Reduction of protease inhibitor activity by expression of a mutant Bowman-Birk gene in soybean seed.
A mutant Bowman-Birk gene was created that encoded an inactive high-sulfur product. It was used to transform soybean line Asgrow 3237. Transformants bearing the mutant gene were identified by GUS expression, PCR analysis, and Southern analysis. The amount of steady state mRNA from the mutant gene in the transformed plants showed that the gene was highly expressed, but the amount of message from the unmodified Bowman-Birk gene did not change detectably. Proteins synthesized at the direction of the mutant Bowman-Birk gene accumulated in seeds of the transformed plants, and there was a marked decrease in the ability of extracts prepared from these seeds to inhibit trypsin and chymotrypsin despite the presence of Kunitz trypsin inhibitor. The more prevalent mRNA from the mutant gene was considered to out-compete message from the native genes to decrease the amount of active Bowman-Birk inhibitor.
Livingstone
Donald
D
Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA.
Beilinson
Vadim
V
Kalyaeva
Marina
M
Schmidt
Monica A
MA
Herman
Eliot M
EM
Nielsen
Niels C
NC
D000595:Amino Acid Sequence; D001483:Base Sequence; D008969:Molecular Sequence Data; D009154:Mutation; D012333:RNA, Messenger / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013025:Glycine max / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000235:genetics / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean