Genome-wide analysis of the family 10 plant pathogenesis-related proteins in Pyrus bretschneideri and functional analysis of PbrMLP for Colletotrichum fructicola resistance

Abstract Pathogenesis-related (PR) genes are key regulators of plant adaptation responses to biotic and abiotic stresses. Family 10 PRs ( PR10 s, also known as major latex proteins) are usually induced by pathogens and environmental stresses. However, the evolutionary trajectory and functional divergence of the PR10 gene family in Chinese white pear ( Pyrus bretschneideri ‘Dangshan Suli’) remain uncharacterized. The presence of 61 PR10 s was detected across six Rosaceae species. The PR10 gene family was classified into two distinct groups by employing phylogenetic analysis and the taxonomic criteria of model plants. Interspecies synchrony revealed an ancient origin of the PR10 family in the six Rosaceae species, with 18 synchronic gene pairs. The expansion and evolution of the PR10 family were driven by various types of gene duplication events, with whole-genome duplication (WGD) being the primary mechanism. A candidate Colletotrichum fructicola ( C. fructicola ) resistance gene Pyr us bretschneideri major latex-like proteins ( PbrMLP ) belonging to the PR10 family was screened through transcriptomics and qRT-PCR. In addition, PbrMLP -silenced pear seedlings were more sensitive to C. fructicola than the controls. These results showed that PbrMLP is a candidate gene vital for anthracnose resistance in pears. These findings offer novel insights into the molecular mechanisms underlying the resistance to pear anthracnose infection in Rosaceae species and identify potential target genes for developing disease-resistant cultivars through genetic engineering.