Identification and Analysis of Resistance-like Genes in the Tomato Genome

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops in the world. However, the tomato production is severely affected by many diseases. The use of host resistance is believed to be the most effective approach to control the pathogens. In this study, a total of 1003 resistance-like genes were identified from the tomato genome using individual full-length search and conserved domain verification approach. Of the predicted resistance genes, serine/threonine protein kinase was the largest class with 384 genes followed by 212 genes encoding receptor-like kinase, 107 genes encoding receptor-like proteins, 68 genes encoding coiled-coil-nucleotide-binding site (NBS)-leucine-rich repeat (LRR) and 19 genes encoding Toll interleukin-1 receptor domain-NBS-LRR. Physical map positions established for all predicted genes using the tomato WGS chromosomes SL2.40 information indicated that most resistance-like genes clustered on certain chromosomal regions. Comparisons of the sequences from the same resistance-like genes in S.pimpinellifolium and S.lycopersicum showed that 93.5% genes contained single nucleotide polymorphisms and 19.7% genes contained insertion/deletion. The data obtained here will facilitate isolation and characterization of new resistance genes as well as marker-assisted selection for disease resistance breeding in tomato.