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The influence of phosphorus nutrition on growth, chlorophyll formation and 14 CO 2 fixation of chlorophyllous carrot callus cultures
Author(s) -
Bender L.
Publication year - 1985
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19851480607
Subject(s) - carbon fixation , photosynthesis , phosphorus , kinetin , phloem , callus , starch , botany , nutrient , biology , phosphorus deficiency , darkness , chloroplast , chlorophyll , chemistry , horticulture , food science , biochemistry , explant culture , ecology , organic chemistry , in vitro , gene
Freshly isolated carrot root sec. phloem explants were cultured in nutrient solution plus inositol, IAA and kinetin and a varied supply of inorganic phosphorus. 14 CO 2 fixation experiments with the greened cultures were carried out under steady state conditions at the age of 21 days in light and darkness for four minutes. The results show that photosynthetic CO 2 fixation by the Calvin cycle is greatly reduced in phosphorus deficient cultures whereas CO 2 fixation via PEPC is enhanced. Under phosphorus deficiency the export of primary photosynthetates from the chloroplasts seems to be suppressed while the radioactivity of the labelled insoluble fraction, which represents mainly chloroplastic starch after this short time of 14 CO 2 fixation, was increased. The results are discussed with respect to the influence of phosphorus nutrition on photosynthetic CO 2 fixation and PEP carboxylation in carrot tissue cultures.