When to cut your losses: Dispersal allocation in an asexual filamentous fungus in response to competition

Abstract

Fungal communities often form on ephemeral substrates and dispersal is critical for the persistence of fungi among the islands that form these metacommunities. Within each substrate, competition for space and resources is vital for the local persistence of fungi. The capacity to detect and respond by dispersal away from unfavorable conditions may confer higher fitness in fungi. Informed dispersal theory posits that organisms are predicted to detect information about their surroundings which may trigger a dispersal response. As such, we expect that fungi will increase allocation to dispersal in the presence of a strong competitor. In a laboratory setting, we tested how competition with other filamentous fungi affected the development of conidial pycnidiomata (asexual fruiting bodies) in Phacidium lacerum over 10 days. Phacidium lacerum was not observed to produce more asexual fruiting bodies or produce them earlier when experiencing interspecific competition with other filamentous fungi. However, we found that a trade‐off existed between growth rate and allocation to dispersal. We also observed a defensive response to specific interspecific competitors in the form of hyphal melanization of the colony which may have an impact on the growth rate and dispersal trade‐off. Our results suggest that P. lacerum have the capacity to detect and respond to competitors by changing their allocation to dispersal and growth. However, allocation to defence may come at a cost to growth and dispersal. Thus, it is likely that optimal life history allocation in fungi constrained to ephemeral resources will depend on the competitive strength of neighbors surrounding them.

Fungal–fungal and fungal–bacterial interactions in aquatic decomposer communities: bacteria promote fungal diversity

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Fungal genome size and composition reflect ecological strategies along soil fertility gradients

“…hyphal extension and branching rates, hyphal chemistry; Camenzind et al, 2020;Camenzind et al, 2021), reproduction (e.g. spore size and sporulation behaviour; Aguilar-Trigueros et al, 2019;Chan et al, 2019Chan et al, , 2020 and resource uptake (gene expression of enzymatic pathways; Talbot et al, 2015). However, these traits have been studied largely (if not entirely) under highly controlled conditions, which limits our understanding of how fungal traits can shape species distributions in their natural environment.…”

Many foliar endophytic fungi of Quercus gambelii are capable of psychrotolerant saprotrophic growth

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