金雀异黄素和环鸟苷酸调控离体葡萄果实花青苷积累

以离体‘巨峰’葡萄为材料，观察到金雀异黄素（GNT）对果皮花青苷积累的促进效应，而且证明GNT的诱导过程（约10 ~ 12 h）不需要光照，但其后的花青苷积累却依赖于光照。如果在GNT预处理后6 h内用环鸟苷酸（cGMP）处理，可以明显抑制GNT的促进效应，但在GNT预处理后12 h再用cGMP处理，则抑制效应消失。半定量RT-PCR检测表明，光和GNT诱导葡萄果皮花青苷合成相关基因PAL、CHS和UFGT表达量上调，而对LDOX表达量无明显影响；cGMP处理抑制了GNT诱导的PAL和CHS等基因表达的促进作用，说明GNT和cGMP相互拮抗，共同调控葡萄果皮花青苷积累。

Regulation of Anthocyanin Accumulation in Grapes in Vitro by Genistein and cGMP

It was found in previous paper that the anthocyanin accumulation in peach fruit skin was promoted by genistein (GNT) but inhibited by cGMP. Which is quite different from the prevailing hypotheses in this field. In this study, we once again observed that GNT promoted anthocyanin accumulation in grape berry skin in vitro. The anthocyanin accumulation induced by GNT was dependent on light exposure. However, a dark period about 10 - 12 h was necessary during GNT induction. This may suggest that light is unnecessary for the direct physiological responses for berries to GNT treatment, but necessary for anthocyanin accumulation. Furthermore, it was found that if the berries were treated with cGMP at once following GNT pretreatment, the GNT-induced anthocyanin accumulation was significantly inhibited. However, if cGMP treatment was conducted 12 h after GNT pretreatment, the inhibition of cGMP was no longer observed, suggesting that the GNT-induced physiological responses might be completed in 12 h. Detection by semi-quantitative RT-PCR showed the expression of the genes including PAL, CHS and UFGT, which are related with anthocyanin biosynthesis, were up-regulated by light exposure and GNT treatment in grape skin, while LDOX seemed no response to these two factors. Treatment with cGMP inhibited RNA accumulation of PAL and CHS induced by GNT, suggesting that GNT and cGMP be of antagonism in regulation of anthocyanin accumulation in grape skins.