Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado 80523, United States.
Weed Resistance Competence Centre, Bayer AG, Industriepark Hoechst, Frankfurt 65926, Germany.
J Agric Food Chem. 2020 Mar 11;68(10):3026-3032. doi: 10.1021/acs.jafc.9b07046. Epub 2020 Feb 25.
Glufosinate is considered a contact herbicide because of its fast activity and limited translocation in plants. We used Palmer amaranth ( S. Watson) as a model species to study plant-related factors affecting glufosinate uptake and translocation. Glufosinate uptake increased rapidly during the initial 24 h, achieving maximum uptake from this time on. The rate of uptake saturated with doses higher than 250 μM glufosinate, suggesting the involvement of a membrane transporter. When glufosinate concentrations were higher (>1 mM), uptake was a simple diffusion process in favor of a concentration gradient between the inside and the outside of the cells. Glufosinate uptake was inhibited by the presence of glutamine. The fast action of glufosinate did not limit its own translocation. Because glufosinate is highly water soluble, it translocates mostly through the apoplast or the xylem system. Consequently, old leaves tend to accumulate more herbicide than young meristematic leaves.
草铵膦被认为是一种触杀型除草剂，因为它在植物体内活性高且向其他部位移动性有限。我们选择了刺儿菜（ S. Watson）作为模式物种来研究影响草铵膦吸收和移动的植物相关因素。在最初的 24 小时内，草铵膦的吸收迅速增加，此后一直保持最大吸收速率。当草铵膦剂量高于 250 μM 时，吸收速率达到饱和，这表明存在一种膜转运蛋白。当草铵膦浓度较高（>1 mM）时，吸收是一种简单的扩散过程，有利于细胞内外的浓度梯度。谷氨酰胺的存在会抑制草铵膦的吸收。草铵膦的快速作用并不限制其自身的转移。由于草铵膦具有高水溶性，它主要通过质外体或木质部系统进行转移。因此，老叶比幼嫩的分生组织叶片积累更多的除草剂。
