Papaver rhoeas biotypes displaying multiple herbicide resistance to ALS inhibitors and synthetic auxin herbicides (SAH) are spreading across Europe. In Spain, enhanced metabolism to imazamox was confirmed in one population, while cytochrome-P450 (P450) based metabolism to 2,4-D in another two. The objectives of this research were to further confirm the presence of P450 mediated enhanced metabolism and, if so, to confirm whether a putative common P450 is responsible of metabolizing both 2,4-D and imazamox. Metabolism studies were undertaken in five P. rhoeas populations with contrasted HR profiles (herbicide susceptible, only HR to ALS inhibitors, only HR to SAH, or multiple HR to both), and moreover, three different P450 inhibitors were used. The presence of enhanced metabolism to these SoA was confirmed in three more HR P. rhoeas populations. This study provides the first direct evidence that imazamox metabolism in these biotypes is P450-mediated, also in one population without an altered target site. Additionally, it was further confirmed that enhanced metabolism of 2,4-D in biotypes only HR to SAH or multiple HR to ALS inhibitors and SAH involves P450 as well. No metabolism was detected using the three inhibitors in all the herbicide-metabolizing P. rhoeas biotypes, suggesting that a common metabolic system involving P450s is responsible of degrading herbicides affecting both SoAs. Thus, selection pressure with either SAH or imidazolinone ALS inhibitors can select not only for resistance to each of them, but it can also confer cross-resistance between them in P. rhoeas.

显示对ALS抑制剂和合成生长素除草剂（SAH）具有多种除草剂抗性的罂粟红花生物型正在欧洲各地蔓延。在西班牙，一个人群证实了新的代谢成咪唑酮，而另外两个人群中基于细胞色素-P450（P450）的代谢变成了2,4-D。这项研究的目的是进一步确认P450介导的新陈代谢的存在，如果是，则确认是否可能的常见P450负责代谢2，4-D和咪唑。在五个红斑假单胞菌中进行了代谢研究HR分布对比的人群（易除草剂，仅HR抑制ALS抑制剂，仅HR抑制SAH或对AH抑制多个HR），并且使用了三种不同的P450抑制剂。增强代谢的这些SOA中的存在被证实在三个HR P.虞美人种群。这项研究提供了第一个直接证据，即在这些生物型中，Izamox的代谢也是由P450介导的，并且在没有改变靶位的人群中也是如此。另外，还证实了仅HR至SAH或多种HR至ALS抑制剂和SAH的生物型中2,4-D的代谢增强也涉及P450。在所有除草剂代谢的非洲假单胞菌中，使用这三种抑制剂均未检测到新陈代谢生物型，这表明涉及P450的常见代谢系统负责降解影响两种SoAs的除草剂。因此，使用SAH或咪唑啉酮ALS抑制剂的选择压力不仅可以选择对它们各自的抗性，而且还可以赋予它们在美洲红斑狼疮之间的交叉抗性。