Sarocladium zeae is a systemic endophyte of wheat and conveys resistance toward Fusarium head blight

Authors: KEMP, NATHAN - Orise Fellow; Vaughan, Martha; McCormick, Susan; Brown, Jacob; BAKKER, MATTHEW - Former ARS Employee

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/2020
Publication Date: 3/26/2020
Citation: Kemp, N., Vaughan, M.M., McCormick, S.P., Brown, J.A., Bakker, M. 2020. Sarocladium zeae is a systemic endophyte of wheat and conveys resistance toward Fusarium head blight [abstract].

Interpretive Summary:

Technical Abstract: Macrochloa tenacissima (esparto or needle grass) is an economically important grass native to several Mediterranean countries in northern Africa (Algeria, Morocco and Tunisia), the Iberian Peninsula (Spain and Portugal) and southern France. In 2018 this grass was listed on the International Union for Conservation of Nature’s (IUCN) red list as vulnerable due to over harvesting and climate change. The esparto fiber produced from this species is used extensively for making paper, rope and various crafts. Because M. tenacissima is well-adapted to arid and semi-arid regions, we hypothesized that Fusarium communities associated with this grass might be genetically diverse in the Mediterranean. The fungal genus Fusarium includes many species that produce toxins that pose health risks to humans and other animals. Fusaria are also responsible for a wide range of diseases on economically important crops. In prior research, we investigated the diversity of Fusarium species associated with M. tenacissima roots and stems at six different sites in central Tunisia. Of the 324 strains that were recovered during pathogen surveys conducted in 2011 and 2012, three isolates were determined to represent a novel species based on morphological, molecular and chemical data. Described here as F. spartum, this novel species differs from the other two plant pathogenic species within this complex, F. redolens and F. hostae, by its association with M. tenacissima and its unique position within Fusarium. The potential for the three F. redolens clade species to produce toxins was assessed by screening whole genome sequence data for gene clusters required for toxin production and by chemical analyses of strains grown on cracked corn. These analyses revealed that most strains of the three F. redolens clade species could produce two toxins, beauvericin and enniatin B1. These research findings will be of interest to diverse agricultural scientists who are focusing on developing novel strategies to reduce and eliminate Fusarium toxin contamination of food and feed.