Selenium nanomaterials promoted ferredoxin and iron–sulfur protein synthesis and acetyl CoA carboxylase activity to improve the photosynthesis and fatty-acid synthesis in soybean

Abstract

Herein, the effect of selenium engineered nanomaterials (Se ENMs) on soybean photosynthesis and fatty-acid synthesis by regulating ferredoxin (Fd) and iron–sulfur (Fe/S) protein synthesis and acetyl CoA carboxylase (ACC) activity was explored. The fresh weight and dry weight of shoots was increased by 63.7% and 62.5%, respectively, and the fresh weight and dry weight of roots was increased by 182.5% and 161.1%, respectively, through the foliar application of Se ENMs (0.1 mg L⁻¹). This is due to the fact that soybean plants utilize selenium (Se) to synthesize a greater amount of Fd and Fe/S proteins, which contain Se, resulting in an acceleration of the electron transport rate (ETR) during the photosynthesis process. Meanwhile, the content of fatty acids, including palmitic acid, stearic acid, oleic acid, linoleic acid, α-linolenic acid, arachidic acid, and oil (triglycerides), was increased by 50.6%, 47.2%, 57.6%, 56.7%, 84.0%, 32.5%, and 50.4%, respectively, in soybean seeds upon exposure to Se ENMs. The specific mechanism is that Se ENMs can enhance the activity of the rate-limiting ACC enzyme and upregulate the expression of DGAT genes in the soybean lipid synthesis pathway as well as the expression of FAD2-1A, FAD2-1B, and FAD3B genes in the fatty acid desaturation process. Moreover, the content of beneficial nutrient elements (Fe and Se) in soybean seeds was significantly increased. These results demonstrated the beneficial effects of Se ENMs on soybean growth and nutrient quality, suggesting their potential use as a fertilizer to improve crop quality in sustainable agriculture.