Interactions between functionally diverse fungal mutualists inconsistently affect plant performance and competition

Abstract

Plants form mutualistic relationship with a variety of belowground fungal species. Such a mutualistic relationship can enhance plant growth and resistance to pathogens. Yet, we know little about how interactions between functionally diverse groups of fungal mutualists affect plant performance and competition. We experimentally determined the effects of interaction between two functional groups of belowground fungi that form mutualistic relationship with plants, arbuscular mycorrhizal (AM) fungi and Trichoderma, on interspecific competition between pairs of closely related plant species from four different genera. We hypothesized that the combination of two functionally diverse belowground fungal species would allow plants and fungi to partition their symbiotic relationships and relax plant–plant competition. Our results show that: 1) the AM fungal species consistently outcompeted the Trichoderma species independent of plant combinations; 2) the fungal species generally had limited effects on competitive interactions between plants; 3) however, the combination of fungal species relaxed interspecific competition in one of the four instances of plant–plant competition, despite the general competitive superiority of AM fungi over Trichoderma. We highlight that the competitive outcome between functionally diverse fungal species may show high consistency across a broad range of host plants and their combinations. However, despite this consistent competitive hierarchy, the consequences of their interaction for plant performance and competition can strongly vary among plant communities.

Microbial mediators of plant community response to long‐term N and P fertilization: Evidence of a role of plant responsiveness to mycorrhizal fungi

“…The AMF mediated plant community dynamics are context-dependent, as soil nutrient availabilities and C allocation from plants to extraradical hyphae determine the relationships between plants and symbiotic partners (Walder & van der Heijden, 2015). Many previous studies have found that mycorrhizal fungi mediate competitive abilities between plant species and alter plant community structure under different nutrient conditions (Lin et al, 2015;Scheublin et al, 2007;Thakur et al, 2019;Wagg et al, 2011). Under low nutrient conditions, plants with high mycorrhizal responses can be facilitated by AMF to gain a competitive advantage.…”

Cascading Effects of Root Microbial Symbiosis on the Development and Metabolome of the Insect Herbivore Manduca sexta L.

“…Ten days after germination, the seedlings were transplanted into 400 mL pots containing a sterile sand/vermiculite mixture (1:1, v/v). Inoculation with R. irregularis was performed by mixing the R. irregularis inoculum with the sand/vermiculite mixture at 10% (v/v) before transplanting [95]. Inoculation with T. harzianum was achieved by mixing the T. harzianum inoculum with the substrate to achieve a final density of 1 × 10 6 conidia g −1 before transplanting [95].…”

“…Inoculation with R. irregularis was performed by mixing the R. irregularis inoculum with the sand/vermiculite mixture at 10% (v/v) before transplanting [95]. Inoculation with T. harzianum was achieved by mixing the T. harzianum inoculum with the substrate to achieve a final density of 1 × 10 6 conidia g −1 before transplanting [95]. The plants were then placed in a completely randomized design in controlled climate chambers at 16 h/8 h day/night cycle, 65-70% RH.…”

Considerations on Field Methodology for Macrofungi Studies in Fragmented Forests of Mediterranean Agricultural Landscapes

“…In particular, the Mediterranean region could be especially vulnerable, with the extinction of more than 2000 plant species [67] and negative consequences on the structure, dynamics and functioning of forests [68,69]. Therefore, populations will have to adapt to and compete in new environmental conditions, and the response of the fungal communities will be part of that ecological competition [70,71], producing changes in the composition of the species in the ectomycorrhizal communities [8,72]. For this reason, taxa collected in the summer season, although not important from a quantitative point of view, should be of great importance as they are able to fructify in the most adverse weather conditions, and potentially, they are the best adapted to some conditions that could be extended throughout the year.…”