Xylem network connectivity and embolism spread in grapevine (Vitis vinifera L.)

0546312 - BÚ 2022 RIV US eng J - Journal Article
Wason, J. - Bouda, Martin - Lee, E. F. - McElrone, A. J. - Phillips, R. J. - Shackel, K. A. - Matthews, M. A. - Brodersen, C.
Xylem network connectivity and embolism spread in grapevine (Vitis vinifera L.).
Plant Physiology. Roč. 186, č. 1 (2021), s. 373-387. ISSN 0032-0889. E-ISSN 1532-2548
Institutional support: RVO:67985939
Keywords : xylem * plant hydraulics * network analysis
OECD category: Plant sciences, botany
Impact factor: 8.005, year: 2021
Method of publishing: Limited access
https://doi.org/10.1093/plphys/kiab045

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.
Permanent Link: http://hdl.handle.net/11104/0322861