In vitro interactions between the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare fungi: morphological aspects and volatile production

Paula Baptista,Paula Guedes De Pinho,Nathalie Moreira,Ricardo Malheiro,Francisca Reis,Jorge Padrão,Rui Tavares,Teresa Lino-Neto

doi:10.1080/21501203.2021.1876778

Abstract

ABSTRACT Ectomycorrhizal fungi are crucial for forests sustainability. For Castanea sativa, ectomycorrhizal fungus Pisolithus tinctorius is an important mutualist partner. Saprotrophic fungi Hypholoma fasciculare, although used for biocontrol of Armillaria root disease, it negatively affected the interaction between the P. tinctorius and plant host roots, by compromise the formation of P. tinctorius-C. sativa mycorrhizae. In this work, fungal morphology during inhibition of H. fasciculare against P. tinctorius was elucidated. P. tinctorius growth was strongly affected by H. fasciculare, which was significantly reduced after six days of co-culture and become even more significant through time. During this period, P. tinctorius developed vesicles and calcium oxalate crystals, which were described as mechanisms to stress adaption by fungi. H. fasciculare produced different volatile organic compounds in co-cultures over time and differ between single or in dual-species. H. fasciculare highly produced sesquiterpenes (namely, α-muurolene) and nitrogen-containing compounds, which are recognised as having antimicrobial activity.

Highlights

Ectomycorrhizal (ECM) symbiosis is a significant component of several forest ecosystems (Courty et al 2010)
Up to 6 d of P. 'nctorius – H. fasciculare (Pt-Hf) interacAon a radial and uniform P. 'nctorius growth had been observed, the mycelium in the interacAng zone with H. fasciculare became denser, more compact and exhibited less air growth when compared to P. 'nctorius – P. 'nctorius (Pt-Pt) control
When the relaAve growth of P. 'nctorius in Pt-Hf interacAon in relaAon to Pt-Pt control was determined, towards and away the interacAng fungi, a relevant inhibitory effect of H. fasciculare on the growth of P. 'nctorius was obvious (Figure 2). This inhibiAon occurred prior to mycelial contact between P. 'nctorius and H. fasciculare that only occurred at 22 d of dual-culture, which is typical of an antagonisAc interacAon at a distance (Boddy 2000)

Summary

Introduction

Ectomycorrhizal (ECM) symbiosis is a significant component of several forest ecosystems (Courty et al 2010). This associaAon results in several benefits for the health and growth of host plants, the most important of which are the exploitaAon of soil water and solutes Evidences of decomposer capacity/strategy for ECM fungi have revealed that they could take an acAve part in organic maMer decomposiAon, sharing some funcAonal parameters with saprotrophs The belowground fungal interacAons that occur among plant roots and several soil microorganisms are highly dynamic and could considerably affect the overall ecosystem funcAon (Werner et al 2002)

Methods

Results

Conclusion