Tremellomycetes Yeasts in Kernel Ecological Niche: Early Indicators of Enhanced Competitiveness of Endophytic and Mycoparasitic Symbionts against Wheat Pathobiota

Abstract

Tremellomycetes rDNA sequences previously detected in wheat kernels by MiSeq were not reliably assigned to a genus or clade. From comparisons of ribosomal internal transcribed spacer region (ITS) and subsequent phylogenetic analyses, the following three basidiomycetous yeasts were resolved and identified: Vishniacozymavictoriae, V. tephrensis, and an undescribed Vishniacozyma rDNA variant. The Vishniacozyma variant’s clade is evolutionarily close to, but phylogenetically distinct from, the V. carnescens clade. These three yeasts were discovered in wheat kernel samples from the Canadian prairies. Variations in relative Vishniacozyma species abundances coincided with altered wheat kernel weight, as well as host resistance to chemibiotrophic Tilletia (Common bunt—CB) and necrotrophic Fusarium (Fusarium head blight—FHB) pathogens. Wheat kernel weight was influenced by the coexistence of Vishniacozyma with endophytic plant growth-promoting and mycoparasitic biocontrol fungi that were acquired by plants. Kernels were coated with beneficial Penicillium endophyte and Sphaerodes mycoparasite, each of which had different influences on the wild yeast population. Its integral role in the kernel microbiome renders Vishniacozyma a measurable indicator of the microbiome–plant interaction. The ability of NGS technology to detect specific endophytic DNA variants and early changes in dynamics among symbionts within the kernel ecological niche enables the prediction of crop disease emergence, suggesting that advanced microbiological testing may be a potentially useful tool for both phytoprotection and more efficient wheat breeding programs.

Minimizing Tillage Modifies Fungal Denitrifier Communities, Increases Denitrification Rates and Enhances the Genetic Potential for Fungal Relative to Bacterial Denitrification

“…Their prevalence in the upper layers of shallow disked-tilled soils could therefore be explained by their association with enriched crop residues that are retained in these soils, resulting in increased amounts of fungal substrates. Tremellomycetes, on the other hand, are yeasts with the ability to degrade complex compounds quickly and overcome anoxic events by fermentation (Yurkov, 2018;Vujanovic, 2021). The greater availability of labile C in less intensely tilled soils (Bongiorno et al, 2019) may promote copiotrophic fermenting yeasts.…”

Genetic, Phenotypic and Metabolic Diversity of Yeasts From Wheat Flag Leaves

“…In addition to oscillating nutrient availability, phyllosphere yeasts also need to adapt to oscillating temperatures, which can differ drastically between day and night, winter and spring. Yeasts from the genera Sporobolomyces , Rhodotorula and Vishniacozyma have been proposed to tolerate extreme environmental conditions and to help plants adapting to cold environments ( Buzzini et al, 2018 ; Vujanovic, 2021 ). Our results showed that all isolates from these genera grew at different temperatures, including low temperatures.…”

Fungal Diversity and Composition of the Continental Solar Saltern in Añana Salt Valley (Spain)

“…Most of these are wood, plant, lichen, or fruit surface fungi distributed in natural environments. Specifically, Vishniacozyma victoriae and Stereum hirsutum, detected in this study, are related with lichens, mosses, and plants [47][48][49][50].…”