Premium
The Uptake and Fractional Distribution of Differentially Labeled Indoleacetic Acid in Light Grown Stems
Author(s) -
DAVIES P. J.
Publication year - 1973
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.1399-3054.1973.tb01157.x
Subject(s) - pisum , phaseolus , chemistry , ethanol , sativum , residue (chemistry) , fraction (chemistry) , decarboxylation , chromatography , botany , biochemistry , biology , catalysis
The uptake of exogenously applied indoleacetic acid (IAA) by light grown stems of bean ( Phaseolus vulgaris L. cv. Red kidney) and pea ( Pisum sativum L. cv. Alaska) was examined. The IAA was labeled in the 1 and 2 side chain positions with 14 C and the 5 ring position with 3 H. The distribution of label in the sections was analyzed by recording the elution into water, ethanol and 1.0 N NaOH, and the amount in the insoluble residue also recorded. Total uptake consisted of a rapid uptake for about 1 h followed by continued uptake at a slower rate for 24 h to give a radioactive concentration in the tissues four to five times, that of the external solution. Most of the radioactivity was initially extractable by water, later by ethanol. With IAA‐2‐ 14 C there was a slow increase in radioactivity in NaOH and residue fractions but with IAA‐1‐ 14 C most of the radioactivity was present in insoluble residue at times longer than 3 h. From the different residue patterns estimates of the extent of decarboxylation of the IAA were made. The radioactivity in the tissues was largely IAA after 1 h and the content increased until 6 h but there after there was little further increase. The water fraction initially contained the most IAA but by 24 h most IAA was found in the NaOH fraction in bean and the ethanol fraction in pea. The NaOH fraction was the only fraction in which the IAA content continually increased.