Present address: Institut de Recherche en Biologie Végétale (IRBV), Montreal, QC H1X 2B2, Canada.
Gene expression patterns underlying changes in xylem structure and function in response to increased nitrogen availability in hybrid poplar
Article first published online: 19 JUL 2012
© 2012 Blackwell Publishing Ltd
Plant, Cell & Environment
Volume 36, Issue 1, pages 186–199, January 2013
How to Cite
PLAVCOVÁ, L., HACKE, U. G., ALMEIDA-RODRIGUEZ, A. M., LI, E. and DOUGLAS, C. J. (2013), Gene expression patterns underlying changes in xylem structure and function in response to increased nitrogen availability in hybrid poplar. Plant, Cell & Environment, 36: 186–199. doi: 10.1111/j.1365-3040.2012.02566.x
- Issue published online: 3 DEC 2012
- Article first published online: 19 JUL 2012
- Accepted manuscript online: 26 JUN 2012 07:12AM EST
- Received 24 April 2012; received in revised form 14 June 2012; accepted for publication 18 June 2012
- phenotypic plasticity;
- transcriptome analysis;
Nitrogen availability has a strong influence on plant growth and development. In this study, we examined the effect of nitrogen availability on xylogenesis in hybrid poplar (Populus trichocarpa × deltoides H11-11). Saplings of hybrid poplar were fertilized for 33 d with either high or adequate levels of ammonium nitrate. We observed enhanced radial growth, wider vessels and fibres and thinner fibre walls in the secondary xylem of high N relative to adequate N plants. These anatomical differences translated into altered hydraulic properties with xylem being more transport efficient but also more vulnerable to drought-induced cavitation in high N plants. The changes in xylem structure and function were associated with differences in gene expression as revealed by the transcriptome analysis of the developing xylem region. We found 388 genes differentially expressed (fold change ±1.5, P-value ≤ 0.05), including a number of genes putatively involved in nitrogen and carbohydrate metabolism and various aspects of xylem cell differentiation. Several genes encoding known transcriptional regulators of secondary cell wall deposition were down-regulated in high N plants, corresponding with thinner secondary cell walls in these plants. The results of this study provide us with gene candidates potentially affecting xylem hydraulic and structural traits.