Cotton (Gossypium spp.) is the fifth largest oil crop in the world, and cottonseed provides abundant vegetable oil resources and industrial bioenergy fuels for people; therefore, it is of practical significance to increase the oil content of cotton seeds for improving the oil yield and economic benefits of planting cotton. Long-chain acyl-coenzyme A (CoA) synthetase (LACS) capable of catalyzing the formation of acyl-CoAs from free fatty acids has been proven to significantly participate in lipid metabolism, of which whole-genome identification and functional characterization of the gene family have not yet been comprehensively analyzed in cotton. In this study, a total of sixty-five LACS genes were confirmed in two diploid and two tetraploid Gossypium species, which were divided into six subgroups based on phylogenetic relationships with twenty-one other plants. An analysis of protein motif and genomic organizations displayed structural and functional conservation within the same group but diverged among the different group. Gene duplication relationship analysis illustrates the LACS gene family in large scale expansion through WGDs/segmental duplications. The overall Ka/Ks ratio indicated the intense purifying selection of LACS genes in four cotton species during evolution. The LACS genes promoter elements contain numerous light response cis-elements associated with fatty acids synthesis and catabolism. In addition, the expression of almost all GhLACS genes in high seed oil were higher compared to those in low seed oil. We proposed LACS gene models and shed light on their functional roles in lipid metabolism, demonstrating their engineering potential for modulating TAG synthesis in cotton, and the genetic engineering of cottonseed oil provides a theoretical basis.

Members of DOMAIN OF UNKNOWN FUNCTION 679 membrane proteins (DMPs) have the DUF679 domain, which plays an important role in the process of plant fertilization. In this study, bioinformatics methods were used to identify and analyze the DMP gene family in pepper. The location of the expression of the DMP gene family was explored according to the transient expression of Nicotiana benthamiana, and its expression patterns in different tissues and abiotic stress treatments were analyzed by qRT-PCR. A total of 17 CaDMP genes were identified from the three capsicum varieties, and sub-cellular localization prediction showed that CaDMPs were located on the cell membrane. Phylogenetic analysis showed that CaDMP5 in subgroup Ⅳ was highly homologous with haploid induction genes in Arabidopsis and maize, and its expression level in reproductive organs was significantly higher than that in other tissues, suggesting that CaDMP5 could be a candidate gene for haploid induction in pepper. The expression of CaDMPs increased to varying degrees after different stress treatments, indicating that the DMP gene plays an important role in plant growth and development. The CaDMP gene family was systematically analyzed in this study, which provided preliminary insights for the further research of Capsicum haploid breeding.