‘紫枝’玫瑰(Rosa rugosa ‘Zi zhi’)开花过程花青素相关化合物及代谢途径分析

【目的】分析‘紫枝’玫瑰5个开花时期花瓣中的花青苷、类黄酮苷和类胡萝卜素的种类和含量,推定‘紫枝’玫瑰花的花青苷代谢途径,为探讨玫瑰花色的呈色机理和花色育种提供参考。【方法】以‘紫枝’玫瑰不同开花时期的花瓣为试材,用高效液相色谱(HPLC)和超高效液相色质联用分析法(UPLC-DAD-Q-TOF-MS)对其花青苷、类黄酮苷和类萝卜素进行结构推定和定量分析,结合化学反应过程推测‘紫枝’玫瑰花青苷代谢途径。【结果】在‘紫枝’玫瑰中鉴定出8种花青苷、16种类黄酮苷和β-胡萝卜素,没有检测到叶黄素;花青苷主要以芍药素、飞燕草素、矢车菊素和天竺葵素的双糖苷为主,四类花青苷都在花蕾期和初开期相对含量最高;检测到芍药苷的两种甲基化衍生物,没有发现飞燕草苷的甲基化衍生物;类黄酮苷以槲皮素和山萘酚的糖苷化、酰基化和甲基化的衍生物为主。定量分析显示,芍药苷和飞燕草苷占‘紫枝’玫瑰总花青苷含量的90%以上;芍药苷含量在‘紫枝’玫瑰开花过程中随花色变浅而降低,飞燕草苷在开花过程含量变化不大;芍药苷和飞燕草苷的比例(Pn/Dp)随花色变浅而降低。【结论】‘紫枝’玫瑰花中含有芍药素、飞燕草素、矢车菊素和天竺葵素,这四类花青素在半开期之前完成全部积累,盛开期后只降解不合成。芍药素是形成‘紫枝’玫瑰花色的主要成分。‘紫枝’玫瑰的花青苷代谢途径中,甲基酶(Rr AOMT)的催化作用有底物特异性。

Analysis of Anthocyanins Related Compounds and Their Biosynthesis Pathways in Rosa rugosa ‘Zi zhi’ at Blooming Stages

【Objective】The composition content and structure of pigments in Rosa rugosa ‘Zi zhi’ and their biosynthetic pathways were studied in order to lay a foundation for further investigation of the floral pigment mechanism and molecular breeding of R. rugosa. 【Method】 Anthocyanins, flavonoids and carotenes in the petals of flowers at different blooming stages were determined using HPLC and ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-DAD-Q-TOF-MS). The biosynthetic pathways of anthocyanins in R. rugosa ‘Zi zhi’ were proposed according to the results of HPLC, UPLC-DAD-Q- TOF-MS and chemical reactions. 【Result】 In all, 8 kinds of anthocyanins, 16 kinds of flavones and flavonol glycosides and β-carotene were detected from the petals of R. rugosa ‘Zi zhi’, but xanthin was not detected. The main structures of the anthocyanins were bioside of peonidin, delphinidin, cyanindin and pelargondin. The highest relative contents of the four anthocyanins were detected at budding-flower and initial flowering stages. Two types of methylation of paeonidin were detected while no methylation was detected in delphindin. The main compounds of flavonoid were glycosylations, acylations, methylated quercetin and kaempferol. The results of quantitative analysis showed that the contents of paeonidin and delphindin accounted for more than 90% of the total anthocyanins. The content of paeonidin was reduced with the color fading while the content of delphindin was stable at all stages and the ratio of paeonidin to delphindin was reduced with the flower blooming.【Conclusion】There are peonidin, delphinidin, cyanindin and pelargondin in the petals of R. rugosa‘Zi Zhi’. The four anthocyanins are synthesized at the budding-flower and initial flowering stages, and the contents of them are reduced during the flower blooming. Peonidin is the main composition that determines the flower color of R. rugosa‘Zi zhi’. The catalytic reactions of RrAOMT exhibit substrate specific patterns.