依据理化性质分析牡丹花色形成的影响因素

Formation Mechanism of Different Tree Peony Flower Colors by Anatomy and Biochemistry

对5个不同花色的牡丹品种花瓣解剖结构、色素分布、理化性状及类黄酮合成相关基因的表达进行了观测与分析,结果表明:不同花色牡丹品种的表皮细胞形态存在差异,类黄酮和金属元素(Al和Fe)质量分数与牡丹花色值显著相关。类黄酮为主要影响因素,天竺葵素、矢车菊素和芍药素作为主要色素,槲皮素和木樨草素作为辅助色素,共同参与了红色系的形成;查尔酮、芹菜素、槲皮素和金圣草黄素影响了黄色花的形成。结合8个类黄酮生物合成相关结构基因的表达模式分析显示,CHI、DFR、ANS基因控制花青苷的合成,CHI、F3H、F3’H和FLS基因控制黄酮、黄酮醇以及查尔酮的合成,分别在红色及黄色品种中高表达。因此,牡丹不同花色的形成主要受相关基因表达以及类黄酮质量分数的调控,而金属元素(Al、Fe)和花瓣表皮细胞形态也能在一定程度上影响花色的呈现。

We observed and analyzed the anatomical structure,pigment distribution,physicochemical characteristics and the expression profiles of flavonoid biosynthetic genes in five differentially colored cultivars of tree peony.The results showed that the morphology of epidermal cells in differentially colored cultivars of tree peony is distinct,and the contents of flavonoid and metal elements(Al and Fe)were significantly correlated with the flower color indices.Pelargonidin-cyanidin-and peonidin-based anthocyanins primarily determined the red pigmentation,while quercetin and luteolin acted as copigments to affect the formation of red flower colors;Chalcone,apigenin,quercetin and chrysoeriol determined the formation of yellow flower color.Comprehensive analysis of expression patterns of eight flavonoid biosynthetic structural genes indicated that CHS,CHI,DFR,and ANS genes controlling the synthesis of anthocyanins,and F3H,F3’H,and FLS genes regulating mainly the synthesis of flavonoids,flavonols,and chalcone,exhibited high expressly levels in red and yellow cultivars,respectively.Therefore,the formation of different flower colors of tree peony is mainly regulated by the expression of related genes and the contents of flavonoids.Furthermore,the accumulation of Al and Fe as well as morphology of petal epidermal cells can also affect the flower color to some extent.