*2.4. OsCAF1 Involved in Splicing of Multiple Chloroplast Group II Introns*

Previous studies have shown that *ZmCAF1* and *AtCAF1* participate in intron splicing in the chloroplast [21]. To test whether OsCAF1 was involved in the RNA splicing of chloroplast genes, we amplified the chloroplast genes that contained at least one intron in WT and *oscaf1* mutants using the RT-PCR method. We observed that the introns of chloroplast *atpF*, *rpl2*, and *rps12* could not be spliced, whereas the intron splicing efficiency of *ndhA*, *ndhB*, and *ycf3* decreased in group II introns in *oscaf1* mutants (Figure 5). In *oscaf1*, the splicing efficiency of group I introns (*trnL*) was normal. The results indicated that OsCAF1 might participate in the splicing of multiple chloroplast group II introns.

**Figure 5.** Splicing analysis of chloroplast gene transcripts in WT and *oscaf1* mutants. U, unspliced transcripts; S, spliced transcripts.
