热带作物学报2022，Vol.43Issue(6)：1129-1143,15.DOI:10.3969/j.issn.1000-2561.2022.06.005
基于加权关联网络分析的辣椒(Capsicum annuum L.)果实颜色转变相关基因的鉴定
Weighted Correlation Network Analysis Reveals Candidate Genes Related to Fruit Color Transition in Pepper (Capsicum annuum L.)
摘要
Abstract
Pepper belongs to the annual or perennial pepper genus (Capsicum L.) in the Solanaceae. Amid all vegetables grown in China, pepper is ranked first as per its sowing area and output value. Fruit color is one of the most intuitive economic traits of pepper, which directly affects people's purchase choice. Nevertheless, the regulation of pepper fruit color is affected by many factors, especially the key regulatory factors in the process of fruit pigment formation and the regulation of related pigment biosynthesis are not clear. To understand the mechanism of pepper fruit color formation, physiological testing, transcriptome sequencing and weighted gene co-expression network analysis (WGCNA) was per-formed using Capsicum germplasm HNCA0076 as the experimental material, presenting five colors during fruit devel-opment. During the five different color periods of the fruit, the chlorophyll content was significantly different, the caro-tenoids content showed an increasing trend, the flavonoid content was relatively stable, and the anthocyanin content decreased gradually after purple fruit stage, and increased after orange fruit stage. The quality of the RNA sequencing data met the requirements for further analysis. The number of differentially expressed genes (DEGs) up-regulated and down-regulated in each period was 826 (276), 390 (588), 1248 (1800) and 1528 (2485). As the fruit matures, the number of differential genes in adjacent comparison combinations gradually increased. DEGs were analyzed by gene ontology (GO) enrichment with a main focus on molecular functional such as tetrapyrrole binding, heme binding, transferase activity, oxidoreductase activity, iron ion binding and hydrolase activity. After KEGG enrichment analysis, DEGs were found mainly enriched in carotenoid biosynthesis, flavonoid biosynthesis, starch and sucrose metabolism. Among these, the expression of the three genes from the carotenoid metabolic pathway were up-regulated during the transition from purple to yellow, and the expression of 11 genes from the flavonoid metabolic pathway were down-regulated during the transition from yellow to red. The differentially expressed genes of four comparative combinations were anno-tated to 8877, 8736, 8689, and 8573 transcription factors (TFs), and together to 8049 TFs, including AP2, F-box, MYB, and UDPGT. We performed a WGCNA using non-redundant DEGs associated with four modules including chlorophyll, carotenoid, coloring, and flavonoid content. Further analysis indicated that 29 TFs such as p450 (LOC107859314), Pkinase (LOC107839192, LOC107875415), F-box (LOC107863894), and zf-MYND (LOC107852593) may be involved in the regulation of pepper fruit color conversion. This study would provide an important data for further exploring the key regulatory factors in the process of pepper fruit coloring and analyzing the regulation of related pigment biosynthesis.关键词
一年生辣椒/转色/类胡萝卜素/类黄酮/转录因子Key words
Capsicum annuum/color transition/carotenoids/flavonoids/transcription factor分类
农业科技引用本文复制引用
金威恒,MUMTAZ Muhammad Ali,何成尧,夏禹,郝园园,李彩朝,汪志伟..基于加权关联网络分析的辣椒(Capsicum annuum L.)果实颜色转变相关基因的鉴定[J].热带作物学报,2022,43(6):1129-1143,15.基金项目
国家重点研发计划项目(No.2018YFD1000800). （No.2018YFD1000800）
