3rd Edition Of Plant Science and Molecular Biology World Conference 2026

Abstract

In the context of accelerating climate change, salt stress is one of the main challenges affecting plant growth by altering morphological characteristics and physiological processes. This problem has both global and local dimensions, particularly in the Kingdom of Saudi Arabia. Among the crops sensitive to salt stress, tomato (Solanum lycopersicum) stands out due to its nutritional and agricultural importance. One of the proposed approaches to mitigate this stress is the use of nanoparticles and biostimulants, as they represent sustainable and environmentally friendly solutions. In this study, S. lycopersicum plants were exposed to salt stress using 100 mM NaCl, and foliar spray treatments were applied using AgNPs and biostimulants extracted from Moringa oleifera leaves, either individually or combined, at three concentrations (20, 40, and 60 mg/L). The results showed that the salt-stressed plants exhibited morphological and physiological damage compared to the control. Nevertheless, when nanoparticles and biostimulants applied, whether in the presence or absence of stress, contributed to improve most of morphological and physiological traits, such as shoot length, root length, plant biomass, as well as chlorophyll content. Elevated levels of proline and protein were detected, accompanied by the activation of key antioxidant enzymes, including ascorbate peroxidase (APX), glutathione reductase (GR), and superoxide dismutase (SOD); however, a reduction in thiobarbituric acid reactive substances (TBARS) was observed. The results indicated that low concentrations of AgNPs, whether applied alone or combined with the biostimulant, were the most effective under salinity. However, the concentrations of 40 and 60 mg/L of biostimulants also showed beneficial effects and may be considered optimal for S. lycopersicum. These findings highlight the potential of AgNPs and biostimulants, as promising strategies to enhance tomato tolerance to salt stress.