title: Post-transcriptional regulation of photosynthetic genes is a key driver of C4 leaf ontogeny.
abstract: C4photosynthesis allows highly efficient carbon fixation that originates from tightly regulated anatomical and biochemical modifications of leaf architecture. Recent studies showed that leaf transcriptome modifications during leaf ontogeny of closely related C3(Tarenaya hassleriana) and C4(Gynandropsis gynandra) species within the Cleomaceae family existed but they did not identify any dedicated transcriptional networks or factors specifically driving C4leaf ontogeny. RNAseq analysis provides a steady-state quantification of whole-cell mRNAs but does not allow any discrimination between transcriptional and post-transcriptional processes that may occur simultaneously during leaf ontogeny. Here we use exon-intron split analysis (EISA) to determine the extent to which transcriptional and post-transcriptional processes are involved in the regulation of gene expression between young and expanded leaves in both species. C4-specific changes in post-transcriptional regulation were observed for genes involved in the Calvin-Benson cycle and some photosystem components but not for C4core-cycle genes. Overall, this study provides an unbiased genome-wide insight into the post-transcriptional mechanisms that regulate gene expression through the control of mRNA levels and could be central to the onset of C4photosynthesis. This mechanism is cytosolic which implies cell-specific modifications of mRNA stability. Understanding this mechanism may be crucial when aiming to transform C3crops into C4crops.
authors.affiliation: Clinical Trials Unit, University of Bern, Finkenhubelweg 11, 3012 Bern, Switzerland.
authors.forename: Nicklaus
authors.initials: N
authors.lastname: Fankhauser
authors.affiliation: Institute of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, 8008 Zürich, Switzerland sylvain.aubry@botinst.uzh.ch.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Aubry
mesh_terms: D031483:Capparaceae / Q000235:genetics / Q000378:metabolism*; D031485:Cleome / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010788:Photosynthesis / Q000235:genetics*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism*
keywords: C4
  ; Cleomaceae; EISA; leaf ontogeny; photosynthesis; post-transcription.