Positive effects of nitric oxide on Solanum lycopersicum

The present work examines benzoic acid (BA) induced stress in Solanum lycopersicum and explores the possible mechanism through which sodium nitroprusside (SNP) protects plants. Tomato seeds were soaked for 3 h in 250 µM SNP and 0.5, 1.0, and 1.5 mM BA with and without SNP. Seeds soaked in distilled water were treated as control. Seed germination (SG) and radicle length (RL) were recorded in Petri plate culture. SG and RL inhibition was concentration dependent in BA. SNP enhanced SG and RL. Twenty-one-days old seedlings were grown in hydroponic culture in Hoagland solution and BA at 0.5, 1.0, and 1.5 mM with and without SNP. The morphological and biochemical parameters of seedlings were assayed. Average growth rate of root and shoot, dry weight, sugar, pigment and protein content, and activity of nitrate reductase decreased in seedlings treated with BA while increased in SNP with and without BA. Lipid peroxidation increased in seedlings treated with BA but decreased in BA+SNP. SNP protected the seedlings a...