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THE RELATIONSHIP OF COMPARTMENTATION OF ORGANIC ACID METABOLISM TO BICARBONATE‐ION SENSITIVITY OF ROOT GROWTH IN CALCICOLES AND CALCIFUGES
Author(s) -
LEE J. A.,
WOOLHOUSE H. W.
Publication year - 1971
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1971.tb02515.x
Subject(s) - bicarbonate , biology , elongation , botany , organic acid , metabolism , biochemistry , endocrinology , materials science , metallurgy , ultimate tensile strength
S ummary It was shown previously that cell elongation in the roots of certain calcifuge grasses was inhibited by concentrations of bicarbonate and malate which promoted cell elongation in related calcicole species. The present paper reports experiments in which [2‐ 14 C]‐acetate was supplied to excised roots of a calcifuge Deschampsia flexuosa and a calcicole species Arrhenatherum elatius. Time course studies of the pattern of [2‐ 14 C] incorporation into the organic and amino acids of the roots indicates an active tricarboxylic acid cycle in both species but differing in that in Deschampsia the respiratory malate pool was more completely compartmented from other malate pools in the cells, whereas in Arrhenatherum a progressive mixing of the malate pools occurred. Treatment of roots with a pulse of [2‐ 14 C]‐acetate followed by exposure to 10 m‐equiv./1 HCO − 3 for 3 hours resulted in a substantial modification in the pattern of 14 C incorporation from acetate in Deschampsia but not in Arrhenatherum. The results are discussed in relation to the differential effects of bicarbonate on root growth in the two species.