Abstract Carotenoids belong to a major family of isoprenoids which play vital roles in plant growth and development. Pepper (Capsicum annuum L.) is not only a vegetable and condiment grown worldwide, but also can be used as a model organism in fruit color research. In this study, 61 genes known to be involved in mevalonate (MVA), plastidial 2-C-methyl-d-erythritol-4-phosphate (MEP) and carotenoid metabolism (biosynthesis and catabolism) pathways were identified and characterized based on the genome of pepper plants. In the present study, it was found that 56 of the 61 carotenoid metabolism genes in pepper were unevenly distributed throughout 12 chromosomes. CaGGPPS2, CaGGPPS4a and CaGGPPS4b were generally clustered into one region. This study identified CaHMGR1/CaHMGR3 and CaHMGR1/CaHMGR2 as segregation duplication events. In addition, the pepper carotenoid metabolism genes had high variations in gene structure. The key carotenoid metabolism genes showed different expression patterns during the pepper fruit development and under environmental stress conditions. The results obtained in this research investigation will contribute insight to the evolution and function of carotenoid metabolic pathways in pepper fruit.

中文翻译：

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辣椒类胡萝卜素代谢途径基因的全基因组鉴定及表达分析（Capsicum annuum L.）

摘要 类胡萝卜素属于类异戊二烯的一个主要家族，在植物生长发育中起着至关重要的作用。胡椒 (Capsicum annuum L.) 不仅是世界范围内种植的蔬菜和调味品，还可作为水果颜色研究的模式生物。在这项研究中，基于基因组鉴定和表征了 61 个已知参与甲羟戊酸 (MVA)、质体 2-C-甲基-d-赤藓糖醇-4-磷酸 (MEP) 和类胡萝卜素代谢（生物合成和分解代谢）途径的基因辣椒植物。在本研究中，发现辣椒中 61 个类胡萝卜素代谢基因中有 56 个在 12 条染色体中分布不均。CaGGPPS2、CaGGPPS4a 和 CaGGPPS4b 通常聚集在一个区域中。该研究将 CaHMGR1/CaHMGR3 和 CaHMGR1/CaHMGR2 鉴定为分离重复事件。此外，辣椒类胡萝卜素代谢基因的基因结构变异较大。关键类胡萝卜素代谢基因在辣椒果实发育和环境胁迫条件下表现出不同的表达模式。这项研究调查中获得的结果将有助于深入了解辣椒果实中类胡萝卜素代谢途径的进化和功能。