Investigation on the biochemical and physiological effects of silver nanoparticles on tomato (Lycopersicon esculentum Mill.) seeds

With the rapid development of nanotechnology in recent years, the use of metal-based nanoparticles has been increasing due to their large surface areas, rapid action mechanisms and low toxicity. Silver nanoparticles (AgNP) are widely used in health, food, textile, agricultural and cosmetic industries. In this study, the morphological, physiological and biochemical effects of 10 nm silver nanoparticles on tomato (Lycopersicon esculentum Mill.) seeds were investigated. Distilled water (Control) and silver nanoparticle solutions prepared at 10, 20, 40 ppm concentration were used in the study. The seeds were soaked to pretreat (imbibition) with four different solutions for 2, 4 and 8 hours, then transferred to sterile Petri dishes with filter papers soaked in distilled water and allowed to germinate in the growth chamber at 24 ºC temperature. 7-day-old tomato seedlings were harvested and root and shoot length, germination rate (%), vigour and tolerance index (%), anthocyanin, chlorophyll and carotenoid contents, hydrogen peroxide (H2O2) and malondialdehyde (MDA) amount, antioxidant enzyme (APOX, CAT, GR, GST, POX, SOD) activities were measured. It is seen that root and shoot lengths decrease with 2, 4 and 8 hours AgNP pre-treatment. This effect was also observed in the vigour and tolerance index, but there was no significant difference in germination rates. In chlorophyll and carotenoid content analyzes, 2 hours AgNP pre-treatment was increased photosynthetic pigments while 4 and 8 hours pre-treatment was decreased photosynthetic pigments. In 7-day-old tomato seedlings' various tissues MDA, H2O2 content and antioxidant enzymes (APOX, CAT, GR, GST, POX, SOD) activities were determined. Increases and decreases were determined depending on the concentration and pre-treatment hours. As a result; 2, 4 and 8 hours pre-treatment of tomato seeds with solutions containing Ag nanoparticle (10 nm) caused morphological, physiological and biochemical phytotoxic effects on 7–day-old seedlings. This study will also shed light on the problems that may arise during the use of pesticides containing silver nanoparticles in agriculture.