title: Natural variation in stomatal response to closing stimuli among Arabidopsis thaliana accessions after exposure to low VPD as a tool to recognize the mechanism of disturbed stomatal functioning.
abstract: Stomatal responses to closing stimuli are disturbed after long-term exposure of plants to low vapour pressure deficit (VPD). The mechanism behind this disturbance is not fully understood. Genetic variation between naturally occurring ecotypes can be helpful to elucidate the mechanism controlling stomatal movements in different environments. We characterized the stomatal responses of 41 natural accessions of Arabidopsis thaliana to closing stimuli (ABA and desiccation) after they had been exposed for 4 days to moderate VPD (1.17 kPa) or low VPD (0.23 kPa). A fast screening system was used to test stomatal response to ABA using chlorophyll fluorescence imaging under low O2 concentrations of leaf discs floating on ABA solutions. In all accessions stomatal conductance (gs) was increased after prior exposure to low VPD. After exposure to low VPD, stomata of 39 out of 41 of the accessions showed a diminished ABA closing response; only stomata of low VPD-exposed Map-42 and C24 were as responsive to ABA as moderate VPD-exposed plants. In response to desiccation, most of the accessions showed a normal stomata closing response following low VPD exposure. Only low VPD-exposed Cvi-0 and Rrs-7 showed significantly less stomatal closure compared with moderate VPD-exposed plants. Using principle component analysis (PCA), accessions could be categorized to very sensitive, moderately sensitive, and less sensitive to closing stimuli. In conclusion, we present evidence for different stomatal responses to closing stimuli after long-term exposure to low VPD across Arabidopsis accessions. The variation can be a useful tool for finding the mechanism of stomatal malfunctioning.
authors.affiliation: Horticultural Production Chains, Department of Plant Sciences, Wageningen University, p.o. Box 630, 6700 AP Wageningen, The Netherlands Department of Horticulture, College of Abureyhan, University of Tehran, PC. 3391653775, Pakdasht, Tehran, Iran Sasan.Aliniaeifard@wur.nl.
authors.forename: Sasan
authors.initials: S
authors.lastname: Aliniaeifard
authors.affiliation: Horticultural Production Chains, Department of Plant Sciences, Wageningen University, p.o. Box 630, 6700 AP Wageningen, The Netherlands.
authors.forename: Uulke
authors.initials: U
authors.lastname: van Meeteren
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D003890:Desiccation; D060146:Ecotype; D014644:Genetic Variation; D005843:Geography; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010802:Phylogeny; D054046:Plant Stomata / Q000502:physiology*; D018526:Plant Transpiration / Q000502:physiology; D025341:Principal Component Analysis; D055548:Vapor Pressure; D014867:Water
chemical_list: D045332:Photosystem II Protein Complex; D014867:Water; D000040:Abscisic Acid
keywords: Arabidopsis thaliana; abscisic acid; desiccation.; natural variation; stomata; vapour pressure deficit (VPD)