부산대학교 도서관

Endophytes play important roles in the host plants. However, there are a few studies about tree seed endophytes, and its physiological regulation mechanism of seed germination is unclear yet. We characterized the composition of the endophytic bacteria in Picea asperataseeds, and explored its role and mechanism in seed germination. Seeds were surface sterilized on agar to culture endophytes for extracting DNA and sequencing. Bacillus amyloliquefaciens(BA), isolated and purified from P. asperataseeds in this study, was used to inoculations. Then, we conducted a factorial combination of three seed sterilization patterns (no sterilization (as control), surface sterilization and complete sterilization, respectively) and two BA applications (with or without BA) as experimental treatments to further reveal the effects of BA on seed germination and its mechanism. Seed complete sterilization significantly decreased seed germination percentage. BA application improved seed germination percentage, germination index and shortened mean germination time. The germinating seeds with BA application also exhibited higher reactive oxygen species (ROS) levels, cell wall degrading enzyme (cellulase and pectinase) and amylase activity. BA also has strong ROS-producing and cellulose-decomposing properties. These results suggested that endophyte BA contributes to the induction of ROS and enzyme activity, thereby promotes seed germination. This study highlights the potential exploitation of BA in woody plant seed germination and management.