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Catabolism of indole‐3‐acetic acid in chloroplast fractions from light‐grown Pisum sativum L. seedlings
Author(s) -
BROWN B. H.,
CROZIER A.,
SANDBERG G.
Publication year - 1986
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/1365-3040.ep11616262
Subject(s) - pisum , indole 3 acetic acid , sativum , acetic acid , chloroplast , indole test , decarboxylation , biochemistry , chemistry , catabolism , chromatography , enzyme , biology , botany , auxin , gene , catalysis
The catabolism of indole‐3‐acetic acid was investigated in chloroplast preparations and a crude enzyme fraction derived from chloroplasts of Pisum sativum seedlings. Data obtained with both systems indicate that indole‐3‐acetic acid undergoes decarboxylative oxidation in pea chloroplast preparations. An enhanced rate of decarboxylation of [1′‐ 1 C]indole‐3‐acetic acid was obtained when chloroplast preparations were incubated in the light rather than in darkness. Results from control experiments discounted the possibility of this being due to light‐induced breakdown of indole‐3‐acetic acid. High performance liquid chromatography analysis of [2′‐ 14 C]indole‐3‐acetic acid‐fed incubates showed that indole‐3‐methanol was the major catabolite in both the chloroplast and the crude enzyme preparations. The identification of this reaction product was confirmed by gas chromatography‐mass spectrometry when [ 2 H 5 ]indole‐3‐methanol was detected in a purified extract derived from the incubation of an enzyme preparation with 32 H 5 ]indole‐3‐acetic acid.