Trypsin inhibitors inPisum: variation in amount and pattern of accumulation in developing seed

Abstract

AbstractA survey ofPisumgenotypes for seed trypsin inhibitors revealed a tenfold range in the extent of inhibition. Approximately 90% of trypsin inhibitory activity was associated with two albumin fractions in selected variant lines. The differences among extreme variants were consistent in three environments, between two sources of trypsin tested and whether expressed on a unit protein or dry weight basis.A study of the appearance of trypsin inhibitors during seed development in selected highand low-inhibitor lines showed differences in the accumulation pattern of active inhibitors. An endogenous protease was identified inPisumseed protein preparations, whosein vitrotrypsin-like activity was predominant in protein from early stages of seed development, when little or no trypsin inhibitor was present. However, there was no correlation between the amount of this protease and the extent of trypsin inhibitory activity in lines that varied for inhibitor content.