Pepper is widely cultivated, and the application of CO 2 promotes photosynthesis and increases its yield. However, the molecular mechanisms underlying this are still unclear. In this study, the photosynthetic correlation indexes under elevated CO 2 and control conditions were compared. The application of CO 2 increased the photosynthetic capacity of pepper. Moreover, RNA-Seq analysis was used to identify genes that were differentially expressed between pepper leaves grown in CO 2 -enriched conditions and those grown in control conditions. The 149 differentially expressed genes (DEGs) were found to be involved in photosynthesis and other metabolic processes. According to GO significant enrichment analysis, the proteins encoded by the DEGs were mainly found to be located in the chloroplast, the chloroplast matrix, and the apoplast. According to KEGG significant enrichment analysis, the DEGs were found to be involved in glutathione metabolism; starch and sucrose metabolism; and stilbenoid, diarylheptanoid, gingerol, flavonoid, and phenylpropanoid biosynthesis. The DEGs were also involved in the pentose phosphate pathway, carbon metabolism, and porphyrin and chlorophyll metabolism. Based on the GO annotation and the KEGG database analysis, ten of the DEGs identified were suggested to be involved in photosynthesis and related processes; these genes were predicted to have roles in carbohydrate, soluble sugar, and glutathione metabolism, and in raffinose, cysteine, nucleotide, and ABA biosynthesis. These DEGs are involved in the pentose phosphate pathway and tricarboxylic acid cycle of carbon assimilation during photosynthesis. One of the DEGs was also found to be involved in chlorophyll biosynthesis. These results lay the foundation for further investigation of the molecular mechanisms and genes involved in the response to CO 2 enrichment in peppers.

中文翻译：

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使用 RNA-Seq 分析鉴定参与 CO2 富集反应的辣椒基因

辣椒广泛栽培，施用CO 2 促进光合作用，增加产量。然而，其背后的分子机制仍不清楚。本研究比较了CO 2 升高和对照条件下的光合相关指标。CO 2 的施用提高了辣椒的光合能力。此外，RNA-Seq 分析用于鉴定在富含 CO 2 的条件下生长的辣椒叶与在对照条件下生长的辣椒叶之间差异表达的基因。发现 149 个差异表达基因 (DEG) 参与光合作用和其他代谢过程。根据GO显着富集分析，发现DEGs编码的蛋白质主要位于叶绿体、叶绿体基质和质外体中。根据KEGG显着富集分析，发现DEGs参与谷胱甘肽代谢；淀粉和蔗糖代谢；芪、二芳基庚烷、姜酚、黄酮和苯丙烷生物合成。DEG 还参与磷酸戊糖途径、碳代谢以及卟啉和叶绿素代谢。根据 GO 注释和 KEGG 数据库分析，确定的 10 个 DEG 被认为参与了光合作用和相关过程；这些基因被预测在碳水化合物、可溶性糖和谷胱甘肽代谢以及棉子糖、半胱氨酸、核苷酸和 ABA 生物合成中起作用。这些DEGs参与光合作用过程中碳同化的戊糖磷酸途径和三羧酸循环。还发现其中一种 DEG 参与叶绿素生物合成。这些结果为进一步研究辣椒中CO 2 富集响应的分子机制和基因奠定了基础。