The ability of a host plant to associate with different symbiotic partners affects ectomycorrhizal functioning

Abstract

Some plants that associate with ectomycorrhizal (ECM) fungi are also able to simultaneously establish symbiosis with other types of partners. The presence of alternative partners that may provide similar benefits may affect ECM functioning. Here we compared potential leucineaminopeptidase (LA) and acid phosphatase (AP) enzyme activity (involved in N and P cycling, respectively) in ECM fungi of three hosts planted under the same conditions but differing in the type of partners: Pinus (ECM fungi only), Eucalyptus (ECM and arbuscular mycorrhizal -AMfungi) and Acacia (ECM, AM fungi and rhizobial bacteria). We found that the ECM community on Acacia and Eucalyptus had higher potential AP activity than the Pinus community. The ECM community in Acacia also showed increased potential LA activity compared to Pinus.Morphotypes present in more than one host showed higher potential AP and LA activity when colonizing Acacia than when colonizing another host. Our results suggest that competition with AM fungi and rhizobial bacteria could promote increased ECM activity in Eucalyptus and Acacia. Alternatively, other host-related differences such as ECM community composition could also play a role. We found evidence for ECM physiological plasticity when colonizing different hosts, which might be key for adaptation to future climate scenarios.

Mycorrhizal Fungi Associated With Juniper and Oak Seedlings Along a Disturbance Gradient in Central Mexico

“…Interactions between mycorrhizal fungi and their plant hosts shape below-and aboveground communities, but few studies have addressed the outcomes of ECM and AM fungi associated with the same plant host (Queralt et al, 2019;Tedersoo and Bahram, 2019;Teste et al, 2019). Likewise, the costs and benefits of associations with either ECM or AM fungi across environmental gradients remains largely unknown in the context of forest restoration (Phillips et al, 2013;Williams et al, 2013).…”

“…In our study, soil available P was highest in the native site, in correlation with a higher ECM fungal richness (Tables 1, 2). Few studies have investigated the role of ECM fungi for P uptake (Köhler et al, 2018;Queralt et al, 2019), but evidence showed that ECM-dominated stands can have easier access to organic P than AM-dominated forests (Albornoz et al, 2016;Rosling et al, 2016). Moreover, plants that form both AM and ECM associations can allocate C preferably to the fungal symbiont that provides more benefits relative to the abundance of readily available nutrients (Albornoz et al, 2016).…”

“…Nonetheless, other studies repeatedly found that AM associations had a neutral or positive effect on seedling growth (van der Heijden and Horton, 2009). Moreover, few studies have been conducted on plants that are colonized by both AM and ECM fungi during part of their life cycle, a feature known as dual mycorrhization (Queralt et al, 2019;Tedersoo and Bahram, 2019;Teste et al, 2019). The benefits and costs of dual mycorrhization for plants depend on a variety of factors including plant age and nutrient demands (Meinhardt and Gehring, 2012;Holste et al, 2017).…”

Aromatic Plants and Their Associated Arbuscular Mycorrhizal Fungi Outcompete Tuber melanosporum in Compatibility Assays with Truffle-Oaks

“…Few studies have shown the effects of interactions between truffle plants (forming ectomycorrhizas, ECM) and shrubs and herbs (companion plants, mostly forming arbuscular mycorrhizas, AM) either cultivated or growing spontaneously in truffle brûlés [ 18 , 19 ]. Previous studies on AM–ECM fungal interactions were mostly conducted at the scale of plant individuals hosting multiple types of mycorrhizal fungi [ 20 , 21 ]. Among them, plants of the genus Quercus are confirmed to form both kinds of mycorrhizal symbioses, forming AM and ECM structures [ 22 ].…”