Response of Tomato Seeds (Solanum lycopersicum L.) to Inorganic Arsenic Under a Germination Assay—An Insight into a Hormesis Process

The irrigation of crops with As-enriched water, along with the use of agrochemicals and mining, are considered the main source of accumulation of this element in arable land and thus, in plants. The aim of this study is to analyze the responses of As at five different concentrations, in the germination of seeds of tomato (Solanum lycoperisum), through measuring the morphological variables (root, shoot and total length), phenolic compounds, antioxidant activity, arsenic content and phytochemical profile of the sprouts. After 12 days, 89.16% germinated. According to the germination variables of Germination percentage, Germination rate, Mean germination time, Seed vigor index and percent of phytotoxicity, treatment 0.8 ppm shows a better performance in comparison with the rest. The stem, root and total length showed differences with control at 0.8 and 5 ppm. Phenolic compounds and antioxidant activity in the sprouts among treatments showed a potential range of hormesis between 0.8 and 2 ppm. Treatment 5 ppm showed the worse performance. The sprouts showed that the accumulation of As increased with the concentration of the treatment. The behavior of the variables measured suggest the activation of a stress response in the sprout causing positive effects such as growth enhancing, faster and better germination process and more production of molecules of biochemical interest. The opposite of the latter were also found. These findings provide an insight into the development of seeds under As contamination in irrigation water.