Trifluralin-induced disorganization of microtubular cytoskeleton alters the development of roots inHordeum vulgareL.

Abstract

The extensive use of herbicides in agriculture becomes an important factor in environmental pollution, especially in case of slowly degradable compounds. Some agents act on plants during a long period of time, even if a very low concentration of the herbicide remains in the soil. Here, we investigated the toxicological effect of a low concentration of dinitroaniline herbicide, trifluralin, on growing seedlings of Hordeum vulgare L. Trifluralin in concentration of 1 microg/ml inhibited root growth. The mitotic activity of meristematic cells was suppressed due to the retardation of metaphase progression--alteration that can be caused by cytoskeleton disorder. Using antibodies to alpha-tubulin, we investigated the distribution of microtubules in root meristem cells. During all stages of mitosis, the highly regular system of microtubular cytoskeleton observed in control cells was slightly disorganized. An examination of root structure using light and electron microscopy demonstrated that the cell walls did not form normally during cell division that led to the appearance of large multinucleated cells. Also, the premature (pathological) cell differentiation was induced by trifluralin. A part of differentiating cells showed intracellular structural changes that are consistent with programmed cell death. It seems that the development of alterations in trifluralin-treated roots was due to the microtubular cytoskeleton disorganization.

Dinitroaniline herbicides: a comprehensive review of toxicity and side effects on animal non-target organisms

“…They are well-known compounds to bind tubulin dimers of plants (Vaughn and Lehnen 1991;Sheval et al 2008;Rose et al 2016), protozoa (Traub-Cseko et al 2001Fennell et al 2006) and fungi (Qu et al 2018), most likely interacting with alpha-tubulin and interfering with microtubule polymerisation (Morejohn et al 1987;Anthony and Hussey 1999;Morrissette and Sept 2009;Nyporko et al 2009). In Chlamydomonas, a beta-tubulin mutation (Lys-350-Glu/ Met) conferring resistance to dinitroanilines indicates that beta-tubulins may also be a target of these herbicides (Lee and Huang 1990).…”

Identification of plant α-tubulin amino acids playing a key role in specific binding of nitroaniline compounds

“…The structural unit of microtubules is / -tubulin heterodimers that, in its turn, are interconnected in linear protofilaments [2,3]. All basic functions of MTs are realized through their instability caused by permanent polymerization/depolymerization, including dynamic rearrangements of microtubules in interphase and mitosis [4,5]. This phenomenon explain why α-and β-tubulins are in the front row of molecular targets for antitumor, antiprotozoal, antihelminthic, fungicide and herbicide compounds [6,7].…”