Differential aluminum tolerance and absorption characteristics in Pinus massoniana seedlings colonized with ectomycorrhizal fungi of Lactarius deliciosus and Pisolithus tinctorius

Abstract

Plant tolerance to aluminum (Al) toxicity can be enhanced by an ectomycorrhizal (ECM) fungus through biological filtering or physical blockage. To understand the roles of ECM colonization in Al absorption with regard to Al tolerance, Pinus massoniana seedlings were inoculated with either Lactarius deliciosus (L.:Fr.) Gray isolate 2 or Pisolithus tinctorius (Pers.) Coker et Couch isolate 715 and cultivated in an acid yellow soil with or without 1.0 mM Al3+ irrigation for 10 weeks. Biomass production, Al bioaccumulation and transport in seedlings colonized by the two ECM fungi were compared, and the three absorption kinetics (pseudo-first order, pseudo-second order and intraparticle diffusion) models used to evaluate variances in root Al3+ absorption capacity. Results show that both fungi increased aboveground biomass and Al tolerance of P. massoniana seedlings, but L. deliciosus 2 was more effective than P. tinctorius 715. Lower Al absorption capacity, fewer available active sites and decreased affinity and boundary layer thickness for Al3+, and higher Al accumulation and translocation contributed to the increased Al tolerance in the ECM-inoculated seedlings. These results advance our understanding of the mechanisms and strategies in plant Al-tolerance conferred by ECM fungi and show that inoculation with L. deliciosus will better enhance Al tolerance in P. massoniana seedlings used for forest plantation and ecosystem restoration in acidic soils, particularly in Southwest China and similar soils worldwide.

Nitrogen transfer mechanism of mycorrhizal network between Pinus massoniana Lamb. seedlings

“…Apart from the maximum uptake of nitrogen by the roots at N6, the maximum uptake of nitrogen by the donor/recipient stems and leaves happened at N4, and then at N6. While ECM fungi can supply nitrogen to their host plants, when nitrogen is scarce, they also store different amounts of nitrogen to suit their own requirements (Benavent et al 2019; Gu et al 2023). Additionally, the study discovered that donor/recipient seedlings absorbed very little 15 N during N0 treatment, and that this may have been due to soil 15 N. When nitrogen application increased during the Sm treatment, the amount of 15 N absorbed by the recipient's roots, donor roots, stems, and leaves grew progressively.…”

Effects of Stand Types on Ectomycorrhizal Fungal Community Composition and Structure of Pinus massoniana in Subtropical Mountain Forest Ecosystems

“…Lactarius can enhance the aluminum (Al) toxicity tolerance of plants. L. deliciosus can enhance Al tolerance in P. massoniana seedlings used for forest plantation and ecosystem restoration in acidic soils, particularly in Southwest China [40]. Tomentella species are a typically dominant group in EMF communities of coniferous and deciduous forests [41], the members of which play a broad range of saprophytic roles and can readily adapt to environmental change by altering their survival strategies [42].…”

Effects of vertical forest stratification on precipitation material redistribution and ecosystem health of Pinus massoniana in the Three Gorges Reservoir area of China

“…The accumulation of acidic compounds in the soil increases the content of active aluminum, and this inhibits the division and elongation of root cells. Aluminum can also combine with root cell membrane proteins, thereby causing cell membrane damage (Víctor et al, 2006;Gu et al, 2023). The portion of aluminum that enters the root cells directly affects cellular metabolism by inhibiting the absorption of nutrients such as calcium, phosphorus, and potassium (Gu et al, 2020).…”