Plant Physiology 67:728-732 (1981)
© 1981 American Society of Plant Biologists
Articles
The Effects of Levulinic Acid and 4,6-Dioxoheptanoic Acid on the Metabolism of Etiolated and Greening Barley Leaves 1
Erna Meller and
Merrill L. Gassman2
Department of Biological Sciences, University of Illinois at Chicago Circle, Chicago, Illinois 60680
Application of levulinic acid (LA), a competitive inhibitor of -aminolevulinic acid (ALA) dehydratase, to greening plant tissues causes ALA to accumulate at the expense of chlorophyll. 4,6-Dioxoheptanoic acid (DA), which has been reported to be an effective inhibitor of this enzyme in animal systems, has a similar but more powerful effect on ALA and chlorophyll metabolism in greening leaves of Hordeum vulgare L. var. Larker. Both LA and DA also inhibit the uptake of [14C]amino acids into etiolated and greening barley leaves and reduce their incorporation into protein. Treatment of etiolated and greening leaves with these compounds results in the inhibition of 14CO2 evolution from labeled precursors, including amino and organic acids. Inhibition of 14CO2 evolution by these compounds is more effective in greening leaves than in etiolated leaves when [4-14C]ALA or [1-14C]glutamate are employed as precursors. Both LA and DA also inhibit the uptake and increase the incorporation of 32Pi into organophosphorus by etiolated barley leaves. These results indicate that LA and DA have more far-reaching effects upon plant metabolism than was previously believed.
2 To whom reprint requests should be addressed.
1 This work was supported by National Science Foundation Grant PCM 79-01605 to M. L. G.
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