[Isolation and characteristic of SmbHLH1 gene in Salvia miltiorrhiza].

OBJECTIVE: A novel bHLH-like gene, designated SmbHLH1, was isolated from Salvia miltiorrhiza, in order to identify a bHLH gene in related to danshinone biosysnthesis. METHOD: SmbHLH1 was isolated by RT-PCR,and Semi-quantitative RT-PCR was used to detect the gene expression level. RESULT: The full length of SmbHLH1 cDNA has an open reading frame of 999 bp. The deduced amino acid sequence of SmbHLH1 has 332 amino acid residues which forms a 36 kDa polypeptide with a calculated pI of 5.4. SmbHLH1 gene was expressed at high level in root, but low level in stem, leaf and flower of S. miltiorrhiza. The transcripts of SmbHLH1 was suppressed when the plants were treated with exogenous MeJA, Yeast + Ag+. The transcripts of SmbHLH1 constitutively accumulated in response to exogenous ABA and low concentration of salicylic acid. CONCLUSION: SmbHLH is a new member of the S. miltiorrhiza bHLH family, and its possible roles in brassinosteriods signaling responses.