摘要：

MADS-box转录因子广泛存在于植物中,在生长发育和次生代谢过程中发挥重要作用。为探究MADS-box转录因子家族在辣椒素不同积累时期的表达情况。利用辣椒素不同积累时期转录组数据,鉴定辣椒MADS-box转录因子家族成员,并进行亚细胞定位、保守基序、系统进化树和染色体定位分析,对其功能进行初步分析。结果表明,在辣椒转录组数据中共鉴定出95个MADS-box转录因子;含有105~395个氨基酸;分子质量为11.55~44.46 ku;理论等电点为5.16~10.01;主要在细胞核表达,均含有MADS 保守结构域,系统发育分析表明,MADS蛋白可分为8个亚家族。有73条CaMADS家族成员定位到12条染色体上。差异表达的MADS-box基因有26个,其中6个基因在C1 vs C2时期上调,在C2 vs C3时期下调。基于KEGG富集和蛋白互作预测到CaMADS13可能参与辣椒中木质素的合成。CaMADS24可能参与辣椒素和木质素合成前体香豆酰辅酶A的合成。利用生物信息学分析,鉴定了辣椒MADS-box家族转录因子,为深入研究辣椒素次生代谢中的分子调控机制提供理论基础。

关键词: 辣椒, MADS-box, 转录因子, 次生代谢

Abstract:

MADS-box transcription factors are widely found in plants and play important roles in plant growth and development and secondary metabolism.To investigate the expression of MADS-box transcription factor family in different accumulation periods of capsaicin.MADS-box transcription factor family was identified by using transcriptome data from different accumulation periods of capsaicin,and their functions were preliminarily analyzed.Subcellular localization,conserved motifs,phylogenetic tree and chromosomal localization of members of the MADS-box transcription factor family of chili peppers were carried out.The results showed that a total of 95 MADS-box transcription factors were identified in the Capsicum annuum L.transcriptome data;containing 105-395 amino acids;with molecular weight ranging from 11.55-44.46 ku;with theoretical isoelectric points ranging from 5.16-10.01;mainly expressed in the nucleus,and all of them contained MADS conserved structural domains,and phylogenetic analysis showed that MADS proteins could be divided into eight subfamilies.There were 73 CaMADS family members localized to 12 chromosomes.There were 26 differentially expressed MADS-box genes,six of which were up-regulated during C1 vs C2 and down-regulated during C2 vs C3.Based on KEGG enrichment and protein interactions,it was predicted that CaMADS13 might be involved in lignin synthesis in chili peppers.CaMADS24 might be involved in the synthesis of capsaicin and lignin synthesis precursor,coumaroyl-coenzyme A.Bioinformatics analysis was used to identify the MADS-box family of transcription factors in chili peppers,which provides data reference and theoretical basis for in-depth study of the molecular mechanism of action in the secondary metabolism of capsaicin.

Key words: Peppers, MADS-box, Transcription factor, Secondary metabolism