Characterization of trypsin and chymotrypsin inhibitors in the wild perennial Glycine species

Eleven wild perennial species were used for characterizing the seed protease inhibitors in the genus Glycine Wilid. subgenus Glycine to determine the presence and examine the variability and expression patterns. Seeds of all the species contained trypsin and chymotrypsin inhibitors. There were highly significant variations among the wild perennial species in the electrophoretic profiles of trypsin and chymotrypsin inhibitors, migration patterns of anti-KTI and anti-BBI (mAB 238) immunocrossreactive proteins, and trypsin and chymotrypsin inhibitor activities of seeds. These variations were greater in A genome species than those B or C genome species. Seeds of the B genome species had the lowest trypsin and chymotrypsin inhibitor activities. Most of the trypsin inhibitors found in the wild perennial species had a weaker chymotrypsin inhibitor activity. All of the wild perennial species also contained DNA sequences that crosshybridized to the soybean BBI cDNA (pB38) and produced transcripts that were of the same size as but less abundant than those of soybean. The pattern of developmental expression of these transcripts in Glycine clandestina was the same as that found in the soybean seed. Variations in the trypsin and chymotrypsin inhibitor banding patterns are useful in the genetic studies of the protease inhibitors and biosystematic studies in the genus Glycine