Cargando…
Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress
During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further reduce transpiration to prevent irreversible conductance loss. Here, we investigate two of them:...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8448192/ https://www.ncbi.nlm.nih.gov/pubmed/34539705 http://dx.doi.org/10.3389/fpls.2021.715127 |
_version_ | 1784569184058867712 |
---|---|
author | Nadal-Sala, Daniel Grote, Rüdiger Birami, Benjamin Knüver, Timo Rehschuh, Romy Schwarz, Selina Ruehr, Nadine K. |
author_facet | Nadal-Sala, Daniel Grote, Rüdiger Birami, Benjamin Knüver, Timo Rehschuh, Romy Schwarz, Selina Ruehr, Nadine K. |
author_sort | Nadal-Sala, Daniel |
collection | PubMed |
description | During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further reduce transpiration to prevent irreversible conductance loss. Here, we investigate two of them: the reversible impacts on the photosynthetic apparatus, lumped as non-stomatal limitations (NSL) of photosynthesis, and the irreversible effect of premature leaf shedding. We integrate NSL and leaf shedding with a state-of-the-art tree hydraulic simulation model (SOX+) and parameterize them with example field measurements to demonstrate the stress-mitigating impact of these processes. We measured xylem vulnerability, transpiration, and leaf litter fall dynamics in Pinus sylvestris (L.) saplings grown for 54 days under severe dry-down. The observations showed that, once transpiration stopped, the rate of leaf shedding strongly increased until about 30% of leaf area was lost on average. We trained the SOX+ model with the observations and simulated changes in root-to-canopy conductance with and without including NSL and leaf shedding. Accounting for NSL improved model representation of transpiration, while model projections about root-to-canopy conductance loss were reduced by an overall 6%. Together, NSL and observed leaf shedding reduced projected losses in conductance by about 13%. In summary, the results highlight the importance of other than purely stomatal conductance-driven adjustments of drought resistance in Scots pine. Accounting for acclimation responses to drought, such as morphological (leaf shedding) and physiological (NSL) adjustments, has the potential to improve tree hydraulic simulation models, particularly when applied in predicting drought-induced tree mortality. |
format | Online Article Text |
id | pubmed-8448192 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-84481922021-09-18 Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress Nadal-Sala, Daniel Grote, Rüdiger Birami, Benjamin Knüver, Timo Rehschuh, Romy Schwarz, Selina Ruehr, Nadine K. Front Plant Sci Plant Science During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further reduce transpiration to prevent irreversible conductance loss. Here, we investigate two of them: the reversible impacts on the photosynthetic apparatus, lumped as non-stomatal limitations (NSL) of photosynthesis, and the irreversible effect of premature leaf shedding. We integrate NSL and leaf shedding with a state-of-the-art tree hydraulic simulation model (SOX+) and parameterize them with example field measurements to demonstrate the stress-mitigating impact of these processes. We measured xylem vulnerability, transpiration, and leaf litter fall dynamics in Pinus sylvestris (L.) saplings grown for 54 days under severe dry-down. The observations showed that, once transpiration stopped, the rate of leaf shedding strongly increased until about 30% of leaf area was lost on average. We trained the SOX+ model with the observations and simulated changes in root-to-canopy conductance with and without including NSL and leaf shedding. Accounting for NSL improved model representation of transpiration, while model projections about root-to-canopy conductance loss were reduced by an overall 6%. Together, NSL and observed leaf shedding reduced projected losses in conductance by about 13%. In summary, the results highlight the importance of other than purely stomatal conductance-driven adjustments of drought resistance in Scots pine. Accounting for acclimation responses to drought, such as morphological (leaf shedding) and physiological (NSL) adjustments, has the potential to improve tree hydraulic simulation models, particularly when applied in predicting drought-induced tree mortality. Frontiers Media S.A. 2021-09-03 /pmc/articles/PMC8448192/ /pubmed/34539705 http://dx.doi.org/10.3389/fpls.2021.715127 Text en Copyright © 2021 Nadal-Sala, Grote, Birami, Knüver, Rehschuh, Schwarz and Ruehr. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Plant Science Nadal-Sala, Daniel Grote, Rüdiger Birami, Benjamin Knüver, Timo Rehschuh, Romy Schwarz, Selina Ruehr, Nadine K. Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title | Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title_full | Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title_fullStr | Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title_full_unstemmed | Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title_short | Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress |
title_sort | leaf shedding and non-stomatal limitations of photosynthesis mitigate hydraulic conductance losses in scots pine saplings during severe drought stress |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8448192/ https://www.ncbi.nlm.nih.gov/pubmed/34539705 http://dx.doi.org/10.3389/fpls.2021.715127 |
work_keys_str_mv | AT nadalsaladaniel leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT groterudiger leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT biramibenjamin leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT knuvertimo leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT rehschuhromy leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT schwarzselina leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress AT ruehrnadinek leafsheddingandnonstomatallimitationsofphotosynthesismitigatehydraulicconductancelossesinscotspinesaplingsduringseveredroughtstress |