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Interactions between K + and NH 4 + : effects on ion uptake by rice roots
Author(s) -
WANG M. Y.,
SIDDIQI M.Y.,
GLASS A. D. M.
Publication year - 1996
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/j.1365-3040.1996.tb00210.x
Subject(s) - oryza sativa , chemistry , flux (metallurgy) , ion , analytical chemistry (journal) , nuclear chemistry , horticulture , botany , zoology , biochemistry , environmental chemistry , biology , organic chemistry , gene
Interactive effects of K + and N (principally NH 4 + ) on plant growth and ion uptake were investigated using hydroponically grown rice ( Oryza sativa L. cv. M202) seedlings by varying the availability of NH 4 + or NO 3 − and K + during an 18d growth period, a 3d pretreatment period and during flux measurements. Plants grew best in media containing 100 mmol m −3 NH 4 + and 200mmolm −3 K + (N100/K200), followed by N2/K200 < N100/K2 < N2/K2. 86 Rb + (K + ) fluxes were increased by exposure to N during the 18 d growth period and the 3 d of pretreatment, but decreased by the presence of NH 4 + during flux measurements. This inhibition was a function of prior N/K provision and the [NH 4 + ] 0 present during flux determinations. NH 4 + was least inhibitory to 86Rb + (K + ) influx in high‐N/low‐K plants. Pretreatments with K + failed to stimulate NH 4 + uptake, and the presence of K + in the uptake solutions reduced NH 4 + fluxes only in high‐N/low‐K plants.