紫外光促进苦荞中黄酮类化合物积累的分子机制探究

目的研究紫外光对苦荞Fagopyrumtataricum幼苗中黄酮类化合物的影响及其分子机制。方法采用中波紫外光紫外线B(Ultraviolet Radiation B,UVB)处理苦荞幼苗,通过超高效液相色谱仪检测紫外光处理前后苦荞中芦丁等黄酮类化合物含量变化,同时采用实时荧光定量PCR(qRT-PCR)检测苦荞中黄酮类化合物合成途径中关键酶基因的表达量。结果紫外光处理后苦荞中芦丁、儿茶素和表儿茶素3种黄酮类化合物的含量均显著增加,其中芦丁含量是黑暗处理对照组的1.5倍。同时通过qRT-PCR检测发现苦荞中黄酮类化合物合成途径中苯丙氨酸解氨酶(phenylalanine ammonia lyase,PAL)、肉桂酸-4-羟化酶(cinnamate-4-hydroxylase,C4H)、黄烷酮-3-羟化酶(flavanone-3-hydroxylase,F3H)、二氢黄酮醇-4-还原酶(dihydroflavonol-4-reductase,DFR)等11个关键酶基因的表达量均有不同程度升高。结论UVB通过正调控多个黄酮合成关键酶基因的表达促进苦荞中黄酮类化合物的积累,为阐明UVB对苦荞中黄酮类化合物的调控机制奠定基础。

Molecular mechanisms of UVB-induced flavonoid accumulation in Fagopyrum tataricum

Objective Study on the effect of UVB on flavonoids in Fagopyrum tataricum seedlings and its molecular mechanism. Methods In this study, the F. tataricum seedlings were treated with UVB light, and the content changes of rutin and other flavonoids in F. tataricum before and after UVB treatment was detected by Ultra-high performance liquid chromatography, and then the expression of key enzyme genes in the biosynthesis pathway of flavonoids in F. tataricum was detected by qRT-PCR. Results The content of rutin, catechin and epicatechin in F. tataricum increased significantly after UVB treatment, among which the content of rutin was 1.5 times than that of the dark treatment group. At the same time, qRT-PCR showed that the expression levels of 11 key enzyme genes such as phenylalanine ammonia lyase (PAL), cinnamate-4-hydroxylase (C4H), flavanone-3-hydroxylase (F3H) and dihydroflavonol-4-reductase (DFR) in F. tataricum were increased to different degrees in the biosynthesis pathway of flavonoids. Conclusion This study indicated that UVB light can promote the accumulation of flavonoids in F. tataricum by upregulating the expression levels of key enzyme genes in flavonoid biosynthesis pathway, which will provide scientific basis for elucidating the regulation mechanism of UVB light on flavonoids in F. tataricum.