title: Horizontal gene transfer drives adaptive colonization of apple trees by the fungal pathogen Valsa mali.
abstract: Horizontal gene transfer (HGT) often has strong benefits for fungi. In a study of samples from apple canker in Shaanxi Province, China, diverse microbes, along with the necrotrophic pathogen Valsa mali, were found to colonize the apple bark, thus providing ample opportunity for HGT to occur. In the present study, we identified 32 HGT events in V. mali by combining phyletic distribution-based methods with phylogenetic analyses. Most of these HGTs were from bacteria, whereas several others were from eukaryotes. Three HGTs putatively functioned in competition with actinomycetes, some of which showed a significant inhibitory effect on V. mali. Three HGTs that were probably involved in nitrogen uptake were also identified. Ten HGTs were thought to be involved in pathogenicity because they were related to known virulence factors, including cell wall-degrading enzymes and candidate effector proteins. HGT14, together with HGT32, was shown to contribute to bleomycin resistance of V. mali.These results suggest that HGT drives the adaptive evolution of V. mali. The HGTs identified here provide new clues for unveiling the adaptation mechanisms and virulence determinants of V. mali.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Baitao
authors.initials: B
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Huang
mesh_terms: D039903:Actinobacteria / Q000235:genetics; D001203:Ascomycota / Q000235:genetics* / Q000472:pathogenicity*; D001419:Bacteria / Q000235:genetics / Q000472:pathogenicity; D001761:Bleomycin / Q000378:metabolism; D002473:Cell Wall / Q000235:genetics; D002681:China; D056890:Eukaryota / Q000235:genetics; D022761:Gene Transfer, Horizontal / Q000235:genetics*; D027845:Malus / Q000235:genetics* / Q000382:microbiology*; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors; D001761:Bleomycin; D009584:Nitrogen