© 2003 Heron Publishing—Victoria, Canada
Identification and characterization of water-stress-responsive genes in hydroponically grown maritime pine (Pinus pinaster) seedlings
Christian Dubos (1), Gregoire Le Provost (1), David Pot (1), Franck Salin (2), Celine Lalane (1), Delphine Madur (1), Jean-Marc Frigerio (1) and Christophe Plomion (1, 3)
1. >Equipe de Génétique et Amélioration des Arbres Forestiers, INRA, 69 route d'Arcachon, 33612 Cestas Cédex, France / 2. Laboratoire de Chimie des Substances Végétales, Institut du Pin, 351, Cours de la libération, 33405 Talence Cédex, France / 3. Author to whom correspondence should be addressed (plomion@pierroton.inra.fr) / Received July 9, 2002; accepted August 30, 2002; published online January 31, 2003
Summary
Growth, development and productivity of long-lived organisms such as forest trees are continuously challenged by abiotic stresses,
and may also be greatly affected by predicted climatic change. As a first step toward creating stress-resistant maritime pine
(Pinus pinaster Ait.) varieties by marker-assisted breeding, we describe the identification and characterization of water-stress-responsive
genes in hydroponically grown seedlings that were well watered (–0.08 MPa) or subjected to water deprivation (–0.45 MPa) by
the addition of polyethylene glycol. The cDNA amplified fragment-length polymorphism (cDNA-AFLP) technique was used to identify
genes regulated by water deprivation. Approximately 4000 transcript-derived fragments (TDFs) were screened, of which 28 increased
and 20 decreased in seedlings subjected to water deprivation. Of these 48 TDFs, 62.6% corresponded to proteins of known function,
which indicate the main mechanisms involved in the osmotic stress response (photosynthesis, carbohydrate metabolism, cell
wall synthesis and plant defense). We found that 16.6% of the 48 TDFs were similar to Arabidopsis thaliana (L.) Heynh gene products, 10.4% were similar to Pinus taeda L. expressed sequence tags (ESTs) and 10.4% did not match any sequences in the public databases. The relative abundance of
these transcripts was quantitatively analyzed by reverse northern of both needle and root tissues, confirming the effectiveness
of the cDNA-AFLP technique in detecting differentially expressed genes. The identification and characterization of water-stress-responsive
genes provide new insights into the nature of the machinery involved in the response to water deprivation in a forest tree.
Keywords:
cDNA-AFLP, osmotic stress, polyethylene glycol, reverse northern.
