Carotenoids are important pigments in pepper fruits. The colors of each pepper are mainly determined by the composition and content of carotenoid. The ‘ZY’ variety, which has yellow fruit, is a natural mutant derived from a branch mutant of ‘ZR’ with different colors. ZY and ZR exhibit obvious differences in fruit color, but no other obvious differences in other traits. To investigate the main reasons for the formation of different colored pepper fruits, transcriptome and metabolome analyses were performed in three developmental stages (S1–S3) in two cultivars. The results revealed that these structural genes (PSY1, CRTISO, CCD1, CYP97C1, VDE1, CCS, NCED1 and NCED2) related to carotenoid biosynthesis were expressed differentially in the two cultivars. Capsanthin and capsorubin mainly accumulated in ZR and were almost non-existent in ZY. S2 is the fruit color-changing stage; this may be a critical period for the development of different color formation of ZY and ZR. A combination of transcriptome and metabolome analyses indicated that CCS, NCED2, AAO4, VDE1 and CYP97C1 genes were key to the differences in the total carotenoid content. These new insights into pepper fruit coloration may help to improve fruit breeding strategies.

Drought stress is an important factor that reduces plant biomass production and quality. The APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) gene family is widely involved in biological processes such as plant growth, development, and stress response. However, the characteristics of the AP2/ERF gene family in hybrid tea rose (Rosa × hybrida) and their potential functions in responding to drought stress are still unclear. In the current study, 127 AP2/ERF genes were identified in hybrid tea rose. Phylogenetic analysis showed that the corresponding 127 AP2/ERF transcription factors belonged to five subfamilies. There was a large number of cis-acting elements in the AP2/ERF gene promoters related to regulation of stress response, growth and development. By examining the RNA sequencing data in the PlantExp database, the RhAP2/ERF genes exhibiting tissue-specific and stress-responsive expression in rose were identified. Furthermore, three candidate RhAP2/ERF genes (RhDREB36, RhERF59, and RhDREB44) that might participate in drought response were determined via qRT-PCR analysis in rose cultivars under drought treatment. Subcellular localization analysis revealed that RhDREB44 was located in the nucleus. These results provide a foundation for exploring the regulatory functions of RhAP2/ERF genes in the growth and development of roses, as well as for selecting key genes for future molecular breeding.

Pepper is an important vegetable and economic crop, and the MYB family is one of the most numerous transcription factor families in plants, extensively participating in various biological processes such as plant growth, development, and stress resistance. In this study, CcMYB330 is identified as a differentially expressed gene in the pepper fruit, and CcMYB330 is expressed with higher expression levels in the placenta and pericarp at different development stages of pepper fruit. Analysis of the promoter cis-elements revealed that this gene contains not only core elements but also environmental factor response elements and plant hormone response elements. The silencing of CcMYB330 could reduce the capsaicinoid accumulation in pepper fruit, while the overexpression of CcMYB330 could increase capsaicinoid accumulation. Additionally, silencing or overexpressing CcMYB330 could regulate the expression of structural genes involved in capsaicinoid biosynthesis. In addition, through yeast one-hybrid experiments, we identified an interaction between CcMYB330 and the capsaicinoid biosynthesis structural gene CcPAL. Further evidence from EMSA experiments and dual luciferase assays confirmed that CcMYB330 can bind to the cis-element ACCAACAACCAAA in the CcPAL promoter. These results indicate that CcMYB330 may regulate the synthesis of capsaicinoids by modulating structural genes in the capsaicinoid biosynthesis pathway, providing new insights into the regulatory mechanisms of capsaicinoid synthesis.

Pepper is a fruit, vegetable, and spice crop and is widely cultivated around the world. This study analyzed the transcriptomes and metabolomes of pepper fr

Dried yellow chili is highly appreciated by consumers due to its excellent quality and flavor. The quality of products is determined by the drying and storage methods. In this study, dried yellow chilis were processed by natural air drying and hot air drying methods and then stored under three conditions: ambient temperature, ambient temperature with light avoidance, and at 10 °C with light avoidance for 12 months. The changes in the bioactive compounds during this period were analyzed attempting to reveal correlations between the different treatments and these compounds, with the aim of providing references for maintaining the bioactive compounds of pepper products. The results showed that samples treated with hot air had higher levels of fatty acids, resulting in a more pronounced flavor. During storage, samples stored at 10 °C with light avoidance were more effective in preserving soluble solids, total protein content, total phenols, capsaicinoids and most fatty acids.

Fruit color serves as a crucial visual indicator in chili peppers and is closely linked to the bioactive components that determine their economic and nutritional value. However, the specific components and potential molecular mechanisms that impact fruits’ development and color changes are less thoroughly understood. Here, we utilized three chili pepper varieties (CS03, CS29, and L816) at different developmental stages (young fruit stage, turning color stage, and mature stage) as research materials and integrated transcriptome and non-targeted metabolome analyses to explore the variation in bioactive components and color to explain the molecular regulatory mechanisms underlying different colors of chili peppers during the young fruit stage. Our results showed that flavonoids were the most enriched differential metabolites; aromadendrin 4′-glucoside, diospyrin, precarthamin, kaempferol-3-O-rutinoside, and kaempferol-3-O-Glucoside were significantly enriched in the young fruit stage of pepper CS03; and cyanidin, delphinidin, and cyanidin 3-glucoside were major contributors to the color formation. The upregulation of anthocyanin was related to the structural genes CaC4H, Ca4CL, CaCHS, CaF3H, CaANS, and CaUFGT, and key transcription factors such as CaMYBs and CabHLHs may have contributed to the differential accumulation of anthocyanins in CS03; in addition, RT-qPCR validation was correlated with anthocyanins, but also with flavonoids. This article mainly focuses on the changes in chili pigments, particularly anthocyanins, and explores the molecular mechanisms involved. This provides a reference for research on color in solanaceae vegetables and lays a theoretical foundation for further research on the bioactive components of chili peppers, as well as for optimizing harvesting practices and dietary recommendations.