Genes containing GTP_EFTU domain mainly express elongation factors (EF), Small GTPases, and GTP-binding proteins, which are closely related to protein synthesis, extension and ATP synthesis. In this study, we identified 39 genes containing GTP_EFTU domains from peppers. The evolutionary trees constructed from capsicum, Arabidopsis, rice, and tomato are mainly divided into 7 subfamilies. Using PacBio (Pacific Biosciences) sequencing and assembly data, we extracted these 39 gene sequences, from which 25 genes had alternative splicing. Particularly, the Capana08g000545 had 16 alternative splicing processes. Accordingly, we performed promoter sequence analysis, subcellular location prediction, the expression analysis of different tissues and periods, and also the GO (Gene ontology) analysis of co-expressed genes. Lastly we did the qRT-PCR analysis in 5 stages of pepper fruit development. These analyses revealed important structural and functional information for the identified 39 genes that contain GTP_EFTU domains, providing important references for further follow-up experiments to verify the genes function on plants or their unique roles in peppers.

The male-sterile line has been largely used in the hybrid seed production of pepper, which can effectively improve the efficiency of hybrid seed production. However, the formation mechanism of male sterility in pepper remains unclear. In the present study, we compared the gene expression patterns between pepper cytoplasmic male sterile line 9704A and its maintainer 9704B during floral bud development using RNA sequencing technology. A total of 547976 and 2416 Differentially Expressed Genes (DEGs) were identified in the stage S1, S2 and S3, respectively, and more than 70% of the DEGs were down-regulated in the sterile line. Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to further understand the functions of these identified DEGs. The results showed that the DEGs were mainly enriched in pathways of starch and sucrose metabolism, pentose and glucuronate interconversions. A number of genes, such as MS1, PME5, ATPB, and lots of transcription factors were found down-regulated in the sterile line, and we also identified a series of genes with large differences in expression patterns between sterile line and maintainer line. Collectively, our findings laid a foundation for further molecular breeding in pepper and provided new insights into its mechanism underlying the male sterility.