Physiological basis of submergence tolerance in rice genotypes with reference to carbohydrate metabolism

Abstract

Rice genotypes viz., Swarna Sub1A, FR13A and Swarna were evaluated for their carbohydrate profiles on seven days of submergence. Swarna Sub1A showed minimum increase in proline content than FR13A and Swarna. The depletion of total carbohydrate in roots was recorded having maximum and minimum depletion in Swarna and FR13A respectively. In shoots the depletion was maximum in Swarna Sub1A and minimum in Swarna. Depletion of starch under submergence was maximum in Swarna Sub1A and minimum in Swarna. Sucrose was maximally consumed in Swarna Sub1A and minimally in Swarna in shoots. Invertase activity was increased in roots in Swarna and FR13A but it declined in Swarna Sub1A. In shoots, the activity got declined in Swarna and FR13A and increased in Swarna Sub1A. SPS activity in shoots was down regulated under submergence with maximum and minimum values in FR13A and Swarna respectively. Amylase activity was significantly upregulated in other two varieties but got declined in Swarna Sub1A. Cellulose in root and shoot was accumulated maximally and minimally in Swarna and FR13A respectively. Hemicellulose was accumulated with maximum and minimum values in Swarna Sub1A and in FR13A respectively in roots whereas it was maximum in Swarna Sub1A and minimum in Swarna in shoots. Abbreviations FW, Fresh weight; DW, Dry weight; DNSA, 3,5 Dinitrosalicylic acid; DTT, Dithiothreitol; MOPS, 3-(N-morpholino) propanesulfonic acid; ATP, Adenosine triphosphate; GA, Gibberellic acid; ABA, Abscissic acid; ROS, Reactive Oxygen Species; SPS, Sucrose Phosphate Synthase.