Characterization of Gene Family in Pepper ( L.) under Abiotic Stress and ABA Treatment.

Plant glutathione peroxidases (GPXs) are important enzymes for removing reactive oxygen species in plant cells and are closely related to the stress resistance of plants. This study identified the gene family members of pepper ( L.), "CM333", at the whole-genome level to clarify their expression patterns and enzyme activity changes under abiotic stress and ABA treatment. The results showed that eight genes were unevenly distributed across four chromosomes and one scaffold of the pepper genome, and their protein sequences had Cys residues typical of the plant GPX domains. The analysis of collinearity, phylogenetic tree, gene structure, and conserved motifs indicated that the gene sequence is conserved, structurally similar, and more closely related to the sequence structure of . Meanwhile, many cis elements involved in stress, hormones, development, and light response were found in the promoter region of the gene. In addition, / and were basically expressed in all tissues, and their expression levels were significantly upregulated under abiotic stress and ABA treatment. Subcellular localization showed that CaGPX1 and CaGPX4 are localized in chloroplasts. Additionally, the variations in glutathione peroxidase activity (GSH-Px) mostly agreed with the variations in gene expression. In summary, the gene may play an important role in the development of peppers and their response to abiotic stress and hormones.