Document Type : Original Article
Hydroponically grown ten grape genotypes (Vitis vinifera L.) were treated with different concentrations of NaCl. Chawga genotype accumulated K+ in its root and shoot even at high salinity. The correlation between Na+ and K+ concentrations in root and lamina of all genotypes was negative (P<0.05, r2=-0.841) except for Chawga (P<0.01, r2=0.998). Km calculated for K+ and Na+ uptake into root and shoot of Chawga showed that K+ and Na+ compete to enter the plant, especially through roots. Chawga accumulated K+ in plant parts in spite of external higher Na+ due to increasingsalinity.Two KUP/KT/HAK-type potassium transporters are expressed highly in the grapevine during stress. VvK1.1 could play a major role in K+ loading into grape tissues. Under salinity stress the expression of VvKUP1 and VvKUP2 transporter and VvK1.1 channel increased significantly (P<0.05) in roots and leaves of Chawga genotype, but that increase was higher in roots than in leaves.