Amelioration of NaCl stress by arginine in rice seedlings: changes in endogenous polyamines

Effects of NaCl (0.1 - 0.2 M) alone or in combination with 1 mM arginine on growth and endogenous polyamine (PA) content have been observed in two cul tivars of rice differing in NaCl stress tolerance. The germination, seedlin gs fresh mass and water content decreased with increase in salinity in both the cultivars. This inhibition was partially alleviated by application of arginine. Cv. CSR-27 exhibited relatively better germination than cv. Bas 3 70 at different salinities. Total PA content increased in both the cultivar s under NaCl stress alone and in combination with arginine. Putrescine to s permidine and spermine ratio was higher in NaCl-treated seedlings being mor e in cv. Bas-370 as compared to cv. CSR-27 and the ratio reversed to almost control level when arginine was applied along with NaCl.