| Flavonoids are a class of natural secondary metabolites, which can be used as antioxidant, to prevent osteoporosis, treat tumor, and so on. They have been widely researched recently by many scientists all over the world. This study cloned CHI (chalcone isomerase) and FLS (flavonol synthase) genes through RACE and PCR, which are key genes of flavonoid biosynthetic pathway of Caragana intermedia. We constructed the binary vector of these two genes and obtained the homozygous transgenic Arabidopsis thaliana plants overexpressing these two genes respectively to analyze their function. The results are as follows.1. The full length cDNA sequence of CiCHI gene was 1005bp, consist of ORF(678bp, 111-788bp),5’-UTR(110bp) and 3’-UTR(217bp). The deduced protein comprised 226 amino acids with a calculated molecular weight of 24.413KD, and isoelectric point was 5.66, it’s amphoteric and stable. The full length cDNA sequence of CiFLS gene is 1 844bp, consisted of ORF (1020bp,568-1 587bp),5’-UTR(567bp) and 3’-UTR(257bp). The deduced protein comprises 340 amino acids with a calculated molecular weight of 38.765KD, and isoelectric point was 6.01, it’s hydrophobic and unstable.2. The expression of these two genes in different parts of plants and under different stresses was detected by qRT-PCR. CiCHI was induced by UV, NaCl, suppressed by ABA; CiFLS had no response under these treatments. These two genes both expressed highly in leaves and lowly in roots.3. Binary vectors p35S:CiCHI and p35S::CiFLS were constructed and the homozygous transgenic Arabidopsis thaliana overexpressing these two genes were obtained respectively.4.The content of total flavonoids and anthocyanins were detected. We found that the content of total flavonoids in Arabidopsis thaliana overexpressing CiCHI was higher than wild type, but the content of anthocyanins changed little. Neither the content of flavonoids nor anthocyanins changed in Arabidopsis thaliana overexpressing CiFLS. |
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