Characterization of the gibberellic oxidase gene in (Franch.) skeels and interaction protein screening.

Gibberellin 20-oxidases () are multifunctional enzymes involved in regulating gibberellin (GA) biosynthesis and controlling plant growth. We identified and characterized the GA20ox1 gene in a plant height mutant of , referred to as . This gene was expressed in root, stem, and leaf tissues of the adult plant height mutant, with the highest expression observed in the stem. The expression of was regulated by various exogenous hormones. Overexpression of in Arabidopsis resulted in significant elongation of hypocotyl and root length in seedlings, earlier flowering, smaller leaves, reduced leaf chlorophyll content, lighter leaf color, a significant increase in adult plant height, and other phenotypes. Additionally, transgenic plants exhibited a substantial increase in biologically active endogenous GAs (GA1, GA3, and GA4) content, indicating that overexpression of accelerates plant growth and development. Using a yeast two-hybrid (Y2H) screen, we identified two SdGA20ox1-interacting proteins: the ethylene receptor (11430582) and the (11416005) protein. These interactions suggest a potential regulatory mechanism for growth. Our findings provide new insights into the role of and its interacting proteins in regulating the growth and development of .