INCREASE OF PROLINE AND AMINOACIDS IN COWPEA CULTIVARS WITH DIFFERENTIAL SALT STRESS TOLERANCE

The aim of this work was the study of proline and aminoacids accumulation in two cowpea cultivars, previously identified as tolerant (Pitiuba) and sensitive to salinity (TVu 2331), along the stress exposition time. Plants of both cultivars were exposed to NaCl 75 mM (salt stress), added at rate of 25 mM day(-1) in nutritious solution and its behavior was compared with control ones, kept at the same environmental conditions. In general, salt stress inhibited more the growth in TVu 2331 cultivar. The stressed plants of this cultivar also presented larger proline accumulation in their leaves, suggesting the existence of a protection mechanism. TVu 2331 cultivar also presented tendency of more accumulation of aminoacids in the leaves and roots, which could have occurred due its higher growth inhibition.