Abstract:Gibberellin receptor (GID) plays an important role in gibberellin signal transduction pathway, which directly affects plant growth and development. In this study, a gibberellin receptor gene, MsGID1b, was first isolated from Medicago sativa by homologous cloning. Sequence analysis showed that MsGID1b contains 350 amino acid residues with 39.839 kD molecular weight, and has high nucleotide (98%) and amino acid (99%) similarity with its orthologous gene in Medicago truncatula. Physical and chemical properties analysis defined that MsGID1b was a kind of hydrophilic protein without signal peptide and transmembrane structures. MsGID1b contains the binding site of GA, DELLA and some conserved domain of hormonesensitive lipase family (HSL) like HGG and GXSXG. Spatio and temporal expression profile investigated by realtime PCR indicated that MsGID1b expressed comprehensively with its highest expression level in root. MsGID1b was sensitive to GA3, ABA, NaCl, PEG and dark treatments. It maintained a high transcript level under GA3 treatment, suggesting that MsGID1b might participate in the response of abiotic stress of M. sativa.