title: Transcriptome profiling to identify genes involved in pathogenicity of Valsa mali on apple tree.
abstract: Apple Valsa canker, caused by the fungus Valsa mali (Vm), is one of the most destructive diseases of apple in China. A better understanding of this host-pathogen interaction is urgently needed to improve management strategies. In the current study we sequenced the transcriptomes of Vm during infection of apple bark and mycelium grown in axenic culture using Illumina RNA-Seq technology. We identified 437 genes that were differentially expressed during fungal infection compared to fungal mycelium grown in axenic culture. One hundred and thirty nine of these 437 genes showed more than two fold higher transcript abundance during infection. GO and KEGG enrichment analyses of the up-regulated genes suggest prevalence of genes associated with pectin catabolic, hydrolase activity and secondary metabolite biosynthesis during fungal infection. Some of the up-regulated genes associated with loss of pathogenicity and reduced virulence annotated by host-pathogen interaction databases may also be involved in cell wall hydrolysis and secondary metabolite transport, including a glycoside hydrolase family 28 protein, a peptidase and two major facilitator superfamily proteins. This highlights the importance of secondary metabolites and cell wall hydrolases during establishment of apple Valsa canker. Functional verification of the genes involved in pathogenicity of Vm will allow us to better understand how the fungus interferes with the host machinery and assists in apple canker establishment.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xiwang
authors.initials: X
authors.lastname: Ke
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 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, Shaanxi 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, Shaanxi 712100, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Dai
authors.affiliation: Institut für Phytomedizin, Universität Hohenheim, Stuttgart, Germany.
authors.forename: Ralf T
authors.initials: RT
authors.lastname: Voegele
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yangyang
authors.initials: Y
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, Shaanxi 712100, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 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, Shaanxi 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, Shaanxi 712100, China. Electronic address: huanglili@nwsuaf.edu.cn.
authors.forename: Lili
authors.initials: L
authors.lastname: Huang
mesh_terms: D001203:Ascomycota / Q000378:metabolism / Q000472:pathogenicity*; D002681:China; D020869:Gene Expression Profiling; D005800:Genes, Fungal; D059014:High-Throughput Nucleotide Sequencing; D027845:Malus / Q000382:microbiology*; D025282:Mycelium; D024301:Plant Bark / Q000382:microbiology; D059467:Transcriptome; D014774:Virulence
keywords: Apple Valsa canker; Cell wall hydrolases; RNA sequencing; Secondary metabolites