Wild grass isolates of Magnaporthe (Syn. Pyricularia) spp. from Germany can cause blast disease on cereal crops

Abstract

Pathogens that cause destructive crop diseases often infect wild host plants. However, surveys of major plant pathogens tend to be skewed towards cultivated crops and often neglect the wild hosts. Here, we report an emerging disease threat generated by the blast fungus Magnaporthe (Syn. Pyricularia) spp. in central Europe. We found that this notoriously devastating plant pathogen infects the wild grasses foxtail millet (Setaria spp.) and crabgrass (Digitaria spp.) in south-western Germany, a region previously deemed unfavorable for blast disease. Using phenotypic characterization and genomic analyses, we determined that the observed disease symptoms are associated with the Setaria spp.-infecting lineage of M. oryzae and its sister species Magnaporthe grisea. We showed that M. oryzae isolates can infect barley and wheat, thus highlighting the risk of pathogen spread to crops. In addition, M. oryzae isolates which co-occur in natural populations display compatible mating types and variable candidate effector gene content, which may enhance the pathogens adaptive potential. Our findings stress the risk of blast fungus infections expanding into European cereal crops through migration and host jumps. This underlines the importance for pathogen surveillance not only on cultivated crops, but also on wild host plants.

A wheat kinase and immune receptor form host-specificity barriers against the blast fungus

“…We designed a KASP marker for the Rwt4-1B homoeologue (Supplementary Tables 7 and 9) that, along with those for Rwt3 and Rwt4-1D, should enable wheat breeders to ensure that cultivars maintain host-specificity barriers. It was recently shown that, even though the pandemic clonal lineages tend to dominate Triticum pathotypes, sexual recombination between Triticum and non-Triticum pathotypes is possible and can raise the adaptive potential of Triticum pathotypes in the absence of host-specificity barriers 22,23 . This suggests that PWT4, which is naturally found in Lolium pathotypes isolated from Avena but not in Triticum pathotypes 6 , can potentially be gained by Triticum pathotypes through sexual recombination.…”

Disentangling the complex gene interaction networks between rice and the blast fungus identifies a new pathogen effector

“…The filamentous ascomycete fungus M . oryzae causes blast disease in cereal crops, such as rice, wheat ( Triticum aestivum ), and foxtail millet ( Setaria italica ) [ 6 – 8 ]. M .…”

“…Studies on the M. oryzae-host pathosystem benefited from examining gene-for-gene interactions. The filamentous ascomycete fungus M. oryzae causes blast disease in cereal crops, such as rice, wheat (Triticum aestivum), and foxtail millet (Setaria italica) [6][7][8]. M. oryzae consists of genetic subgroups that have infection specificities for particular host genera [7].…”

Probiotic <em>Bacillus</em> Species: Promising Biological Control Agents for Managing Worrisome Wheat Blast Disease

“…Both acreage and production of wheat had been increasing until a sudden massive outbreak of wheat blast occurred in 2016 [5]. In February 2016, wheat blast disease was spotted in Bangladesh for the first time in a country outside of South America that devastated more than 15,000 hectares of wheat with up to 100% yield losses [6], and very recently, it was also identified in Zambia [7] and potentially threatens wheat production in Europe [8]. After the epidemic of this pathogen in Bangladesh, it was rapidly identified by field pathogenomics and open data sharing against the aggressive clonal population of a South American lineage of M. oryzae (anamorph Pyricularia oryzae) Triticum (MoT) pathotype [6].…”