Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae

Abstract

Analysis of 49 strains of Fusarium langsethiae originating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia) revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% of F. langsethiae strains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysed F. langsethiae strains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains of F. langsethiae belong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS) region of the rDNA of F. langsethiae belonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations in F. langsethiae observed in the present work have not been previously reported.

Cultivation Area Affects the Presence of Fungal Communities and Secondary Metabolites in Italian Durum Wheat Grains

“…Interestingly, F. langsethiae was detected by qPCR in all the investigated regions, while, it was isolated with both methods only in the grains harvested in Umbria and with a low incidence. This may have happened because F. langsethiae, a fungus characterized by a slow growth rate, might have been overgrown during the isolation process by other more rapidly growing species (such as F. poae) [38]. Therefore, to have a complete overview of the FHB complex composition of a certain cultivation area, the use of methods able to molecularly detect and quantify the different species directly in the grains, such as qPCR, may also be used.…”

“…Type A trichothecenes, such as T-2 and HT-2 toxins [35], are mainly produced by Fusarium sporotrichioides and Fusarium langsethiae [36,37]. The isolation of these last two species from the grains has been demonstrated to be difficult [36,38,39] and their presence might consequently be often underestimated. Other Fusarium species may also be detected with a low incidence in wheat grains.…”

Analysis of Toxigenic Fusarium Species Associated with Wheat Grain from Three Regions of Russia: Volga, Ural, and West Siberia

“…In general, this study shows a need for further research on the Fusarium species capable of producing trichothecenes type A as well as the factors that affect mycotoxin production in grains, even though considerable progress has already been made in this area [44,45,46,47,48].…”

LATEST INFORMATION ON THE DISTRIBUTION OF FUSARIUM LANGSETHIAE, THE PRODUCER OF T-2 AND HT-2 TOXINS, IN RUSSIA

“…Цвет реверса колоний может быть непигментированным или варьировать от персикового до лилового. Различия по окраске реверса и обильности воздушного мицелия позволяют выделить четыре морфотипа F. langsethiae, частота встречаемости которых различается в различных регионах России (Gavrilova et al, 2017).…”

“…В зерне овса и ячменя ДНК F. langsethiae может быть детектирована сразу после появления колоса/метелки, раньше, чем ДНК других видов Fusarium (Parrikka et al, 2012;Imathiu et al, 2013). Механизмы проникновения в растение, жизненный цикл, ареал F. langsethiae, а также влияние различных факторов на его адаптивные признаки активно исследуются (Nazari et al, 2014;Imathiu et al, 2016;Gavrilova et al, 2017;Divon et al, 2019;Schöneberg et al, 2019).…”