Genetic, biochemical, and molecular studies of the Bowman-Birk inhibitors in the genus Glycine Willd

Crosses were made between soybean accessions with reduced Bowman-Birk inhibitor (BBI) content and cvs. Kunitz and Williams 82. The BBI (chymotrypsin inhibitor activity) inherited as a quantitative/multigenic trait with 18-34% of the F\sb2 progeny exceeding the high parent (cv. Kunitz) in their activity suggesting a transgressive nature of inheritance. A "new" electrophoretic band with trypsin and chymotrypsin inhibitor activities segregated in a 3:1 ratio for the presence and absence. No linkage was observed between the Ti allele (the KTI) and the BBI activity or the new isoinhibitor band.The genes encoding BBI are transcriptionally activated early in embryo development and then repressed towards the late-maturation stage in soybean seed. A unique 1.4 kb EcoRI restriction fragment was found in all the soybean low-BBI accessions instead of a 1.8 kb fragment in cvs. Kunitz and Williams 82.A total of 568 accessions from 12 wild perennial species of the genus Glycine was screened for the presence or absence of immunocrossreactive proteins to a monoclonal antibody against soybean BBI (mAB 238) using a competitive ELISA method. Wild perennial Glycine species with A, E, and F genomes contained proteins that were crossreactive to mAB 238. By contrast, the B and C genome species did not contain mAB 238 crossreactive proteins (BBI-nulls). The presence or absence of mAB 238 crossreactive proteins can be used as a marker in the genome analysis of Glycine species.All the wild perennial Glycine 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 immunocrossreactive proteins, and trypsin and chymotrypsin inhibitor activities of seeds. All the wild perennial species also contained DNA sequences that crosshybridized to the soybean BBI cDNA and produced transcripts that were of same size as but less abundant than those of soybean.Total seed protein profiles, trypsin and chymotrypsin inhibitor migration patterns, and anti-KTI, anti-BBI and anti-soybean seed lectin immunocrossreactive protein profiles confirmed the presence of three distinct genomic groups (T\sb1, T\sb5, and T\sb6) in 78-chromosome G. tomentella accessions. Phylogenetic analysis of restriction fragment length polymorphism data using a maximum parsimony method also supported such grouping.U of I OnlyETDs are only available to UIUC Users without author permissio