Wheat seed germination based on alpha-amylase activity to study promoting mechanism of Bacillus subtilis QM3

The mechanism of promoting wheat seed germination by Bacillus subtilis has been paid great attention by many scholars. The germination rate and alpha-amylase activity of wheat seeds were significantly increased after germinating with Bacillus subtilis QM3 in this paper. Inhibitor and promoter of alpha-amylase were used to study relationship between bacteria and alpha-amylase. Compared with inhibitor group (10 mmol.L-1 EDTA), alpha-amylase activity of seeds treated by B. subtilis QM3 (106 CFU.mL-1) increased by 19.8%. It indicates that the inhibition has been alleviated. Similarly, alpha-amylase activity of co-treated group (2 mmol.L-1 CaCl2 and 106 CFU.mL-1 B. subtilis QM3) was higher than that of the promoter alone, reaching 14.9%. Furthermore, the results of alpha-amylase isozyme electrophoresis showed that there were three isozyme types in the gels, and the expression of alpha-amylase isoenzyme was significantly increased after treatment with B. subtilis QM3 (106 CFUmL.-1), which was reflected in the width and brightness of band mainly, especially band C alpha. In addition, germination rate, alpha-amylase activity and isozyme electrophoresis of other three kinds of wheat seeds were also tested and similar results were obtained. Therefore, one of the possible mechanisms by which B. subtilis QM3 promotes seed germination is as a potential exogenous factor that can enhance activity and expression of alpha-amylase.