RESUMEN
Objective: Paris fargesii is an important medicinal plant and its secondary metabolites, steroidal saponins, synthesized by the mevalonate pathway are the active ingredients. The study on the gene of the key enzyme 3-hydroxy-3-methyl- glutaryl-coenzyme A reductases (HMGR) in the mevalonate pathway is helpful for the regulation of steroidal saponins syntheses. Methods: In the basis of degenerate primers designed according to mRNA homologous conserved regions of 11 HMGRs from 11 plant species published on NCBI and total RNA extracted from the seedling of P. fargesii, a 404 bp fragment of HMGR was amplified by reverse transcription PCR technology, which is a new cDNA as searching in the Genbank. Results: Sequence analysis showed that the obtained fragment had 76%-81% identification compared with other seven plant species. The deduced amino acid seqence was predicted to have a wider and higher homology with other plants. Conclusion: Protein characteristic zones, conserved regions, and phylogenetic analysis by Prosite and ClustalX could give preliminary evidence for the existence of HMGR in P. fargesi, which is the report of HMGR gene isolated from the plants in Liliaceae for the first time.