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 

机构地区：[1]Institute of Ecology, Jishou University, Jishou 416000, China [2]Key Laboratory of Rubber Biology, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou 571737, China [3]Institute of Botany, Northwest University, Xi'an 710069, China

出　　处：《Journal of Integrative Plant Biology》2009年第4期352-359,共8页植物学报（英文版）

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

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.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.

关 键 词：annual growth cycle Chinese soapberry IMMUNO-LOCALIZATION seasonal nitrogen storage trypsin inhibitor. 

分 类 号：Q942.6[生物学—植物学] TS214.2[轻工技术与工程—粮食、油脂及植物蛋白工程]