Barrier Properties of Fungal Fruit Body Skins, Pileipelles, Contribute to Protection Against Water Loss

Author: mycolabadmin
2021-04-22
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Summary

This research revealed that mushroom caps have a specialized outer skin that helps protect them from drying out. Like how human skin keeps our bodies from losing too much water, these fungal skins act as barriers that regulate water loss while still allowing some gas exchange. The effectiveness of this barrier changes based on humidity levels, helping mushrooms survive in varying environmental conditions. Impacts on everyday life: – Helps explain why mushrooms tend to appear after rain and in humid conditions – Provides insights for mushroom cultivation and storage – Contributes to understanding how fungi adapt to different environments – Could inspire new materials for moisture control – Helps explain mushroom preservation techniques

Background

The driving force for transpirational water loss from living cells is mainly the result of the water potential gradient between cells and the surrounding atmosphere as well as temperature differences. The water potential of the atmosphere decreases rapidly with decreasing humidity and exceeds -200 MPa at a relative humidity of 20%. This creates a hostile environment for cells having a water potential of about -0.5 to -5 MPa. While plants have evolved water-proofing mechanisms like cuticles, fungal fruit bodies have not been previously studied for specialized barrier structures against water loss.

Objective

To test the hypothesis that the pileipellis (fungal fruit body skin) constitutes a significant water-barrier, decreasing transpirational water loss of fungal fruit bodies, while also reducing oxygen permeance. The study aimed to assess the importance of structural, biophysical and chemical features such as fungal lipids and water content for the survival of fruit bodies in hostile environments.

Results

The fungal skins reduced water loss by factors of 10 to 30 compared to an uncovered water surface, with permeability ranging from 2.8 to 9.8 × 10−4ms−1. Oxygen permeability was much lower, ranging from 0.8 to 6.0 × 10−6ms−1. Chloroform-extractable substances played a minor but significant role as transport barriers. Both water and oxygen permeability increased with higher humidity in the aerial compartment. The skins could absorb 40-60% of their weight in water at 93% humidity.

Conclusion

The pileipelles of fungal fruit bodies provide significant barrier properties against water loss, though not as effective as plant cuticles. The barrier properties are directly correlated to water content, with the skins acting as dynamic barriers that help regulate water loss based on environmental conditions. This adaptation allows mushrooms to maintain necessary moisture for spore production and release while preventing excessive water loss in drier conditions.

Published in:Scientific Reports,
Study Type:Laboratory Research,
Source: 10.1038/s41598-021-88148-0