Trichoderma harzianummight impact phosphorus transport by arbuscular mycorrhizal fungi

Abstract

Trichoderma sp. is a biocontrol agent active against plant pathogens via mechanisms such as mycoparasitism. Recently, it was demonstrated that Trichoderma harzianum was able to parasitize the mycelium of an arbuscular mycorrhizal (AM) fungus, thus affecting its viability. Here, we question whether this mycoparasitism may reduce the capacity of Glomus sp. to transport phosphorus ((33)P) to its host plant in an in vitro culture system. (33)P was measured in the plant and in the fungal mycelium in the presence/absence of T. harzianum. The viability and metabolic activity of the extraradical mycelium was measured via succinate dehydrogenase and alkaline phosphatase staining. Our study demonstrated an increased uptake of (33)P by the AM fungus in the presence of T. harzianum, possibly related to a stress reaction caused by mycoparasitism. In addition, the disruption of AM extraradical hyphae in the presence of T. harzianum affected the (33)P translocation within the AM fungal mycelium and consequently the transfer of (33)P to the host plant. The effects of T. harzianum on Glomus sp. may thus impact the growth and function of AM fungi and also indirectly plant performance by influencing the source-sink relationship between the two partners of the symbiosis.

Modulation of the Root Microbiome by Plant Molecules: The Basis for Targeted Disease Suppression and Plant Growth Promotion

“…Endophytic fungi belonging to the order of Sebacinales, such as Serendipita indica (formerly known as Piriformospora indica) can also promote plant growth through Pi acquisition (Yadav et al, 2010;Weiss et al, 2016). Similarly, Trichoderma fungi can produce chelating metabolites that solubilize phosphate and increase its acquisition by plants to promote plant growth (Altomare et al, 1999;De Jaeger et al, 2011). Nitrogen acquisition is mediated on non-leguminous plants by other microbes which are not belonging in the N-fixing bacteria group (Jacoby et al, 2017;Martin et al, 2017).…”

Towards the Biological Control of Devastating Forest Pathogens from the Genus Armillaria

“…The interactions of introduced Trichoderma strains with other beneficial microorganisms such as mycorrhizal fungi need further investigations, as they may represent both advantages and disadvantages to the host plant [45]. Trichoderma may act negatively on mycorrhizal fungi via competition for the colonization sites and nutrients [46], or via direct mycoparasitic attack, which, however, may also increase the uptake of phosphorous by the mycorrhizal fungus as the result of stress reaction [47]. Using beneficial fungi in forestry therefore requires the adjustment of Trichoderma-mycorrhizal fungus combinations to the host tree, as well as the optimization of the inoculation methods and the applied sylvicultural practices.…”

Association of highly and weakly mycorrhizal seedlings can promote the extra- and intraradical development of a common mycorrhizal network

“…Two parameters were considered to select homogenous systems: (1) the surface of the ERM determined by tracing on a plastic sheet laid onto the plate according to de Jaeger et al . (); (2) the hyphal length in this compartment. Hyphal length was estimated using a method adapted from Voets et al .…”