Chitosan nanoparticles enhance drought tolerance in tomatoes (Solanum lycopersicum L) via gene expression modulation

Drought waves are currently invading the world and affecting crop production. Such a problem requires continuous research to develop more tolerant plants without affecting productivity. In the present study, the impact of chitosan nanoparticles (CHNPs) on the expression of four drought-responsive genes, namely HsfA1a, SlAREB1, LeNCED1, and LePIP1 in Solanum lycopersicum, was investigated. For this purpose, chitosan nanoparticles were prepared and characterized for their physicochemical properties. Then, Solanum lycopersicum seedlings were cultivated in soil containing either 60 or 90 ppm of CHNPs. The results showed a successful preparation of CHNPs with an average size of 92–404 nm and a zeta potential of +29.20 mV. The gene expression analysis showed a significant upregulation in the expression of all tested genes in both CHNPs concentrations compared with drought stress. The study concluded that the CHNPs might be used to enhance the drought tolerance of tomatoes.