Differential inhibition of indole-3-acetic acid and tryptophan biosynthesis by indole analogues. I. Tryptophan dependent IAA biosynthesis

Plant Growth Regulation - Tập 27 - Trang 57-62 - 1999
Nebojsa Ilić1, Anders Östin2, Jerry D. Cohen3
1Department of Plant Biology, University of Maryland, College Park
2Department of Forest Genetics and Plant Physiology, The Swedish University of Agricultural Sciences, Umeå, Sweden
3Horticultural Crops Quality Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville

Tóm tắt

Maize liquid endosperm extracts contain the enzymes necessary for all of the steps of the plant IAA biosynthetic pathway from tryptophan, and provide a means to assay the pathway in vitro. We have analyzed the reactions in the presence of a series of indole and indole-like analogues in order to evaluate the potential of these compounds to act as inhibitors of IAA biosynthesis. Such inhibitors will be useful to investigate the tryptophan to IAA pathway, to determine the precursors and intermediates involved, and to select for mutants in this process. A number of such compounds were tested using in vitro enzyme assays for both the tryptophan dependent IAA biosynthesis pathway and for tryptophan synthase β activity. Some compounds showed strong inhibition of IAA biosynthesis while having only a slight effect on the reaction rate of tryptophan synthase β. These results: (1) show that IAA biosynthesis can be selectively inhibited relative to tryptophan biosynthesis; (2) suggest potential ways to screen for IAA biosynthetic pathway mutations in plants; and (3) provide additional tools for studies of IAA biosynthesis in plants.

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Tài liệu tham khảo

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Plant Growth Regulation

Tập 27

57-62

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