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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sugarbeet and Potato Research » Research » Publications at this Location » Publication #306709

Title: The genome of the saprophytic fungus Verticillium tricorpus reveals a complex effector repertoire largely resembling its pathogenic relatives

Author
item SEIDL, MICHAEL - Wageningen University
item FAINO, LUIGI - Wageningen University
item VAN DEN BERG, GRARDY - Wageningen University
item Bolton, Melvin
item THOMMA, BART - Wageningen University

Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2014
Publication Date: 3/1/2015
Citation: Seidl, M.F., Faino, L., Van Den Berg, G.C., Bolton, M.D., Thomma, B.P. 2015. The genome of the saprophytic fungus Verticillium tricorpus reveals a complex effector repertoire largely resembling that of its pathogenic relatives. Molecular Plant-Microbe Interactions. 28(3):362-373.

Interpretive Summary: Vascular wilts belong to the most destructive plant diseases, affecting hundreds of economically and ecologically important plant species. The fungal genus Verticillium presently comprises ten species, of which only few cause disease in plants. Of these, V. dahliae is the most notorious pathogen that causes Verticillium wilt on hundreds of host plants. In contrast, V. tricorpus is mainly known to live on dead or decaying plant debris (saprophytic) and only an opportunistic pathogen of plants. Whereas the genomes of several V. dahliae strains are publically available, no saprophytic Verticillium species has yet been sequenced. Based on a hybrid sequencing and assembly approach that combines second and third generation sequencing techniques, a high-quality, near-gapless assembly of the 36 Mb genome of V. tricorpus was obtained. By comparing the genomes of sequenced Verticillium pathogens, we aimed to identify genomic features in pathogenic Verticillium species that can confer the ability to cause vascular wilt disease. Unexpectedly, we reveal a highly similar repertoire of putative genes known to be involved in pathogenicity in plant pathogenic Verticillium species. Moreover, both species seem to share their genomic structure, with genes encoding secreted proteins clustered in genomic islands. Rather than pathogenicity-related traits in pathogenic Verticillium, an extended spectrum of secreted carbohydrate active enzymes was found in V. tricorpus that may foster the effective utilization of sugars during saprophytic lifestyle. In conclusion, we highlight the technical advances of a hybrid sequencing and assembly approach and reveal that saprophytic and pathogenic Verticillium spp. share many hallmark features with their pathogenic relatives, and pathogenicity of V. dahliae cannot be explained by obvious amendments in its effector repertoire.

Technical Abstract: Vascular wilts belong to the most destructive plant diseases, affecting hundreds of economically and ecologically important plant species. The fungal genus Verticillium presently comprises ten species, of which only few are causal agents of vascular wilt diseases. Of these, V. dahliae is the most notorious pathogen that causes Verticillium wilt on hundreds of host plants. In contrast, V. tricorpus is mainly known as a saprophyte and only an opportunistic causal agent of vascular wilt. Whereas the genomes of several V. dahliae strains are publically available, no saprophytic Verticillium species has yet been sequenced. Based on a hybrid sequencing and assembly approach that combines second and third generation sequencing techniques, a high-quality, near-gapless assembly of the 36 Mb genome of V. tricorpus was obtained. With comparative genomics, we aimed to identify genomic features in pathogenic Verticillium species that can confer the ability to cause vascular wilt disease. Unexpectedly, we reveal a highly similar repertoire of putative effectors in pathogenic Verticillium and V. tricorpus. Moreover, both species seem to share their genomic structure, with genes encoding secreted proteins clustered in genomic islands. Rather than pathogenicity-related traits in pathogenic Verticillium, an extended spectrum of secreted carbohydrate active enzymes was found in V. tricorpus that may foster the effective utilization of carbohydrate during saprophytic lifestyle. In conclusion, we highlight the technical advances of a hybrid sequencing and assembly approach and reveal that saprophytic and pathogenic Verticillium spp. share many hallmark features with their pathogenic relatives, and pathogenicity of V. dahliae cannot be explained by obvious amendments in its effector repertoire.