Identification of DMP Family Members in Solanaceous Vegetables Potentially Involved in Haploid Induction

Haploid breeding technology offers a promising means of significantly shortening the breeding cycle by rapidly generating homozygous inbred lines. Previous studies have shown that DMP8 is involved in haploid induction across various plant species. In this study, we performed whole-genome identification and bioinformatics analyses to investigate the evolutionary relationships, gene structures, conserved domains, and expression patterns of DMP gene family members in tomato (Solanum lycopersicum), pepper (Capsicum annuum) and eggplant (S. melongena). A total of seven, six, and eight DMP genes were identified in the genomes of tomato, pepper, and eggplant, respectively. All encoded proteins contained the DUF679 domain, and the DMP family members were clustered into three distinct groups. Collinearity analysis revealed species-specific expansions of DMP genes in the Solanaceae family. Phylogenetic analysis indicated that CaDMP8 and SmDMP8 are homologous to SlDMP8, with conserved gene and protein structures, suggesting that CaDMP8 and SmDMP8 are potential targets for developing haploid induction lines. Expression pattern analysis demonstrated that SlDMP4 and SlDMP8 are highly expressed in tomato flower tissues, suggesting their potential functional synergy. This study provides the first comprehensive insight into the evolutionary characteristics and functional diversification of the DMP gene family in Solanaceous vegetables. The findings offer a theoretical foundation for the targeted editing of DMP8 homologs to create haploid induction lines, which is critical for accelerating the genetic improvement of Solanaceous crops.