PROTEOME ANALYSIS IN MARITIME PINE

INRA-Equipe de Genetique et Amelioration des arbres forestiers BP45 F-33610 Cestas, France

We have developed and optimized two-dimensional gel electrophoresis of proteins for diverse maritime pine tissues and used this technique to study qualitative and quantitative protein variations. In respect to qualitative variants, 68 proteins showing mendelian inheritance in a segregating progeny, were localized on a genetic map, providing interesting markers to map the expressed genome. Such markers are physiologically relevant in that they reveal loci whose transcripts are translated in the organ analyzed. In respect to quantitative variants, we will report on the identification of compression wood responsive proteins. Compression wood is formed in xylem tissue in response to an abnormal orientation of the stem and is mainly produced in reaction to external influences, e.g. wind, snow, obstacle. Changes in cell wall structure and chemistry that are associated with compression wood, constitutes a major defect in wood quality (e.g. longitudinal shrinkage) and fiber products. Changes in gene/protein expression are likely to underlie the anatomical and chemical differences observed between compression wood and normal wood. Proteins differentially expressed between both types of wood were characterized by internal microsequencing. A clustering analysis was performed based on spot expression profiles recorded for xylem samples associated with different growth strain values (i.e. a range of chemical and physical wood characteristics). This multivariate analysis allows classification of the studied proteins with respect to similar shapes of pattern profiles that could identify : (i) gene products under the same control mechanism, (ii) functional groups corresponding to specialized pathways or involved in specific mechanisms, or (iii) partner proteins.