Diversification of Vascular Occlusions and Crystal Deposits in the Xylem Sap Flow of Five Tunisian Grapevines

Badra Bouamama-Gzara; Hassene Zemni; Noomene Sleimi; Abdelwahed Ghorbel; Lassaad Gzara; Naima Mahfoudhi

doi:10.3390/plants11162177

Plants (Aug 2022)

Diversification of Vascular Occlusions and Crystal Deposits in the Xylem Sap Flow of Five Tunisian Grapevines

Badra Bouamama-Gzara,
Hassene Zemni,
Noomene Sleimi,
Abdelwahed Ghorbel,
Lassaad Gzara,
Naima Mahfoudhi

Affiliations

Badra Bouamama-Gzara: Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj-Cédria, University of Carthage, BP. 905, Hammam-Lif 2050, Tunisia
Hassene Zemni: Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj-Cédria, University of Carthage, BP. 905, Hammam-Lif 2050, Tunisia
Noomene Sleimi: Laboratory RME—Resources, Materials and Ecosystems, Faculty of Sciences of Bizerte, University of Carthage, Bizerte 7021, Tunisia
Abdelwahed Ghorbel: Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj-Cédria, University of Carthage, BP. 905, Hammam-Lif 2050, Tunisia
Lassaad Gzara: Center of Excellence in Desalination Technology, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia
Naima Mahfoudhi: Laboratory of Plant Protection, National Institute of Agronomic Research of Tunisia, University of Carthage Rue Hedi Karray, El Menzah 1004, Tunisia

DOI: https://doi.org/10.3390/plants11162177
Journal volume & issue: Vol. 11, no. 16
p. 2177

Abstract

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Xylem vessels are essential pivotal organs in bulk hydraulic flow through the whole woody plant. However, environmental constraints generate disagreements in xylem structures, which are characterized by air emboli and occlusions formations, compromising water conductivity in grapevines. The aim of this work was to explore xylem morphology dynamics through the xylem sap flow of five Tunisian grapevine cultivars during the natural bleeding sap periods of 2019, 2021, and 2022. In fact, Sakasly, Khamri, Hencha, Razegui1, and Razegui2 rain-fed grapevine cultivars revealed differential responses towards xylem sap movement. The results demonstrated that the xylem sap flow was significantly more abundant in 2019 than 2021 and 2022 bleeding sap campaigns. A variation was revealed between the cultivars regarding the xylem sap flow. In fact, Sakasly gave the best xylem flow during the three campaigns. Razegui1 and Razegui2 registered approximately similar xylem sap flow, while Hencha and Khamri present the lowest sap fluxes during the three campaigns. Moreover, several vascular occlusions forms were identified from stem cross sections using environmental scanning electron microscopy (ESEM), including tyloses, gels, starch, and gum deposits. The highest occlusion number was observed in Sakasly, Razegui1, and Razegui2 cultivars. Among different biogenic calcium shapes, several were observed for the first time in grapevine, including multi-faceted druse, cubic, crystalline sand, styloids, spherical, or drop-like structures. Considering their lower flow and totally blocked vessels, both Hencha and Khamri confirmed their susceptibility to environmental constraints. However, Sakasly, Razegui1, and Razegui2 cultivars presented higher tolerance according to their sap flow and xylem morphology.

Published in Plants

ISSN: 2223-7747 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Botany
Website: http://www.mdpi.com/journal/plants

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