Reducing Chromium Toxicity in Chinese Cabbage through Synergistic Effects of Silicon and Selenium: A Study of Plant Growth, Chromium Content, and Biochemical Parameters

Silicon (Si) and selenium (Se) have been found to reduce chromium (Cr) toxicity in plants, which is important for crop production and human health. However, there is limited understanding of the interaction between Si and Se in mitigating Cr toxicity and its mechanisms. This study investigated the impact of Si and Se on Cr-treated Chinese cabbage growth, Cr content, and biochemical parameters in a hydroponic experiment. The results showed that both Si and Se effectively alleviate Cr toxicity and have a strong synergistic effect. They reduced Cr content in cabbage by 73.99% and increased photosynthetic pigments by 62.50% and 47.51%, respectively. Antioxidant enzyme activity increased by 28.20 and 21.37%, while non-enzyme antioxidants such as proline and GSH decreased by 27.44 and 28.51%. It was observed that the addition of Si and Se to Chinese cabbage under Cr stress resulted in a 29.58 and 134.37% increase in soluble protein and soluble sugar, respectively, as well as improved nutrient contents (N, P, K, Ca, and Mg). This suggests that Si and Se can improve the physiological ecology of Chinese cabbage, reducing the effects of Cr stress and contributing to the global control of heavy metal pollution in food crops.