Molecular Mechanisms of Herbicide Resistance in Rapeseed: Current Status and Future Prospects for Resistant Germplasm Development

Rapeseed (Brassica napus) is a globally important oilseed crop whose yield and quality are frequently limited by weed competition. In recent years, there have been significant advances in our understanding of herbicide-resistance mechanisms in rapeseed and in the development of herbicide-resistant rapeseed germplasm. Here, we summarize the molecular mechanisms of resistance to three herbicides: glyphosate, glufosinate, and acetolactate synthase (ALS) inhibitors. We discuss progress in the identification of new resistance genes and the development of herbicide-resistant rapeseed germplasm, from the initial identification of natural mutants to artificial mutagenesis screening, introduction of exogenous resistance genes, and gene editing. In addition, we describe how synthetic biology and directed protein evolution will contribute to precision-breeding efforts in the near future. This is the first review to systematically integrate non-target resistance mechanisms and the potential applications of multi-omics and AI technologies for breeding of herbicide-resistant rapeseed, together with strategies for managing the risks associated with gene flow, the evolution of herbicide-resistant weeds, and the occurrence of volunteer plants resulting from deployment of herbicide-resistant rapeseed. By synthesizing current knowledge and future trends, this review provides guidance for safe, effective, and innovative approaches to the sustainable development of herbicide-resistant rapeseed.