Genome interplay in the grain transcriptome of hexaploid bread wheat
Abstract
Allohexaploid bread wheat (Triticum aestivum L.) provides approximately 20% of calories consumed by humans. Lack of genome sequence for the three homeologous and highly similar bread wheat genomes (A, B, and D) has impeded expression analysis of the grain transcriptome. We used previously unknown genome information to analyze the cell type–specific expression of homeologous genes in the developing wheat grain and identified distinct co-expression clusters reflecting the spatiotemporal progression during endosperm development. We observed no global but cell type– and stage-dependent genome dominance, organization of the wheat genome into transcriptionally active chromosomal regions, and asymmetric expression in gene families related to baking quality. Our findings give insight into the transcriptional dynamics and genome interplay among individual grain cell types in a polyploid cereal genome.
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Published In
Science
Volume 345 | Issue 6194
18 July 2014
18 July 2014
Copyright
Copyright © 2014, American Association for the Advancement of Science.
Submission history
Received: 23 December 2013
Accepted: 21 May 2014
Published in print: 18 July 2014
Acknowledgments
This work was supported by research grant 199387 from the Norwegian Research Council to the Norwegian University of Life Sciences and Graminor AS to O.A.O. K.F.X.M. acknowledges generous funding by the Deutsche Forschungsgemeinschaft (DFG) to project SFB924 “Molecular mechanisms regulating yield and yield stability in plants,” the German Federal Ministry of Education and Research (BMBF) in frame of the Synbreed project, and the European Commission’s 7th Framework Program in frame of the TransPLANT project. The data reported in this paper are tabulated in the supplementary materials and archived at the ArrayExpress database www.ebi.ac.uk/arrayexpress, accession no. E-MTAB-2137. No conflict of interest is known for the authors of this manuscript regarding data reported herein. S. I. Chi, E. I. Ako, A. Maharajan, and Ø. Jørgensen are thankfully acknowledged for grain dissection and plant cultivation. We thank P. Langridge, P. Shewry, B. Keller, and two anonymous reviewers for helpful suggestions on the manuscript. The RNA-seq was carried out at the Norwegian Sequencing Centre of University of Oslo. Graminor AS is acknowledged for generous support throughout this work.
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