EjGASA6 promotes flowering and root elongation by enhancing gibberellin biosynthesis

The Gibberellic Acid-stimulated Arabidopsis (GASA) gene family is involved in the regulation of gene expression and plant growth, development, and stress responses. To investigate the function of loquat GASA genes in the growth and developmental regulation of plants, a loquat EjGASA6 gene homologous to Arabidopsis AtGASA6 was cloned. EjGASA6 expression was induced by gibberellin, and ectopic transgenic plants containing this gene exhibited earlier bloom and longer primary roots since these phenotypic characteristics are related to higher gibberellin content. Transcriptome analysis and qRT-PCR results showed that the expression levels of GA3ox1 and GA20ox1, which encode key enzymes in gibberellin biosynthesis, were significantly increased. Furthermore, we confirmed that EjGASA6 could promote the expression of GA20ox1 via the luciferase reporter system. Overall, our results suggest that EjGASA6 promotes blooming and main-root elongation by positively regulating gibberellin biosynthesis. These findings broaden our understanding of the role of GASAs in plant development and growth, and lay the groundwork for future research into the functions of EjGASA6 in regulating loquat growth and development.