Department of Biochemistry, Faculty of Science, Banams Hindu University, Varanasi-221005
Seedlings of salt susceptible rice, cvs. Jaya and Cauvery were raised under increasing levels of NaCl salinity. Increase in salinity caused decrease in seedling vigour, i.e. length and weight of root and shoot decreased with salinity. Acid phosphatase activity was always more in root than in shoot. Acid and alkaline phosphatase activity increased during early period of growth, maximum being at 10 days and decreased thereafter. Low salinity level caused increase in acid phosphatase activity while the activity decreased at higher salinity. Unlike acid phosphatase, alkaline phosphatase activity enhanced under moderate to high salinity. Under similar treatment levels, acid phosphatase was 10-15 times more active than alkaline phosphatase. Isoenzyme profiles of acid phosphatase revealed that salt tolerant varieties are characterised by the presence of 5 bands whereas susceptible varieties by 4 bands in 15 day old shoot. Increased salinity caused disappearance of 4 bands in tolerant cultivar and 3 in susceptible one. Only one band corresponding to acid phosphatase activity could be detected in shoot under 14 mmhos/cm of salinity.
