Effect of complete submergence on the activity of starch phosphorylase enzyme in rice (Oryza sativa L.) leaves

Abstract

Activity of starch phosphorylase enzyme and its isozymes were studied in one-week and two-week-old seedlings of four cultivars of rice, viz. FR13A, Gangasiuli (submergence tolerant), Sarala and IR42 (submergence susceptible) under submerged as well as control conditions. In one-week-old seedlings there was no apparent increase in enzyme activity, whereas in the two-week-old seedlings the activity rose steadily and reached to a maximum after 144 h of submergence and then declined. The increase in activity was also reflected in the isozyme profiles of this enzyme wherein both qualitative as well as quantitative (suppression and over-expression of certain bands) differences were observed. It was concluded that, in addition to other enzymes of starch degradation, starch phosphorylase too may be involved in starch degradation during submergence stress in rice plants