观赏向日葵不同花色物质组成的靶标代谢组学分析

Target metabolomic analysis of material composition using a pair of near isogenic lines with different floral colors in sunflower

[目的]本文旨在解析不同花色观赏向日葵的代谢物差异。[方法]通过靶向代谢组学的方法,对‘盐葵4号’和‘盐葵5号’不同颜色的花和茎中相关代谢产物含量进行测定,筛选差异代谢物,并对差异代谢物参与的代谢通路进行鉴定与分析,解析组织呈现不同颜色的代谢物质基础。[结果]通过广泛靶向代谢组学,共检测到647种代谢物,其中紫色花组织显著高于白色花组织的代谢物有140种,紫色花组织显著低于白色花组织的代谢物有224种;紫色茎组织显著高于白色茎组织的代谢物有48种,紫色茎组织显著低于白色茎组织的代谢物有104种。‘盐葵4号’紫色花中特异上调物质有123种,紫茎中特异上调物质有31种,紫花和紫茎共同上调的物质有17种。对差异代谢物进行KEGG代谢通路富集分析,结果显示差异代谢物参与多条代谢途径,其中花青素代谢途径在不同颜色的组织都显著富集。在紫色组织中参与花青素代谢途径的显著上调代谢物为矢车菊素、矢车菊素-3-O-葡萄糖苷和飞燕草素-3-O-3′,6″-O-二甲酰葡萄糖苷;在白色组织中显著上调的与颜色相关的代谢物为槲皮素、黄芪碱、异槲皮素、杨梅素和芦丁。另外,3种山奈酚类衍生物质在紫色组织中显著上调,可能在紫色组织形成过程中扮演重要角色。[结论]矢车菊素可能是‘盐葵4号’紫色组织呈色的主要物质,而槲皮素、黄芪碱、异槲皮素、杨梅素和芦丁等与其他颜色相关的代谢物是‘盐葵5号’呈色的主要物质。部分黄酮类物质合成下调,而花青素类物质合成上调可能是‘盐葵4号’花和茎组织呈现紫色的主要原因。

[Objectives]The aim of this study was to analyze the metabolite differences of different flower colors of ornamental sunflower.[Methods]In this study,the contents of metabolites of floral and stem of sunflower varieties‘Yankui 4’and‘Yankui 5’with different color were determinated using the widely targeted metabonomics.The different metabolites and the metabolic pathways were screened and analyzed,and the metabolic material basis about the tissue present different colors was acquired preliminarily.[Results]In this study,647 metabolites were detected by widely targeted metabolomics using different color flower and stem of‘Yankui 4’and‘Yankui 5’.Among them,140 metabolites in purple flowers were significantly higher than those in white flowers,and 224 metabolites in purple flowers were significantly lower than those in white flowers.48 kinds of metabolites were significantly higher and 104 kinds of metabolites were significantly lower in purple stem compared to white stem.There were 123 specific up-regulated substances in the purple flower of‘Yankui 4’,but only 31 specific up-regulated substances in the purple stem,17 simultaneously up-regulated substances in the purple flower and the purple stem compared to the white flower and stem of‘Yankui 5’.The result of KEGG pathways enrichment analysis showed that the differential substances participated in multiple metabolic pathways,among which anthocyanin metabolism pathway was significantly enriched in different color tissues.The mainly significantly up-regulated metabolites were anthocyanin,cyanidin-3-O-glucoside and delphinidin-3-O-3′,6″-O-dicarboxylic glucoside which participated in anthocyanin metabolic pathway in purple tissues.Quercetin,astragalosine,isoquercetin,myricetin and rutin were significantly up-regulated in white tissues.Three kaempferol derivatives were significantly up-regulated in purple tissue,which might play important roles in the color formation of purple tissue.[Conclusions]Cyanidin was the main substance which presented the purple colour for the tissue of‘Yankui 4’,while quercetin,astragalosine,isoquercetin,myricetin and rutin were the main substances related to the different color of the tissues of‘Yankui 5’.The down-regulation of some flavonoids synthesis and the up-regulation of anthocyanins synthesis might be the main reason for the color formation of purple flower and stem of‘Yankui 4’.