Drought-stress-induced polypeptide accumulation in tomato leaves

Abstract. Tomato ( Lycopersicon esculentum Mill ev. Ailsa Craig) leaf polypeptides, radiolabelled with L-[³⁶S] methionine during drought stress, were separated by two-dimensional polyacrylamide gel electrophoresis. Three sets of polypeptides were distinguished: those that decreased, increased or transiently increased in response to drought stress. Three sets of polypeptides also could be distinguished during recovery from drought stress: those that increased, decreased rapidly or decreased slowly and could still be detected after 6 h of recovery. The set of polypeptides that decreased during drought stress was the same set that increased during recovery and those that increased during stress, decreased during recovery. The leaf ABA concentration increased rapidly in response to drought stress and decreased rapidly during recovery from drought stress, returning to the nonstress level after 6 h of rehydration. There was a correlation between the accumulation of some of the drought-induced polypeptides and the pattern of ABA accumulation during stress and recovery from stress.