蓝光和蔗糖对拟南芥花色素苷积累和CHS基因表达的影响

Effects of Blue Light and Sucrose on Anthocyanin Accumulation and Chalcone Synthase Gene Expression in Arabidopsis

摘要:

以在20 μmol m^-2s^-1白光下生长13 d的拟南芥(Arabidopsisthaliana,Landsberg生态型)幼苗为材料,采用测定叶片花色素苷含量和Northernblot方法,研究蓝光与蔗糖在诱导植物花色素苷积累及相关基因表达中的作用。结果表明蓝光处理后,叶片花色素苷积累随光强和照光时间的延长而增加,突变体hy4叶片的花色素苷含量明显低于野生型(WT),说明隐花色素1(cry1)是蓝光诱导花色素苷积累的主要光受体;WT中苯基苯乙烯酮合酶基因(CHS)的表达受蓝光诱导,处理4h即有表达,8 h达到最高,之后逐渐下降;蓝光不能诱导突变体hy4中CHS基因的表达,说明cry1介导蓝光诱导CHS基因的表达。培养基中不含蔗糖,削弱了蓝光诱导的拟南芥叶片花色素苷的积累,CHS基因表达也受到抑制。蔗糖不仅作为碳源参与蓝光诱导的花色素苷积累,还可能作为信号分子参与蓝光诱导的CHS表达。

Abstract:

To evaluate the effects of blue light and sucrose on anthocyanin accumulation and chalcone synthase gene (CHS) expression, the leaves of 13-day-old seedlings of wild type Arabidopsis (WT) and hy4 mutant grown under 20μmol m-2 s-1 white light were used in the experiments. After irradiation by blue light (BL), anthocyanin content in leaves of WT increased with the increase of blue light intensity and irradiation duration. Anthocyanin content in hy4 mutant was lower than that in WT after BL treatment, which demonstratedthat cryptochrome 1(cry1)mediated the BL response in anthocyanin accumulation．CHS gene expression detected by Northern blot in the、WT leaves was induced by BL and it could be detected after 4 hours and reached a peak after 8 hours，and then the gene expression declined．BL could not induce any gene expression in hy4 mutant indicating cryl is the photoreceptor mediating the blue-light-induced CHS gene expression． It was observed that the increase ofan thocyanin an d gene expression were weakened in sucrose-free medium under blue light treatment． Sucrose may act not only as an energy source but also a component in blue-light-induced signal transduction of anthocyanin accumulation and CHS expression.