Chilling Stress Triggers VvAgo1-Mediated miRNA-like RNA Biogenesis in Volvariella volvacea

Author: mycolabadmin
2020-09-15
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Summary

This research investigated why the edible straw mushroom (Volvariella volvacea) breaks down when exposed to cold temperatures, a problem that limits its storage and distribution. The scientists discovered that cold temperatures activate a specific genetic mechanism that causes the mushroom to self-destruct through a process called RNA interference. This finding helps explain the mushroom’s unique cold sensitivity and could lead to ways to develop more cold-resistant varieties. Impacts on everyday life: – Helps explain why straw mushrooms have such a short shelf life in refrigeration – Could lead to development of cold-resistant mushroom varieties that last longer – May improve availability and reduce waste of this nutritious food source – Provides insights that could help mushroom farmers improve storage and transportation – Demonstrates how understanding genetic mechanisms can help solve practical food production challenges

Background

Volvariella volvacea (straw mushroom) is extensively cultivated in tropical and subtropical regions but requires high temperatures (28-35°C) for growth. When exposed to low temperatures (4°C), V. volvacea undergoes cryogenic autolysis where the mycelia autolyze and the fruiting body becomes soft and liquid. This unique cold sensitivity limits distribution and storage of this economically important mushroom. Previous research identified upregulation of an Argonaute protein (VvAgo1) during cold stress, suggesting involvement of RNA interference mechanisms.

Objective

To investigate the role of VvAgo1-mediated RNA interference in the cryogenic autolysis of V. volvacea by analyzing its expression, evolution, structure and function during cold stress response.

Results

Chilling stress significantly upregulated VvAgo1 expression in strain V23 but not in cold-resistant VH3. VvAgo1 belongs to the Ago-like family and evolved through gene duplication, loss and purifying selection. Cold stress triggered increased milRNA expression in V23 but not VH3. The target genes of increased milRNAs were enriched in signal transduction and ubiquitination pathways. Most target genes were not translated into proteins, suggesting VvAgo1-mediated RNA interference affects these pathways.

Conclusion

Cold stress triggers VvAgo1-mediated RNA interference to facilitate cryogenic autolysis in V. volvacea through regulation of milRNAs targeting genes involved in signal transduction and ubiquitination pathways. This mechanism appears specific to cold-sensitive strains and provides new insights into cold sensitivity in this species.

Published in:Frontiers in Microbiology,
Study Type:Laboratory Research Study,
Source: 10.3389/fmicb.2020.523593