Light regulates plant alternative splicing through the control of transcriptional elongation

GRZEGORZ BRZYżEK; CRAIG G. SIMPSON; EZEQUIEL PETRILLO; MA. GUILLERMINA KUBACZKA; MICHAL KRZYSZTON; SZYMON SWIEZEWSKI; MICAELA A. GODOY HERZ; LUCAS SERVI; JOHN W.S. BROWN; ALBERTO KORNBLIHTT

Paraná

Congreso; SAIB, Reunión Annual Sociedad Argentina de Investigación Bioquímica y Biología Molecular.; 2018

Light makes carbon fixation possible allowing plant and animal life on Earth. We have previously shown that light regulates alternative splicing in plants. Light initiates a chloroplastretrograde signaling that regulates nuclear alternative splicing of a subset of Arabidopsis thaliana transcripts. Here we show that light promotes RNAPII elongation in the affected genes,while in darkness elongation is lower. These changes in transcription are consistent with elongation causing the observed changes in alternative splicing, as revealed by different drugtreatments and genetic evidence. The light control of splicing and elongation is abolished in an Arabidopsis mutant defective in the elongation factor TFIIS. We report that thechloroplast control of nuclear alternative splicing in plants responds to the kinetic coupling mechanism found in mammalian cells, providing unique evidence that coupling is importantfor a whole organism to respond to environmental cues