مهدی محمدی

Tomato plants grown in nutrient solutions with different K+ levels were used to study the effect of salicylic acid and Potassium status on Na+ uptake and Na+ accumulation in the shoot and root. Changes in the nutrient K+ levels induced evident differences in internal K+ content. When low and normal – K+ plants treated with SA were exposed in saline condition (50 mM Nacl) during experiment, Na+ uptake in low- K+ plants was greater than in normal – K+ plants. At the presence of SA, Na+ uptake in low- K+ plants was lower than low- K+ plants alone. Normal – K+ plants plus SA showed lowest amount of Na uptake and accumulation. In addition, K+ starvation favored the Na+ uptake and the Na+ accumulation both in the root and in the shoot. When the plants were exposed to heat stress by a sharp increase of the temperature to 320 C during the same period of time, the stimulating effect of K+ starvation on the water uptake was even greater. The high temperature increased Na+ uptake in both types of plants, but the Na+ accumulation in the shoot was only favored in low K+ plants.