Ecotypic variability in the metabolic response of seeds to diurnal hydration-dehydration cycles and its relationship to seed vigor
| Autor: | Simon Barak, Inna Khozin-Goldberg, Aaron Fait, Yana Kazachkova, Gideon Grafi, Noga Sikron, Tanya Gendler, Bing Bai |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Membrane permeability
Physiology Citric Acid Cycle Arabidopsis Germination Plant Science Biology Models Biological Antioxidants Gas Chromatography-Mass Spectrometry chemistry.chemical_compound Cell Wall Botany medicine Dehydration Amino Acids chemistry.chemical_classification Ecotype Principal Component Analysis Glutathione Disulfide Arabidopsis Proteins Fatty Acids Electric Conductivity food and beverages Fatty acid Cell Biology General Medicine Tricarboxylic acid medicine.disease Lipid Metabolism Circadian Rhythm Oleic acid Horticulture chemistry Seeds Imbibition Glycolysis Oxidation-Reduction |
| Zdroj: | Plantcell physiology. 53(1) |
| ISSN: | 1471-9053 |
| Popis: | Seeds in the seed bank experience diurnal cycles of imbibition followed by complete dehydration. These conditions pose a challenge to the regulation of germination. The effect of recurring hydration-dehydration (Hy-Dh) cycles were tested on seeds from four Arabidopsis thaliana accessions [Col-0, Cvi, C24 and Ler]. Diurnal Hy-Dh cycles had a detrimental effect on the germination rate and on the final percentage of germination in Col-0, Cvi and C24 ecotypes, but not in the Ler ecotype, which showed improved vigor following the treatments. Membrane permeability measured by ion conductivity was generally increased following each Hy-Dh cycle and was correlated with changes in the redox status represented by the GSSG/GSH (oxidized/reduced glutathione) ratio. Among the ecotypes, Col-0 seeds displayed the highest membrane permeability, whilst Ler was characterized by the greatest increase in electrical conductivity following Hy-Dh cycles. Following Dh 2 and Dh 3, the respiratory activity of Ler seeds significantly increased, in contrast to the other ecotypes, indicative of a dramatic shift in metabolism. These differences were associated with accession-specific content and patterns of change of (i) cell wall-related laminaribiose and mannose; (ii) fatty acid composition, specifically of the unsaturated oleic acid and α-linoleic acid; and (iii) asparagine, ornithine and the related polyamine putrescine. Furthermore, in the Ler ecotype the content of the tricarboxylic acid (TCA) cycle intermediates fumarate, succinate and malate increased in response to dehydration, in contrast to a decrease in the other three ecotypes. These findings provide a link between seed respiration, energy metabolism, fatty acid β-oxidation, nitrogen mobilization and membrane permeability and the improved germination of Ler seeds following Hy-Dh cycles. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|