Stress-responsive alpha-dioxygenase expression in tomato roots
| Autor: | Theingi S. T. Aung, Ashley Byun McKay, Aine L. Plant, Ananchanok Tirajoh |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Physiology
Molecular Sequence Data Plant Science Sodium Chloride Plant Roots Lycopersicon Dioxygenases chemistry.chemical_compound Solanum lycopersicum Gene Expression Regulation Plant Osmotic Pressure Amino Acid Sequence Pythium aphanidermatum Abscisic acid Differential display biology Sequence Homology Amino Acid Wild type food and beverages Oxylipin Ethylenes biology.organism_classification chemistry Biochemistry Fluridone Sequence Alignment Ethephon Abscisic Acid Signal Transduction |
| Zdroj: | Journal of experimental botany. 56(412) |
| ISSN: | 0022-0957 |
| Popis: | Alpha-dioxygenase (alpha-DOX) enzymes catalyse the oxygenation of fatty acids to yield a newly identified group of oxylipins that play a role in protecting tissues from oxidative damage and cell death. In tomato (Lycopersicon esculentum Mill.) alpha-DOX was identified as salt-regulated by differential display of mRNA, and is represented by a small gene family comprising at least three members: LEalpha-DOX1, -2, and -3 of which only LEalpha-DOX1 was salt-responsive. The enhancement of LEalpha-DOX1 expression in roots by salt, wounding and challenge with Pythium aphanidermatum (Edson) Fitzp. suggests that alpha-DOX-generated oxylipins may mediate the response of roots to these environmental stresses. In roots, LEalpha-DOX1 was abscisic acid (ABA)-responsive. However, in the ABA-deficient mutant flacca salt-responsive expression was equivalent to that in the wild type. Similarly, in roots exposed to fluridone (FLU) salt up-regulated expression; however, in this case salt-responsive LEalpha-DOX1 expression was greater than that in roots that were not exposed to FLU. A possible explanation for this is provided by the role of ABA in suppressing ethylene accumulation in osmotically stressed roots. The ethylene-generating agent ethephon and precursor 1-aminocyclopropane-1-carboxylic acid markedly elevated LEalpha-DOX1 expression, and this enhanced expression was suppressed by ABA. LEalpha-DOX1 expression in salt-stressed roots was not markedly affected by AVG indicating that ABA may be responsible for enhanced alpha-DOX expression in salt-treated roots. |
| Databáze: | OpenAIRE |
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