Abstract
Butanedione monoxime (BDM) is well-known inhibitor of actomyosin interaction. However, it was reported that BDM up to 10 mM did not inhibit the cytoplasmic streaming of characean alga, well-known actomyosin driven system in plant (McCurdy, 1999). On the other hand, Tominaga et al. (2000) reported that the motile activity of myosin from lily pollen tube was inhibited when BDM at concentrations higher than 10 mM was applied. We examined if characean cytoplasmic streaming was inhibited by BDM at concentrations higher than 10 mM. It was found that cytoplasmic streaming of characean cells was inhibited by BDM at concentrations higher than 10 mM. This inhibition was reversible. Inhibition of characean actomyosin by BDM was confirmed by in vitro motility assay using crude characean myosin fraction. We concluded that characean actomyosin interaction is sensitive to BDM though its sensitivity is much lower than animal myosin.
