Effects of nitrate on influx, efflux and translocation of potassium in young sunflower plants |
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| Authors: | Sune Pettersson |
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| Institution: | S. Pettersson, Dept of Plant Physiology, Swedish Univ. of Agricultural Sciences, S-750 07 Uppsala 7, Sweden. |
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| Abstract: | Influx, efflux and translocation of K+(86Rb) were studied in the roots of sunflower seedlings ( Helianthus annuus L. cv. Uniflorus) treated with 0–4.0 m M NO3? during a 9 day growth period or a 24 h pretreatment period. Roots treated with high levels of NO3? absorbed and translocated more K+(86Rb) than seedlings treated with low levels of NO3?. The content of K+ in the shoots was, however, higher in seedlings treated with low levels of NO3?, indicating a low rate of retranslocation of K+ in those plants. K+(86Rb) efflux was highest into the low-NO3? solutions. All effects on K+(86Rb)-fluxes were more obvious in high-K plants than in low-K plants. The results are discussed in relation to the Dijkshoorn-Ben Zioni hypothesis for K++ NO3?-uptake and translocation in plants. |
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| Keywords: | Helianthus annuus K+ uptake regulation |
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