EFFECT OF CYTOCHALASINS ON ACTIN IN DIVIDING ROOT-TIP CELLS OF ALLIUM AND TRITICUM - A COMPARATIVE IMMUNOCYTOCHEMICAL STUDY

A collaborative effort was initiated to resolve differences in two recent papers on the effects of cytochalasins in root cells. While both studies reported similar effects on interphase cells (i.e., replacement of microfilaments by many small specks and rods), Palevitz (Cell Motil. Cytoskeleton 9:283-298, 1988) maintained that cytochalasins B and D induce actin aggregation at the poles of dividing Allium root cells at a concentration of 10-mu-M with rhodamine phalloidin as a reporter probe, whereas McCurdy and Gunning (Cell Motil. Cytoskeleton 15:76-87, 1990) could not find these aggregates following antiactin immunocytochemistry in Triticum roots treated with CB at 50-mu-M. Employing identical methods and materials in the same laboratory, we found that CD induces polar actin aggregates in dividing cells of both species. However, the aggregates in Titicum are smaller and occur less frequently than those in Allium. A smaller pattern is seen with CB.