RT Journal Article
SR Electronic
T1 Ethylene signaling induces gelatinous layers with typical features of tension wood in hybrid aspen
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 204602
DO 10.1101/204602
A1 Judith Felten
A1 Jorma Vahala
A1 Jonathan Love
A1 András Gorzsás
A1 Markus Rüggeberg
A1 Nicolas Delhomme
A1 Joanna Leśniewska
A1 Jaakko Kangasjärvi
A1 Torgeir R. Hvidsten
A1 Ewa J. Mellerowicz
A1 Björn Sundberg
YR 2017
UL http://biorxiv.org/content/early/2017/10/17/204602.abstract
AB Research conducted The phytohormone ethylene impacts secondary stem growth in plants by stimulating cambial activity, xylem development and fiber over vessel formation. Here we report the effect of ethylene on secondary cell wall formation and the molecular connection between ethylene signaling and wood formation.Methods We applied exogenous ethylene or its precursor 1-aminocyclopropane-1-carboxylic acid (ACC) to wild type and ethylene insensitive hybrid aspen trees (Populus tremula x tremuloides) and studied secondary cell wall anatomy, chemistry and ultrastructure. We furthermore analyzed the transcriptome (RNA Seq) after ACC application to wild type and ethylene insensitive trees.Key results We demonstrate that ACC and ethylene induce gelatinous-layers (G-layers) and alter the fiber cell wall cellulose microfibril angle. G-layers are tertiary wall layers rich in cellulose, typically found in tension wood of aspen trees. A vast majority of transcripts affected by ACC are downstream of ethylene perception and include a large number of transcription factors (TFs). Motif-analyses reveal potential connections between ethylene TFs (ERFs, EIN3/EIL1) and wood formation.Conclusion G-layer formation upon ethylene application suggests that the increase in ethylene biosynthesis observed during tension wood formation is important for its formation. Ethylene-regulated TFs of the ERF and EIN3/EIL1 type could transmit the ethylene signal.