β-galactosidase is involved in rice seed germination

Abstract

The purpose of this study was to explore the relationship between β-galactosidase and rice seed germination. Exogenous β-galactosidase (1 U) facilitated germination while abscisic acid (ABA) delayed germination. Histo- chemical staining and spectrophotometry revealed that the activity of endogenous β-galactosidase increased gradually during germination. 1 μM ABA and GA4+7 could, respectively, inhibit and promote the activity of β-galactosidase in the rice embryo. This indicated that the regulation of rice seed germination by these two phytohormones may be through mediation of β-galactosidase activity. During seed germination, the transcriptional expressions of OsBAGL1, OsBAGL4, OsBAGL8 and OsBAGL11 were higher than those of other homologous genes, suggesting that these four genes may be involved in the germination process. GA4+7 significantly increased the expression of the above four genes. By contrast, the transcriptional expression of OsBAGL8 and OsBAGL11 were significantly reduced by ABA, but not that of OsBAGL1 and OsBAGL4. Our study has important theoretical and practical significance for illustrating the relationship between β-galactosidase and seed germination.