A Genome-Wide Association Study Identifies Genomic Regions for Virulence in the Non-Model Organism Heterobasidion annosum s.s

Abstract

The dense single nucleotide polymorphisms (SNP) panels needed for genome wide association (GWA) studies have hitherto been expensive to establish and use on non-model organisms. To overcome this, we used a next generation sequencing approach to both establish SNPs and to determine genotypes. We conducted a GWA study on a fungal species, analysing the virulence of Heterobasidion annosum s.s., a necrotrophic pathogen, on its hosts Picea abies and Pinus sylvestris. From a set of 33,018 single nucleotide polymorphisms (SNP) in 23 haploid isolates, twelve SNP markers distributed on seven contigs were associated with virulence (P<0.0001). Four of the contigs harbour known virulence genes from other fungal pathogens and the remaining three harbour novel candidate genes. Two contigs link closely to virulence regions recognized previously by QTL mapping in the congeneric hybrid H. irregulare × H. occidentale. Our study demonstrates the efficiency of GWA studies for dissecting important complex traits of small populations of non-model haploid organisms with small genomes.

Identification of Diverse Mycoviruses through Metatranscriptomics Characterization of the Viromes of Five Major Fungal Plant Pathogens

“…For example, because of the importance of pathogenic fungi to human and plant health, fungal genomes are being characterized to identify virulence effectors and other sequences associated with pathogenesis (96)(97)(98)(99). However, infection of pathogenically diverse fungal isolates with virulencealtering mycoviruses could reduce the abilities of such studies to identify chromosomal regions linked to disease severity.…”

Accumulation of iron-binding compounds in root of Pinus sylvestris challenged by Heterobasidion annosum sensu lato

“…& Otrosina in contrast to nonpathogenic basidiomycetes. Besides, H. annosum s.s. genom studies showed that genes coded proteins responsible for virulence factor are also connected with iron metabolism (Dalman et al 2013). Oxalic acid has also been reported to play a role in the pathogenicity of Sclerotinia sclerotiorum (Lib.)…”

“…& Otrosina in contrast to other nonpathogenic basidiomycetes. The regions essential in virulence of H. annosum s.s. coded proteins involved in iron metabolism (Dalman et al 2013). Our previous studies showed that iron together with H 2 O 2 is involved in cell death of P. sylvestris challenged by H. annosum s.s. .…”

Call for a California Coccidioidomycosis Consortium to Face the Top Ten Challenges Posed by a Recalcitrant Regional Disease

“…Recent work with other chronic granulomatous diseases, most notably tuberculosis, has led to the recognition of a subset of pathogenic strains that cause more serious infections due to enhanced expression of virulence determinants [57]. Similar genome-wide association studies (GWAS) in other fungi including pathogens have revealed important understanding of virulence mechanisms [58][59][60]. GWAS is a promising approach to understand genetic basis of disease severity in Coccidioides strains.…”