Impact of silicon nanoparticle priming on metabolic responses and seed quality of chia (Salvia hispanica L.) under salt stress

Salinity stress poses a significant challenge to agriculture, threatening global food security. Seed priming with nanomaterials, such as silicon nanoparticles (nSi), has shown potential to enhance plant tolerance to such stresses. However, limited research exists on the effects of nSi priming in medicinal and oilseed crops, such as chia (Salvia hispanica). This study investigates the effects of various nSi concentrations on fatty acid composition, oil yield, and metabolic responses of chia under salinity stress, proposing strategies to mitigate the impact of salinity. The experiment was conducted using a completely randomized design in a greenhouse in 2022. Seeds were primed with nSi concentrations (0, 100, 200, and 400 mgL- 1) and sown in pots with standard soil. Salinity stress was applied at three levels (0, 50, and 100 mM NaCl). Severe salinity stress caused a 232% increase in malondialdehyde, 134% rise in hydrogen peroxide, and a 36% decrease in seed yield and 25% reduction in oil content. In contrast, priming with nSi-200 significantly increased proline (90.1%), carbohydrates (146%), flavonoids (78%), and phenols (83.4%). Antioxidant enzyme activities, including catalase (183%), superoxide dismutase (147%), and ascorbate peroxidase (334%), were markedly enhanced, while the sodium-to-potassium ratio decreased by 95%. Additionally, nSi-200 treatment boosted seed yield by 149%, oil yield by 327%, and increased alpha-linolenic and linoleic acids by 49% and 38%, respectively. Overall, priming with nSi-200 significantly improved seed and oil yield of chia under salinity stress and can be considered an effective strategy for enhancing the production of this crop in saline environments.