Abstract
Activity of nitrate reductase and glycolate dehydrogenase in spinach leaves changes in identical patterns following changes in the levels of nitrate available in the nutrient solution of the plants. Replacing nitrate by ammonium ions caused loss of activity of both enzymes in cauliflower but this loss was less extensive in spinach plants. Glycolate dehydrogenase and nitrate reductase activities were negligible in Mo-deficient spinach and cauliflower leaves, but increased to identical extents upon addition of Mo to the nutrient medium. The activity of both enzymes was increased to levels found in control plants when tungstate was added to Mo-deficient plants. Phosphate buffer was found to be the best extraction medium for both enzymes, stimulating nitrate reductase by 15% and glycolate dehydrogenase 3-fold. Both enzymes showed a similar pH sensitivity but differed in their thermal denaturation activation energies. Gel chromatography indicated that glycolate dehydrogenase protein differs from that of nitrate reductase.
Original language | English |
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Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | Israel Journal of Botany |
Volume | 33 |
Issue number | 1 |
DOIs | |
State | Published - 1 Jan 1984 |
ASJC Scopus subject areas
- General Agricultural and Biological Sciences