Boron Alleviates the Aluminum Toxicity in Tartary Buckwheat by Regulating Antioxidant Defense System and Maintaining Osmotic Balance

Purpose Aluminum (Al) pollution in acidic soils is a significant environmental problem worldwide. Although boron has been shown to alleviate Al toxicity in acidic soils, the exact mechanism in Tartary buckwheat is still unknown. The research investigated the mitigation effect of exogenous boron on the Al toxicity of Tartary buckwheat and unveiled the mechanism through growth characteristics, antioxidant enzyme system, and osmotic regulation. Methods This study conducted germination and greenhouse pot experiments under four different Al concentration levels (0, 5, 10, and 15 mM) and four different boron concentrations (0, 10, 30, and 50 μM). Results The results showed that boron supply reduced the accumulation of Al in Tartary buckwheat roots, increased the activity of antioxidant enzymes, and the content of osmotic adjustment substances in roots and leaves, reduced Al damage to root and leaf cells, maintained the osmotic balance of cells, improved root activity and leaf photosynthetic pigment content, ultimately leading to a significant increase in biomass. Conclusions The application of varying levels of boron treatment can effectively enhance the tolerance of Tartary buckwheat to Al toxicity, ultimately promoting its growth.