Detection of interactions between the pea root rot pathogens Aphanomyces euteiches and Fusarium spp. using a multiplex qPCR assay

Abstract

Pea root rot complex (PRRC) describes a group of closely associated soilborne pathogens that cause root rot disease in field pea. Aphanomyces euteiches and several Fusarium spp. are the most prevalent and damaging microorganisms within this complex, although the impact of interspecific interactions on disease progression remains largely unexplored. Furthermore, a fast and reliable method of detecting and quantifying these pathogens is not currently available. The objectives of this experiment were to: (i) investigate the effect of microbial interactions on root rot severity in pea under greenhouse conditions; and (ii) characterize changes in colonization rates when multiple pathogens are present using qPCR. Seeds were exposed to three species of Fusarium and were planted into A. euteiches‐infested soil in varying combinations. For each experimental treatment, an index of disease severity was used to visually rate disease symptoms. Additionally, two triplex quantitative PCR (qPCR) assays were designed to detect and quantify changes in pathogen population dynamics on the roots. Both assays demonstrated a high degree of sensitivity and efficiency. Results from two independent greenhouse trials indicated an increase in disease severity in the presence of multiple pathogen species compared to single inoculations. Specifically, roots infected with A. euteiches were more susceptible to fusarium root rot than those exposed only to Fusarium spp. These observations were confirmed by qPCR results, which revealed significant changes in colonization rates when multiple species were present. These findings suggest an increased risk of yield loss in regions where A. euteiches and Fusarium spp. co‐occur.

Enniatin Production Influences Fusarium avenaceum Virulence on Potato Tubers, but not on Durum Wheat or Peas

“…Thus, the presence of enniatins inhibiting toxin export could increase the susceptibility of plant host cells to other mycotoxins. This could explain the reported increase in disease symptoms in peas co-contaminated with F. avenaceum and other root rot pathogens [62]. While ENN production by F. avenaceum does not appear to directly influence disease severity in pea roots or durum wheat spikes in controlled inoculation experiments, they may enhance disease pressure during interactions with pathogen complexes.…”

“…The importance of ENNs in pea root rot and FHB may be related to the interaction or competition of F. avenaceum with other fungi and/or mycotoxins. Willsey et al [62] showed that F. avenaceum is always present with other pathogens in pea fields plagued with root rot. This species accumulates in roots later than the other pathogens and disease severity increases in its presence compared with single pathogen inoculations.…”

Heritable Variation in Pea for Resistance Against a Root Rot Complex and Its Characterization by Amplicon Sequencing

“…It has repeatedly been shown that root-infecting pathogens interact and aggravate disease in pea (Kerr, 1963;Muehlbauer and Kraft, 1973;Shehata et al, 1983). However, research has only recently readopted this line of work in order to understand the complexity, distribution and interplay among multiple pathogens in PRRC (Šišić et al, 2017;Taheri et al, 2017;Willsey et al, 2018). Moreover, the rhizosphere harbors a vast diversity of microorganisms involved in plant-microbe and microbe-microbe interactions, ranging from plant pathogenic to plant beneficial and antagonistic to synergistic, respectively (Müller et al, 2016).…”

Beheersing van bodempathogenen via bodemgezondheidsmaatregelen : Een overzicht van de beschikbare kennis voor een selectie van akkerbouwgewassen met hun bijbehorende bodemziekten

“…Sterilisatie van de grond leidde na toediening van het pathogeen tot meer ziekte, wat aangeeft dat er sprake is van biologische ziektewering (Oyarzun et al, 1998). Het gezamenlijk optreden van meerdere soorten wortelrotschimmels kan leiden tot meer schade (Wilsey et al, 2018). Het lijkt erop dat erwt de meest vatbare peulvrucht is voor wortelrot, maar ook andere peulvruchten kunnen veel schade ondervinden.…”