Effect of salicylic acid on total phenol, flavonoid, anthocyanin and PAL and TAL enzymes in tomato (Solanum lycopersicum Mill) plants

Tomato is one of the valuable crop plant that is used as a model plant. Salicylic acid leads to the synthesis and accumulation of secondary metabolites such as phenol, flavonoids, lignin and anthocyanin by changing the activity of the key enzymes involved in their biosynthesis pathway. For study of the effect of SA on secondary metabolites and its biosynthesis pathway, the current experiment carried out using 0, 000.1, 00.1, 0.01, 0.1 and 0.5 mM Salicylic acid in MS medium under in vitro culture condition. After four weeks, seedlings removed from culture container and were analyzed. Results showed that with increasing of salicylic acid concentration dry and fresh weight of roots and shoot as well as the amount of chlorophyll a and b were increased significantly compared with control plants but they were decreased significantly in some concentrations. The total phenol compounds, flavonoids and anthocyanin, as well as PAL, TAL and Peroxidase activity were also gradually increased by increasing of salicylic acid concentration. The maximum level of these parameters were observed at 0/01 mM salicylic acid. The results suggested that, salicylic acid improved plant growth in optimum levels and decreased pigments and plant weight in toxic levels. Phenolic compounds and biosynthesis enzymes were increased by inductive role of SA against ROS production and oxidative stress.