Evidence of nickel (Ni) efflux in Ni‐tolerant ectomycorhizal Pisolithus albus isolated from ultramafic soil. Issue 5 (5th June 2014)

• Record Type: Journal Article
• Authors: Majorel, Clarisse; Hannibal, Laure; Ducousso, Marc; Lebrun, Michel; Jourand, Philippe
• Is Part Of: Environmental microbiology reports. Volume 6:Issue 5(2014)
• Page Start: 510
• Page End: 518
• Publication Date: 2014-06-05
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; Electronic journals; 579.17
• DOI: 10.1111/1758-2229.12176
• Languages: English
• ISSNs: 1758-2229

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Nickel (Ni)‐tolerant ectomycorrhizal <italic>P</italic><italic>isolithus albus</italic> was isolated from extreme ultramafic soils that are naturally rich in heavy metals. This study aimed to identify the specific molecular mechanisms associated with the response of <italic>P</italic><italic>. albus</italic> to nickel. In presence of high concentration of nickel, <italic>P</italic><italic>. albus</italic> Ni‐tolerant isolate showed a low basal accumulation of nickel in its fungal tissues and was able to perform a metal efflux mechanism. Three genes putatively involved in metal efflux were identified from the <italic>P</italic><italic>. albus</italic> transcriptome, and their overexpression was confirmed in the mycelium that was cultivated <italic>in vitro</italic> in the presence of nickel and in fungal tissues that were sampled <italic>in situ</italic>. Cloning these genes in yeast provided significant advantages in terms of nickel tolerance (+ 31% Ni EC<sub>50</sub>) and growth (+ 83% μ) compared with controls. Furthermore, nickel efflux was also detected in the transformed yeast cells. Protein sequence analysis indicated that the genes encoded a P‐type‐ATPase, an ABC transporter and a major facilitator superfamily permease (MFS). This study sheds light on a global mechanism of metal efflux by <italic>P</italic><italic>. albus</italic> cells that supports nickel tolerance. These specific responses to nickel might contribute to the fungal adaptation in ultramafic soil.</p> </abstract>