This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Burke, J. J. Articles by Hatfield, J. L. Search for Related Content PubMed PubMed Citation Articles by Burke, J. J. Articles by Hatfield, J. L. Agricola Articles by Burke, J. J. Articles by Hatfield, J. L.

Environmental and Stress Physiology

Plant Morphological and Biochemical Responses to Field Water Deficits

III. Effect of Foliage Temperature on the Potential Activity of Glutathione Reductase

United States Department of Agriculture, Agricultural Research Service, Box 215, Lubbock, Texas 79401, Plant Stress and Water Conservation Research Unit, Box 215, Lubbock, Texas 79401

Activity of glutathione reductase has been related to stress tolerance; however, these enzyme assays are generally conducted at 25°C. Foliage temperature varies greatly in the field in response to soil water availability and ambient conditions and this may affect enzyme response. This study was conducted to determine the effect of changing foliage temperature on glutathione reductase activity of wheat under field conditions. Wheat leaf glutathione reductase was purified and the temperature response of the enzyme was determined at 2.5°C intervals between 12.5 and 45°C. These data, in conjunction with continuous measurements of field-grown wheat foliage temperatures, were used to compare the temperature-related changes in potential glutathione reductase activities in water stressed and control plants. Assuming saturating substrate levels, the results indicate that early in the season the daily potential enzyme activity of the irrigated and stressed plants could never have reached the daily activity predicted from the 25°C (room temperature) measurements. Later in the season, the daily potential activity of the irrigated plants was lower, and the daily potential activity of the stressed plants was higher, than the activities predicted from the 25°C determinations. These results suggest that a better understanding of the regulation of plant metabolism will be obtained by linking continuous temperature measurements of plant foliage with enzyme responses to temperature.

This article has been cited by other articles:

				J. R. Mahan and D. F. Wanjura Seasonal Patterns of Glutathione and Ascorbate Metabolism in Field-Grown Cotton under Water Stress Crop Sci., January 1, 2005; 45(1): 193 - 201. [Abstract] [Full Text] [PDF]