Responses of Oat Grains to Fusarium poae and F. langsethiae Infections and Mycotoxin Contaminations

Abstract

Recent increases of Fusarium head blight (FHB) disease caused by infections with F. poae (FP) and F. langsethiae (FL) have been observed in oats. These pathogens are producers of nivalenol (NIV) and T-2/HT-2 toxin (T-2/HT-2), respectively, which are now considered major issues for cereal food and feed safety. To date, the impact of FP and FL on oat grains has not yet been identified, and little is known about oat resistance elements against these pathogens. In the present study, the impact of FL and FP on oat grains was assessed under different environmental conditions in field experiments with artificial inoculations. The severity of FP and FL infection on grains were compared across three field sites, and the resistance against NIV and T-2/HT2 accumulation was assessed for seven oat genotypes. Grain weight, β-glucan content, and protein content were compared between infected and non-infected grains. Analyses of grain infection showed that FL was able to cause infection on the grain only in the field site with the highest relative humidity, whereas FP infected grains in all field sites. The FP infection of grains resulted in NIV contamination (between 30-500 µg/kg). The concentration of NIV in grains was not conditioned by environmental conditions. FL provoked an average contamination of grains with T-2/HT-2 (between 15-132 µg/kg). None of the genotypes was able to fully avoid toxin accumulation. The general resistance of oat grains against toxin accumulation was weak, and resistance against NIV accumulation was strongly impacted by the interaction between the genotype and the environment. Only the genotype with hull-less grains showed partial resistance to both NIV and T-2/HT-2 contamination. FP and FL infections could change the β-glucan content in grains, depending on the genotypes and environmental conditions. FP and FL did not have a significant impact on the thousand kernel weight (TKW) and protein content. Hence, resistance against toxin accumulation remains the only indicator of FHB resistance in oat. Our results highlight the need for new oat genotypes with enhanced resistance against both NIV and T-2/HT-2 to ensure food and feed safety.

Influence of temperature, humidity duration and growth stage on the infection and mycotoxin production by Fusarium langsethiae and Fusarium poae in oats

“…The two oat varieties tested in the field differed in mycotoxin contamination; Zorro accumulated higher amounts of NIV and T‐2/HT‐2, whereas Husky accumulated higher amounts of DON. As for other cereal crops, this result indicates that oat varieties also vary in their susceptibility to infection by different Fusarium species and accumulation of various mycotoxins, as has been recently shown in a Swiss field experiment (Martin et al ., ).…”

Contrasting responses of T-2, HT-2 and DON mycotoxins and Fusarium species in oat to climate, weather, tillage and cereal intensity

“…Nivalenol (NIV), currently less important, yet considered a notable mycotoxin, which is mainly produced by F. poae (Peck) Wollenw. (FP) (Pettersson et al 1995;Yli-Mattila et al 2008;Bernhoft et al 2010;Fredlund et al 2013;Martin et al 2018;Schöneberg et al 2018). The most comprehensive data on toxin contamination in cereals has been collected by the cereal industry, but is not publicly available.…”

Relationship between the Content of β-D-Glucans and Infection with Fusarium Pathogens in Oat (Avena sativa L.) Plants

“…Besides, the accumulation of toxins, Fusarium poae ( FP ) and Fusarium langsethiae ( FL ) altered the β-D-glucans content in oat grains. Depending on the genotype and environmental conditions, the β-D-glucans contents increased or decreased subsequent to FP and FL infections [ 49 ]. In particular, the β-D-glucans content in grains of the naked variety Samuel substantially increased following infections by both FP and FL (+48% and +64%, respectively), whereas the changes in β-D-glucans content caused by FHB were limited for the other genotypes (approximately +20%).…”

“…In particular, the β-D-glucans content in grains of the naked variety Samuel substantially increased following infections by both FP and FL (+48% and +64%, respectively), whereas the changes in β-D-glucans content caused by FHB were limited for the other genotypes (approximately +20%). Hence, no clear tendency in β-D-glucans content was identified [ 49 ]. In a very similar study on barley grains, a 10% reduction of β-D-glucans content was observed in six barley varieties after inoculation with FG [ 31 ].…”