In vitro assembly of plant tubulin in the absence of microtubule-stabilizing reagents

The assembly of microtubules is essential for physiological functions of mi crotubules. Addition of microtubule-stabilizing reagents or microtubule "se eds" is usually necessary for plant tubulin assembly in vitro, which hinder s the investigation of plant microtubule dynamics. In the present note, hig hly purified plant tubulins have been obtained from lily pollen, a non-micr otubule-stabilizing reagent or microtubule "seed" system for plant tubulin assembly has been established and the analysis of plant tubulin assembly pe rformed. Experiment results showed that purified tubulin polymerized in vit ro, and a typical microtubule structure was observed with electron microsco py. The kinetics curve of tubulin assembly exhibited typical "parabola". Th e presence of taxol significantly altered the character of plant tubulin as sembly, including that abnormal microtubules were assembled and the critica l concentration for plant tubulin assembly was decreased exceedingly from 3 mg/mL in the absence of taxol to 0.043 mg/mL in the presence of taxol.