title: Genome sequence of Valsa canker pathogens uncovers a potential adaptation of colonization of woody bark.
abstract: Canker caused by ascomycetous Valsa species are among the most destructive diseases of woody plants worldwide. These pathogens are distinct from other pathogens because they only effectively attack tree bark in the field. To unravel the potential adaptation mechanism of bark colonization, we examined the genomes of Valsa mali and Valsa pyri that preferentially infect apple and pear, respectively. We reported the 44.7 and 35.7 Mb genomes of V. mali and V. pyri, respectively. We also identified the potential genomic determinants of wood colonization by comparing them with related cereal pathogens. Both genomes encode a plethora of pathogenicity-related genes involved in plant cell wall degradation and secondary metabolite biosynthesis. In order to adapt to the nutrient limitation and low pH environment in bark, they seem to employ membrane transporters associated with nitrogen uptake and secrete proteases predominantly with acidic pH optima. Remarkably, both Valsa genomes are especially suited for pectin decomposition, but are limited in lignocellulose and cutin degradation. Besides many similarities, the two genomes show distinct variations in many secondary metabolism gene clusters. Our results show a potential adaptation of Valsa canker pathogens to colonize woody bark. Secondary metabolism gene clusters are probably responsible for this host specificity.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Huiquan
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Zhengpeng
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Xiwang
authors.initials: X
authors.lastname: Ke
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, 1 Weigang Road, Nanjing, 210095, China.
authors.forename: Daolong
authors.initials: D
authors.lastname: Dou
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Na
authors.initials: N
authors.lastname: Song
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.|Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Zhensheng
authors.initials: Z
authors.lastname: Kang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, 712100, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Huang
mesh_terms: D000220:Adaptation, Biological; D001203:Ascomycota / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D001483:Base Sequence; D002874:Chromosome Mapping; D005800:Genes, Fungal; D016681:Genome, Fungal; D027845:Malus / Q000382:microbiology; D026901:Membrane Transport Proteins / Q000378:metabolism; D010368:Pectins / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D024301:Plant Bark / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D031989:Pyrus / Q000382:microbiology; D013045:Species Specificity; D014197:Trees / Q000382:microbiology*; D014934:Wood / Q000382:microbiology*
chemical_list: D026901:Membrane Transport Proteins; D010368:Pectins; D010447:Peptide Hydrolases
keywords: Cytospora spp.; fungal genomics; necrotrophic fungi; pectinase; secondary metabolism; tree disease