Molecular Determinants that Convert Hormone Sensitive Lipase into Gibberellin Receptor

Gibberellins (GAs) are tetracyclic, diterpenoid plant hormones, essential for many developmental processes in higher plants. Plants perceive GA through a nuclear-localized GA receptor, GA INSENSITIVE DWARF1 (GID1). From sequence similarity, it is suggested that GID1 evolved from a hormone-sensitive lipase (HSL), and recent x-ray crystallography of the GA-GID1 complex has given insights into how GID1 recognizes GA. Analyses of the GA signaling pathway in several plant species further suggest that the GID1-mediated GA signaling pathway emerged in the vascular plant lineage and since then regulation of GA recognition specificity seems to have been fine tuned to strictly regulate the on – off GA signal. Keywords: DELLA protein, gibberellin (GA), GA INSENSITIVE DWARF1 (GID1), hormone-sensitive lipase (HSL), Selaginella moellendorffii, rice, epoxidation, crystallography, Arabidopsis