Leaves lose approximately 400 HO molecules for every 1 CO gained during photosynthesis. Most long-distance water transport in plants, or xylem sap flow, serves to replace this water to prevent desiccation. Theory predicts that the largest vessels contribute disproportionately to overall sap flow because flow in pipe-like systems scales with the fourth power of radius. Here, we confront these theoretical flow predictions for a vessel network reconstructed from X-ray μCT imagery with in vivo flow MRI observations from the same sample of a first-year grapevine stem. Theoretical flow rate predictions based on vessel diameters are not supported. The heterogeneity of the vessel network gives rise to transverse pressure gradients that redirect flow from wide to narrow vessels, reducing the contribution of wide vessels to sap flow by 15% of the total. Our results call for an update of the current working model of the xylem to account for its heterogeneity.
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http://dx.doi.org/10.1038/s41467-019-13673-6 | DOI Listing |
Biomedicines
December 2024
Department of Cardiology, West China Hospital, Sichuan University, Chengdu 610041, China.
Coronary obstruction following plaque rupture is a critical pathophysiological change in the progression of stable angina (SAP) to acute coronary syndrome (ACS). The accumulation of platelets and various inflammatory cells on apoptotic endothelial cells is a key factor in arterial obstruction after plaque rupture. Through single-cell sequencing analysis (scRNA-seq) of plaques from SAP and ACS patients, we identified significant changes in the annexin V and P-selectin glycoprotein ligand 1 pathways.
View Article and Find Full Text PDFNew Phytol
January 2025
Centre of Excellence PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610, Wilrijk, Belgium.
Recent studies have shown that stem fluxes, although highly variable among trees, can alter the strength of the methane (CH) sink or nitrous oxide (NO) source in some forests, but the patterns and magnitudes of these fluxes remain unclear. This study investigated the drivers of subdaily and seasonal variations in stem and soil CH, NO and carbon dioxide (CO) fluxes. CH, NO and CO fluxes were measured continuously for 19 months in individual stems of two tree species, Eperua falcata (Aubl.
View Article and Find Full Text PDFPlant Cell Environ
January 2025
Civil, Environmental, and Mining Engineering, University of Western Australia, Perth, Western Australia, Australia.
Understanding and predicting plant water dynamics during and after water stress is increasingly important but challenging because the high-dimensional nature of the soil-plant-atmosphere system makes it difficult to identify mechanisms and constrain behaviour. Datasets that capture hydrological, physiological and meteorological variation during changing water availability are relatively rare but offer a potentially valuable resource to constrain plant water dynamics. This study reports on a drydown and re-wetting experiment of potted Populus trichocarpa, which intensively characterised plant water fluxes, water status and water sources.
View Article and Find Full Text PDFTree Physiol
January 2025
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
Although the separate effects of water and nitrogen (N) limitations on forest growth are well known, the question of how to predict their combined effects remains a challenge for modeling of climate change impacts on forests. Here, we address this challenge by developing a new eco-physiological model that accounts for plasticity in stomatal conductance and leaf N concentration. Based on optimality principle, our model determines stomatal conductance and leaf N concentration by balancing carbon uptake maximization, hydraulic risk and cost of maintaining photosynthetic capacity.
View Article and Find Full Text PDFBiosystems
January 2025
University of Coimbra, ADAI, LAETA, Polo II, Rua Luis Reis Santos, Coimbra, 3030-788, Portugal. Electronic address:
Infodynamics is the study of how information behaves and changes within a system during its development. This study investigates the insights that informational analysis can provide regarding the ramifications predicted by constructal design. First, infodynamic neologisms informature, defined as a measure of the amount of information in indeterminate physical systems, and infotropy - contextualized informature representing the degree of transformation of indeterminate physical systems - are introduced.
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