Fig. 4. AS efficiency of  APXII-Fluc  gene in the  apsi  mutants. Semi-quantitative RT-PCR analysis detected AS variants (sAPX-II, -III, and tAPX-I types) produced from the  APXII-Fluc  gene in  apsi  mutants. Semi-quantitative RT-PCR analysis (24–28 cycles) was carried out using sets of primers ( Supplementary Table 1 ) in extracts from the rosette leaves of 2-week-old  apsi  mutants (M3 generation). The primer positions are shown in  Fig. 2a . Amplified products were electrophoresed on a 2% (w/v) agarose gel. Equal loading of each amplified cDNA was determined using the control actin2 PCR product. M, molecular marker. Control,  APXII - Fluc  plants. The experiments were repeated at least 3 times using plants grown independently, and the representative results are shown.