A distinct and genetically diverse lineage of the hybrid fungal pathogen Verticillium longisporum population causes stem striping in British oilseed rape

Abstract

Summary Population genetic structures illustrate evolutionary trajectories of organisms adapting to differential environmental conditions. Verticillium stem striping disease on oilseed rape was mainly observed in continental Europe, but has recently emerged in the United Kingdom. The disease is caused by the hybrid fungal species Verticillium longisporum that originates from at least three separate hybridization events, yet hybrids between Verticillium progenitor species A1 and D1 are mainly responsible for Verticillium stem striping. We reveal a hitherto un‐described dichotomy within V. longisporum lineage A1/D1 that correlates with the geographic distribution of the isolates with an ‘A1/D1 West’ and an ‘A1/D1 East’ cluster. Genome comparison between representatives of the A1/D1 West and East clusters excluded population distinctiveness through separate hybridization events. Remarkably, the A1/D1 West population that is genetically more diverse than the entire A1/D1 East cluster caused the sudden emergence of Verticillium stem striping in the UK, whereas in continental Europe Verticillium stem striping is predominantly caused by the more genetically uniform A1/D1 East population. The observed genetic diversity of the A1/D1 West population argues against a recent introduction of the pathogen into the UK, but rather suggests that the pathogen previously established in the UK and remained latent or unnoticed as oilseed rape pathogen until recently.

In silico prediction and characterisation of secondary metabolite clusters in the plant pathogenic fungus Verticillium dahliae

“…To examine whether the SMCs identified in V. dahliae strain JR2 are also present in other Verticillium spp., we queried core enzymes of each cluster using BLAST against the proteomes of previously published Verticillium spp. (Jasper Depotter, Xiaoqian Shi-Kunne, Helene Missionnier, Tingli Liu, Luigi Faino, Grardy van den Berg, Thomas Wood, Baolong Zhang, Alban Jacques, Michael Seidl, 2017; Shi-Kunne et al, 2018). In total, 10 SMC core enzymes are present in all Verticillium spp., seven of which showed considerable sequnence conservation (>80% sequence identity) (Figure 2).…”

“…The fungal genus Verticillium contains nine haploid species plus the allodiploid V. longisporum (Inderbitzin et al, 2011; Jasper Depotter, Xiaoqian Shi-Kunne, Helene Missionnier, Tingli Liu, Luigi Faino, Grardy van den Berg, Thomas Wood, Baolong Zhang, Alban Jacques, Michael Seidl, 2017). These ten species are phylogenetically subdivided into two clades; Flavexudans and Flavnonexudans (Inderbitzin et al, 2011; Shi-Kunne et al, 2018).…”

Comprehensive analysis ofVerticillium nonalfalfae in silicosecretome uncovers putative effector proteins expressed during hop invasion

“…Two isolates from infected hop were used, differing in 412 aggressiveness: lethal pathotype (isolate T2) and mild pathotype (isolate Rec) [97]. Verticillium nonalfalfae candidate effectors 21 HMMER searches against CAZy database and blastp searches against the MEROPS database were 466 performed using the same pipeline as for V. nonalfalfae. Two way ANNOVA followed by Tukey's 467 multiple comparisons test (p-value < 0.05) in GraphPad Prism 7.03 (GraphPad Software, Inc., USA) 468 was used to find differences between sets of fungal proteins.…”

Dynamic virulence-related regions of the fungal plant pathogen Verticillium dahliae display remarkably enhanced sequence conservation

“…are haploids, except for V. longisporum that is an interspecific hybrid that contains approximately twice the amount of genetic material of haploid Verticillium spp. (Inderbitzin et al 2011b; Depotter et al 2017). V. dahliae is the most notorious plant pathogen within the Verticillium genus, causing disease on hundreds of plant species (Inderbitzin and Subbarao 2014).…”