with Trypsin Inhibitor Activity Occurs in Sapindus mukorassi,a Sapindaceae Deciduous Tree

作     者：Shi-Biao Liu Xu-Chu Wang Min-Jing Shi Yue-Yi Chen Zheng-Hai Hu Wei-Min Tian 

作者机构：Institute of Ecology Jishou University Jishou 416000 China Key Laboratory of Rubber Biology Rubber Research Institute Chinese Academy of Tropical Agricultural Sciences Danzhou 571737 China Institute of Botany Northwest University Xi'an 710069 China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2009年第51卷第4期

页      面：352-359页

核心收录：

学科分类：0710[理学-生物学] 0832[工学-食品科学与工程（可授工学、农学学位）] 071010[理学-生物化学与分子生物学] 07[理学] 08[工学] 083202[工学-粮食、油脂及植物蛋白工程] 

基　　金：Supported by the National Natural Science Foundation of China(No.30460107) 

主　　题：annual growth cycle Chinese soapberry immuno-localization seasonal nitrogen storage trypsin inhibitor. 

摘      要：A vegetative storage protein （VSP） with trypsin inhibitor activity in a deciduous tree, Sapindus mukorassi, was characterized by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western-blot, immuno-histochemical localization, light- and electro-microscopy, together with analysis of proteinase inhibitor activity of the purified VSP in vitro. There were two proteins with molecular masses of about 23 and 27 kDa in a relatively high content in the bark tissues of terminal branches of S. mukorassi in leafless periods. The proteins decreased markedly during young shoot development, indicating their role in seasonal nitrogen storage. Immuno-histochemical localization with the polyclonal antibodies raised against the 23 kDa protein demonstrated that the 23 kDa protein was the major component of protein inclusions in protein-storing cells. The protein inclusions were identified by protein-specific staining and should correspond to the electron-dense materials in different forms in the vacuoles of phloem parenchyma cells and phloem ray parenchyma cells under an electron microscope. So, the 23 kDa protein was a typical VSP in S. mukorassi. The 23 and 27 kDa proteins shared no immuno-relatedness, whereas the 23 kDa protein was immuno-related with the 22 kDa VSP in lychee and possessed trypsin inhibitor activity. The 23 kDa protein may confer dual functions： nitrogen storage and defense.