Impact of Salicylic Acid Content and Growing Environment on Phytoprostane and Phytofuran (Stress Biomarkers) in Oryza sativa L.

Abstract

Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are oxylipins synthesized by nonenzymatic peroxidation of α-linolenic acid. These compounds are biomarkers of oxidative degradation in plant foods. In this research, the effect of environment and supplementation with salicylic acid (SA) on PhytoPs and PhytoFs was monitored by ultra-high-performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS/ MS) on seven rice genotypes from Oryza sativa L. subsp. japonica. The plastic cover environment and spray application with 1 and 15 mM SA produced a reduction in the concentration of most of these newly established stress biomarkers [9-F 1t -PhytoP, ent-16-F 1t -PhytoP, ent-16-epi-16-F 1t -PhytoP, 9-D 1t -PhytoP, 9-epi-9-D 1t -PhytoP, 16-B 1 -PhytoP, 9-L 1 -PhytoP, ent-16(RS)-9-epi-ST-Δ 14 -10-PhytoF, ent-9(RS)-12-epi-ST-Δ 10 -13-PhytoF, and ent-16(RS)-13-epi-ST-Δ 14 -9-PhytoF] by 60.7% on average. The modification observed in the level of PhytoPs and PhytoFs differed according to the specific oxylipins and genotype, demonstrating a close linkage between genetic features and resistance to abiotic stress, to some extent mediated by the sensitivity of plants to the plant hormone SA that participates in the physiological response of higher plants to stress. Thus, in plants exposed to stressing factors, SA contribute to modulating the redox balance, minimizing the oxidation of fatty acids and thus the syntheis of oxylipins. These results indicated that SA could be a promising tool for managing the thermotolerance of rice crop. However, it remains necessary to study the mechanism of action of PhytoPs and PhytoFs in biochemical processes related to the defense of plants and define their role as stress biomarkers through a nonenzymatic pathway.

Phytoprostanes and Phytofurans—Oxidative Stress and Bioactive Compounds—in Almonds are Affected by Deficit Irrigation in Almond Trees

“…Since plants do not present chain elongation and desaturase enzymes needed to form arachidonic acid (AA), higher plants cannot produce isoprostanes, which are molecules produced in mammals from AA under oxidative conditions. ,− However, plants produce important amounts of other oxylipins generated from α-linolenic acid (ALA), from which the phytoprostanes (PhytoPs) stand out from the crowd. − These compounds are generated from ALA bounded to plant membranes by a nonenzymatic peroxidation process initiated by reactive oxygenated species (ROS), and they have been described as biomarkers of oxidative stress (OS) condition in plant tissues (Figure ). − On the contrary, phytofurans (PhytoFs) are biosynthesized under 21% oxygen pressure and also represent valuable biomarkers in higher plants. − Both types of plant oxylipins can be found free or esterified in plant foods …”

Evaluation of Phoenix dactylifera Edible Parts and Byproducts as Sources of Phytoprostanes and Phytofurans

“…With concern to the other types of plant oxylipins, the PhytoFs, the information available nowadays on their presence in plant-based foods and foodstuffs is even more scarce than regarding PhytoPs (the reports available in the literature just refer to vegetable oils (0.03–27.92 μg/mL), melon leaves (130.0 to 4400.0 ng/g), rice (0.1–27.7 ng/g), cocoa (118.0–1313.0 ng/100 g), and some types of legumes (20.0–500.0 mg/100 g fw). ,,,,,,, The comparison of the samples analyzed in the present work evidenced that date palm edible parts and byproducts are at an intermediate level relative to the information provided on additional plant-food matrixes and foodstuffs.…”

“…However, it has to be noted the wide dispersion of the concentration regarding matching species and plant-foodstuffs and plant-based foods due to the key effect of agro-climatic conditions in the abiotic stress suffered by plants, the resistance of the separate species according to their genotype, as well as the impact of the industrial processes on oxidation reaction in plant-foods. ,,, …”

“…These compounds represent a broad array of oxidized lipids generated as a result of oxidative stress and redox unbalance that has been suggested as bioactive molecules. , These compounds can be found in nature as free and esterified forms . In this aspect, to the present date, much attention has been paid to plant oxylipins due to their structural analogy with mediators of biological reactions in mammals, such as isoprostanes and prostanoids. , The diversity of PhytoPs and PhytoFs, as well as their concentration in higher plants, has been reported throughout the last 2 decades concerning a variety of species and plant-based foods, including vegetable oils, seeds, and nonedible plant materials that has encouraged the study of their functional potential as biomarkers of plant physiology (especially relevant in the frame of the current climate change), , oxidative degradation in plant-derived foods and foodstuffs, as well as in biological systems as bioactive compounds, for instance, with respect to their anti-inflammatory and immunomodulatory properties as well as the capacity to prevent neuronal lesions in humans. ,,− …”

Moving forward with isoprostanes, neuroprostanes and phytoprostanes: where are we now?

“…PhytoPs and PhytoFs were determined in crops to unveil the oxidative response to irrigation deficit, and also to evaluate their importance as functional food [118]. A recent study [123] investigated the interrelation of the farming practice, i.e. open field and plastic cover, and spraying of salicylic acid on rice flour with the concentration of Phy-toPs where a decrease in most PhytoP levels was observed.…”