Enhancing UV-B Protection and Abiotic Stress Tolerance in Tomato Plants: The Role of Silicon Nanoparticles in Photosynthetic Parameters, Pigments, and Secondary Metabolite Production
Florina Copaciu, Cosmin-Alin Faur, Andrea Bunea, Loredana Leopold, Rodica Sima, Mihai Andrei Lăcătuș, Andreea Lupitu, Cristian Moisă, Dana Maria Copolovici, Lucian Copolovici
Abstract
Tomato fruit (Solanum lycopersicum) is a valuable agricultural crop worldwide due to its nutritional value and culinary applications, making it one of the most widely consumed vegetables in the human diet. However, excessive solar UV-B radiation represents a significant factor in decreasing productivity, marketable yields, and fruit quality in tomato crops by causing damage to both DNA and the photosynthetic system, as well as chlorophyll degradation. The application of silicon nanoparticles has been shown to increase tolerance to abiotic stressors, including enhanced UV-B radiation. Therefore, this study aims to evaluate the protective effects of foliar silicon nanoparticle (SiNP) application on photosynthetic parameters, photosynthetic pigments, and secondary metabolites under enhanced UV-B stress in tomato plants. Photosynthetic parameters (stomatal conductance to water vapor, net CO2 assimilation rate, transpiration rate, and intercellular CO2 molar fraction), biogenic volatile organic compounds (BVOCs), chlorophylls, and carotenoids were evaluated. The application of SiNPs showed beneficial effects on plants grown under ambient UV-B conditions, increasing photosynthetic parameters while also enhancing chlorophyll and carotenoid levels. In plants exposed to enhanced UV-B radiation, SiNP treatment helped to maintain and even improve photosynthetic parameters and stomatal function in leaves while also promoting the accumulation of photosynthetic pigments. Additionally, the application of SiNPs also resulted in a slightly higher content of lycopene and total carotenoids in tomato fruits.