تاثیر سنتز سبز نانو ذرات اکسید روی در کاهش آسیب اکسیداتیو و افزایش آنزیم‌های آنتی‌اکسیدانی ناشی از آلودگی سفید بالک در گیاه گوجه‌فرنگی

In the current study, biogenic ZnO-NPs (hexagonal structures and particle sizes from 5 nm to 65 nm) of green ZnO synthesized by Sargassum ilicifolium extract and bulk ZnO (B ZnO) were used. This study investigated the efficacy of different concentrations (0, 5, 10, 25, 50 and 100 ppm) of ZnO-NPs and B ZnO foliar spray on the photosynthetic profile and associated biochemical changes of tomato plants under whitefly infestation. The results showed that the Fourier-transform infrared spectroscopy (FT-IR) of the extract of S. ilicifolium and the green synthesis of ZnO-NPs exhibited different elongation and transition peaks associated with different functional groups such as carboxyl groups, amines, alkynes and alcohols. Application of 25 ppm green-synthesized ZnO-NPs decreased whitefly-induced oxidative stress by increasing total flavonoid content (TFC), chlorophyll a, b and total chlorophyll compared to 5 ppm, while spraying with 50 ppm B ZnO significantly increased the levels compared to 5 ppm. Application of all concentrations of green ZnO-NPs significantly increased total carotenoids and anthocyanins (TAC) content and peroxidase (POX) activity compared to control plants under infected whitefly conditions. Application of 50 ppm green ZnO-NPs reduced the oxidative stress induced by the infected whitefly as shown by the increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and phenylalanine ammonia-lyase (PAL) compared to 10 ppm and untreated controls. Application of 50 ppm green ZnO-NPs decreased oxidative stress induced by the infected whitefly as shown by the reduction in malondialdehyde (MDA) concentrations compared to 10 ppm and untreated controls, while this concentration of B ZnO increased MDA concentrations compared to 5 ppm. Thus, out of other ZnO-NPs concentrations tested, 25 and 50 ppm ZnO-NPs not only increased the secondary metabolites and defense mechanism of tomato leaves under biotic stress, but also could be a promising approach to promote a healthy crop to reduce the use of pesticides to control this pest.