辣椒果实类胡萝卜素调控因子转录组和靶向代谢组分析

Integrated Transcriptomic and Targeted Metabolomic Analysis Reveals Regulation of Carotenoid Accumulation During Pepper Fruit Development

分析了辣椒自交系1189不同发育时期果实转录组和类胡萝卜素靶向代谢组,基于加权基因共表达网络分析(weight gene co-expression network analysis,WGCNA)鉴定了可能参与调控辣椒类胡萝卜素生物合成相关基因的转录因子。靶向代谢组共鉴定出60种类胡萝卜素代谢物,分析发现,幼果期和绿熟期果实类胡萝卜素主要组分均为叶黄素(73.4%和64.5%),转色期叶黄素含量急剧下降,红熟期主要为辣椒红素(32.5%),无法检测到叶黄素。转录组分析共鉴定出14148个差异表达基因和15个类胡萝卜素代谢相关差异表达基因。通过WGCNA将筛选所得的12286个差异表达基因划分至16个模块,发现MEdarkseagreen4、MElightcyan1和MEbrown2模块与11种主要类胡萝卜素组分显著相关。基于3个模块中类胡萝卜素相关差异表达基因构建代谢调控网络,并通过分析启动子结合基序,筛选出bHLH48、SEP3、CMB1、AGL27、YABBY2、GT-3B、NF-YA3、NAC2、HOX5和GATA26等10个转录因子可能在类胡萝卜素积累中发挥重要调控作用。

In this study,the fruit of pepper inbred line 1189 during different developmental stages was used to investigate the profiles of carotenoids by combination of metabolomic and transcriptomic analyses.Transcription factors that may be involved in regulating carotenoid biosynthesis in pepper were identified by weighted gene co-expression network analysis(WGCNA).A total of 60 carotenoids were identified by targeted metabolome.After analysis,it was found that the main components at young fruit stage and mature green fruit stage were lutein(73.4%and 64.5%)and the lutein contents sharply decreased at color-changed fruit stage.The capsanthin content(32.5%)was highest at red ripe fruit stage and the lutein In this study,the fruit of pepper inbred line 1189 during different developmental stages was used to investigate the profiles of carotenoids by combination of metabolomic and transcriptomic analyses.Transcription factors that may be involved in regulating carotenoid biosynthesis in pepper were identified by weighted gene co-expression network analysis(WGCNA).A total of 60 carotenoids were identified by targeted metabolome.After analysis,it was found that the main components at young fruit stage and mature green fruit stage were lutein(73.4%and 64.5%)and the lutein contents sharply decreased at color-changed fruit stage.The capsanthin content(32.5%)was highest at red ripe fruit stage and the lutein could not be detected.The 14148 differentially expressed genes(DEGs)and 15 DEGs related to carotenoid metabolism were identified respectively by transcriptomic.The 12286 DEGs screened were divided into 16 modules by WGCNA.It was found that MEdarkseagreen4,MElightcyan1 and MEbrown2 module were significantly correlated with 1l major carotenoids.The metabolic regulatory network was constructed based on carotenoid-related DEGs in the three modules,and ten transcription factors,including bHLH48,SEP3,CMB1,AGL27,YABBY2,GT-3B,NF-YA3,NAC2,HOX5 and GATA26,were obtained through promoter binding motif analysis,which may play important regulatory roles in carotenoid accumulation.