Issue Archive

Purification and properties of #beta#-galactosidase from intercellular fluidof tomato leaves

Shi Yimin, Yan Jiqiong, Fei Xuenan, Xu Yuquan

Department of Plant Science, Shanghai Agricultural College.Shanghai；China(200062)

Abstract

High #beta#-galactosidase activity was found in the apoplastic spaces oftomato(Lycopersicon esculentum)leaves whether the plant was healthy orsystemically infected by TMV. The enzyme was purified from intercellular fluidof tomato leaves systemically in fected with TMV by -20℃ acetoneprecipitation and ion exchange chromatography on CM-Sephadex C-25, onDEAE-Sephadex A-25 and on Sephadex G-150, successively to homogeneity. Itsmolecular weight was determined by SDS PAGE, it was identified as aglycoprotein. The enzyme activity had an optimal pH of 4.0~4.4 and an optimaltemperature between 50~55℃, it was stable between pH 3.4~6.4. The K_(m) ofthe enzyme was 0.71 mmol/L and V_(max) was 6.1 #mu#mol mg~(-1) proteinmin~(-1). It was one of the predominant proteins in the intercellularfluid of tomato leaves systemically infected by TMV.

Key words: Tomato;apoplast protein;#beta#-palactosidase;Tobacco mosaic virus

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Shi Yimin, Yan Jiqiong, Fei Xuenan, Xu Yuquan. Purification and properties of #beta#-galactosidase from intercellular fluidof tomato leaves. Acta Physiol Sin 1994; 46 (2): (in Chinese with English abstract).