[Tobacco gamma-tubulin gene silencing mediated by recombinant potato virus X vector]

Gamma-tubulin gene is a very important house-keeping gene and plays key roles in cell division, microtubule nucleation and cell cycle regulation in both plants and animals. In this paper, we studied the gamma-tubulin gene silencing in Nicotiana tabacum var. Samsun NN using the recombinant PVX vector with D fragment of gamma-tubulin cDNA. Special phenotype appeared from recombinant PVX-vector-infected plants, the different morphological leaves grew alternatively in leaf layers (Figs.3-5), and all the buds fell off gradually (Fig.4), resulting in failure of all the microspores to develop to the tetrad stage (Fig.8). The silencing initiated from the apical tissue and kept on until it was mature (Figs.3, 4). There was the increasing of target gene mRNA obviously during gene silencing, even to exceed the positive control (Fig.6). The PVX vector was also suppressed strongly and could fluctuate to some degree (Fig.9), which was probably correlated with target gene mRNA expression.