Form of Silica Improves Yield, Fruit Quality and Antioxidant Defense System of Tomato Plants under Salt Stress

• Main Authors: Zeus H. Pinedo-Guerrero, Gregorio Cadenas-Pliego, Hortensia Ortega-Ortiz, Susana González-Morales, Adalberto Benavides-Mendoza, Jesús Valdés-Reyna, Antonio Juárez-Maldonado
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Agriculture
• Subjects: nanotechnology; environmental stress; antioxidants; biocompounds; reactive oxygen species
• Online Access: https://www.mdpi.com/2077-0472/10/9/367

Tomato crop is valuable worldwide thanks to its commercial and nutritional value, which plays a very important role in the human diet. However, in arid areas, tomato crops can be found with high salt content. Salinity is a major problem for agriculture, as it decreases productivity, lowers economic yields, and induces soil erosion. The application of silicon has been observed to increase tolerance to abiotic stress and specifically to salt stress. Therefore, the aim of this study is to evaluate the application of K₂SiO₃ and SiO₂ nanoparticles (SiO₂ NPs) on the growth, antioxidant content, and tolerance to saline stress of tomato plants. Plant growth, fruit quality parameters (pH, titratable acidity, total soluble solids, firmness), antioxidant capacity (ABTS, DPPH), enzymatic (SOD, PAL, APX, CAT, GPX) and non-enzymatic (flavonoids, phenols, vitamin C, β-carotene, lycopene) antioxidant compounds, chlorophylls, proteins, and H₂O₂ were evaluated. The application of SiO₂ NPs at 500 mg L⁻¹ had positive effects on the plants that were not subjected to stress, increasing the average fruit weight, fruit yield, and chlorophyll, phenol, glutathione, and GPX activity. Meanwhile, in plants under salt stress, it helped to maintain the concentration of chlorophylls, GSH, PAL activity, and vitamin C. The application of SiO₂ NPs is more effective than K₂SiO₃ at inducing positive responses in tomato plants subjected to stress by NaCl.