The phenomenon of cavitation in grapevine… Unravelling implicated mechanisms = El fenómeno de la cavitación en vid… Descifrando los mecanismos implicados

Cavitation is a physiological dysfunction that takes place in the xylem of water stressed plants. It leads to a loss of hydraulic conductance (kL)as the vessels are filled with air. This impacts water supply, water potential (ΨL) and canopy hydration. Stomatal clossure is an effective response upon...

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Detalhes bibliográficos
Autores: Hugalde, Ines Pilar, Bonada, Marcos, Vila, Hernan Felix
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:Argentina
Recursos:Instituto Nacional de Tecnología Agropecuaria
Repositorio:INTA Digital (INTA)
Idioma:inglés
OAI Identifier:oai:localhost:20.500.12123/4084
Acesso em linha:http://revista.fca.uncu.edu.ar/images/stories/pdfs/2018-02/Cp_04_Hugalde-.pdf
http://hdl.handle.net/20.500.12123/4084
Access Level:acceso abierto
Palavra-chave:Vid
Trastornos Funcionales
Xilema
Conductancia Estomática
Conductancia Hidráulica de Raíces
Grapevines
Functional Disorders
Xylem
Stomatal Conductance
Root Hydraulic Conductivity
Cavitación
Déficit Hídrico
Descrição
Resumo:Cavitation is a physiological dysfunction that takes place in the xylem of water stressed plants. It leads to a loss of hydraulic conductance (kL)as the vessels are filled with air. This impacts water supply, water potential (ΨL) and canopy hydration. Stomatal clossure is an effective response upon diminishing momentary or seasonal foliar hydraulic contents. Depending on each type of plant, stomata may close preventing catastrophic cavitations. This research intended to understand how stomatal control acts upon cavitation events in two contrasting grapevine varieties, Syrah and Grenache. A mechanistic was developed model based on the water and vapour fluxes, kL, stomata conductance (gs), and the vulnerability to cavitation of the xylematic tissue. The theoretical model explains how plants respond to drought and avoid catastrophic cavitation. Water stressed grapevines couple their gs with their kL in order to avoid embolism. It is not stomatal closure, by istself, the controlling mechanism. Grapevines under mild water stress, do not need to completely close their stomata in order to avoid cavitation, therefore, photosynthesis is not completely impeded, and the cost in terms of carbon assimilation is less than expected for other species.