Effect of slug mycophagy on Tuber aestivum spores

Area of Science:

• Ecology
• Mycology
• Animal Behavior

Background:

• Truffles (genus Tuber) are subterranean fungi dependent on animals for spore dispersal due to their inability to actively discharge spores.
• Mycophagy (fungus consumption) is observed in various vertebrates and invertebrates, with mammals being the most studied.
• While mycophagy is documented in arthropods, it is less common in molluscs, highlighting a gap in understanding invertebrate roles in truffle dispersal.

Purpose of the Study:

• To investigate the effects of passage through the digestive tracts of slugs (Deroceras invadens) and mice (Mus musculus) on Tuber aestivum spores.
• To assess the impact of ingested spores on oak mycorrhization compared to fresh spores.
• To determine if slugs act as dispersers for Tuber species through molecular analysis of slug gut contents.

Main Methods:

• Microscopic analysis (light, scanning electron, atomic force) of Tuber aestivum spores after gut passage.
• Assessment of oak mycorrhization rates using spores processed by slugs and mice versus fresh spores.
• Molecular barcoding of slug gut contents from truffle-rich environments to identify ingested Tuber species.

Main Results:

• Digestion, particularly by slugs, freed Tuber aestivum spores from asci and altered their morphology.
• Oak mycorrhization improved significantly with spores ingested by slugs and mice compared to fresh spores.
• Molecular analysis confirmed the presence of Tuber melanosporum and Tuber brumale spores in slug guts, indicating slugs consume and potentially disperse these species.

Conclusions:

• Invertebrates, specifically slugs, can efficiently disperse Tuber spores.
• Passage through animal digestive systems modifies truffle spores, enhancing their mycorrhizal potential.
• Slugs and rodents play a crucial role in the reproductive cycle of truffles by aiding spore dispersal and improving colonization success.