Genome-Wide Identification and Expression Analysis of Auxin-Responsive Gene Family in Pepper ( L.).

As an auxin-responsive gene, () maintains hormonal homeostasis by conjugating excess auxin with amino acids in plant stress-related signaling pathways. genes have been characterized in many plant species, but the characteristics of pepper ( L.) () gene family members in response to multiple stimulants are largely unknown. In this study, we systematically identified the gene family at the genome level and identified eight members on four chromosomes in pepper. s were divided into two groups (I and III) and shared conserved motifs, domains, and gene structures. Moreover, s had close evolutionary relationships with tomato ( L.), and the promoters of most genes contained hormone and abiotic stress response elements. A protein interaction prediction analysis demonstrated that the CaGH3-3/3-6/3-7/3-8 proteins were possibly core members of the family interaction. In addition, qRT-PCR results showed that genes were differentially expressed in pepper tissues and could be induced by phytohormones (IAA, ABA, and MeJA) and abiotic stresses (salt, low temperature, and drought) with different patterns. In addition, and were cloned, and the sequences showed a high degree of conservation. Moreover, the results of subcellular localization indicated that they were located in the membrane and chloroplast. Notably, after overexpressing in tomato, RNA-seq was performed on wild-type and transgenic lines, and the differentially expressed genes were mainly enriched in response to external stimuli. This study not only lays the foundation for a comprehensive understanding of the function of the gene family during plant growth and stress responses but also provides potential genetic resources for pepper resistance breeding.