Xylem network connectivity and embolism spread in grapevine( Vitis vinifera L.)
[1];
[2];
[7];
[8]
- School of Forest Resources, University of Maine, Orono, Maine 04469, School of the Environment, Yale University, New Haven, CT 06520
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
- Department of Engineering Sciences, Clackamas Community College, Oregon City, Oregon 97045
- Department of Viticulture and Enology, University of California Davis, Davis, California, Crops Pathology and Genetics Research Unit, USDA-ARS, Davis, California
- Department of Chemical Engineering, University of California Davis, Davis, California
- Department of Plant Science, University of California Davis, Davis, California
- Department of Viticulture and Enology, University of California Davis, Davis, California
- School of the Environment, Yale University, New Haven, CT 06520
Abstract Xylem networks are vulnerable to the formation and spread of gas embolisms that reduce water transport. Embolisms spread through interconduit pits, but the three-dimensional (3D) complexity and scale of xylem networks means that the functional implications of intervessel connections are not well understood. Here, xylem networks of grapevine (Vitis vinifera L.) were reconstructed from 3D high-resolution X-ray micro-computed tomography (microCT) images. Xylem network performance was then modeled to simulate loss of hydraulic conductivity under increasingly negative xylem sap pressure simulating drought stress conditions. We also considered the sensitivity of xylem network performance to changes in key network parameters. We found that the mean pit area per intervessel connection was constant across 10 networks from three, 1.5-m stem segments, but short (0.5 cm) segments fail to capture complete network connectivity. Simulations showed that network organization imparted additional resistance to embolism spread beyond the air-seeding threshold of pit membranes. Xylem network vulnerability to embolism spread was most sensitive to variation in the number and location of vessels that were initially embolized and pit membrane vulnerability. Our results show that xylem network organization can increase stem resistance to embolism spread by 40% (0.66 MPa) and challenge the notion that a single embolism can spread rapidly throughout an entire xylem network.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1784825
- Journal Information:
- Plant Physiology (Bethesda), Journal Name: Plant Physiology (Bethesda) Journal Issue: 1 Vol. 186; ISSN 0032-0889
- Publisher:
- Oxford University PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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