On the Putative Role of Microtubules in Gravitropism of Maize Coleoptiles

1991 Plant and Cell Physiology  
The antimicrotubular drug ethyl-TV-phenylcarbamate (EPC), at 1 to 10 mM, strongly inhibits gravitropism in coleoptiles of Zea mays L. Under the same conditions, phototropism remains essentially unimpaired. Propyzamide, a antimicrotubular drug specific for plant microtubules, at 0.02 to 0.2 mM causes qualitatively identical results, but to a weaker extent. Immunofluorescence data show that even only partial elimination of cortical microtubules in the outer epidermis is correlated with complete
more » ... ted with complete inhibition of gravitropism. Phototropism can proceed to some extent even after complete removal of cortical microtubules. Together with previous work the data indicate a complex role of the microtubular cytoskeleton in gravitropism: (1) late transduction of both, photo-and gravitropism and (2) early transduction of gravity, possibly by perceiving and transducing pressure or displacement of statoliths.
doi:10.1093/oxfordjournals.pcp.a078155 fatcat:np6dyzqq6ja5hfnzeturo7umfq