DCPA Causes Cell Plate Disruption in Wheat Roots

Abstract

Light and electron microscopy were used to investigate the effects of the herbicide DCPA (dimethyl tetrachloroterephalate) on wheat root meristems. Three different sorts of disruption are found. In the epidermal cells, the walls are incomplete and/or curved, as well as being oriented in directions other than perpendicular to the long axis of the root. In developing cell plates, phragmoplast microtubule arrays are oriented in many directions in this layer, probably accounting for the wall abnormalities. In the calyptrogen and cortical layers, no walls or incomplete walls are formed between the nuclei, so that these cell layers are essentially one large cell with multiple nuclei. This effect has not been observed for any other herbicide. Prometaphase figures with a few microtubules and multipolar mitosis are the predominant abnormalities in the meristematic zone. Aberrant cell walls are also found in this tissue layer. These data indicate that DCPA is effective at disrupting phragmoplast micTotubule arrays and cell wall formation.