Abstract:

【Objective】 This study is to identify and analyze the flavonol synthetase FLS gene family as a key enzyme in the secondary metabolism of polyphenols in Caryophyllum plants and to explore the function of FLSs in Chenopodium quinoa. 【Method】 Bioinformatics analysis website was used to identify the CqFLS family members, and analyze their gene structure, protein physicochemical properties, secondary structure, tertiary structure, promoter cis element and phylogenetic relationship. The gene cloning and expression vector construction was to analyze their protein expression. 【Result】 The 3 CqFLSs genes were identified, and they were unevenly distributed on two chromosomes, and the promoter region of CqFLSs contained salicylic acid, abscisic acid, methyl jasmonate and drought-induced elements. There were multiple InDel and SNP variations in CqFLS2.1g,the coding nucleotides were deleted at ch01 28871893, 28871125, and 28872881, and all of them were annotated as upstream effects, and no frameshift mutations were detected. Phylogenetic tree analysis showed that CqFLS2.1g were in different branches from CqFLS1.1g and CqFLS3.10g, their expressions varied, and CqFLS2.1g were also differentiated. Meanwhile gene expression analysis revealed that the overall expressions of the three CqFLSs genes in “Qingbai 1” grains were higher than those of “Qinghei 1” and “Gongzha 4”. The cloned CqFLS1.1g was induced with 0.3 mmol/L IPTG and was successfully expressed at both 20℃ and 37℃. 【Conclusion】 CqFLS1.1g plays a role in the formation of flowers and grain development, while CqFLS2.1g is mainly involved in the formation of quinoa grains, and the expression of CqFLS is tissue-specific and plays an important role in the growth and development of quinoa.

Key words: Chenopodium quinoa, flavonol synthase, qRT-PCR, DNA variation, prokaryotic expression