Inhibitory effect of antisense γ-tubulin expression on seedling growth of rice plant

gamma -tubulin has been suggested to be highly concentrated at microtubule organizing centers (MTOC) for microtubule (MT) assembly in helping chromosome dispersion. It is not known, however, whether gamma -tubulin is essential in cell division for plant development. When a gamma -tubulin gene (OsTUBG2) antisense expressing construct was introduced into rice embryo by imbibition technique, seedling growth was significantly inhibited in comparison to rice plant imbibed with OsTUBG2 sense expression construct or control DNA. When we measured the length of stem and root from 13 days-old seedlings, normal growth of root has rarely been found in antisense construct-imbibed plant but stem did not show significant growth inhibition. These data suggest that inhibition of gamma -tubulin expression by antisense technique contributes to the growth of seedlings, especially root. Furthermore, because gamma -tubulin is less expressed by imbibition with antisense construct and appear redundant to MT assembly, our result suggests that inhibition of gamma -tubulin expression by antisense technique contributes to the growth of seedlings, especially root, by blocking mitotic spindle formation during cell division.