title: Differential physiological and molecular response of barley genotypes to water deficit.
abstract: Changes in physiological parameters (relative water content (RWC), biomass, water use efficiency (WUE), net photosynthetic yield (PN) and quantum yield of PSII (Fv/Fm)), in proline and sugar content, and expression profile of genes reported to be associated with the barley response to water deficit, including LEA genes, NHX1, Hsdr4, BLT101 and genes encoding transcription factors (HvDREB1, HvABF1, HvABI5 and HvZIP1), were analyzed in seedlings of nine barley genotypes subjected to a progressive increase in water deficit. Seedlings of all genotypes wilted when the soil water content (SWC) declined from 65% (control conditions) to 10% (severe drought conditions), but recovered turgor within a few hours of re-watering. However, when severe drought conditions were prolonged for a week, large differences in survival characteristics were observed between genotypes after re-watering. Multivariate analysis of the changes in physiological and molecular characteristics allowed several different homogenous groups within the genotypes to be distinguished, depending on stress intensity. Furthermore, integration between the stress-response traits was found and was shown to vary depending on the genotype and the stress level. Based on analysis of physiological traits and survival characteristics, two barley genotypes with high adaptability to the stress conditions (cv. Saida and breeding line Cam/B1), and two with low adaptability (cv. Express and breeding line Harmal), were identified. In addition, only changes in expression of the genes HvZIP1, encoding a b-ZIP-type transcription factor, and Hsdr4, encoding a protein of unknown function, were shown to be linked with adaptability of barley to water deficit. In summary, physiological and molecular data revealed large, stress-level-dependent differences between the barley cultivars and breeding lines tested in their response to water deficit.
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland. Electronic address: mmez@igr.poznan.pl.
authors.forename: Mateusz
authors.initials: M
authors.lastname: de Mezer
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Turska-Taraska
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Kaczmarek
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Glowacka
authors.affiliation: Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 64-701 Poznań, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Swarcewicz
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Rorat
mesh_terms: D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005838:Genotype; D001467:Hordeum / Q000378:metabolism* / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D014867:Water
keywords: Barley (Hordeum vulgare L.); Drought tolerance; Hsdr4 (Hordeum spontaneum dehydration responsive 4); LEA; Relative water content; Water use efficiency; bZIP transcription factor