Effects of nitrite and sulfate on K+ uptake and growth of wheat and cucumber seedlings.
The uptake of K+ ion was studied in the roots of wheat (Triticum aestivum L. cv. GK Szeged) and cucumber (Cucumis sativus L. cv. Budai csemege) seedlings grown in nutrient solution under nitrite and sulfate stress conditions. Seedlings pretreated with 1 or 10 mM NaNO2 absorbed more K+(86Rb) than those treated with 0.1 mM NaNO2. However, the posteffect was influenced considerably by Na2SO4 treatment. The results suggest that at least a partial feed-back regulation of K+ uptake may occur. However, due to the high Na+ content of the roots and the possible toxicity of NO2-, effects of Na+ and NO2- in this process cannot be excluded. The dry matter yields of the roots and shoots were strongly influenced by the NO2- supply of the plants. However, appreciable differences were observed between wheat and cucumber seedlings. The optimal SO4(2-) and NO2- concentrations of the growth solution for maximal growth differed considerably for the two species, and also for the roots and shoots in a given species. The root growth was strongly inhibited by increasing NO2- concentrations, but the shoot development was favourably affected, indicating that plants can assimilate NO2- taken up by the roots.
Zsoldos
F
F
Department of Plant Physiology, József Attila University, Szeged, Hungary.
Haunold
E
E
Vashegyi
A
A
Herger
P
P
D017136:Ion Transport / Q000187:drug effects; D009573:Nitrites / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D013431:Sulfates / Q000494:pharmacology; D013455:Sulfur / Q000378:metabolism; D014908:Triticum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D014675:Vegetables / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
D009573:Nitrites; D013431:Sulfates; D013455:Sulfur; D012964:Sodium; D011188:Potassium