黄酮类化合物与植物生物钟的相互作用

黄酮类化合物是一种已知的特化代谢产物，在植物的发育、繁殖和生存中起着关键作用。黄酮类化合物作为植物营养素和药物，从人体健康的角度来看也具有相当大的价值。查尔酮合成酶(chalcone synthase, CHS)催化类黄酮生物合成的第一步，通过对拟南芥查尔酮合成酶(chalcone synthase, CHS)的RNA-Seq分析，发现了这些化合物影响植物生物钟基因表达的证据。启动子荧光素酶结构分析表明，编码中央时钟两个组分CCA1和TOC1的基因在昼夜周期内的转录活性在chs突变体的幼苗中发生了改变。黄酮类化合物对生理功能的影响进一步体现在光合活性上，叶绿素循环在突变体中被破坏。对一个缺乏类黄酮3’-羟化酶(f3’h)活性的突变体的分析表明，后者至少是部分原因，槲皮素对野生型幼苗CCA1启动子活性的影响进一步证实了这一点。总的来说，这些实验指出了黄酮和植物昼夜循环之间的未知联系，并为更好地理解类黄酮作用的分子基础开辟了道路。

Flavonoids are a well-known class of specialized metabolites that play key roles in plant development, reproduction, and survival. Flavonoids are also of considerable interest from the perspective of human health, both as phytonutrients and pharmaceuticals. RNA-Seq analysis of an Arabidopsis null allele for chalcone synthase (CHS), which catalyzes the first step in flavonoid biosynthesis, has uncovered evidence that these compounds influence the expression of circadian clock genes in plants. Analysis of promoter-luciferase constructs showed that the transcriptional activity of genes encoding two components of the central clock, CCA1 and TOC1, across the day/night cycle is altered in CHS-deficient seedlings. The effect of flavonoids on circadian function was furthermore reflected in photosynthetic activity, with chlorophyll cycling abolished in the mutant line. Analysis of a mutant lacking flavonoid 3’-hydroxylase (F3’H) activity, and thus able to synthesize mono- but not di-hydroxylated B-ring flavonoids, suggests that the latter are at least partially responsible, as further supported by the effects of quercetin on CCA1 promoter activity in wild-type seedlings. Collectively, these experiments point to a previously-unknown connection between flavonoids and circadian cycling in plants and open the way to better understanding of the molecular basis of flavonoid action.

文章原创；如有侵权请及时联系PaperRSS小编删除，转载请注明来源。

温馨提示：

为方便PaperRSS粉丝们科研、就业等话题交流。我们根据10多个专业方向（植物、医学、药学、人工智能、化学、物理、财经管理、体育等），特建立了30个国内外博士交流群。群成员来源欧美、日韩、新加坡、清华北大、中科院等全球名校。