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Characterization of the high‐affinity K + (Rb + )‐uptake system in roots of intact Taraxacum microspecies: comparison of 12 microspecies in relation to their mineral ecology
Author(s) -
HOMMELS C. H.,
SAAT T. A. W.,
KUIPER P. J. C.
Publication year - 1990
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.1469-8137.1990.tb00441.x
Subject(s) - context (archaeology) , biology , potassium , botany , chemistry , ecology , paleontology , organic chemistry
SUMMARY Taraxacum microspecies differ with respect to nutritional levels in their habitats. In the context of marked differences in growth response to internal potassium concentration between two ecologically contrasting microspecies, K + ‐uptake characteristics, V m and K m , of the high‐affinity uptake system of 12 microspecies were studied. In this comparative study, CaSO 4 ‐pretreated plants were used. Microspecies differences in V max were more abundant than in K m . Significant differences between kinetic parameters of ecologically related groups of microspecies were largely absent; only the (average) V max of the group of microspecies derived from heavily fertilized and moist grasslands was higher than those of the remaining three groups of microspecies. Within a taxonomically related group of eight microspecies, variation in V max (average) and K m (average) values was almost as high as total variation. The results on kinetic characteristics of the high‐affinity K + ‐uptake system are discussed in the context of additional differences in physiology such as the critical internal K + concentration and growth potential between two representative microspecies of different mineral ecology.