Isolation and characterization of endogenous inhibitors of nitrate reductase of peach [Prunus persica (l.) Batsch] and their distribution in the genus Prunus 1 |
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| Authors: | Charles C. Reilly J. H. Edwards W. R. Okie |
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| Affiliation: | 1. U.S. Department of Agriculture , Agricultural Research Service, Southeastern Fruit and Tree Nut Research Laboratory , Byron, GA, 31008;2. Research Plant Pathologist , Southeastern Fruit and Tree Nut Research Laboratory , Byron, GA, 31008;3. Soil Scientist, Soil‐Plant Interactions Research Unit , Auburn University , AL, 36849;4. Research Horticulturist , Southeastern Fruit and Tree Nut Research Laboratory , Byron, Ga, 31008 |
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| Abstract: | Endogenous inhibitors of nitrate reductase (NR) of peach [Prunus persica (L.) Batsch] seedlings were identified as mandelonitrile and cyanide. The compounds gave greater than 90% inhibition at 0.019 μM and were noncompetitive with respect to nitrate when preincubated with the enzyme in the absence of nitrate. Competitive inhibition in respect to nitrate occurred when nitrate was present prior to the addition of enzyme. Concentration and distribution of NR inhibitors were: leaf > stem > roots as determined by two independent methods. Nitrate reductase inhibitor was detected in 12 diverse species of Prunus and was tentatively identified as cyanide by high‐performance liquid chromatography (HPLC) and biological activity. The degradation products of the cyanogenic‐glucoside amygalin were tested to determine NR inhibition. Amygdalin, prunasin and benzaldehyde were not inhibitors of NR, whereas mandelonitrile and cyanide were. Prunasin was determined to be the precursor of the NR inhibitors in peach leaf, stem, and root tissue. |
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| Keywords: | Amygdalin prunasin mandelonitrile cyanide benzaldehyde |
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