Ethylene stimulates tracheary element differentiation in Zinnia elegans cell cultures
Article first published online: 10 JAN 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 190, Issue 1, pages 138–149, April 2011
How to Cite
Pesquet, E. and Tuominen, H. (2011), Ethylene stimulates tracheary element differentiation in Zinnia elegans cell cultures. New Phytologist, 190: 138–149. doi: 10.1111/j.1469-8137.2010.03600.x
- Issue published online: 25 FEB 2011
- Article first published online: 10 JAN 2011
- Received: 14 October 2010, Accepted: 15 November 2010
- 1-aminocyclopropane-1-carboxylic acid (ACC);
- tracheary element;
- Zinnia elegans
- •The exact role of ethylene in xylogenesis remains unclear, but the Zinnia elegans cell culture system provides an excellent model with which to study its role during the differentiation of tracheary elements (TEs) in vitro.
- •Here, we analysed ethylene homeostasis and function during Z. elegans TE differentiation using biochemical, molecular and pharmacological methods.
- •Ethylene evolution was confined to specific stages of TE differentiation. It was found to peak at the time of TE maturation and to correlate with the activity of the ethylene biosynthetic 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase. The ethylene precursor ACC was exported and accumulated to high concentrations in the extracellular medium, which also displayed a high capacity to convert ACC into ethylene. The effects of adding inhibitors of the ethylene biosynthetic ACC synthase and ACC oxidase enzymes to the TE cultures demonstrated for the first time strict dependence of TE differentiation on ethylene biosynthesis and a stimulatory effect of ethylene on the rate of TE differentiation.
- •In a whole-plant context, our results suggest that ethylene synthesis occurs in the apoplast of the xylem elements and that ethylene participates, in a paracrine manner, in the control of the cambial stem cell pool size during secondary xylem formation.