PT - JOURNAL ARTICLE AU - David Sundell AU - Nathaniel R. Street AU - Manoj Kumar AU - Ewa J. Mellerowicz AU - Melis Kucukoglu AU - Christoffer Johnsson AU - Vikash Kumar AU - Chanaka Mannapperuma AU - Nicolas Delhomme AU - Ove Nilsson AU - Hannele Tuominen AU - Edouard Pesquet AU - Urs Fischer AU - Totte Niittylä AU - Bjöern Sundberg AU - Torgeir R. Hvidsten TI - AspWood: High-spatial-resolution transcriptome profiles reveal uncharacterized modularity of wood formation in <em>Populus tremula</em> AID - 10.1101/094060 DP - 2017 Jan 01 TA - bioRxiv PG - 094060 4099 - http://biorxiv.org/content/early/2017/02/23/094060.short 4100 - http://biorxiv.org/content/early/2017/02/23/094060.full AB - Trees represent the largest terrestrial carbon sink and a renewable source of ligno-cellulose. There is significant scope for yield and quality improvement in these largely undomesticated species, and efforts to engineer new, elite varieties will benefit from an improved understanding of the transcriptional network underlying cambial growth and wood formation. We generated high-spatial-resolution RNA Sequencing data spanning the secondary phloem, vascular cambium and wood forming tissues. The transcriptome comprised 28,294 expressed, previously annotated genes, 78 novel protein-coding genes and 567 long intergenic non-coding RNAs. Most paralogs originating from the Salicaceae whole genome duplication were found to have diverged expression, with the notable exception of those with high expression during secondary cell wall deposition. Co-expression network analysis revealed that the regulation of the transcriptome underlying cambial growth and wood formation comprises numerous modules forming a continuum of active processes across the tissues. The high spatial resolution enabled identification of novel roles for characterised genes involved in xylan and cellulose biosynthesis, regulators of xylem vessel and fiber differentiation and lignification. The associated web resource (AspWood, http://aspwood.popgenie.org) integrates the data within a set of interactive tools for exploring the expression profiles and co-expression network.