title: A morpho-physiological approach differentiates bread wheat cultivars of contrasting tolerance under cyclic water stress.
abstract: Leaf micromorphological traits and some physiological parameters with potential relevance to drought tolerance mechanisms were investigated in four selected winter wheat varieties. Plants were subjected to two cycles of drought treatment at anthesis. Yield components confirmed contrasting drought-sensitive and -tolerant behavior of the genotypes. Drought tolerance was associated with small flag leaf surfaces and less frequent occurrence of stomata. Substantial variation of leaf cuticular thickness was found among the cultivars. Thin cuticle coincided with drought sensitivity and correlated with a high rate of dark-adapted water loss from leaves. Unlike in Arabidopsis, thickening of the cuticular matrix in response to water deprivation did not occur. Water stress induced epicuticular wax crystal depositions preferentially on the abaxial leaf surfaces. According to microscopy and electrolyte leakage measurements from leaf tissues, membrane integrity was lost earlier or to a higher extent in sensitive than in tolerant genotypes. Cellular damage and a decline of relative water content of leaves in sensitive cultivars became distinctive during the second cycle of water deprivation. Our results indicate strong variation of traits with potential contribution to the complex phenotype of drought tolerance in wheat genotypes. The maintained membrane integrity and relative water content values during repeated water limited periods were found to correlate with drought tolerance in the selection of cultivars investigated.
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Brunszvik u. 2, 2462 Martonvásár, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Jäger
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Brunszvik u. 2, 2462 Martonvásár, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Fábián
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Brunszvik u. 2, 2462 Martonvásár, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Eitel
authors.affiliation: Department of Functional and Structural Materials, Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út 59-67, 1025 Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Szabó
authors.affiliation: Department of Plant Physiology and Plant Biochemistry, Faculty of Horticultural Science, Corvinus University of Budapest, Villányi út 29-43, 1118 Budapest, Hungary.
authors.forename: Csilla
authors.initials: C
authors.lastname: Deák
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Brunszvik u. 2, 2462 Martonvásár, Hungary.
authors.forename: Beáta
authors.initials: B
authors.lastname: Barnabás
authors.affiliation: Department of Plant Physiology and Plant Biochemistry, Faculty of Horticultural Science, Corvinus University of Budapest, Villányi út 29-43, 1118 Budapest, Hungary. Electronic address: istvan.papp2@uni-corvinus.hu.
authors.forename: István
authors.initials: I
authors.lastname: Papp
mesh_terms: D055864:Droughts; D035264:Flowers / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D005838:Genotype; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019441:Plant Epidermis / Q000502:physiology / Q000648:ultrastructure; D018515:Plant Leaves / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure*; D054046:Plant Stomata / Q000502:physiology / Q000648:ultrastructure; D012639:Seeds / Q000254:growth & development / Q000502:physiology / Q000648:ultrastructure; D013312:Stress, Physiological; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure*; D014867:Water; D014882:Water-Electrolyte Balance
chemical_list: D014867:Water
keywords: Cellular integrity; Cuticle; Drought tolerance; Stomatal density; Wheat (Triticum aestivum L.)