Figure 4.

Soluble leaf protein, Rubisco, and rbcL/M transcript contents, and Rubisco carbamylation status in light-adapted leaves of transformants and controls. Measurements (±sd) were made on samples from leaf 5 of T₂-generation tobacco-rubrum (tr, n = 4), LEV3 (L3, n = 3), and LEV1 (L1, n = 3) transformants and nontransformed plants (nt, n = 3; see “Materials and Methods”). A, Soluble leaf protein (white plus black), Rubisco content (white). B, Carbamylation status of active sites. C, The relative abundances of the bicistronic rbcL-aadA1, rbcL-aadA3, and rbcM-aadA3 transcripts in L1, L3, and tr plants, respectively, measured from RNA blots probed with the aadA probe (cross-hatched bars) and of the monocistronic rbcL transcript in nontransformed and L1 plants (black bars) and the bicistronic transcripts rbcL-aadA1 in L1 (white cross-hatched bars) and rbcL-aadA3 (black bars) in L3 plants probed with the rbcL probe. The mRNA abundance was normalized relative to that of the rbcL transcript in nontransformed plants. The relative responses to the rbcL and aadA probes was determined using the L3 plants, where the two probes detect the same mRNA species (Fig. 1). D, Relative translational efficiency of Rubisco mRNAs in tr, L3, and L1 transformants was obtained by dividing Rubisco content by transcript abundance and normalized relative to the result obtained with nontransformed leaves (see “Materials and Methods”). For L1 samples, the translational efficiency is calculated from the sum of the abundances of the rbcL and rbcL-aadA1 transcripts (black bar) and from the abundance of the rbcL transcript alone (black plus white bar).