Metabolome and Mycobiome of Aegilops tauschii Subspecies Differing in Susceptibility to Brown Rust and Powdery Mildew Are Diverse

The present study demonstrated the differences in the seed metabolome and mycobiome of two <i>Aegilops tauschii</i> Coss accessions with different resistance to brown rust and powdery mildew. We hypothesized that the seeds of resistant accession k-1958 <i>Ae. tauschii</i> ssp. <i>strangulata</i> can contain a larger number of metabolites with antifungal activity compared with the seeds of susceptible <i>Ae. tauschii</i> ssp <i>meyeri</i> k-340, which will determine differences in the seed fungal community. Our study emphasizes the differences in the seed metabolome of the studied <i>Ae. tauschii</i> accessions. The resistant accession k-1958 had a higher content of glucose and organic acids, including pyruvic, salicylic and azelaic acid, as well as pipecolic acids, galactinol, glycerol and sitosterol. The seeds of <i>Ae. tauschii</i>-resistant accession k-1958 were found to contain more active substances with antifungal activity. The genera <i>Cladosporium</i> and <i>Alternaria</i> were dominant in the seed mycobiome of the resistant accession. The genera <i>Alternaria</i>, <i>Blumeria</i> and <i>Cladosporium</i> dominated in seed mycobiome of susceptible accession k-340. In the seed mycobiome of the resistant k-1958, a higher occurrence of saprotrophic micromycetes was found, and many of the micromycetes were biocontrol agents. It was concluded that differences in the seed metabolome of <i>Ae. tauschii</i> contributed to the determination of the differences in mycobiomes.