[Cloning and tissue expression of mevalonate disphosphate decarboxylase genes from Andrographis paniculata]

Andrographolide is a main bioactive substance in Andrographis paniculata, and extensively used in anti-inflammatory drugs. In order to increase andrographolide production in plant, three 1260 bp ORFs encoding mevalonate disphosphate decarboxylases with 419 amino acids were cloned from A. paniculata by RACE method and analyzed by bioinformatic software. Their tissue expression patterns were predicted by real time PCR. Eleven conserved amino acid residues determining specificity and activity of these MVDs were predicted in these amino acid sequences, but no plastid targeted signal peptides were detected. These MVDs have high similarities with the MVD protein (GenBank number: AEZ55675.1) from Salvia miltiorrhiza. In stems and leaves, expression levels of these MVD genes were constant, and reached the highest level at bud stage and the beginning of flowering. The MVD genes we have cloned from A. paniculata could be used in genetic engineering of andrographolide biosynthsis pathway in future.