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

Abstract:

The mechanism of promoting wheat seed germination by Bacillus subtilis has been paid great attention by many scholars. The germination rate and α-amylase activity of wheat seeds were significantly increased after germinating with Bacillus subtilis QM3 in this paper. Inhibitor and promoter of α-amylase were used to study relationship between bacteria and α-amylase. Compared with inhibitor group (10 mmol.L^-1 EDTA), α-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, α-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 α-amylase isozyme electrophoresis showed that there were three isozyme types in the gels, and the expression of α-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 Cα. In addition, germination rate, α-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 α-amylase.

Index terms:
amylase; Bacillus subtilis; germination rate; promoting mechanism; wheat