Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
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Target Concepts:
Gene/Protein
Disease
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Enzyme
Compound
Query: EC:1.7.1.2 (
nitrate reductase
)
3,861
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Gibberellin
production in Gibberella fujikuroi starts upon exhaustion of the nitrogen source. To determine the role of nitrate and ammonium in the regulation of gibberellin biosynthesis we have isolated mutants that cannot use nitrate as a nitrogen source. Nitrate inhibited partially the production of gibberellins in mutants devoid of
nitrate reductase
activity. The inhibition occurred whether nitrate was added before or after the onset of gibberellin production. Addition of tungstate to the wild type mimicked the results with
nitrate reductase
mutants. We conclude that nitrate inhibits gibberellin biosynthesis by itself, independently of the intracellular signal that conveys nitrogen availability.
...
PMID:Inhibition of gibberellin biosynthesis by nitrate in Gibberella fujikuroi. 928 12
Nitrate induces the formation of
nitrate reductase
activity in barley (Hordeum vulgare L. cv. Himalaya) aleurone layers. Previous work has demonstrated de novo synthesis of alpha-amylase by gibberellic acid in the same tissue. The increase in
nitrate reductase
activity is inhibited by cycloheximide and 6-methylpurine, but not by actinomycin D. Nitrate does not induce alpha-amylase synthesis, and it has no effect on the gibberellic acid-induced synthesis of alpha-amylase. Also, there is little or no direct effect of gibberellic acid (during the first 6 hr of induction) or of abscisic acid on the nitrate-induced formation of
nitrate reductase
.
Gibberellic acid
does interfere with
nitrate reductase
activity during long-term experiments (greater than 6 hr). However, the time course of this inhibition suggests that the inhibition may be a secondary one. Barley aleurone layers therefore provide a convenient tissue for the study of both substrate- and hormone-induced enzyme formation.
...
PMID:Substrate induction of nitrate reductase in barley aleurone layers. 1665 37
