Objective: To clone and analysis a new 3-hydroxy-3methylglutary CoA reductase cDNA from Salvia miltiorrhiza (SmHMGR3).
Method: Transcription database of S. miltiorrhiza was used and a new regulatory gene from terpene secondary metabolic pathway has been cloned. ORF Finder was used to find the open reading frame of SmHMGR3 cDNA and ClustalW has been performed to analysis the multiple amino acid sequence alignment. Phylogenetic tree has been constructed using MEGA5.0. RT-PCR has been applied to detect the transcription level of SmHMGR3 in roots, stems and leaves from flowering S. miltiorrhiza plant. The mRNA level of SmHMGR3 gene from hairy roots was detected after elicitor Ag+ supplied.
Result: The SmHMGR3 cDNA sequence was obtained. The total length of SmHMGR3 cDNA was 1,692 bp encoding 563 amino acids. The homology rate was 75.04% and 80.64% comparing with SmHMGR1 and SmHMGR2 respectively. QRT-PCR results showed that the highest mRNA level existed in leaves of S. miltiorrhiza. After induced by Ag for 24h, the transcription level reached the highest value.
Conclusion: A new SmHMGR3 gene has been obtained for the first time, and which can provide the new target for the further studies about tepenes metabolism.