The Effects of Nitrate and Phosphate Deficiencies on Certain Biochemical Metabolites in Tomato (Lycopersicon esculentum Mill. c.v. Urbana V.F.) Plant

Nitrogen (N) and phosphorus (P) are two important macronutrients with diverse functions in plants. Therefore, the effects of their deficiencies on different physiological and biochemical characteristics especially in crops have always been investigated. In this study, the effects of nitrate and phosphate deficiencies in two levels of 25% and 35% deficiencies compared to control plants were studied in Lycopersicon esculentum Mill. Results were analyzed statistically that showed a significant increase of root soluble and insoluble sugars and peroxidase activity and a significant decrease of root soluble proteins in both levels of nitrate and phosphate deficiencies which have less been studied. Furthermore, reverse relationships between soluble sugars and soluble proteins (r2=0.996) and between insoluble sugars and soluble proteins (r2=1) under nitrate deficiencies were developed. Also, by decreasing nitrate, β-caroten and xanthophyll contents decreased. By decreasing phosphate, concentration of β-caroten diminished but xanthophyll contents were not affected significantly. On the whole, biochemical characteristics were affected more in nitrate-deficient treatments in tomato plants than those of control plants.