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Metabolism of DL‐Tryptophan‐3‐ 14 C by the Fruitlets of Citrus aurantifolia
Author(s) -
Khalifah Rashad A.
Publication year - 1967
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1967.tb07174.x
Subject(s) - tryptophan , avena , incubation , indole 3 acetic acid , chemistry , acetic acid , metabolism , chromatography , indole test , biochemistry , anthranilic acid , auxin , botany , biology , amino acid , gene
Developing lime fruit [ Citrus aurantifolia (Christm.) Swingle] was supplied with dl‐tryptophan‐3‐ 14 C in a special medium. An incubation period of six hours was sufficient for the radioactivity to reach an equilibrium between the fruit tissue and the incubation medium. Analyses of the fruit tissue and the medium for acidic and neutral metabolites of tryptophan indicated the existence of indolic products. The auxin indole‐3‐acetic acid (IAA) was identified among the products by dry column chromatography and biological assay. Other acidic metabolites included indolepyruvic acid and an unidentified material. Neutral metabolites included indolealdehyde, indoleacetaldehyde, and two unidentified compounds. Biological activity in the Avena curvature test was obtained from extracted compounds which corresponded to IAA and indolepyruvic acid in the acidic fraction and indoleacetaldehyde in the neutral fraction. Radioactive tryptophan was also found in both the acidic and the neutral fractions due to its amphoteric nature. The experiment demonstrated the conversion of tryptophan to its indolic metabolites, including indole‐3‐acetic acid, in this Citrus tissue.