The delayed leaf senescence mutants of Arabidopsis, ore1, ore3, and ore9 are tolerant to oxidative stress

• Published in: Plant and cell physiology Vol. 45; no. 7; pp. 923 - 932
• Main Authors: Woo, H.R. (Pohang Univ. of Science and Technology, Kyungbuk (Korea R.)), Kim, J.H, Nam, H.G, Lim, P.O
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.07.2004; Oxford Publishing Limited (England)
• Subjects: 2-(N-morpholino) ethanesulfonic acid monohydrate; 5 mM N; APX; Arabidopsis - genetics; Arabidopsis - metabolism; ARABIDOPSIS THALIANA; ascorbate peroxidase; CAT; catalase; Cellular Senescence - genetics; DAG; days after germination; DDC; DMF; Enzymes - genetics; Enzymes - metabolism; Gene Expression Regulation, Enzymologic - genetics; Gene Expression Regulation, Plant - genetics; Keywords: Delayed leaf senescence mutants — Leaf longevity — Leaf senescence — Oxidative stress — Tolerance; LEAVES; malondialdehyde; MDA; MES; methyl viologen; MUTANTS; Mutation - genetics; N-diethyldithio carbamic acid; N-dimethylformamide; OXIDATION; Oxidative Stress - genetics; peroxidase; Plant Leaves - cytology; Plant Leaves - genetics; Plant Leaves - metabolism; POD; reactive oxygen species; ROS; SAGs; salicylhydroxamic acid; SENESCENCE; senescence-associated genes; SHAM; SOD; STRESS; superoxide dismutase; TOLERANCE
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pch110

Reactive oxygen species play a critical role in mediating the oxidative damage that causes senescence in a variety of aerobic organisms, from yeast to mammals. Genetic studies of these organisms have revealed that extended longevity is frequently associated with an increased resistance to stress. However, the relationship between life span and oxidative stress tolerance in plants is poorly understood. We have investigated the responses to oxidative stress in the delayed leaf senescence mutants of Arabidopsis thaliana, ore1, ore3, and ore9. The detached leaves of these mutants exhibit increased tolerance to various types of oxidative stress. The ore1, ore3, and ore9 mutants were also more tolerant to oxidative stress at the level of the whole plant, as determined by measuring physiological and molecular changes associated with oxidative stress. However, the activities of antioxidant enzymes were similar or lower in the mutants, as compared to wild type. These results suggest that the increased resistance to oxidative stress in the ore1, ore3, and ore9 mutants is not due to enhanced activities of these antioxidant enzymes. Taken together, our findings provide genetic evidence that oxidative stress tolerance is linked to control of leaf longevity in plants.