Nitrogen fertilisation reduces sink strength of poplar ectomycorrhizae during recovery after drought more than phosphorus fertilisation

The Dark Septate Endophytes and Ectomycorrhizal Fungi Effect on Pinus tabulaeformis Carr. Seedling Growth and their Potential Effects to Pine Wilt Disease Resistance

“…Many studies showed that the colonization of ECMF and DSE could confer pathogen resistance to host plants [20,[53][54][55], and this phenomenon was confirmed in our study too. In the study, the rates of mortality caused by PWN infection were reduced in most of ECMF and DSE treatments ( Figure 4).…”

“…Previous studies showed Pinaceae trees were obligate to ectomycorrhizal fungi (ECMF) [14], whereas recent research reported that dark septate endophytic fungi (DSE) were also the main root-associated fungi of pine [15][16][17]. It is well known that ECMF had tremendous effects on plants, such as facilitating water and nutrient uptake of host plants, improving plant growth, aiding in the accumulation of metabolites, and conferring resistance for host plants to pathogens and other abiotic stresses [14,[18][19][20][21]. DSE has a wide range of ecosystem distribution and variable effects on the growth of host plants [22][23][24].…”

Does resource exchange in ectomycorrhizal symbiosis vary with competitive context and nitrogen addition?

“…A 24h chase period is a small fraction of a mycorrhiza's lifetime (Majdi et al, 2001), and long-term tree C investment may include fungi that are suboptimal in the short term (Moeller & Neubert, 2016). It is also possible that only some ectomycorrhizal fungi engage in C-for-N exchange, while others are governed by different symbiotic mechanisms (Stuart & Plett, 2020) that may be obscured or biased by the market metaphor (Smith & Smith, 2015), such as plant immunity (Dreischhoff et al, 2020) and fungal C sink strength (Bidartondo et al, 2001;Nickel et al, 2017). While we have demonstrated that ectomycorrhizal plant C allocation can scale with fungal N provisioning under some biological and environmental conditions, future work should aim to identify the mechanisms that best account for these patterns, accounting for multiple resources and nonmarket drivers of resource movement such as source-sink dynamics.…”

“…Much of this context-dependency may be explained by source-sink dynamics (Fellbaum et al, 2014) and competition between roots and fungi (Püschel et al, 2016). Mirroring this complexity, ectomycorrhizal symbiosis has so far demonstrated neutral or negative relationships between plant C investment and fungal N provisioning (Näsholm et al, 2013;Hortal et al, 2017;Plett et al, 2020), while fungal C sink strength often predicts plant C movement (Bidartondo et al, 2001;Nickel et al, 2017). Our goal with this study was to clarify the forces affecting resource exchange in ectomycorrhizal symbiosis by investigating the influence of resource availability and competition on C and N movement.…”