Figure 8.

Effect of Dex on the Expression of AtCAP1 and Actin in Tobacco BY-2 Cells, and Frequency Distribution of Mitotic Cells in BY-2 Cells Overexpressing AtCAP1.

(A) Protein gel blot detection of AtCAP1 (52 kD) and actin (46 kD) protein levels in BY-2 suspension-cultured cells at different Dex concentrations. The wild-type line (WT), an empty vector cell line (V3), and the AtCAP1 transgenic cell line (BS8) were grown in liquid medium for 7 days and then treated with different concentrations of Dex for 24 hr.

(B) Time course analysis of AtCAP1 and actin proteins in BY-2 transgenic suspension-cultured cells. BY-2 transgenic suspension cell lines V3 and BS8 were grown for 7 days in liquid medium and then treated with 1 μM Dex for the times indicated.

(C) Growth comparison of BY-2 suspension-cultured cells. Transgenic BY-2 cells cultured for 7 days were transferred to fresh MS liquid medium with or without Dex (1 μM) and cultured at 27°C. Samples were taken at the days indicated, and fresh weight was measured. Data represent averages of two independent experiments. TA, pTA7002 glucocorticoid-inducible vector.

(D) Transgenic BY-2 cells cultured for 7 days were subcultured in medium containing aphidicolin (5 mg/L) for 24 hr. After extensive washing, cells were resuspended in fresh medium with or without Dex (1 μM). Samples were removed at the times indicated, and mitotic cells were recorded as indicated in Methods. At least 500 cells were counted per treatment.