A Termite Symbiotic Mushroom Maximizing Sexual Activity at Growing Tips of Vegetative Hyphae

Author: mycolabadmin
2017-09-19
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Summary

This research reveals how a unique mushroom species that lives symbiotically with termites has evolved an extraordinary way of maintaining genetic diversity through continuous sexual processes during growth. Unlike most fungi that only undergo sexual reproduction at specific times, this fungus constantly mixes its genetic material as it grows. This discovery helps explain how termite agriculture has remained successful for millions of years. Impacts on everyday life: • Provides insights into sustainable agricultural practices by showing how monoculture can be successful with the right adaptations • Demonstrates nature’s novel solutions to maintaining genetic diversity in confined environments • Helps understand how beneficial partnerships between different species can evolve and persist • Could inspire new approaches to crop improvement and breeding • Offers lessons for managing agricultural systems more effectively

Background

Termitomyces mushrooms form mutualistic relationships with fungus-growing termites, with termites typically cultivating a single fungal symbiont genotype within each colony. This is different from human agriculture where genetic diversity is considered beneficial. The relationship between the termite Odontotermes formosanus and its Termitomyces symbiont involves the fungus producing two types of spores – conidia produced in fungus gardens and consumed by termites, and basidiospores produced on fruiting bodies above ground.

Objective

To investigate and characterize the unique life cycle and sexual processes of the Termitomyces fungal symbiont associated with the termite Odontotermes formosanus, particularly focusing on nuclear behavior and genetic recombination during vegetative growth.

Results

The study revealed that the Termitomyces symbiont undergoes meiotic-like nuclear division during each somatic cell division and conidial production, regardless of whether mating has occurred. Cytological studies showed nuclear fusion and division resembling meiosis in growing hyphal tips. Whole-genome sequencing detected genetic recombination occurring genome-wide, with 5.04% of haplotypes being recombinants. Expression of four meiosis-specific genes was confirmed in vegetative mycelia.

Conclusion

The Termitomyces symbiont possesses a novel life cycle that maximizes sexual processes through continuous genetic reshuffling during vegetative growth. This occurs through meiotic-like recombination at somatic stages, which may help the fungus adapt to constant termite consumption. This finding challenges traditional understanding of fungal life cycles and may explain how Termitomyces maintains successful monoculture with termites over millions of years.

Published in:Botanical Studies,
Study Type:Laboratory Research,
Source: 10.1186/s40529-017-0191-9