Accumulation of Rubisco LSU and RLSB protein and mRNA in lower leaf regions from RLSB/RLSB and rlsb-1/rlsb-2 maize seedlings. Panel A: Immunoblot showing accumulation of LSU, RLSB, and PEPCase (as a loading control) proteins in lower regions (lower third) of RLSB/RLSB and rlsb-1/rlsb-2 maize seedlings, using the first or second emerging leaves (4 – 6 cm long). Equalized amounts of total (soluble plus membrane) proteins from non-mutant RLSB/RLSB and mutant rlsb-1/rlsb-2 leaves were separated by SDS-PAGE, and subjected to immunoblot analysis as described for Figure 4, using the indicated antibodies. Panel B: Real-time quantitative PCR showing relative levels of mRNA accumulation for rbcL and RLSB transcripts in RLSB/RLSB and rlsb-1/rlsb-2 maize seedlings. Quantification of transcript levels was standardized to actin mRNA. Data is averaged for four wild type and four mutant siblings, with three repeats run for each of the plant samples. Note differences in scale for panels showing rbcL and RLSB mRNAs, indicating that these two transcripts accumulate to substantially different levels in both wild type and mutant plants. Statistical significance was calculated using Student’s t-test. For each bar, P values were less than 0.05.