Trichothecene production is detrimental to early root colonization by Fusarium culmorum and F. graminearum in fusarium crown and root rot of wheat

Abstract

Fusarium culmorum (Fc) and F. graminearum (Fg) belong to the predominant causal agents of fusarium crown and root rot (FCR) in wheat. While many studies have been done to investigate crown rot, including stem base infection, root colonization and mycotoxin production associated with root rot is not well understood. In this study the impact of mycotoxins on the colonization of wheat roots and stem bases was analysed by using Fc and Fg isolates that varied in both quantity and types of trichothecenes they produce. Seedling inoculations in growth chambers with a high deoxynivalenol (DON)‐ and 3‐acetyldeoxynivalenol (3ADON)‐producing isolate led to more severe symptoms and 20‐times greater colonization of the stem base, as measured by Fc DNA accumulation, than isolates that produced less DON/3ADON. In contrast to stem base colonization, in vitro inoculations of roots with a Tri5 deletion mutant deficient in Fg trichothecene production led to three‐times higher colonization than the wildtype. Furthermore, an Fc isolate that produced low levels of zearalenone resulted in twice the level of colonization of a high DON/3ADON‐producing isolate included in the study. When root inoculation with a low DON/3ADON‐producing Fc isolate was supplemented with exogenous DON, DON production decreased by more than half per unit weight of Fc DNA, and root colonization doubled compared to the untreated control. Therefore, in contrast to its potential role as an aggressiveness factor in stem base infection, trichothecene production by Fc and Fg is detrimental to the early stages of wheat root colonization in FCR.

Efficacy of Lamium album as a natural fungicide: impact on seed germination, ergosterol, and mycotoxins in Fusarium culmorum-infected wheat seedlings

“…Correlations between DON and its acetylated forms were highly significant, which is in accordance with the previous research (Sunic et al, 2021), where DON highly correlated with 3-AcDON in winter wheat, and its production by F. culmorum is believed to play a role in pathogenesis (Morimura et al, 2020). Mycotoxin accumulation affects germination rates, seedling growth, pathogen aggressiveness, and overall disease severity (Bruins et al, 1993;Scherm et al, 2011;Winter et al, 2019). Scherm et al (2011) showed that DON is an aggressiveness factor in F. culmorum stem base infections of durum wheat, whereby disease incidence was decreased by 40%−80% when the trichothecene regulatory gene Tri6 was silenced (Scherm et al, 2011).…”

Changes in soil fungal communities after onset of wheat yellow mosaic virus disease

“…We determined that the genus Fusarium was significantly enriched in RSD treatment as a common pathogenic fungus ( Steinkellner and Langer, 2004 ). The enrichment of Fusarium may lead to the occurrence of wheat root diseases and damage of wheat root surface (M. Winter et al, 2019 ), which may be more conducive to the parasitism of P. graminis on wheat roots (K. Hansen et al, 2013 ; Mestre and Fontenla, 2021 ). In conclusion, the occurrence of Wheat yellow mosaic virus disease affects the composition of soil fungal community, but there are many reasons for this change, such as soil physicochemical interaction and soil nutrient imbalance (C.H.…”

Changes in soil fungal communities after onset of wheat yellow mosaic virus disease

“…We determined that N.fusarium was signi cantly enriched in RSD treatment as a common pathogenic fungus (S SteinkellnerI Langer, 2004). The enrichment of Fusarium may lead to the occurrence of wheat root diseases and damage of wheat root surface (M Winter, 2019), which may be more conducive to the parasitism of P.graminearum on wheat roots (K Hansen, 2013; MC MestreS Fontenla, 2021). In conclusion, the occurrence of Wheat yellow Mosaic virus disease affects the composition of soil fungal community, but there are many reasons for this change, such as soil physicochemical interaction and soil nutrient imbalance (CH Kong, 2008; C Li, 2010), may also be due to the promoting or inhibiting effect of plant rhizosphere exudates on the growth of different fungal communities (X-g Li, 2014a), more detailed reasons need to be explored.…”