Abstract
Effects of sodium nitroprusside (SNP; nitric oxide donor) treatments on enhancement of secondary metabolites production, oxidative stress mediators (
O
2
-
) accumulation and antioxidant defense enzymes of Potato Spunta Sp. suspension culture cells elicited by a fungal extract from
phytophthora infestans
mycelium. The obtained data confirmed the significant increase in various oxidative burst (super oxide anion, hydrogen peroxide and total glutathione) contents. The administration of various NO concentrations strongly decreased hydrogen peroxide concentration and superoxide anion levels. Moreover, the SNP treatments regulate elicitor-induced activation of phenylalanine ammonium-lyase and total soluble phenols accumulation. The highest concentrations of NO donor sodium nitroprusside potentiated elicitor-induced H
2
O
2
production. On the other hand, the lowest H
2
O
2
contents coincided with elicitation regulated various activities of enzymes superoxide-dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and Phenyl alanine ammonia lyase (PAL) activity, the decrease in H
2
O
2
concentration was probably due to a direct reduction interaction of NO-H
2
O
2
. On the other hand, the addition of these previous NO treatments affects mRNA peroxidase gene expression using RT-PCR techniques. In general, the addition of lower concentrations of nitric oxide reduce the mRNA peroxidase activity on contrary, the higher concentrations induced the mRNA peroxidase activity, which induce the hypersensitive reactions against fungus infection.