LIGHT REGULATES PLANT ALTERNATIVE SPLICING THROUGH THE CONTROL OF TRANSCRIPTIONAL ELONGATION

GODOY HERZ, MICAELA A.; KUBACZKA, M. GUILLERMINA; BRZYżEK, GREGORZ; SIMPSON, CRAIG; BROWN, JOHN; SWIEZEWSKI, SZYMON; PETRILLO, EZEQUIEL; KORNBLIHTT, ALBERTO R.

Congreso; LIV Reunión Anual SAIB; 2018

Light makes carbon fixation possible allowing plant and animal life on Earth. We have previously shown that light regulates alternative splicingin plants. Light initiates a chloroplast retrograde signaling that regulates nuclear alternative splicing of a subset of Arabidopsis thalianatranscripts. Here we show that light promotes RNAPII elongation in the affected genes, while in darkness elongation is lower. These changes intranscriptional elongation are causative of the observed changes in alternative splicing, as revealed by different drug treatments and geneticevidence. The light control of splicing and elongation is abolished in an Arabidopsis mutant defective in the elongation factor TFIIS. We reportthat 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.