Growth rate and TRI5 gene expression profiles of Fusarium equiseti strains isolated from Spanish cereals cultivated on wheat and barley media at different environmental conditions

Abstract

Fusarium equiseti is a toxigenic spedes that often contaminates cereal crops from diverse climatic regions such as Northern and Southern Europe. Previous results suggested the existence of two distinct populations within this species with differences in toxin profile which largely corresponded to North and South Europe (Spain). In this work, growth rate profiles of 4 F equiseti strains isolated from different cereals and distinct Spanish regions were determined on wheat and barley based media at a range of temperatures (15,20,25,30,35 and 40 t) and water potential regimens (-0.7, -2.8, -7.0, and -9.8 MPa, corresponding to 0.99,0.98,0.95 and 0.93 a w values). Growth was observed at all temperatures except at 40 °C, and at all the solute potential values except at -9.8 MRa when combined with 15 °C. Optimal growth was observed at 20-30 "Cand -0.7/-2.8 MPa The effect of these factors on trichothecene biosynthesis was examined on a F equiseti strain using a newly developed real time RT-PCR protocol to quantify TRI5 gene expression at 15,25 and 35 °C and -0.7, -2.8, -7.0 and -9.8 MPa on wheat and barley based media. Induction of TRI5 expression was detected between 25 and 35 °C and -0.7 and -2.8 MPa, with maximum values at 35 °C and-2.8 MPa being higher in barley than in wheat medium. These results appeared to be consistent with a population well adapted to the present climatic conditions and predicted scenarios for Southern Europe and suggested some differences depending on the cereal considered. These are also discussed in relation to other Fusarium species co-occurring in cereals grown in this region and to their significance for prediction and control strategies of toxigenic risk in future scenarios of climate change for this region.

Mycoflora isolation and molecular characterization of Aspergillus and Fusarium species in Tunisian cereals

“…This is the case of most Fusarium species whose favorable conditions are concomitant with wheat/barley post anthesis. The main Fusarium species isolated from wheat and barley in this work was F. equiseti (Table 5) , whose ecophysiological profile might be considered between F. graminearum and F. verticillioides (Marín et al, 2015), being F. verticillioides more tolerant to low water potential and higher temperatures (Marín et al, 2010). This profile is compatible with conditions during maize growth in field even approaching harvest time.…”

“…Differences in the climatic and the environmental conditions in field among locations and years might be responsible for differences in Fusarium diversity and incidence in the studies compared. In particular, some reports point out that F. verticillioides, F. proliferatum and F. equiseti might tolerate better low water potential conditions than F. graminearum (Marín et al, 2015, Marín et al, 2012). Therefore, it would be useful to determine the occurrence and prevalence of certain Fusarium species at these early critical stages in order to predict which toxin or toxins could be expected and to decide if control treatments should be applied.…”

Effect of Rhizospheric Fungus on Biological Control of Root Rot (Fusarium equiseti) Disease of Saposhnikovia divaricata

“…As a global pathogenic fungus of the genus Fusarium with a broad range of hosts, Fusarium equiseti can cause disease in more than 100 crop species, including agricultural, horticultural, and medicinal plants [1][2][3]. Saposhnikovia divaricata (Turcz.)…”