Plant polar growth in tobacco disturbed by γ-tubulin gene silencing

To further understand the functions of γ-tubulin in plant cells, we conducted a study in which the γ-tubulin gene was down-regulated in tobacco plants (obtained by the Agrobacterium-mediated method). This involved transforming the target fragments, in which the sense and antisense partial γ-tubulin cDNA fragments were ligated together, into Nicotiana tabacum var. Samsun NN. The γ-tubulin down-regulated transformants developed multiple meristems or branches with trumpet-shaped leaves; their root generation also appeared abnormal, with the taproots undeveloped, whereas lateral roots were developed. In addition, the content of indole-3-acetic acid (IAA) and expression of polarity transportation vector PGP1 were aberrant. These results suggest that γ-tubulin gene silencing disturbed the polar growth of tobacco plants, and that this phenomenon was probably correlated with the IAA content and the polar transportation process.