Abstract
Colletotrichum tanaceti is an emerging foliar fungal pathogen of commercially grown pyrethrum (Tanacetum cinerariifolium). Despite being reported consistently from field surveys in Australia, the molecular basis of pathogenicity of C. tanaceti on pyrethrum is unknown. Herein, the genome of C. tanaceti (isolate BRIP57314) was assembled de novo and annotated using transcriptomic evidence. The inferred putative pathogenicity gene suite of C. tanaceti comprised a large array of genes encoding secreted effectors, proteases, CAZymes and secondary metabolites. Comparative analysis of its putative pathogenicity gene profiles with those of closely related species suggested that C. tanaceti likely has additional hosts to pyrethrum. The genome of C. tanaceti had a high repeat content and repetitive elements were located significantly closer to genes inferred to influence pathogenicity than other genes. These repeats are likely to have accelerated mutational and transposition rates in the genome, resulting in a rapid evolution of certain CAZyme families in this species. The C. tanaceti genome showed strong signals of Repeat Induced Point (RIP) mutation which likely caused its bipartite nature consisting of distinct gene-sparse, repeat and A-T rich regions. Pathogenicity genes within these RIP affected regions were likely to have a higher evolutionary rate than the rest of the genome. This “two-speed” genome phenomenon in certain Colletotrichum spp. was hypothesized to have caused the clustering of species based on the pathogenicity genes, to deviate from taxonomic relationships. The large repertoire of pathogenicity factors that potentially evolve rapidly due to the plasticity of the genome, indicated that C. tanaceti has a high evolutionary potential. Therefore, C. tanaceti poses a high-risk to the pyrethrum industry. Knowledge of the evolution and diversity of the putative pathogenicity genes will facilitate future research in disease management of C. tanaceti and other Colletotrichum spp.
Highlights
Plant pathogens cause diseases world-wide that have devastating economic, social and ecological consequences [1]
The genome of isolate BRIP57314 was assembled into 5,242 contigs with an N50 value of 103,135 bp and assembly size of 57.91Mb
The genome size and GC content of C. tanaceti was within the range previously reported for other Colletotrichum spp. (S1 Fig)
Summary
Plant pathogens cause diseases world-wide that have devastating economic, social and ecological consequences [1]. Fungi are among the dominant causal agents of plant diseases [2] and the genus Colletotrichum has been ranked among the top-ten most important fungal plant pathogens [3]. Many Colletotrichum species are known to cause major economic losses globally, and have been extensively used in the study of the molecular and cellular bases of fungal pathogenicity [4]. The publication of 25 whole genome sequences of Colletotrichum species has significantly improved understanding of the biology, genetics and evolution of this genus [5,6,7,8,9,10,11]. Insights into the genomic organization and the pathogenicity gene repertoire of other Colletotrichum species in the destructivum complex will significantly expand the knowledge base of this important genus
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
