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Localization of newly synthesized indoIe‐3‐methylglucosinolate (= glucobrassicin) in vacuoles from horseradish ( Armoracia rusticana )
Author(s) -
Helmlinger Jürgen,
Rausch Thomas,
Hilgenberg Willy
Publication year - 1983
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.1399-3054.1983.tb04185.x
Subject(s) - tryptophan , vacuole , indole test , dry weight , auxin , biochemistry , biology , biosynthesis , chemistry , botany , amino acid , enzyme , gene , cytoplasm
The presence and concentration of indole‐3‐methylglucosinolate [= glucobrassicin; 0.49 μmol (g dry weight)‐1] and its 1‐methoxy derivative [0.38 umol (g dry weight) −1 ] in Armoracia rusticana P. Gärtner, B. Meyer and Scherb, storage roots were measured. The storage tissue contains L‐tryptophan [1.63 μmol (g dry weight) ‐1 ], which is the common precursor amino acid of the indoleglucosinolates. Tissue cylinders convert [ 14 C]‐ l ‐tryptophan efficiently to the indoleglucosinolates (25%) in vivo. The conversion of [ 14 C]‐ l ‐tryptophan to indole‐3‐methylgluco‐sinolate shows biphasic kinetics. A fraction rich in vacuoles was prepared from tissue sections to which [ 14 C]‐ l ‐tryp‐tophan had been fed and allowed to be metabolized. The predominantly vacuolar location of both L‐tryptophan and the indoleglucosinolates is demonstrated by correlation with the vacuolar marker acid phosphatase. The significance for the regulation of the indoleglucosinolate biosynthesis and the role of indole‐3‐methylglucosinolate as a potential auxin precursor are discussed.