ABSTRACT
Objective To clone the R2R3 MYB transcription factor gene SmMYB87 in subgroup 14 from Salvia miltiorrhiza, and analyze the bioinformatics and expression of this gene. Methods Total RNA extracted from S. miltiorrhiza was used as cDNA synthesis template and the full length cDNA sequence was obtained through homology-based cloning and rapid amplification of cDNA ends (RACE) technology. The structure and physicochemical properties of SmMYB87 gene and its coded protein were analyzed with bioinformatics softwares. The expression of SmMYB87 in different organs was determined with qRT-PCR, and a GFP fusion expression vector was constructed to investigate the subcellular laicization of SmMYB87 protein. Results SmMYB87 gene contained two introns and an open reading frame (ORF) of 732 bp, encoding 243 amino acid polypeptides. It expressed in roots, stems, leaves and flowers with similar expression levels and the SmMYB87 protein located in nucleus and cytomembrane. Conclusion The analysis of sequence structure and expression pattern of SmMYB87 will be helpful to study the regulating roles of this gene in S. miltiorrhiza.
ABSTRACT
Our previous research indicated that the Streptomyces pactum Act12 (Act12) had a certain promotional effect on tanshinone accumulation and up-regulated the expression of genes 3-hydroxy-3-methyglutaryl-CoA reductase (HMGR) and 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) in Salvia miltiorrhiza hairy roots. This study focuses on the roles of reactive oxygen species in S. pactum Act12-induced tanshinone production in S. miltiorrhiza hairy roots. The 4% Act12, 4% Act12 + CAT and 4% Act12 + SOD were added to S. miltiorrhiza hairy root and subcultured for 21 days, the dry weight, contents of reactive oxygen species, contents of tanshinones and expression of HMGR and DXR were determined at different harvest-time. The generation of reactive oxygen species (ROS) in S. miltiorrhiza hairy roots was triggered by 4% Act12 treatment. The relative expressions of genes HMGR and DXR in 4% Act12 treatment were 32.4 and 4.8-fold higher than those in the control. And the total tanshinone in the hairy roots was 10.2 times higher than that of the control. The CAT and SOD could significantly inhibit the ROS accumulation and relative expressions of genes HMGR and DXR in 4% Act12 treatment, which induced the total tanshinone content was decreased by 74.6% comparing with the 4% Act12 treatment. ROS mediated Act12-induced tanshinone production. The Act12 may be via the ROS signal channel to activate the tanshinone biosynthesis pathways. Thereby the tanshinon content in hairy roots was increased.