Proline accumulation in sorghum leaves in enhanced by salt-induced tissue dehydration.

Abstract

Seedlings of two forage sorghum genotypes differing in salt tolerance were subjected to 0 and 100 mM NaCl and inorganic solutes (Na⁺ plus Cl^-) and proline contents in leaves were measured. Proline contents increased in the leaves of the seedlings after treatment with 100 mM NaCl, mainly in the salt sensitive one. Ion accumulation under saline conditions was higher in basal leaves, but proline accumulation occurred mainly in the apical leaf zones, which suffered higher dehydration. Proline accumulation did not seem to be a good indicator of plant tolerance to salinity but of tissue water dehydration which may occur during salt treatment.