Fungal behaviour: a new frontier in behavioural ecology

Aleklett K, Boddy L (2021)

Fungal behaviour: a new frontier in behavioural ecology.

Trends Ecol Evol 36:787–796.

https://gyazo.com/b385b75d2c57e4a3f32f639488293be5

Figure 1Fungal senses and behaviours.

Fungal mycelia are networks that experience a range of conditions at the same time in different places. Mycelial networks communicate and co-ordinate the movement of resources within the mycelium (G,I), between fungi and plants through the mycorrhizal mycelial network (A) [52.,57., and between fungi and the plants and animals that they parasitize (D). The mycelium actively forages for nutrients in the soil (C) [21. and some have evolved the ability to break down complex organic molecules in nature (G) that few other organisms are capable of profiting from [40.. The mycelium can operate a wide range of behaviours by sensing and interacting with the biotic and abiotic environment, some analogous to but not necessarily homologous with animals. Tropisms are ubiquitous, including: (H) chemotropism – growing up or down gradients of volatile or diffusible chemicals [58.; (E) gravitropism – important in ensuring the vertical alignment of gills and pores for spore dispersal during reproduction [59.; (B) phototropism – possessing a range of photoreceptors that respond to light from UV to IR [53.; and (F) thigmotropism – particularly studied in pathogens that respond to surface contours to detect entry points into hosts [60.. When genetically identical mycelia meet, they fuse, recognise that they are self, and then continue to operate as a single individual (F) [40.. When mycelia of different species meet, there is considerable chemical interplay, first at a distance, and following contact, battles for territory ensue, using enzymes and volatile and diffusible chemicals (J) [61.. Illustrations

© Kristin Aleklett.

Higlight

While there is increasing acceptance that non-neural organisms such as plants, slime moulds, and bacteria can perform behaviours, the vast kingdom of fungi is usually forgotten.

We argue that fungi can also be studied through the theoretical framework of behavioural ecology. This would benefit both fungal biologists – yielding a better understanding of the lives of fungi – and behavioural ecologists, providing access to model organisms that can help to explain the evolution of primary senses and potentially discover behaviours new to science.

Fungi have senses analogous to those of other organisms, they exhibit behaviour, and they have memory. This suggests a multitude of questions and new paths that could be taken to broaden our understanding of this forgotten and underestimated branch in the tree of life.

abst

As human beings, behaviours make up our everyday lives. What we do from the moment we wake up to the moment we go back to sleep at night can all be classified and studied through the concepts of behavioural ecology. The same applies to all vertebrates and, to some extent, invertebrates. Fungi are, in most people’s eyes perhaps, the eukaryotic multicellular organisms with which we humans share the least commonalities. However, they still express behaviours, and we argue that we could obtain a better understanding of their lives – although they are very different from ours – through the lens of behavioural ecology. Moreover, insights from fungal behaviour may drive a better understanding of behavioural ecology in general.

Keywords