In vitro interactions between the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare fungi: morphological aspects and volatile production
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.
This work was funded by FEDER through the Operacional Competitiveness Program (COMPETE) and by
Portuguese national funds through the Foundation for Science and Technology (FCT) within the scope of
project PTDC/AGR-AAM/099556/2008, UID/MULTI/04046/2013, and the CIMO (UIDB/00690/2020) and the
Applied Molecular Biosciences Unit—UCIBIO (UID/MulA/04378/2020). Nathalie Moreira acknowledge FCT for
her grant, SFRH/BDP/109668/2015.
