The role of phosphorus in the ectendomycorrhiza continuum of desert truffle mycorrhizal plants

Abstract

The influence of inorganic and organic phosphorus (P) and the absence of P in the culture medium on the type of mycorrhizal colonization formed (ecto-, ectendo-, or endomycorrhiza) during Helianthemum almeriense x Terfezia claveryi symbiosis in in vitro conditions was analyzed. This is the first time that the relative proportions of the different mycorrhizal types in mycorrhizal roots of H. almeriense have been quantified and statistically analyzed. The relative proportions of the mycorrhizal types depended on the P source in the medium, suggesting that it is the organic P form that induces the formation of intracellular colonization. The above association should be considered as a continuum between intra- and intercellular colonizations, the most appropriate term for defining it being ectendomycorrhiza. The influence of the endogenous concentration of P on plant growth was also analyzed. P translocation was observed from shoot to roots, especially in mycorrhizal plants because mycorrhizal roots showed higher growth than non-mycorrhizal roots and/or because of an extra P demand from mycelium inside the roots. Soluble and cell wall acid phosphatases activities from H. almeriense roots were kinetically characterized at optimum pH (5.0), using p-nitrophenyl phosphate as substrate, with K (m) values of 3.4 and 1.8 mM, respectively. Moreover, the plant acid phosphatase and fungal alkaline phosphatases activities were histochemically localised in mycorrhizal H. almeriense roots by fluorescence with enzyme-labelled fluorescence substrate.

Elevated atmospheric CO2 modifies responses to water‐stress and flowering of Mediterranean desert truffle mycorrhizal shrubs

“…Atmospheric CO 2 interaction with water-stress influences physiology of H. almeriense desert truffle plant So far, H. almeriense physiology has been studied mainly because of its interest as the host species for the cultivation of T. claveryi, focusing solely on its adaptation traits to arid environments and its responses to water-stress (Morte et al 2000, Navarro-Ródenas et al 2012, which is Fig. 6.…”

Changes in ectomycorrhizal fungal community composition and declining diversity along a 2‐million‐year soil chronosequence

“…; Navarro‐Ródenas et al . ). Fungal communities covary with host plant communities along soil fertility gradients (Davey et al .…”

“…Soil abiotic properties such as concentrations of N and P and pH affect ECM fungi (Twieg et al 2009;Navarro-R odenas et al 2012). Fungal communities covary with host plant communities along soil fertility gradients (Davey et al 2015), and host plant communities can control their root-associated fungal communities (Ishida et al 2007;Gao et al 2015;Mart ınez-Garc ıa et al 2015).…”

Structural plasticity in root-fungal symbioses: diverse interactions lead to improved plant fitness

“…The EEM association is formed between gymnosperms/angiosperms, including plant species belonging to Pinus (pine), Picea (spruce) and Larix (larch), and certain members of the fungal taxa Ascomycota, Basidiomycota and Mucoromycota (previously within Zygomycota), including species of Wilcoxina , Sphaerosporella , Phialophora and Chloridium ( Egger & Fortin, 1988 ; Trevor et al, 2001 ; Navarro-Ródenas et al, 2012 ). Hartig net and mantle develop in EEM associations similar to the ECM, and hyphae also penetrate epidermal and cortical cells as observed in AM symbiosis.…”

“…This is an example where the symbiosis type (here, presence or absence of fungal interface structures) differs according to environment rather than host. Likewise, Navarro-Ródenas et al (2012) demonstrated that the type of mycorrhizal association (ECM or EEM) between Helianthemum almeriense and Terfezia claveryi is determined by the P source where the organic P form can lead to intracellular (EEM) colonization. In FM symbiosis, fungal hyphae live in the rhizosphere soil and vicinity but do not penetrate plant roots.…”