Effects of drought on soluble protein content and protective enzyme system in cotton leaves

Abstract

The effects of soil drought on soluble protein content and protective enzyme system of cotton leaves at different positions were studied in the transgenic cotton cultivar, Lumianyan28. The results indicated that the soluble protein content in main stem leaves and in middle-fruit branch leaves under drought treatment were higher than that of CK, the normal soil water management treatment. Lower fruit branch leaves under drought treatment had higher protein and enzyme levels than CK treatments. From June 25 to July 22, the activity of superoxide dismutase (SOD) in main stem leaves under drought treatment was lower than that of CK. Other time periods had varying results. The peroxidase (POD) activity in main stem leaves and in fruit branch leaves was lower at early stage and then higher at late stage, showing a trend of descending first, and then ascending obviously under the drought condition. The catalase (CAT) activity showed an increase-decrease trend, higher in main stem leaves under drought treatment than that of CK. However, it was opposite in the lower fruit branch leaves, and there were no significant differences between the two CAT treatments in the middle branch leaves. It is suggested that the soluble protein and cellular protection enzymes, such as superoxide dismutase, peroxidase activity, and catalase in main stem leaves and fruit branching leaves play important physiological functions in the early growth stage under drought stress.

Keywords

drought / cotton / soluble protein / protective enzyme system