title: Molecular cloning and expression profiling of a chalcone synthase gene from hairy root cultures of Scutellaria viscidula Bunge.
abstract: A cDNA encoding chalcone synthase (CHS), the key enzyme in flavonoid biosynthesis, was isolated from hairy root cultures of Scutellaria viscidula Bunge by rapid amplification of cDNA ends (RACE). The full-length cDNA of S. viscidula CHS, designated as Svchs (GenBank accession no. EU386767), was 1649 bp with a 1170 bp open reading frame (ORF) that corresponded to a deduced protein of 390 amino acid residues, a calculated molecular mass of 42.56 kDa and a theoretical isoelectric point (pI) of 5.79. Multiple sequence alignments showed that SvCHS shared high homology with CHS from other plants. Functional analysis in silico indicated that SvCHS was a hydrophilic protein most likely associated with intermediate metabolism. The active sites of the malonyl-CoA binding motif, coumaroyl pocket and cyclization pocket in CHS of Medicago sativa were also found in SvCHS. Molecular modeling indicated that the secondary structure of SvCHS contained mainly α-helixes and random coils. Phylogenetic analysis showed that SvCHS was most closely related to CHS from Scutellaria baicalensis. In agreement with its function as an elicitor-responsive gene, the expression of Svchs was induced and coordinated by methyl jasmonate. To our knowledge, this is the first report to describe the isolation and expression of a gene from S. viscidula.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region of Ministry of Education, School of Life Science, Southwest University, Chongqing China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lei
authors.forename: Shao-Hu
authors.initials: SH
authors.lastname: Tang
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Luo
authors.forename: Min
authors.initials: M
authors.lastname: Sun