Target Site-Based Resistance to ALS Inhibitors, Glyphosate, and PPO Inhibitors in an <i>Amaranthus palmeri</i>Accession from Mississippi

• 作者: Darci A. Giacomini Vijay K. Nandula William T. Molin
• 来源期刊: 美国植物学期刊(英文)
• 学科: 医学
• 关键词: Amaranthus palmeri ALS Inhibitors GLYPHOSATE Palmer Amaranth PPO Inhibitors RESISTANCE
• 年，卷（期）: mgzwxqkyw_2020,（8）
• 页码范围: 1206-1216
• 页数: 11页
• 分类号: R74

摘要

Extensive acceptance of glyphosate-resistant (GR) row crops coupled with the simultaneous increase in glyphosate usage has sped the evolution of glyphosate resistance in economically important weeds. GR </span><i><span style="font-family:Verdana;">Amaranthus</span></i><span style="font-family:Verdana;"> <i>palmeri</i></span><span style="font-family:Verdana;"> populations are widespread across the state with some exhibiting multiple resistance to acetolactate synthase (ALS) inhibiting herbicides such as pyrithiobac. A GR and ALS inhibitor-resistant accession was also resistant to the protoporphyrinogen oxidase (PPO) inhibiting herbicide fomesafen. The PPO inhibitor resistance profile and multiple herbicide resistance mechanisms in </span><span style="font-family:Verdana;">this accession were investigated. In addition to fomesafen, resistance to</span><span style="font-family:Verdana;"> postemergence applications of acifluorfen, lactofen, carfentrazone, and sulfentrazone was confirmed. There was no resistance to preemergence application of fomesafen, flumioxazin, or oxyfluorfen. Molecular analysis of the </span><span style="font-family:Verdana;">ALS</span><span style="font-family:Verdana;"> gene indicated the presence of point mutations leading to single nucleotide substitutions at codons 197, 377, 574, and 653, resulting in proline-to-serine, arginine-to-glutamine, tryptophan-to-leucine, and serine-to-asparagine replacements, respectively. The resistant accession contained up to 87-fold more copies of the </span><span style="font-family:Verdana;">EPSPS</span><span style="font-family:Verdana;"> gene compared to a susceptible accession. A mutation leading to a deletion of glycine at codon 210 (ΔG210) of </span><span style="font-family:Verdana;">PPO2</span><span style="font-family:Verdana;"> gene was also detected. These results indicate that the mechanism of resistance in the Palmer amaranth accession is target-site based, </span><i><span style="font-family:Verdana;">i</span></i><span style="font-family:Verdana;">.