黄芪种子萌发及萌发后生长过程中黄酮类化合物合成的动态变化

Variation in Flavonoids Biosynthesis during Seed Germination and Post-germination Growth in Astragalus membranaceus

在对膜荚黄芪和蒙古黄芪种子萌发和萌发后生长时期进行划分的基础上,研究了黄芪中3种主要黄酮类化合物芒柄花素、毛蕊异黄酮和毛蕊异黄酮苷在萌发和萌发后生长过程中含量的变化。为了弄清黄酮含量变化的机制,我们还对黄芪中黄酮生物合成途径酶的转录水平做了研究。结果表明,在种子萌发和萌发后生长阶段,两种黄芪中均出现了明显的黄酮类化合物累积增加的情况。通过检测黄酮类物质生物合成途径酶基因的转录表达水平,我们发现萌发阶段蒙古黄芪中黄酮类物质积累增加主要由上游途径酶基因的表达水平升高引起,而膜荚黄芪中则几乎涉及到所有途径酶。此外,我们还发现萌发后生长阶段中,两种黄芪中合成途径酶基因转录对黄酮类物质含量的调控则选择性地存在时间延迟效应。

Based on the stage definitions of seed germination and post-germination growth, we investigated the variations of contents of three major flavonoids during the two stages in Astragalus membranaceus and its variety of mongholicus. Besides, in order to understand how the variations were induced, the transcriptions of pathway enzyme involving in flavonoid biosynthesis were profiled. The contents of flavonoids increased during the two stages in both A. membranaceus and the variety. With the detection of gene transcriptions of the pathway enzymes, only the enzymes in upstream of the pathway contributed to the increase of flavonoids in the variety of mongholicus during the germination, whereas it was that almost all the pathway enzymes were involved in A. membranaceus. The transcriptions of pathway enzymes regulated the accumulations of flavonoids during postgermination growth, selectively with a pattern of time delay.