Cloning of HbMCS1 Gene from Hevea brasiliensis and Its Expression Analysis

2C-methyl-D-erythritol 2, 4-cyclodiphosphate synthase (MCS) is the fifth enzyme of the nonmevalonate terpenoid path- way for isopentenyl diphosphate biosynthesis and is involved in the methylerythritol phosphate (MEP) pathway. A MCS gene was isolated from Hevea brasiliensis by RT-PCR and RACE based on the conserved sequences of plant MCS genes. Sequence analysis showed that the cDNA, which is designated HbMCS1, consisted of 965 bp and encoded a protein of 241 amino acids with a predicted molecular mass of 25.82 kD (GenBank accession No. FJ196164). In comparison, this putative HbMCS1 protein showed 70.8%, 69.4%, 64.9%, 63.3% and 62.2% identities with MCS from Catharanthus roseus, Arabidopsis thaliana , Oryza sativa, Ginkgo biloba and Cephalotaxus fortunei. Semi-quantitative RT-PCR analysis indicated that the HbMCS1 was more highly expressed in callius than that in latex and leaves. The transcription of HbMCS1 in latex from tapping tree was induced, whereas ethylene had little effect on its expression.