PDF(Pubmed)
Abstract：
Amaranthus retroflexus L. (redroot pigweed) is one of the most problematic weeds in maize, sugar beet, vegetables, and soybean crop fields in Europe. Two pigweed amaranth biotypes (R1 and R2) from the Czech Republic resistant to photosystem II (PSII)-inhibiting herbicides were analyzed in this study. This study aimed to identify the genetic mechanisms that underlie the resistance observed in the biotypes. Additionally, we also intended to establish the use of chlorophyll fluorescence measurement as a rapid and reliable method for confirming herbicide resistance in this weed species. Both biotypes analyzed showed high resistance factors in a dose-response study and were thus confirmed to be resistant to PSII-inhibiting herbicides. A sequence analysis of the D1 protein revealed a well-known Ser-Gly substitution at amino acid position 264 in both biotypes. Molecular docking studies, along with the wild-type and mutant D1 protein\'s secondary structure analyses, revealed that the S264G mutation did not reduce herbicide affinity but instead indirectly affected the interaction between the target protein and the herbicides. The current study identified the S264G mutation as being responsible for conferring herbicide resistance in the pigweed amaranth biotypes. These findings can provide a strong basis for future studies that might use protein structure and mutation-based approaches to gain further insights into the detailed mechanisms of resistance in this weed species. In many individuals from both biotypes, resistance at a very early stage (BBCH10) of plants was demonstrated several hours after the application of the active ingredients by the chlorophyll fluorescence method. The effective PS II quantum yield parameter can be used as a rapid diagnostic tool for distinguishing between sensitive and resistant plants on an individual level. This method can be useful for identifying herbicide-resistant weed biotypes in the field, which can help farmers and weed management practitioners develop more effective weed control tactics.
摘要：
AmaranthusretrosflexusL.（杜根猪草）是玉米中最有问题的杂草之一，甜菜,蔬菜,和欧洲的大豆作物田。本研究分析了来自捷克共和国的两种对抑制光系统II（PSII）的除草剂具有抗性的猪草a菜生物型（R1和R2）。这项研究旨在确定在生物型中观察到的抗性的遗传机制。此外,我们还打算建立使用叶绿素荧光测量作为一种快速和可靠的方法来确认除草剂抗性在这种杂草。分析的两种生物型在剂量反应研究中都显示出高抗性因子，因此被证实对抑制PSII的除草剂具有抗性。D1蛋白的序列分析揭示了两种生物型中在氨基酸位置264处的众所周知的Ser-Gly取代。分子对接研究,连同野生型和突变型D1蛋白的二级结构分析，表明S264G突变并没有降低除草剂的亲和力，而是间接影响了目标蛋白与除草剂之间的相互作用。当前的研究确定了S264G突变负责在猪草a菜生物型中赋予除草剂抗性。这些发现可以为未来的研究提供坚实的基础，这些研究可能会使用蛋白质结构和基于突变的方法来进一步了解这种杂草物种的详细抗性机制。在许多来自两种生物型的个体中，通过叶绿素荧光法在施用活性成分后数小时证明了植物在非常早期阶段（BBCH10）的抗性。有效的PSII量子产率参数可用作快速诊断工具，以在个体水平上区分敏感植物和抗性植物。该方法可用于识别田间抗除草剂杂草生物型。这可以帮助农民和杂草管理从业者制定更有效的杂草控制策略。
