Growth and potassium transport in common and durum wheat as affected by aluminum and nitrite stress
2001
Zsoldos, F. | Vashegyi, A. | Pecsvaradi, A. | Bona, L.
Aluminum (Al) toxicity has been identified as one of the most important factors limiting plant growth in acid soil. Besides Al, nitrite (NO2(-)) may also be a significant stress factor in an acid environment. The objective of this study was to examine the effects of Al and NO2(-) stress on the growth and potassium (K+) uptake of roots and their transport toward the shoots of an Al-resistant common wheat (Triticum aestivum L. cv. Jubilejnaja 50) and an Al-sensitive durum wheat (T. durum Desf. cv. GK Betadur) grown in 0.5 mM CaSO4 solution at pH 4.1 or 6.5. Root elongation of durum wheat was inhibited with 30% at 10 micromolar AlC13 treatment, while this low Al-concentration did not show a significant effect on root growth of common wheat. In all cases shoot growth was not influenced under low-salt conditions by 10 micromolar AlCl3, but exposure to 100 micromolar KNO2 (alone or in combination with Al) had a definite stimulatory effect on growth. Aluminum was found to stimulate the K+ ((86)Rb) influx in short-term (6 h) experiments, but to inhibit it in long-term (3 days) experiments. This treatment was thought to damage the plasma membrane. When 10 micromolar 2,4-dinitrophenol was present in the uptake solution the Al-stimulated K+ uptake stopped even in short-term experiments. In the case of nitrite and nitrite + Al treatment combinations, however, a striking inhibition was observed in the K+ ((86)Rb) influx and the K+ concentration of the roots and shoots of both species.
显示更多 [+] 显示较少 [-]