Abstract
The extreme temperatures generated in the melon crop, early harvest, induce an increase in reactive oxygen species (ROS) plant levels leading to oxidative stress. Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are plant metabolites derived from α-linolenic acid oxidation induced by ROS. The aims of this work were to evaluate PhytoPs and PhytoFs as oxidative stress biomarkers in leaves of melon plants thermally stressed. In addition, to fortify melon plant antioxidant defenses, foliar spraying was assayed using salicylic and gallic acid solutions and Ilex paraguariensis extract. PhytoP and PhytoF concentration ranges were 109−1146 and 130−4400 ng/g, respectively. Their levels in stressed plants were significantly higher than in nonstressed samples. In stressed samples treated with I. paraguariensis, PhytoP and PhytoF levels were significantly lower than in stressed samples without antioxidants. PhytoPs and PhytoFs represent relevant oxidative stress biomarkers in melon leaves. The use of natural antioxidants could reduce plant oxidative stress.