Molecular cloning and sequencing of a cDNA encoding 3-hydroxy -3-methylglutaryl coenzyme a synthase from hevea brasiliensis (HBK) mull arg

摘要

A 1.8 kb cDNA clone encoding 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase was isolated from a cDNA library prepared from the C-serum of rubber latex from Hevea brasiliensis (H.B.K.) Mull. Arg. using an Arabidopsis thaliana cDNA encoding HMG-CoA synthase as a probe. The nucleotide sequence analysis revealed an open reading frame of 1,392 nucleotides which encoded a protein of 464 amino acids with a predicted molecular mass of 51.28 kDa. The deduced amino acid sequence exhibits strong similarities with plant and mammalian HMG-CoA synthase sequences. Analysis of RNA samples from different tissues of rubber tree seedlings showed a higher mRNA level in stem and petiole than in leaves. In mature rubber trees there were higher mRNA levels in latex and petiole than in leaves. This suggests that the expression of the HMG-CoA synthase gene is higher in laticifer cells than in leaves. Genomic Southern blot analysis using the full-length cDNA as a probe indicates the presence of up to three HMG-CoA synthase genes in Hevea brasiliensis.