Shifting access to pools of shoot water sustains gas exchange and increases stem hydraulic safety during seasonal atmospheric drought
| Autor: | Callum Bryant, Tomas I. Fuenzalida, Nigel Brothers, Maurizio Mencuccini, Lawren Sack, Oliver Binks, Marilyn C. Ball |
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| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0301 basic medicine Pressure-volume curves Physiology Drought tolerance Plant Science Photosynthesis 01 natural sciences Acclimatization 03 medical and health sciences Hydraulic conductivity Dry season Lythraceae Plant Stems fungi food and beverages Water Plant Transpiration Droughts Plant Leaves 030104 developmental biology Sonneratia alba Agronomy Shoot Environmental science Seasons Plant Shoots 010606 plant biology & botany |
| Zdroj: | Plant, cellenvironmentREFERENCES. 44(9) |
| ISSN: | 1365-3040 |
| Popis: | Understanding how plants acclimate to drought is crucial for predicting future vulnerability, yet seasonal acclimation of traits that improve drought tolerance in trees remains poorly resolved. We hypothesized that dry season acclimation of leaf and stem traits influencing shoot water storage and hydraulic capacitance would mitigate the drought-associated risks of reduced gas exchange and hydraulic failure in the mangrove Sonneratia alba. By late dry season, availability of stored water had shifted within leaves and between leaves and stems. While whole shoot capacitance remained stable, the symplastic fraction of leaf water increased 86%, leaf capacitance increased 104% and stem capacitance declined 80%. Despite declining plant water potentials, leaf and whole plant hydraulic conductance remained unchanged, and midday assimilation rates increased. Further, the available leaf water between the minimum water potential observed and that corresponding to 50% loss of stem conductance increased 111%. Shifting availability of pools of water, within and between organs, maintained leaf water available to buffer periods of increased photosynthesis and losses in stem hydraulic conductivity, mitigating risks of carbon depletion and hydraulic failure during atmospheric drought. Seasonal changes in access to tissue and organ water may have an important role in drought acclimation and avoidance. |
| Databáze: | OpenAIRE |
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