SPF45-related splicing factor for phytochrome signaling promotes photomorphogenesis by regulating pre-mRNA splicing in <i>Arabidopsis</i>

Abstract

Significance Pre-mRNA processing not only enhances the diversity encoded in the genome without the need to increase the number of genes but also provides a means to adjust cellular transcript abundance. Environmental light has a profound effect on transcript accumulation, but how this is partitioned between transcriptional and posttranscriptional processes is largely unknown. Here we describe the identification and characterization of the splicing factor for phytochrome signaling (SFPS), which directly interacts with the photoreceptor phytochrome B. sfps seedlings are hyposensitive to light and display pre-mRNA splicing defects in a large number of genes, many of which regulate light signaling and the circadian clock. Thus, light might control pre-mRNA splicing in addition to transcription of many genes through SFPS to promote photomorphogenesis.