de Oliveira Roberto Carlos Eduardo, Pinheiro Patrícia Fontes, de Assis Alves Thammyres, da Silva Josimar Aleixo, Praça-Fontes Milene Miranda, Soares Taís Cristina Bastos
Postgraduate Program in Agronomy at the Federal University of Espírito Santo. Alto Universitário, S/N. ZIP: 29.500-000, Alegre, ES, Brazil.
Department of Chemistry, Federal University of Viçosa, Avenida Peter Henry Rolfs, S/N, Campus Universitário, ZIP: 36570-900, Viçosa, MG, Brazil.
Environ Sci Pollut Res Int. 2023 Mar;30(13):38955-38969. doi: 10.1007/s11356-022-24753-4. Epub 2023 Jan 1.
Herbicides are commonly used to control weed. However, some plants are resistant to such products. To identify less harmful herbicides, it is crucial to search for different mechanisms of action. Thymol is an easily acquired allelopathic compound, capable of producing its respective semisynthetic derivative, thymoxyacetic acid. The aim of this study was to determine the effects of thymol and thymoxyacetic acid molecules as bioherbicides in greenhouse at the concentration of 3 mmol L in pre- and postemergence applications in five species: Amaranthus viridis L., Cucumis sativus L., Lactuca sativa L., Eleusine indica L., and Sorghum bicolor L. The initial seedling development and DNA changes were analyzed. These molecules were contrasting with the solvent, in the negative control, and with the glyphosate, in the positive control, promoting phytogenotoxic activities. The toxic effect of thymoxyacetic acid was more effective in preemergence and thymol's in postemergence. We also observed a reduction in the germination speed index and root growth with a negative correlation to the increase in potassium leaching. Damage to the root and shoot of the seedlings was verified at the DNA level, and the phytotoxicity of the plants treated with the herbicide glyphosate was similar to the plants treated with the natural molecules tested. The bioherbicidal effect of thymol and thymoxyacetic acid exacerbates the reduction of the environmental impact caused by the disordered and increased use of residual pesticides.
除草剂通常用于控制杂草。然而，一些植物对这类产品具有抗性。为了确定危害较小的除草剂，寻找不同的作用机制至关重要。百里香酚是一种易于获取的化感化合物，能够产生其相应的半合成衍生物——百里香氧基乙酸。本研究的目的是在温室中，以3 mmol/L的浓度，在五种植物（绿穗苋、黄瓜、生菜、稗草和高粱）的芽前和芽后施用中，确定百里香酚和百里香氧基乙酸分子作为生物除草剂的效果。分析了初始幼苗发育和DNA变化。这些分子与阴性对照中的溶剂以及阳性对照中的草甘膦形成对比，具有植物遗传毒性活性。百里香氧基乙酸在芽前的毒性作用更有效，而百里香酚在芽后的毒性作用更有效。我们还观察到发芽速度指数和根生长降低，且与钾淋溶增加呈负相关。在DNA水平上证实了对幼苗根和芽的损害，并且用除草剂草甘膦处理的植物的植物毒性与用测试的天然分子处理的植物相似。百里香酚和百里香氧基乙酸的生物除草作用加剧了因残留农药使用无序增加而造成的环境影响的降低。
