title: Transcriptome profiling of Kentucky bluegrass (Poa pratensis L.) accessions in response to salt stress.
abstract: BACKGROUND
  Kentucky bluegrass (Poa pratensis L.) is a prominent turfgrass in the cool-season regions, but it is sensitive to salt stress. Previously, a relatively salt tolerant Kentucky bluegrass accession was identified that maintained green colour under consistent salt applications. In this study, a transcriptome study between the tolerant (PI 372742) accession and a salt susceptible (PI 368233) accession was conducted, under control and salt treatments, and in shoot and root tissues.
  
  
  RESULTS
  Sample replicates grouped tightly by tissue and treatment, and fewer differentially expressed transcripts were detected in the tolerant PI 372742 samples compared to the susceptible PI 368233 samples, and in root tissues compared to shoot tissues. A de novo assembly resulted in 388,764 transcripts, with 36,587 detected as differentially expressed. Approximately 75 % of transcripts had homology based annotations, with several differences in GO terms enriched between the PI 368233 and PI 372742 samples. Gene expression profiling identified salt-responsive gene families that were consistently down-regulated in PI 372742 and unlikely to contribute to salt tolerance in Kentucky bluegrass. Gene expression profiling also identified sets of transcripts relating to transcription factors, ion and water transport genes, and oxidation-reduction process genes with likely roles in salt tolerance.
  
  
  CONCLUSIONS
  The transcript assembly represents the first such assembly in the highly polyploidy, facultative apomictic Kentucky bluegrass. The transcripts identified provide genetic information on how this plant responds to and tolerates salt stress in both shoot and root tissues, and can be used for further genetic testing and introgression.
authors.affiliation: USDA-ARS Forage and Range Research Laboratory, 700 North 1100 East, Logan, UT, 84322-6300, USA. shaun.bushman@ars.usda.gov.
authors.forename: B Shaun
authors.initials: BS
authors.lastname: Bushman
authors.affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, USA. kamundsen2@unl.edu.
authors.forename: Keenan L
authors.initials: KL
authors.lastname: Amundsen
authors.affiliation: USDA-ARS Floral and Nursery Plants Research Unit, Beltsville, MD, USA. scott.warnke@ars.usda.gov.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Warnke
authors.affiliation: USDA-ARS Forage and Range Research Laboratory, 700 North 1100 East, Logan, UT, 84322-6300, USA. joseph.robins@ars.usda.gov.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Robins
authors.affiliation: Department of Plants, Soils, and Climate, Utah State University, Logan, UT, USA. paul.johnson@usu.edu.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Johnson
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018517:Plant Roots / Q000235:genetics; D031785:Poa / Q000235:genetics* / Q000502:physiology; D055049:Salt Tolerance / Q000235:genetics*; D012965:Sodium Chloride / Q000737:chemistry; D013312:Stress, Physiological / Q000235:genetics*; D059467:Transcriptome / Q000235:genetics
chemical_list: D012965:Sodium Chloride