SnToxA, SnTox1andSnTox3originated inParastagonospora nodorumin the Fertile Crescent

Ghaderi, F Akram; Sharifnabi, B.; Javan‐Nikkhah, Mohammad; Brunner, Patrick C.; McDonald, Bruce A.

doi:10.1101/2020.03.11.987214

Cited by 5 publications

(4 citation statements)

References 39 publications

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“…A large portion of the Asian lines were sensitive to all the NEs except Ptr ToxB. One hypothesis for this observation is that the group of Asian lines is largely comprised (84.6%) of landraces, with almost all of these originating in Iran, which is close to the center of wheat domestication and pathogen origin for P. nodorum and P. tritici-repentis (Ghaderi et al 2020;Lamari et al 2003). McDonald et al (2013) found that the SnToxA, SnTox1, and SnTox3 genes were present in 75% or more of the isolates collected from Iran.…”

Section: Discussionmentioning

confidence: 99%

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection

Haugrud¹,

Shi

Seneviratne

et al. 2023

Preprint

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Septoria nodorum blotch (SNB) and tan spot, caused by the necrotrophic fungal pathogens Parastagonospora nodorum and Pyrenophora tritici-repentis, respectively, often occur together as a leaf spotting disease complex on wheat (Triticum aestivum L.). Both pathogens produce necrotrophic effectors (NEs) that contribute to the development of disease. Here, genome-wide association analysis of a diverse panel of 264 winter wheat lines revealed novel loci on chromosomes 5A and 5B associated with sensitivity to the NEs SnTox3 and SnTox5 in addition to the known sensitivity genes for NEs Ptr/SnToxA, SnTox1, SnTox3, and SnTox5. Sensitivity loci for SnTox267 and Ptr ToxB were not detected. Evaluation of the panel with five P. nodorum isolates for SNB development indicated the Snn3-SnTox3 and Tsn1-SnToxA interactions played significant roles in disease development along with additional QTL on chromosomes 2A and 2D, which may correspond to the Snn7-SnTox267 interaction. For tan spot, the Tsc1-Ptr ToxC interaction was associated with disease caused by two isolates, and a novel QTL on chromosome 7D was associated with a third isolate. The Tsn1-ToxA interaction was associated with SNB but not tan spot. Therefore some, but not all, of the previously characterized host gene-NE interactions in these pathosystems play significant roles in disease development in winter wheat. Based on these results, breeders should prioritize the selection of resistance alleles at the Tsc1, Tsn1, Snn3, and Snn7 loci as well as the 2A and 7D QTL to obtain good levels of resistance to SNB and tan spot in winter wheat.

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Section: Discussionmentioning

confidence: 99%

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection

Haugrud¹,

Shi

Seneviratne

et al. 2023

Preprint

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“…However, P. nodorum populations with high SnTox gene sequence diversities were not correlated with high diversity at neutral loci, suggesting that the SnTox genes were under selection by local host cultivars (McDonald et al 2013). A high frequency of the SnToxA, SnTox1 and SnTox3 genes and higher genetic diversity at neutral SSR loci of isolates collected in Iran compared to other geographic origins provided further evidence to the hypothesis that P. nodorum originated as a pathogen on wheat in the Fertile Crescent (Ghaderi et al 2020). A recent study of 197 P. nodorum isolates originating from the United States found evidence of two populations that corresponded to the Upper Midwest and South-Eastern United States (Richards et al 2019).…”

Section: Population Genetics Studies Of P Nodorummentioning

confidence: 91%

“…Epidemics of P. nodorum used to be common in all wheat-growing areas with suitable climatic condition for disease development across all six wheat-growing continents (Ficke et al 2018a;Leath et al 1993). The pathogen shares the same center of origin as its wheat host in the Fertile Crescent and probably spread during wheat germplasm exchange (McDonald et al 2012;Ghaderi et al 2020). As mentioned previously, P. nodorum and Z. tritici often cause coinfection on the host in the same field, because the asexual spores of both pathogens are spread by rain splash and prefer to grow in similar warm and humid conditions (Bearchell et al 2005).…”

Section: Infection Cycle and Epidemicsmentioning

confidence: 99%

Advances in genetic mapping of Septoria nodorum blotch resistance in wheat and applications in resistance breeding

Lin¹,

Lillemo²

2021

Burleigh Dodds Series in Agricultural Science

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Septoria nodorum blotch (SNB) caused by the necrotrophic fungus Parastagonospora nodorum is an important wheat disease in many high rainfall areas across the world. It reduces both yield and grain quality by causing symptoms on wheat leaves and glumes, and can cause yield losses up to 30% under warm and humid conditions. This book chapter gives an update on the recent progress in genetic mapping of SNB resistance in wheat, with focus on adult plant leaf blotch and glume blotch resistance with relevance to resistance breeding. This is followed by a case study on the investigation of the naturally occurring P. nodorum population in Norway and mapping of resistance loci in relevant wheat germplasm using MAGIC populations and GWAS panels as well as how this information can be used to improve resistance breeding and disease management. In the end, some future perspectives of SNB resistance breeding is provided.

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“…However, between B. sorokiniana and these other two species, only ToxhAT is shared (20). Questions such as the order of acquisition by each species, and the origins of ToxhAT and ToxA remain (21).…”

Section: Introductionmentioning

confidence: 99%

Sanctuary: AStarshiptransposon facilitating the movement of the virulence factor ToxA in fungal wheat pathogens

Bucknell,

Wilson,

Gonçalves do Santos

et al. 2024

Preprint

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There is increasing evidence that mobile genetic elements can drive the emergence of pathogenic fungal species by moving virulence genes horizontally. The 14 kbp ToxhAT transposon has been shown to be moving the necrotrophic effector, ToxA, horizontally between fungal species that infect Triticum aestivum (wheat), namely Parastagonospora nodorum, Pyrenophora tritici-repentis, and Bipolaris sorokiniana. All three species utilise the ToxA protein to infect wheat. Previous genomic evidence found ToxhAT in distinct chromosomal positions in two isolates of B. sorokiniana, indicating that the transposon is still active in this species. Here we confirm the movement of ToxhAT using long-read Nanopore MinION sequencing of eight novel and one previously published B. sorokiniana isolates. One event of independent transposition of ToxhAT was observed, and target site duplications of "TA" were identified, confirming this was an autonomous movement facilitated by a yet unidentified transposase. Whole genome analysis revealed that ToxhAT is a passenger embedded in a much larger, conserved 170-196 kbp mobile genetic element. This element, termed Sanctuary, belongs to the newly described Starship transposon superfamily. This classification is based on the presence of short direct repeats, empty insertion sites, a putative tyrosine recombinase gene and other features of Starship transposons. We also show that ToxhAT has been independently captured by two different Starships, Sanctuary and Horizon which share little to no sequenced identity, outside of ToxhAT. This classification makes Horizon and Sanctuary part of a growing number of Starships involved in the horizontal gene transfer of adaptive genetic material between fungal species.

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SnToxA, SnTox1andSnTox3originated inParastagonospora nodorumin the Fertile Crescent

Abstract: 18 19

Cited by 5 publications

References 39 publications

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection

Genome-wide association mapping of resistance to the foliar diseases septoria nodorum blotch and tan spot in a global winter wheat collection

Advances in genetic mapping of Septoria nodorum blotch resistance in wheat and applications in resistance breeding

Sanctuary: AStarshiptransposon facilitating the movement of the virulence factor ToxA in fungal wheat pathogens

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