title: Grapevine species from varied native habitats exhibit differences in embolism formation/repair associated with leaf gas exchange and root pressure.
abstract: Drought induces xylem embolism formation, but grapevines can refill non-functional vessels to restore transport capacity. It is unknown whether vulnerability to embolism formation and ability to repair differ among grapevine species. We analysed in vivo embolism formation and repair using x-ray computed microtomography in three wild grapevine species from varied native habitats (Vitis riparia, V. arizonica, V. champinii) and related responses to measurements of leaf gas exchange and root pressure. Vulnerability to embolism formation was greatest in V. riparia, intermediate in V. arizonica and lowest in V. champinii. After re-watering, embolism repair was rapid and pronounced in V. riparia and V. arizonica, but limited or negligible in V. champinii even after numerous days. Similarly, root pressure measured after re-watering was positively correlated with drought stress severity for V. riparia and V. arizonica (species exhibiting embolism repair) but not for V. champinii. Drought-induced reductions in transpiration were greatest for V. riparia and least in V. champinii. Recovery of transpiration after re-watering was delayed for all species, but was greatest for V. champinii and most rapid in V. arizonica. These species exhibit varied responses to drought stress that involve maintenance/recovery of xylem transport capacity coordinated with root pressure and gas exchange responses.
authors.affiliation: Department of Viticulture & Enology, University of California, Davis, CA, 95616, USA.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Knipfer
authors.affiliation: Department of Viticulture & Enology, University of California, Davis, CA, 95616, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Eustis
authors.affiliation: School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Brodersen
authors.affiliation: Department of Viticulture & Enology, University of California, Davis, CA, 95616, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Walker
authors.affiliation: Department of Viticulture & Enology, University of California, Davis, CA, 95616, USA.|USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA, 95616, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: McElrone
mesh_terms: D017753:Ecosystem; D005740:Gases / Q000378:metabolism*; D018515:Plant Leaves / Q000502:physiology*; D018517:Plant Roots / Q000502:physiology*; D018547:Plant Stems / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology; D011312:Pressure; D013997:Time Factors; D027843:Vitis / Q000502:physiology*; D014867:Water; D055114:X-Ray Microtomography
chemical_list: D005740:Gases; D014867:Water
keywords: Vitis; cavitation; drought; recovery; vulnerability; water stress; xylem