Fig. 2. FT transcript levels are drastically increased in SD-grown, early flowering spa mutants. (A) RT-PCR analysis of CO, FT, SOC1, FLC and ubiquitin (UBQ10) mRNA abundance in wild-type (WT) and spa mutant plants. (B-E) Quantification of mRNA abundance of the blots shown in A. The transcript levels of flowering time genes were normalized by the transcript levels of UBQ10. A representative experiment of two or three independent experiments is shown. Notice the difference in scale of FT/UBQ10 in the two graphs in C. Wild-type (Col), spa1-7, spa1-7 spa3 spa4 and spa2 spa3 spa4 (Col) plants were grown in SD for 25 days. RNA was isolated from these plants and used for RT-PCR analysis.