Light regulates alternative splicing through the control of transcriptional elongation

MA. GUILLERMINA KUBACZKA; ALBERTO R. KORNBLIHTT; GODOY HERZ, MICAELA

Congreso; Xth Meeting of the Latin American Society for Developmental Biology; 2019

Light makes carbon fixation possible, allowing plantand animal life on Earth. We have previously shown that light regulates alternative splicing in plants. Light initiates a chloroplast retrograde signalling that regulates nuclear alternative splicing of a subset of Arabidopsis thaliana transcripts. Here, we show that light promotes RNA polymerase II (Pol II) elongation in the affected genes, whereas in darkness, elongation is lower. These changes in transcription are consistent with elongation causing the observed changes in alternative splicing, as revealed by different drug treatments and genetic evidence. The light control of splicing and elongation is abolished in an Arabidopsis mutant defective in the transcription factor IIS (TFIIS). We report that the chloroplast control of nuclear alternative splicing in plants responds to the kinetic coupling mechanism found in mammalian cells, providing unique evidence that coupling is important for a whole organism to respond to environmental cues. Current work in animal model C. elegans and in Arabidopsis will help us understand coupling mechanisms both in plant and animals.