STUDIES ON THE MECHANISM OF LIGHT DEPENDENT CHANGES IN FLOWERCOLOR

为了在不断变化的环境中稳定花色苷的表达，需要从多个角度分析其作用机理。光依赖色素沉着的机制有两种：1)光感受器介导的反应；2)叶或茎的糖供应介导的反应。为了了解哪种遮荫机制更重要，对东方百合‘阿卡普尔科’和‘矮生玫瑰’进行了部分遮荫和植物整体遮荫的研究。花的部分遮荫抑制了两种植物的色素沉着，表明光感受器介导的反应。在百合中，全株遮荫比花遮荫更严重地抑制了色素沉积，这表明糖介导了反应。研究了PAL、CHS、CHI、DFR基因在‘Nyoho’草莓果实发育过程中的表达。色素沉着与DFR和CHI的表达有关。结果提示，这两种酶与发育调控…有关。花青素生物合成增多。研究了光对‘丰冈’草莓果实花青素积累对光强敏感的花青素生物合成基因表达的影响。PAL、CHS和DFR的表达不受光照的影响，表明这些基因都不参与花青素生物合成的光依赖性调控。用铝箔遮盖整个根，可完全阻止‘津达’萝卜根花青素的积累。遮荫处理后，花色苷在20小时后开始积累，80小时后完全积累。以色素结实率分别为光依赖型和非独立型的‘津竹’和‘赤木’为材料进行杂交试验。虽然表型分离模式非常复杂，但光依赖性状倾向于显性。结果表明，有2个以上的基因参与了花色苷积累的光依赖性决定。较少

To stabilize the expression of anthocyanin under changing environment, analysis of their mechanism from various point of view is required.1. There are two suggested mechanism of light dependent pigmentation: 1 ) the reaction mediated by photoreceptors, 2) those mediated by sugar supply from leaves or stems. To understand which mechanism is more important, the effects of partial shading of flowers or whole shading of plants were investigated in oriental lily 'Acapulco' and stock 'pigmy rose'. Partial shading of flowers suppressed pigmentation in both species, indicating photoreceptor mediated reaction. In lilies, whole plant shading restricted pigmentation more severely than did flower shading, indicating sugar mediated reaction.2. The expression of PAL, CHS, CHI, DFR genes were investigated in 'Nyoho' strawberry fruits as fruit development. The pigmentation was correlated to the expression of DFR and CHI. The result suggested that these two enzymes are involved in the developmental reg … More ulation of anthocyanin biosynthesis.3. The effect of light on the expression of anthocyanin biosynthesis genes were investigated in 'Toyonoka' strawberry fruits, in which anthocyanin accumulation was sensitive to light intensity. The expressions of PAL, CHS, and DFR were not influenced by light irradiation, suggesting that none of these genes are not involved in light dependent regulation of anthocyanin biosynthesis.4. The anthocyanin accumulation in 'Tsudakabu' turnip root was completely prevented when whole roots were shaded by aluminum foil. When shaded roots were irradiated, the anthocyanin started to accumulate after 20 hours and completed after 80 hours. Using 'Tsudakabu' and 'Yurugi Akamarukabu', in which the pigmentation was light-dependent and -independent, respectively, crossing experiment was conducted. Although segregation pattern of phenotypes was very complex, light dependent trait tended to be dominant. The results suggested that more than 2 genes are involved in the determination of light dependency of anthocyanin accumulation. Less