Figure 3.

Quantification of SaExp mRNA.

Quantities of SaExp1 (circles), SaExp2 (squares), and SaExp3 (diamonds) transcripts in the seedlings exposed to 2 μM DMBQ as determined by competitive RT-PCR. The inset gel was subjected to imaging with a PhosphoImager and contains the RT-PCR product for SaExp1 at 12-hr induction. An aliquot of 0.5 μg of seedling RNA was combined with each of three separate samples containing a dilution series, 20-fold each, of a synthetic SaExp1 RNA with a 30-bp insertion (construct). Each RNA sample was reverse-transcribed, PCR-amplified with ³²P-labeled SaExp1 primers, and used to determine the wild-type concentration from a standard curve by using the ratiometric method described by Pfaffl et al. (1998). Tube-to-tube variation showed R > 0.98; errors based on variation between triplicate runs are expressed as ±sd.