Time course of expression of chalcone synthase gene in Ginkgo biloba.
Chalcone synthase (CHS) catalyses the first and key regulatory step of flavonoid biosynthetic pathway. A chalcone synthase gene was isolated from Ginkgo biloba leaves using the method of rapid amplification of the cDNA ends (RACE). The full-length cDNA, designated as GbCHS2, is 1,608 bp in length (GenBank accession No. DQ054841) and contains an open reading frame of 1,173 bp encoding a protein of 391 amino acids. Alignment of the predicted amino acid sequence of GbCHS2 has been shown to have high sequence similarity with GbCHS1. All the active sites and active site motifs in GbCHS1 protein were also found in GbCHS2. Correlation analysis between CHS activity and flavonoid accumulation during ginkgo leaf growth indicated that CHS might be the rate-limiting enzyme in the biosynthesis pathway of flavonoids in ginkgo leaves. Results of semi-quantitative RT-PCR analysis showed that flavonoid accumulation paralleled the transcription level of change in chs gene, suggesting chs gene as the specific key gene regulating flavonoid accumulation in ginkgo leaves.
College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
Feng
F
Xu
Shui-Yuan
SY
Cheng
Shu-Han
SH
Cheng
Yan
Y
Wang
He-Wei
HW
Du
D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005419:Flavonoids / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D020441:Ginkgo biloba / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
D018076:DNA, Complementary; D005419:Flavonoids; D010940:Plant Proteins; D000217:Acyltransferases; C020141:flavanone synthetase