Influence of Salicylic Acid on the Growth of Lettuce (Lactuca sativa var longifolia) During Reduced Leaf Water Potential

Salicylic acid (sa) a signal molecule which is responsible for inducing defense mechanisms in plants and also has a protective role in stress sensitivity. a study was conducted to determine the effect of water deficit stress on the growth of lactuca sativa l. (lettuce) using sa (1 mm and 3 mm) during reduced leaf water potential. plants were subjected to 7 days drought after four weeks of growth. stressed plants exhibited a lower leaf water potential (ψw) of -0.499 mpa as compared with the control (ψw of -0.460 mpa). plants with lower leaf ψw exhibited reduction in almost all the parameters studied: 1 mm sa foliar treatment caused increase of 8 % in plant height and 53.16 % in plant biomass. foliar treatment of 3 mm sa of the relative water content stimulated 13 % increase in the growth as compared to the control plant which was statistically significant at p<0.05. overall, sa in stressed plant exhibited higher ameliorative capacity which has the beneficial role of mediating defense response in plants under stress.