Tubulin Cytoskeleton in Arabidopsis thaliana Root Cells Under Clinorotation

The effect of horizontal clinorotation (2 rpm) on the spatial organization of cortical microtubules (CMTs) in the living Arabidopsis root cells has been investigated. MTs were visualized by using a stably transformed line of transgenic Arabidopsis thaliana expressing GFP-MAP4 fusion protein. To monitor total changes in MT dynamics, the sensitivity to MT-inhibitor 5 μM/l oryzalin was used as an indicator. It was shown that CMTs in the distal elongation zone (DEZ) of clinorotated 5 day old seedlings exhibited a higher degree of disorder and also they were more sensitive to oryzalin. We suggest that rearrangement of CMTs in DEZ cells under clinorotation is caused by fast rate of MT dynamic turnover.