| Summary: | Herbicides are key weed-control tools, but their repeated use across large areas has favored the evolution of herbicide resistance. Although target-site has been the most prevalent and studied type of resistance, non-target-site resistance (NTSR) is increasing. However, the genetic factors involved in NTSR are widely unknown. In this study, four gene groups encoding putative NTSR enzymes, namely, <i>cytochrome-P450</i>, <i>glutathione-S-transferase</i> (<i>GST</i>), <i>uridine 5′-diphospho-glucuronosyltransferase</i> (<i>UDPGT</i>), and <i>nitronate monooxygenase</i> (<i>NMO</i>) were analyzed. The monocot and dicot gene sequences were downloaded from publicly available databases. Phylogenetic trees revealed that most of the <i>CYP450</i> resistance-related sequences belong to <i>CYP81</i> (5), and in <i>GST</i>, most of the resistance sequences belonged to <i>GSTU18</i> (9) and <i>GSTF6</i> (8) groups. In addition, the study of upstream promoter sequences of these NTSR genes revealed stress-related <i>cis</i>-regulatory motifs, as well as eight transcription factor binding sites (TFBS) were identified. The discovered TFBS were commonly present in both monocots and dicots, and the identified motifs are known to play key roles in countering abiotic stress. Further, we predicted the 3D structure for the resistant <i>CYP450</i> and <i>GST</i> protein and identified the substrate recognition site through the homology approach. Our description of putative NTSR enzymes may be used to develop innovative weed control techniques to delay the evolution of NTSR.
|
|---|