Genome-wide identification of lysin motif containing protein family genes in eight rosaceae species, and expression analysis in response to pathogenic fungus Botryosphaeria dothidea in Chinese white pear

Background: Lysin motif-containing proteins (LYP), which act as pattern-recognition receptors, play central roles in growth, node formation, and responses to biotic stresses. The sequence of Chinese white pear genome (cv. 'Dangshansuli') along with the seven other species of Rosaceae has already been reported. Although, in these fruit crops, there is still a lack of clarity regarding the LYP family genes and their evolutionary history. Results: In the existing study, eight Rosaceae species i.e., Pyrus communis,Prunus persica,Fragaria vesca,Pyrus bretschneideri, Prunus avium, Prunus mume,Rubus occidentalis, andMalus x domesticawere evaluated. Here, we determined a total of 124LYPgenes from the underlined Rosaceae species. While eighteen of the genes were from Chinese white pear, named asPbrLYPs. According to theLYPsstructural characteristics and their phylogenetic analysis, those genes were classified into eight groups (group LYK1, LYK2, LYK3, LYK4/5, LYM1/3, LYM2, NFP, and WAKL). Dispersed duplication and whole-genome duplication (WGD) were found to be the most contributing factors ofLYPfamily expansion in the Rosaceae species. More than half of the duplicatedPbrLYPgene pairs were dated back to the ancient WGD (similar to 140 million years ago (MYA)), andPbrLYPgenes have experienced long-term purifying selection. The transcriptomic results indicated that thePbrLYPgenes expression was tissue-specific. MostPbrLYPgenes showed differential expression in leaves under fungal pathogen infection with two of them located in the plasmalemma. Conclusion: A comprehensive analysis identified 124LYPgenes in eight Rosaceae species. Our findings have provided insights into the functions and characteristics of the RosaceaeLYPgenes and a guide for the identification of other candidateLYPsfor further genetic improvements for pathogen-resistance in higher plants.