Plants of Lycopersicon esculentum L. cv. K-25 were subjected to water stress by withholding water for 10 days at
20 (WS I) and 30 (WS II) days after sowing (DAS). Seedlings were sprayed with double distilled water (DDW) or
105
M salicylic acid (SA) at 45 DAS. The water stress at earlier stage of growth (20 day stage) was more
inhibitory as compared to the later stage (30 day stage). The plants exposed to water stress exhibited a significant
(pB0.05) decline in photosynthetic parameters, membrane stability index (MSI), leaf water potential, activity of
nitrate reductase (NR), carbonic anhydrase (CA), chlorophyll and relative water content (RWC). A follow-up
treatment with SA protected against the stress generated by water and significantly improved the above
parameters. However, proline content and antioxidant enzymes increased under drought as well as under SA
treatments.