Developmental Studies on Microbodies in Wheat Leaves

作者：J. Feierabend, Harry Beevers · 发表于：PLANT PHYSIOLOGY · 年份：1972 · DOI：10.1104/pp.49.1.28 · 被引用次数：132 · 研究领域：Photosynthetic Processes and Mechanisms、Plant Stress Responses and Tolerance、Plant Gene Expression Analysis

Catalase, glycolate oxidase, and hydroxypyruvate reductase, enzymes which are located in the microbodies of leaves, show different developmental patterns in the shoots of wheat seedlings. Catalase and hydroxypyruvate reductase are already present in the shoots of ungerminated seeds. Glycolate oxidase appears later. All three enzymes develop in the dark, but glycolate oxidase and hydroxypyruvate reductase have only low activities. On exposure of the seedlings to continuous white light (14.8 x 10(3) ergs cm(-2) sec(-1)), the activity of catalase is doubled, and glycolate oxidase and hydroxypyruvate reductase activities increase by 4- to 7-fold. Under a higher light intensity, the activities of all three enzymes are considerably further increased. The activities of other enzymes (cytochrome oxidase, fumarase, glucose-6-phosphate dehydrogenase) are unchanged or only slightly influenced by light. After transfer of etiolated seedlings to white light, the induced increase of total catalase activity shows a much longer lag-phase than that of glycolate oxidase and hydroxypyruvate reductase. It is concluded that the light-induced increases of the microbody enzymes are due to enzyme synthesis. The light effect on the microbody enzymes is independent of chlorophyll formation or the concomitant development of functional chloroplasts. Short repeated light exposures which do not lead to greening are very effective. High activities of glycolate oxidase and hydroxypyruvate reductase develop i...