ISHS Acta Horticulturae 1419: XII International Workshop on Sap Flow
Gas diffusion kinetics in relation to embolism formation and propagation in angiosperm xylem: a mini-review |
| Authors: | L.M. Silva, B. Bujnowski, L. Pereira, M.T. Miranda, H.J. Schenk, S. Jansen |
| Keywords: | angiosperm xylem, embolism, flow-centrifuge, gas diffusion, hydraulic conductance, pressure gradient, water potential |
| DOI: | 10.17660/ActaHortic.2025.1419.16 |
| Abstract:
Embolism formation in xylem conduits has been given considerable attention in the past as it relates to sap flow efficiency in vascular plants. Once embolism has occurred in some functional conduits of the xylem, a plant’s ability to supply water to its leaves becomes reduced, ultimately affecting gas exchange. Although we do not fully understand the mechanisms behind embolism formation, gas-liquid interfaces are known to play an essential role. The dynamics between sap- and gas-filled vessels indicate that embolism spreading is primarily driven by pressure gradients but is also influenced by gas diffusion. It has been proposed that a diffusion-driven increase in gas concentration within a recently embolized vessel is closely associated with embolism formation. This proposition arises from the concept that once a certain amount of gas has been accumulated in an embolized conduit, this gas reservoir may become a source that increases the likelihood of embolism formation in an interconnected neighboring conduit. As a result, some recent studies aimed to correlate gas diffusion with embolism resistance, considering factors such as anatomical traits and temperature. The development of new methods and models for investigating gas movement through xylem tissue enables a comprehensive exploration of the relationship between gas diffusion and embolism propagation in angiosperms. In this mini-review, we summarize the functional importance of gas diffusion kinetics in embolism formation and spreading based on experimental and modelling evidence. | |
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