Acquisition Of Nicotiana Tabacum Of DFR Variant Gene Of Orange-flower Gentian(Gentiana Lutea L.Var.Aurantiaca)Encoding DHK Substrate-specific DFR

Dihydroflavonol 4-reductase(DFR) is a key enzyme leading the synthesis of different types of anthocyanins in the pathway of anthocyanin synthesis.Therefore,regulating the function of DFR at the gene level provides a new idea and strategy for the improvement of plant flower color and the realization of artificial control and regulation of anthocyanin synthesis.At present,studies have found that DFR derved from different plants has different functions.DFR genes from different plant sources play different roles in plant genetic engineering,and DFR genes from the same gene family also play different roles in plant genetic engineering.Research team early found that a significant amount of cornflower and small amounts of pelargonidin pigment accumulated in tobacco leaf,and only the accumulation of these two kinds of pigment,only pelargonidin pigment accumulated in orange flower gentian.The orange flower gentian DFR1 and DFR2 genes transfer to a wild tobacco and that leaf color become deepened,which preliminary proved DFR1 and DFR2 has the function of dihydrogen flavonols reductase.In order to further study the DFR gene with the specificity of dihydrokaempferol(DHK),this study mainly includes the following contents:1.Three plant binary expression vectors were constructed using RNAi interference technology:(1)A plant binary expression vector that inhibits the expression of tobacco endogenous FLS(flavonol synthase) and F3?H(flavonoid 3?-hydroxylase) genes while overexpressing the DFR1 gene of neroli;(2)A plant binary expression vector that inhibits the expression of endogenous FLS and F3'H genes in tobacco while overexpressing the DFR2 gene of Neroli;(3)Plant binary expression vector for inhibiting the expression of endogenous FLS and F3?H genes in tobacco.2.Using agrobacterium leaf disc method and homomycin as resistance screening,the above three expression carriers are imported into wild tobacco(Nicotiana tabacum SR1),and the transgenic plants obtained in the preliminary screening were verified by PCR,and the verification was successful.The cultivation of transgenic plants lays a good foundation for the subsequent research on the functions of the DFR1 and DFR2 genes of neroli.