Molecular Cloning and Expression Analysis of a Chalcone Synthase Gene from Paphiopedilum orchid
In the present study,a full-length cDNA sequence of a chalcone synthase(CHS) gene was cloned from the flowers of Paphiopedilum concolor Pfitz.by reverse transcriptase-polymerase chain reaction(RT-PCR) and rapid amplification of cDNA ends(RACE),named PcCHS,GenBank accession number JQ030889.Sequence analysis indicated that PcCHS is 1 424 bp in full-length,containing a 5'-untranslated region(5'-UTR) of 106 bp,a 3'-UTR of 133 bp,and an opening reading frame(ORF) of 1 185 bp encoding a 394 predicted amino acids residues,possessing all the conserved active sites for the CHS function as well as the family signature.Sequence alignment revealed that PcCHS shared 80%-82% identities with CHS proteins of the cultivars from Phalaenopsis,Oncidium and Dendrobium in Orchidaceae.Phylogenetic analysis clearly showed that PcCHS was close to the second subgroup of CHS protein family in Orchidaceae.Expression analyses revealed that PcCHS was detected in all six flower bud developmental stages,but showed different expression patterns in tissues examined.The transcripts of PcCHS were the highest levels in mature flowers,moderate levels in columns,lower levels in bracts,ovaries,petals and sepals,lowest levels in lips,and almost no detection in roots,leaves and flower stems.