engleski

Observation on the effects of 2,4-D and trifluralin on the cell cycle and microtubule morphology of shallot root tip and Chinese hamster fibroblast cells

Indirect immunofluorescence was used to study the effect of the selective herbicides trifluralin and 2,4-dichlorophenoxyacetic acid (2,4-D) on microtubule morphology in root-tip cells of shallot (Allium ascalonicum auct.) and cultured Chinese hamster fibroblast cells. Both herbicides induced aberrant mitosis in cells of the root tip as a result of the disruption of the spindle microtubules. The effect was concentration-dependent, with 200 ľM of both trifluralin and 2,4-D destroying most of the cortical and spindle microtubules. After a recovery period in water, microtubules in root tip cell did not reassemble. The effect of these herbicides on the microtubules of the animal cells was negligible, and a few spindles were found to be distrupted in association with aberrant mitotic figures. The study was supplemented by an analysis of both plant and animal cell cycles. It was estimated that after treatment with 2,4-D, most of the root-tip nuclei had accumulated in the S-phase. While mammalian cells showed a similar pattern after 2,4-D treatment, this herbicide,s effect was weak. It is concluded that with respect to trifluralin and 2,4-D, as a result of the greater sensitivity of its microtubular system, a plant cell is potentially better suited for genotoxin screening than an animal cell.

2;4-D; trifluralin; cytotoxicity; shallot; V79 cells; mitotic cycle; cytoskeleton

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