Amelioration of the Oxidative Stress Generated by Simple or Combined Abiotic Stress through the K+ and Ca2+ Supplementation in Tomato Plants

Abstract

Abiotic stressors such as drought, heat, or salinity are major causes of yield loss worldwide due to the oxidative burst generated under these conditions. Recent studies have revealed that plant response to a combination of different environmental stressors is unique and cannot be deduced from the response developed to each stress when applied individually. Some studies have demonstrated that a different management of some nutrients in the irrigation solution may provide an advantage to the plants against abiotic stressors. Thus, the aim of this study was to investigate if an increase in potassium (K+) and calcium (Ca2+) concentration in the nutrient solution may have a positive effect on the amelioration of oxidative stress which occurs under the combination of salinity and heat in tomato plants. Our results indicated that plants irrigated with an increase in K+ and Ca2+ concentrations in the irrigation solution from 7mM (K+) to 9.8 mM and from 4 mM (Ca2+) to 5.6 mM, respectively, induced a recovery of the biomass production compared to the plants treated with salinity or salinity + heat, and subsequently irrigated with the regular Hoagland solution. This was correlated with a better performance of all the photosynthetic parameters, a reduction in the foliar concentration of H2O2 and a lower lipid peroxidation rate, and with a better performance of the antioxidant enzymes ascorbate peroxidase ascorbate peroxidase (APX), dehydroascorbate reductactase (DHAR), glutathione reductase (GR), and NADPH oxidase. Our results showed that these enzymes were differentially regulated at the transcriptional level, showing a higher reactive oxygen species (ROS) detoxification efficiency under salinity and under the combination of salinity and heat, as compared to those plants irrigated with common Hoagland. An increase in K+ and Ca2+ in the irrigation solution also induced a lower Na+ accumulation in leaves and a higher K+/Na+ ratio. Thus, our study highlights the importance of the right management of the plant nutritional status and fertilization in order to counteract the deleterious effects of abiotic stress in plants.

Biostimulants for Plant Growth and Mitigation of Abiotic Stresses: A Metabolomics Perspective

“…The other key cellular event that is observed under both biotic and abiotic stresses is the perturbations in the highly-regulated ROS homeostasis, causing an over-accumulation of ROS such as singlet oxygen ( 1 O 2 ), superoxide anion radical (O 2 •− ), hydroxyl radical ( • OH) and hydrogen peroxide (H 2 O 2 ). The accumulation of these species results from the imbalance between the ROS production and the effectiveness of ROS scavenging systems, subsequently causing an oxidative burst and adversely affecting the plant metabolism by damaging cellular components such as DNA, proteins and lipids [ 42 , 43 , 44 ]. ROS generation can be detrimental as well as advantageous; it can also serve as a biological marker during abiotic stress conditions and can induce stress-signaling pathways to inhibit further damages [ 43 , 45 ].…”

Impact of Silicon Nanoparticles on the Antioxidant Compounds of Tomato Fruits Stressed by Arsenic

“…An aliquot was taken from the supernatant and measured at absorbance values of 453, 505, 645, and 663 nm, as shown in Equations (1) and (2). Lycopene = −0.0458 × Abs 663 + 0.204 × Abs 645 + 0.372 × Abs 505 − 0.0806 × Abs 453 (1) β-carotene = 0.216 × Abs 663 − 1.22 ×Abs 645 − 0.304 × Abs 505 + 0.452 × Abs 453 (2) Vitamin C (mg g −1 DW) was determined by the colorimetric method using 2,6 dichlorophenol, 1 g of fresh tissue, and 1 mL of 1% metaphosphoric acid and filtered with Whatman No. 1 filter paper, as described in Hung and Yeng [31].…”

“…Tomato is the second most important crop in the world from an economic point of view [1]. However, tomato fruit is also important in the human diet because it can provide vitamins and a wide range of bioactive molecules [2], such as vitamins C and E, flavonoids, and phenols [3].…”

Oxidative Stress in Plants

“…(2) Begara-Morales et al, 2019 [ 2 ]. (3) García-Martí et al, 2019 [ 3 ]. (4) Biswas et al, 2020 [ 8 ].…”

“…In addition, they proposed that Tyr73 would be a possible residue to be involved in reducing this enzymatic activity. Moreover, Dr. Rivero’s group [ 3 ] investigated the response of tomato plants to the effects of calcium and potassium on plant tolerance to combined high-temperature and salinity stress conditions. They showed the positive effect of a rise in calcium and potassium in the nutrient medium on the improvement of oxidative stress produced under these environmental stress injuries.…”