The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are a new chemical class of herbicide which possess the same antimicrotubule mechanism of action as dinitroanilines, probably including interaction with the same binding site in alpha-tubulin.

中文翻译：

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具有抗微管作用的除草氰基丙烯酸酯。

研究了新型合成氰基丙烯酸酯（2Z）-3-氨基-2-氰基-4-乙基己-2-烯酸酯（CA1）及其异丙酯衍生物CA2的除草作用方式。为了进行初步表征，使用了一系列生物测定方法，表明其作用方式与有丝分裂破坏性除草剂（如二硝基苯胺二甲戊灵）相似。细胞化学荧光研究包括针对聚合和解聚的微管蛋白的单克隆抗体以及与荧光染料缀合的细菌纤维素酶的纤维素结合结构域，用于阐明对玉米分裂中细胞分裂过程的影响，包括有丝分裂和微管以及细胞壁形成。当用10 microM CA1或CA2根处理幼苗时，分生组织的根尖细胞中的细胞分裂活性在4 h内下降。染色体进行到前中期的浓缩状态，但无法在有丝分裂周期中进一步发展。这些化合物导致微管结构的完全丧失，包括前期，纺锤体，睑板膜和皮质微管。同时，在细胞质中，观察到游离微管蛋白的标记增加。这表明除草剂破坏了聚合反应和微管的稳定性，而微管蛋白的合成或降解似乎没有受到影响。另外，根尖细胞的细胞壁中的纤维素标记不受影响。CA1和CA2的作用与戊二甲乐灵产生的作用相当。在表达绿色荧光蛋白-微管相关蛋白4融合蛋白的转基因拟南芥植物中，暴露于10 microM CA1或二甲戊乐灵后160分钟内，下胚轴活表皮细胞中皮质微管的标记阵列塌陷。此外，在α-微管蛋白中有点突变的猕猴桃的二硝基苯胺抗性生物型（Eleusine indica（L）Gaertn）表现出对CA1和CA2的交叉耐药性。结果强烈表明，氰基丙烯酸酯是一种新型化学除草剂，具有与二硝基苯胺相同的抗微管作用机理，可能包括与α-微管蛋白中相同的结合位点相互作用。