TY - JOUR

T1 - Mycena species can be opportunist-generalist plant root invaders

AU - Harder, Christoffer Bugge

AU - Hesling, Emily

AU - Botnen, Synnøve S.

AU - Lorberau, Kelsey E.

AU - Dima, Bálint

AU - von Bonsdorff-Salminen, Tea

AU - Niskanen, Tuula

AU - Jarvis, Susan G.

AU - Ouimette, Andrew

AU - Hester, Alison

AU - Hobbie, Erik A.

AU - Taylor, Andy F.S.

AU - Kauserud, Håvard

N1 - Publisher Copyright: © 2023 The Authors. Environmental Microbiology published by Applied Microbiology International and John Wiley & Sons Ltd.

PY - 2023

Y1 - 2023

N2 - Traditional strict separation of fungi into ecological niches as mutualist, parasite or saprotroph is increasingly called into question. Sequences of assumed saprotrophs have been amplified from plant root interiors, and several saprotrophic genera can invade and interact with host plants in laboratory growth experiments. However, it is uncertain if root invasion by saprotrophic fungi is a widespread phenomenon and if laboratory interactions mirror field conditions. Here, we focused on the widespread and speciose saprotrophic genus Mycena and performed (1) a systematic survey of their occurrences (in ITS1/ITS2 datasets) in mycorrhizal roots of 10 plant species, and (2) an analysis of natural abundances of 13C/15N stable isotope signatures of Mycena basidiocarps from five field locations to examine their trophic status. We found that Mycena was the only saprotrophic genus consistently found in 9 out of 10 plant host roots, with no indication that the host roots were senescent or otherwise vulnerable. Furthermore, Mycena basidiocarps displayed isotopic signatures consistent with published 13C/15N profiles of both saprotrophic and mutualistic lifestyles, supporting earlier laboratory-based studies. We argue that Mycena are widespread latent invaders of healthy plant roots and that Mycena species may form a spectrum of interactions besides saprotrophy also in the field.

AB - Traditional strict separation of fungi into ecological niches as mutualist, parasite or saprotroph is increasingly called into question. Sequences of assumed saprotrophs have been amplified from plant root interiors, and several saprotrophic genera can invade and interact with host plants in laboratory growth experiments. However, it is uncertain if root invasion by saprotrophic fungi is a widespread phenomenon and if laboratory interactions mirror field conditions. Here, we focused on the widespread and speciose saprotrophic genus Mycena and performed (1) a systematic survey of their occurrences (in ITS1/ITS2 datasets) in mycorrhizal roots of 10 plant species, and (2) an analysis of natural abundances of 13C/15N stable isotope signatures of Mycena basidiocarps from five field locations to examine their trophic status. We found that Mycena was the only saprotrophic genus consistently found in 9 out of 10 plant host roots, with no indication that the host roots were senescent or otherwise vulnerable. Furthermore, Mycena basidiocarps displayed isotopic signatures consistent with published 13C/15N profiles of both saprotrophic and mutualistic lifestyles, supporting earlier laboratory-based studies. We argue that Mycena are widespread latent invaders of healthy plant roots and that Mycena species may form a spectrum of interactions besides saprotrophy also in the field.

U2 - 10.1111/1462-2920.16398

DO - 10.1111/1462-2920.16398

M3 - Journal article

C2 - 37188366

AN - SCOPUS:85159273534

VL - 25

JO - Environmental Microbiology

JF - Environmental Microbiology

SN - 1462-2912

IS - 10

ER -