Hydroxybutyrate accumulation in Arabidopsis and tobacco plants is a general response to abiotic stress: putative regulation by redox balance and glyoxylate reductase isoforms
| Autor: | Wendy L. Allan, Shawn M. Clark, Barry J. Shelp, Jeffrey P. Simpson |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
0106 biological sciences
Pyridines Physiology γ-hydroxybutyrate Arabidopsis Glyoxylate cycle aldehyde detoxification Plant Science Biology 01 natural sciences Gene Expression Regulation Enzymologic Succinic semialdehyde glyoxylate reductase 03 medical and health sciences chemistry.chemical_compound Gene Expression Regulation Plant Tobacco Protein Isoforms Glyoxylate reductase Plant Proteins 030304 developmental biology 2. Zero hunger Abiotic component chemistry.chemical_classification 0303 health sciences redox homeostasis Abiotic stress food and beverages Metabolism biology.organism_classification Research Papers Plant Leaves Alcohol Oxidoreductases Enzyme chemistry Biochemistry Sodium Oxybate Oxidation-Reduction succinic semialdehyde reductase 010606 plant biology & botany |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| DOI: | 10.1093/jxb/ern122 |
| Popis: | Enzymes that reduce the aldehyde chemical grouping (i.e. H-C=O) to its corresponding alcohol are probably crucial in maintaining plant health during stress. Succinic semialdehyde (SSA) is a mitochondrially-generated intermediate in the metabolism of gamma-aminobutyrate (GABA), which accumulates in response to a variety of biotic and abiotic stresses. SSA can be reduced to gamma-hydroxybutyrate (GHB) under oxygen deficiency and high light conditions. Recent evidence indicates that distinct cytosolic and plastidial glyoxylate reductase isoforms from Arabidopsis (designated herein after as AtGR1 and AtGR2, respectively) catalyse the in vitro conversion of SSA to GHB, as well as glyoxylate to glycolate, via NADPH-dependent reactions. In the present report, the responses of GHB and related amino acids, as well as NADP(+) and NADPH, were monitored in leaves from Arabidopsis or tobacco plants subjected to various abiotic stresses (i.e. Arabidopsis during exposure to salinity, drought, submergence, cold, or heat; tobacco during exposure to, and recovery from, submergence). Time-course experiments revealed that GHB accumulated in both Arabidopsis and tobacco plants subjected to stress, and that this accumulation was generally accompanied by higher GABA and alanine levels, higher NADPH/NADP(+) ratio, and lower glutamate levels. Furthermore, the analysis of gene expression in Arabidopsis revealed that the relative abundance of GR1 (salinity, drought, submergence, cold, and heat) and GR2 (cold and heat) transcripts was enhanced by the stress tested. Thus, GHB accumulation in plants is a general response to abiotic stress and appears to be regulated by both biochemical and transcriptional processes. |
| Databáze: | OpenAIRE |
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