Enhanced reactive oxygen species and metabolism are involved in the reduction of tribenuron-methyl residues in Tartary buckwheat mutants

Abstract

Tartary buckwheat, known for its rapid growth, short growth cycles, and adaptability, is cultivated worldwide, particularly in East Asia and Eastern Europe. However, weed infestations severely impact yield and quality, and the absence of effective herbicides poses a considerable challenge to Tartary buckwheat production. To address this, we used ethyl methane sulfonate (EMS) mutagenesis to create a mutant population of Tartary buckwheat seeds. We applied a targeted screening process using the herbicide tribenuron-methyl (TM) to select mutants with reduced sensitivity to the herbicide. Integrative analysis of transcriptomic and metabolomic data indicated that TM primarily inhibited photosynthesis and amino acid biosynthesis pathways in sensitive plants, leading to toxicity. Conversely, resistant plants could reduce the toxic effects of TM on Tartary buckwheat by increasing antioxidant enzyme activity and enhancing secondary metabolic pathways such as flavonoid biosynthesis. TM also upregulated the expression of a gene encoding uridine diphosphate glucuronic acid transferase-like (FtUGT79L). Overexpression of FtUGT79L in Arabidopsis substantially increased total flavonoid content and improved the resistance of Arabidopsis to TM at the seedling and adult stages. The study provides insights into innovative approaches for breeding herbicide-resistant Tartary buckwheat germplasm and serves as an important reference for the development of herbicide-resistant varieties of other crops.