Although boron is known to be an essential element for the growth of all higher plants, the links between primary responses to boron deprivation and the expression of visual symptoms are yet unknown. Western blots with anti-actin and anti-tubulin antibodies revealed an increase of both proteins upon 20-40 min of boron deprivation in roots of hydroponically grown Arabidopsis thaliana. Moreover, actin depolymerizing factor and myosin VIII showed a less pronounced but similiar response to boron deficiency. In contrast, no increase in higher molecular mass ubiquitin was observed, indicating an absence of intensive protein degradation during the experimental time span. This is the first report of cytoskeletal responses of plants to short-term boron removal. Rapid elevation of cytoskeletal proteins after boron deprivation is discussed in relation to the cell wall-plasma membrane-cytoskeleton continuum.