Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase

• Published in: Plant molecular biology Vol. 40; no. 2; pp. 279 - 288
• Main Authors: Alia, Kondo, Y, Sakamoto, A, Nonaka, H, Hayashi, H, Saradhi, P.P, Chen, T.H.H, Murata, N
• Format: Journal Article
• Language: English
• Published: Netherlands Springer Nature B.V 01.05.1999
• Subjects: Adaptation, Physiological - genetics; alcohol oxidoreductases; Alcohol Oxidoreductases - genetics; Alcohol Oxidoreductases - metabolism; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis thaliana; Arthrobacter - enzymology; Arthrobacter globiformis; ascorbate peroxidase; Ascorbate Peroxidases; betaine; biosynthesis; catalase; Catalase - metabolism; chlorophyll; Enzyme Activation - drug effects; enzyme activity; fatty acids; Fatty Acids - chemistry; fluorescence; Free Radical Scavengers - metabolism; Gene Expression; gene transfer; Genes, Bacterial; genetic transformation; glutathione dehydrogenase (ascorbate); glutathione reductase (NADPH); glycerolipids; Glycerophospholipids - chemistry; hydrogen peroxide; Hydrogen Peroxide - metabolism; leaves; Light; light intensity; Lipids; monodehydroascorbate reductase; peroxidases; Peroxidases - metabolism; Photosynthesis - radiation effects; photosystem II; Plant Leaves - drug effects; Plant Leaves - metabolism; Plant Leaves - radiation effects; Plants, Genetically Modified; polar lipids; Sodium Chloride - pharmacology; stress; structural genes; superoxide dismutase; Temperature; tolerance; transgenic plants
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1023/A:1006121821883

Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis. This gene encodes choline oxidase, an enzyme that converts choline to glycinebetaine. The photosynthetic activity, monitored in terms of chlorophyll fluorescence, of transformed plants was more tolerant to light stress than that of wild-type plants. This enhanced tolerance to light stress was caused by acceleration of the recovery of the photosystem II (PS II) complex from the photo-inactivated state. The transformed plants synthesized glycinebetaine, but no changes were detected in the relative levels of membrane lipids or in the relative levels of fatty acids in the various membrane lipids. Transformation with the codA gene increased levels of H(2)O(2), a by-product of the reaction catalyzed by choline oxidase by only 50% to 100% under stress or non-stress conditions. The activity of ascorbate peroxidase and, to a lesser extent, that of catalase in transformed plants were significantly higher than in the wild-type plants. These observations suggest that H(2)O(2) produced by choline oxidase in the transformed plants might have stimulated the expression of H(2)O(2) scavenging enzymes, with resultant maintenance of the level of H(2)O(2) within a certain limited range. It appears that glycinebetaine produced in vivo, but not changes in membrane lipids or in the level of H(2)O(2), protected the PS II complex in transformed plants from damage due to light stress.