Effect of aluminium and nitrite stress on growth and potassium transport of common winter wheat and durum wheat seedlings

The objective of this study was to examine the effects of aluminium (Al3+) and nitrite (NO2-) on the growth and potassium (K+) transport of common winter wheat and durum wheat seedlings grown for 7 days in 0.5 mM CaSO4 solution at pH 4.1 in the presence or absence of AlCl3 and NaNO2. The aluminium inhibition of root elongation in Yubileinaya 50 (Triticum aestivum L.) was pronounced at 10 mu M AlCl3, while this effect was approx. 5-times higher in GK Betadur (Triticum durum Desf). With shortterm Al treatments (6 h) at pH 4.1, the Kt(Rb-86) influx increased with increasing AlCl3 concentrations in the outer medium in the roots and shoots of both both species. At the same time, the K+ content of the roots and shoots was not affected by Al. Ln the case of the nitrite and nitrite + aluminium treatment combinations a striking inhibition was observed in the K+(Rb-86) influx and K+ content of the roots and shoots of both species. Increasing concentrations of soil aluminium (Al3+) and nitrite (NO2-) reduce the ion uptake and growth of wheat at low pH. However, little information is available on the joint effect of these two stress factors. The results clearly indicate that Al treatment at low pH resulted in the inhibition of root growth, but without membrane disruption. Al in combination with nitrite, however, led to total membrane damage even after shortterm treatments. The mechanism of the K+(Rb-86) influx anomaly is at present unclear and will require further investigations. Durum wheat proved to be much more sensitive to the stress conditions examined than common winter wheal.