Recent developments of poplar genomics provide unique resources of new information that this project proposes to exploit in the context of the Popwood programme. It will improve the understanding of genetic and molecular mechanisms controlling vascular development (VD) and wood formation, and engineer transgenic poplars with modified fibres and wood properties. In parallel to the genetic and molecular genetic work, the juvenile poplar fibre and wood properties will be analysed and compared to the characteristics of mature wood. The main purpose will be to evaluate the possibilities of using young trees of only a few years old as a raw material for pulp production, which could offer novel economic opportunities to rapidly exploit transgenic traits.
Properties of vascular tissues such as secondary wall thickness and xylem cell size represent important parameters that influence wood structure and fibre quality in trees. A gradient of the plant hormone auxin within vascular tissues critically influences such parameters. Genes encoding auxin transport components have been identified in the model plant Arabidopsis (A.t). Many of the genes regulating vascular properties are likely to be conserved between the dicot tree, hybrid aspen and A.t. The Popwood programme aims to improve our understanding of the genetic and hormonal regulation of vascular development in hybrid aspen by:
1) selecting genes that regulate vascular properties, using a combination of genetic and functional genomic approaches in A.t
2) manipulating vascular development within transgenic hybrid aspen by targeting the expression of poplar sequences that include auxin transport and signalling
3) evaluating the novel fibre qualities and wood properties of transgenic lines.
We have completed our screen of mutant libraries having screened 4000 Landsberg erecta and 2000 Columbia M2 mutant plants. The screen was carried out entirely using chemically (ethyl methyl sulphonate) mutagenised plants.
Large scale expression analysis on microarrays using poplar ESTs has provided invaluable information on the pattern of expression of about 6000 EST.
Knock out mutants have been identified within the LAX gene family by screening of the SLAT Arabidopsis populations.
Research in wood and fibres has been limited by lack of efficient measurement methods. A set of characterization methods has been established, useful in tree improvement programs for evaluation of properties of young hardwood materials (P6). This includes investigation of age-to-age relationships, based on measurements of property differences between individual growth rings. Measurements of length and width of fibres and vessel elements in poplar have been emphasized.
Most of the POPWOOD objectives have been reached. The programme has conducted to the identification of novel mutants altered in vasculature, novel genes expressed differentially in distinct wood forming zones, to the isolation and characterisation of poplar promoters regulated by auxin or expressed in specific wood forming cell layers, to characterise auxin carriers and auxin responsive genes, to develop methods for measurement of fibers from hardwood species, to analyse and compare juvenile versus mature wood and to adapt 3-D imaging to plant material.
FORESTRY, NON-FOOD PRODUCTS, GENOMICS
Scientist responsible for the project
Ms CATHERINE PERROT-RECHENMANN
Avenue de la Terrasse
91198 Gif sur Yvette
France - FR
Phone: +33 1 69 82 35 88
Fax: +33 1 69 82 35 84
||Centre de la Recherche Scientifique
||01 February 2000
||2 583 830 €
|Total EC contribution
||1 829 292 €