The sound of lichens : ultrasonic acoustic emissions during desiccation question cavitation events in the hyphae
© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprintsoup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink serv...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 75(2024), 20 vom: 30. Okt., Seite 6579-6592 |
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| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Cavitation LTSEM chlorophyll a fluorescence desiccation lichen turgor loss point ultrasonic acoustic emission water status dynamics Water |
| Zusammenfassung: | © The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprintsoup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com. Lichens are a mutualistic symbiosis between a fungus and one or more photosynthetic partners. They are photosynthetically active during desiccation down to relative water contents (RWCs) as low as 30% (on dry mass). Experimental evidence suggests that during desiccation, the photobionts have a higher hydration level than the surrounding fungal pseudo-tissues. Explosive cavitation events in the hyphae might cause water movements towards the photobionts. This hypothesis was tested in two foliose lichens by measurements of ultrasonic acoustic emissions (UAEs), a method commonly used in vascular plants but never in lichens, and by measurements of PSII efficiency, water potential, and RWC. Thallus structural changes were characterized by low-temperature scanning electron microscopy. The thalli were silent between 380% and 30% RWCs, when explosive cavitation events should cause movements of liquid water. Nevertheless, the thalli emitted UAEs at ~5% RWC. Accordingly, the medullary hyphae were partially shrunken at ~15% RWC, whereas they were completely shrunken at <5% RWC. These results do not support the hypothesis of hyphal cavitation and suggest that the UAEs originate from structural changes at hyphal level. The shrinking of hyphae is proposed as an adaptation to avoid cell damage at very low RWCs |
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| Beschreibung: | Date Completed 30.10.2024 Date Revised 27.11.2024 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erae318 |