Ultrastructure change and transcriptome analysis of GA3 treatment on seed germination of moso bamboo(Phyllostachys edulis)

Exploring the mechanism of Gibberellic acid (GA(3)) treatment on seed germination of moso bamboo can lay a foundation for its future breeding and research. In this study, the germination-related indicators (germination rate, germination potential, vigor index, respiration rate) with different content of GA(3) treatment were measured, and the ultrastructure of moso bamboo seeds treated with low and high GA(3) concentrations was observed during the germination process. In addition, the transcriptome data of the germination seeds, with and without GA(3) treatment were analyzed. The results showed that the low GA(3) concentration (10 mol/L) increased the germination rate, germination potential, vigor index and respiration rate, thus promoting the germination of moso bamboo seeds, but a high concentration of GA(3) (50 mol/L) inhibited the seed germination. The low GA(3) concentration accelerated the decomposition of starch and fat and promoted the vacuole formation of cells, but the high GA(3) concentration damaged organelles and increased the endocytosis of cells. Compared with untreated moso bamboo seeds, the seeds had fewer genes expressed after GA(3) treatment. Starch and carbon metabolism play a very important role in seed development and embryo viability, whether the seed is treated with GA(3) or not. After hormone treatment, GID1 and DELLA-related genes homologous to rice genes is not expressed, but the expression of PIF4, PIF5, GA(3) ox2, GA(2) oxs, etc., were up-regulated.