title: Regulation of photosynthesis and stomatal and mesophyll conductance under water stress and recovery in olive trees: correlation with gene expression of carbonic anhydrase and aquaporins.
abstract: The hypothesis that aquaporins and carbonic anhydrase (CA) are involved in the regulation of stomatal (g s) and mesophyll (g m) conductance to CO2 was tested in a short-term water-stress and recovery experiment in 5-year-old olive plants (Olea europaea) growing outdoors. The evolution of leaf gas exchange, chlorophyll fluorescence, and plant water status, and a quantitative analysis of photosynthesis limitations, were followed during water stress and recovery. These variables were correlated with gene expression of the aquaporins OePIP1.1 and OePIP2.1, and stromal CA. At mild stress and at the beginning of the recovery period, stomatal limitations prevailed, while the decline in g m accounted for up to 60% of photosynthesis limitations under severe water stress. However, g m was restored to control values shortly after rewatering, facilitating the recovery of the photosynthetic rate. CA was downregulated during water stress and upregulated after recovery. The use of structural equation modelling allowed us to conclude that both OePIP1.1 and OePIP2.1 expression could explain most of the variations observed for g s and g m. CA expression also had a small but significant effect on g m in olive under water-stress conditions.
authors.affiliation: Group of Irrigation and Crop Ecophysiology, Instituto de Recursos Naturales y Agrobiología, IRNAS-CSIC, Apartado 1052, 41080, Sevilla, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Perez-Martin
authors.affiliation: Biolabs, ISV, Scuola Superiore Sant'Anna, Piazza M. della Libertà 33, 56127 Pisa, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Michelazzo
authors.affiliation: Group of Irrigation and Crop Ecophysiology, Instituto de Recursos Naturales y Agrobiología, IRNAS-CSIC, Apartado 1052, 41080, Sevilla, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Torres-Ruiz
authors.affiliation: Research Group in Plant Biology under Mediterranean Conditions, Universitat de les Illes Balears; Carretera de Valldemossa Km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Flexas
authors.affiliation: Group of Irrigation and Crop Ecophysiology, Instituto de Recursos Naturales y Agrobiología, IRNAS-CSIC, Apartado 1052, 41080, Sevilla, Spain.
authors.forename: José E
authors.initials: JE
authors.lastname: Fernández
authors.affiliation: Biolabs, ISV, Scuola Superiore Sant'Anna, Piazza M. della Libertà 33, 56127 Pisa, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Sebastiani
authors.affiliation: Group of Irrigation and Crop Ecophysiology, Instituto de Recursos Naturales y Agrobiología, IRNAS-CSIC, Apartado 1052, 41080, Sevilla, Spain a.diaz@csic.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Diaz-Espejo
mesh_terms: D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000235:genetics* / Q000378:metabolism; D003890:Desiccation; D018506:Gene Expression Regulation, Plant; D031658:Olea / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D010788:Photosynthesis; D018515:Plant Leaves / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D020346:Aquaporins; D002256:Carbonic Anhydrases
keywords: AQP; CA; OePIP; Olea; mesophyll conductance; photosynthesis limitations; stomatal conductance; water stress.