Activity of ACS and ethylene production increased in the presence of salt. Nitrogen treatment reduced the ACS activity and ethylene production by 19% and 16% at 5 mM N and by 36% and 38% at 10 mM N in the absence of salt stress. However, 20 mM N significantly increased the ACS activity and ethylene production by 27% and 54% over control. Supplementation of N to salt stressed plants decreased the ACS activity and ethylene evolution. Maximum reduction in ACS activity and ethylene production occurred with 20 mM N in the presence of salt (Fig. 6).