Exogenous application of SiO2 nanoparticles enhances drought stress tolerance in wild and cultivated chickpea plants

Drought is one of the most significant stress factors that constrain plant growth. Many studies focused on methods to enhance the plant stress tolerance against drought. Recently, the focus has been on the exogenous applications and, in particular, the nanomaterials powered by advancements in the field of nanotechnology. Silicon appears to support some plants against different stress factors, including drought. Despite this, there is a remarkable lack of studies on the use of silicon for enhancing drought tolerance in wild and cultivated chickpeas. In this study, 150 mg L-1 SiO2 nanoparticle spraying was applied to two chickpea varieties, cultivated and wild, under drought stress. Changes were analyzed in morphological, physiological, and biochemical traits to find the change in plants' drought tolerance. Under drought stress, SiO2 treatment increased antioxidant enzyme activities in both species. Similarly, nanoparticle treatment increased some growth characteristics of plants. Additionally, significant increases in leaf relative water content were detected in plants treated with SiO₂ under drought conditions. In this study, the effect of SiO2 nanoparticle application on the stress tolerance of wild and cultivated chickpea plants has been studied. Basically, the results showed that exogenous application of SiO2 NPs increases drought tolerance by stimulating water status and growth parameters, and by activities of antioxidant enzymes in both wild and cultivated species of chickpea.