Tuber aestivum association with non-host roots

Abstract

Mycorrhizal fungi provide direct and functional interconnection of soil environment with their host plant roots. Colonization of non-host plants have occasionally been described, but its intensity and functional significance in complex plant communities remain generally unknown. Here, the abundance of ectomycorrhizal fungus Tuber aestivum was measured in the roots of host and non-host (non-ectomycorrhizal) plants in a naturally occurring T. aestivum colony using a quantitative PCR approach. The roots of non-host plant species found inside the brûlé area were extensively colonized by T. aestivum mycelium, although the levels were significantly lower than those found in host Carpinus betulus roots. However, fungal biomass concentration in the non-host roots was one to two orders of magnitude higher than that in the surrounding soil. This indicates existence of an important biotic interaction between T. aestivum mycelium and the non-host, mostly herbaceous plants. Roots, either host or non-host, thus probably constitute hot spots of T. aestivum activity in the soil ecosystem with as yet uncovered functional significance.

Five years investigation of female and male genotypes in périgord black truffle (Tuber melanosporum Vittad.) revealed contrasted reproduction strategies

“…We have made the assumption that these male genotypes have a poor ability to form associations with the host and that they likely survive as free‐living mycelium in the soil or are associated with the roots of non‐ectomycorrhizal plants. It has been demonstrated that roots of herbaceous plants can host truffle mycelium, but the nature of this interaction (such as colonization of the rhizosphere, endophytism,and endomycorrhiza as with orchids) is unknown (Gryndler et al ., ). In our study, we detected the presence of both mating types in 16 out of 20 soil cores.…”

Arbuscular mycorrhizal fungal diversity in the Tuber melanosporum brûlé

“…However, the colonization of non-host plants by ectomycorrhizal fungi has occasionally been described. Selosse et al (2004) and Gryndler et al (2014) have reported an association between these plants and T. aestivum. While the former detected the fungus in orchid roots, the latter measured its abundance in roots of all plants growing in a brûlé and concluded, from a microscopical inspection of the roots, that T. aestivum is located on the root surface.…”

Time to re‐think fungal ecology? Fungal ecological niches are often prejudged

“…() evidenced biotrophic colonization in 17% of species, while three species induced formation of some characteristic features of ectomycorrhizas (see the Commentary by Baldrian & Kohout, ). Truffle species of the ectomycorrhizal genus Tuber (truffles) were shown to also colonize the roots of herbaceous plants where they likely live as endophytes (Gryndler et al ., ; Schneider‐Maunoury et al ., ). Although the latter interaction is still poorly understood, it may account for a specific feature of truffles’ habitat, the brûlé.…”