Elsevier

Pedosphere

Volume 24, Issue 5, October 2014, Pages 683-689
Pedosphere

Mobilization of Inorganic Phosphorus from Soils by Ectomycorrhizal Fungi

https://doi.org/10.1016/S1002-0160(14)60054-0Get rights and content

Abstract

Ectomycorrhizal (EM) fungi could form symbiosis with plant roots and participate in nutrient absorption; however, many EM species commonly found in forest soils, where phosphorus (P) concentration and availability are usually very low, particularly in tropical and subtropical areas, have not yet been investigated for their efficiencies to mobilize soil P. In this study, fungal growth, P absorption, efflux of protons and organic acids, and soil P depletion by four isolates of EM fungi isolated either from acidic or calcareous soils were compared in pure liquid culture using soil as a sole P source. Boletus sp. 7 (Bo 7), Lactarius deliciosus 3 (Ld 3), and Pisolithus tinctorius 715 (Pt 715) from acidic and P-deficient soils of southwestern China showed higher biomass and P concentration and accumulation than Cenococcum geophilum 4 (Cg 4) from a calcareous soil of Inner Mongolia, northern China, after 4 weeks of liquid culture. Oxalate, malate, succinate, acetate, and citrate concentrations in the culture solutions varied significantly with fungal species, and oxalate accounted for 51.5%–91.4% of the total organic acids. Organic acids, particularly oxalate, in the culture solutions may lead to the solubilization of iron-bound P (Fe-P), aluminum-bound P (Al-P), and occluded P (O-P) from soil phosphates. Fungal species also varied greatly in proton efflux, which decreased the culture solution pH and may dissolve calcium-bound P (Ca-P) in soil. This could be the reason for the increment of both inorganic P in the culture solutions and Olsen P in the soil when EM fungi were present. Total inorganic P, the sum of Al-P, Fe-P, O-P, and Ca-P, in the culture solutions was positively correlated with the total concentration of organic acids in the culture solutions (r = 0.918*, n = 5), but negatively with both the total inorganic P in soil (r = −0.970**, n = 5) and the culture solution pH (r = −0.830*, n = 5). These suggested variable efficiencies of EM fungal species to mobilize inorganic P fractions from soil, which could make EM trees to utilize inorganic P in the same way like EM fungi and adapt to the soils with various P concentrations and availabilities.

References (32)

Cited by (25)

  • Increase of soil phosphorus bioavailability with ectomycorrhizal tree dominance in subtropical secondary forests

    2022, Forest Ecology and Management
    Citation Excerpt :

    ECM fungi can produce phosphomonoesterase (acid and alkaline phosphatase), phosphodiesterase and phytase (Burke et al., 2014) to promote the mineralization of Po, which in turn liberates Pi for plant uptake (Read and Perez-Moreno, 2003; Treseder and Lennon, 2015). ECM fungi can also produce and release low-molecular-weight organic acids, including citric, malonic and oxalic acids (Wallander, 2000; Tuason and Arocena, 2009; Zhang et al., 2014), which in turn can augment the P availability from mineral-bound Pi sources (Hinsinger, 2001; Hodge, 2017). For instance, Wallander (2000) reported a positive relationship between the concentration of easily extractable Pi (Olsen-P) and the concentration of oxalate, as well as a negative correlation with pH in the rhizosphere soil samples from ECM trees.

  • Soil phosphorus mobilization and utilization by Suillus isolates and Suillus-mycorrhized pine plants

    2021, Forest Ecology and Management
    Citation Excerpt :

    Culture solution pH was measured with a pH meter (Mettler Toledo FE20, Shanghai Analysis Instrument Co., Ltd., Shanghai, China). Oxalate in culture solutions was analyzed with high-performance liquid chromatography (HPLC; HITACHI, Japan) following acidification by 0.1 mol L−1 HCl (Zhang et al., 2014). A total of 100 seedlings were randomly harvested from each nursery bed and morphologically checked for fungal colonization.

  • Accessibility of Inorganic and Organic Nutrients for Mycorrhizas

    2017, Mycorrhizal Mediation of Soil: Fertility, Structure, and Carbon Storage
  • The lime-silicate question

    2015, Soil Biology and Biochemistry
    Citation Excerpt :

    In addition, enzymes such as alkaline (Chhabra et al., 2013) or acid phosphatases (Mahdi et al., 2012), produced by the plants or microorganisms, might also serve in solubilising phosphates in soils (Fernandez et al., 2012). Likewise, plant growth promoting bacteria (Masalha et al., 2000; Colombo et al., 2014) and mycorrhizal fungi (Colombo et al., 2014; Zhang et al., 2014a,b,c,d) can augment the solubilization of Fe from soils and their uptake into plants. Similar data for potassium are also available (Zhang and Kong, 2014).

View all citing articles on Scopus

Supported by the National Basic Research Program (973 Program) of China (No. 2013CB127405), the National Natural Science Foundation of China (Nos. 40771112 and 41171215), and the Technology Innovation Program of Southwest University of China (No. Ky2009022).

View full text