Figure 4.

HMGR activity assays, immunoblots, and Southern blots of extracts from the wild-type (WT) and transgenic plant lines (1S and CD1) that were analyzed by confocal microscopy (Fig. 3). A, Histograms show the densitometric values for the immunoblot polypeptide bands corresponding to 63-kD HMGR1S (B) revealed by anti-CD1 antiserum (light bars), and the corresponding HMGR activities (dark bars), normalized per total protein content, of extracts from 9-d-old seedlings grown under a continuous-light regime. The specific activity of wild-type plants was 0.26 ± 0.01 nmol mevalonate min⁻¹ mg protein⁻¹. The activities are the mean values of duplicate analyses ±10% variation. Fifteen micrograms of total protein were loaded per lane of SDS gels used for immunoblots. C, Staining of the PVDF membrane with Ponceau to reveal the band corresponding to Rubisco, used as an assessment for equal protein loading. D, Southern blots of the three lines.