Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/6/2006
Publication Date: 5/30/2006
Citation: Baldwin, J.C., Dombrowski, J.E. 2006. Evaluation of lolium temulentum as a model grass species for the study of salinity stress by pcr-based subtractive suppression hybridization analysis. Plant Science.171:459-469.
Interpretive Summary: Stress due to increased salinity of soils is becoming a limiting factor in of biomass production in modern agriculture. Due to the limited research tools available in the study of forage and turf grasses, the development of model systems is of paramount importance. Forage grass species are generally polymorphic, obligate out-crossers, that are self-incompatible and many of which require vernalization to induce flowering. We propose the use of Lolium temulentum L. (Darnel ryegrass), a diploid self-fertile species with a short life cycle (2-3 months) which is amenable to both tissue culture and plant breeding, as a model system for the study of forage/turf grass species. These characteristics make L. temulentum an ideal candidate for future studies utilizing modern molecular tools. Our analysis of salt stress, by PCR based subtractive suppression hybridization library, identified 528 unique sequences, 167 of which have been linked to stress responses in other plant species. Many of the genes identified may provide valuable insight into the mechanisms utilized by grasses to mediate water stress tolerance. This analysis demonstrated the utility of Lolium temulentum as a model grass species for the study of salinity stress.
Technical Abstract: Soil salinity is one of the major abiotic stresses responsible for reduced persistence, yield and biomass accumulation in many crops including forage grass. Forage grass species are generally polymorphic, obligate out-crossers, that are self-incompatible. Because of their high genetic diversity the mechanisms of salt tolerance are poorly understood. Consequently, the development of a useful model grass plant for the study of abiotic stresses is of great importance. We propose the use of Lolium temulentum L. (Darnel ryegrass), a diploid self-fertile species with a short life cycle (2-3 months), as a model system for the study of forage/turf grass species. To evaluate the utility of L. temulentum as a model grass species to study salt stress, a PCR based subtractive suppression hybridization library was generated and sequenced. A total of 528 unique sequences were identified, among which 167 corresponded to orthologs of previously identified plant stress response genes. The expression patterns in leaf, crown and root tissues of selected genes were analyzed by Northern blot analysis, demonstrating salinity depended regulation of gene expression. These preliminary studies provide proof of concept supporting the use of L. temulentum as a model forage grass for molecular genetic analyses of salinity stress.