title: Transcript analysis in two alfalfa salt tolerance selected breeding populations relative to a non-tolerant population.
abstract: With the growing limitations on arable land, alfalfa (a widely cultivated, low-input forage) is now being selected to extend cultivation into saline lands for low-cost biofeedstock purposes. Here, minerals and transcriptome profiles were compared between two new salinity-tolerant North American alfalfa breeding populations and a more salinity-sensitive western Canadian alfalfa population grown under hydroponic saline conditions. All three populations accumulated two-fold higher sodium in roots than shoots as a function of increased electrical conductivity. At least 50% of differentially expressed genes (p < 0.05) were down-regulated in the salt-sensitive population growing under high salinity, while expression remained unchanged in the saline-tolerant populations. In particular, most reduction in transcript levels in the salt-sensitive population was observed in genes specifying cell wall structural components, lipids, secondary metabolism, auxin and ethylene hormones, development, transport, signalling, heat shock, proteolysis, pathogenesis-response, abiotic stress, RNA processing, and protein metabolism. Transcript diversity for transcription factors, protein modification, and protein degradation genes was also more strongly affected in salt-tolerant CW064027 than in salt-tolerant Bridgeview and salt-sensitive Rangelander, while both saline-tolerant populations showed more substantial up-regulation in redox-related genes and B-ZIP transcripts. The report highlights the first use of bulked genotypes as replicated samples to compare the transcriptomes of obligate out-cross breeding populations in alfalfa.
authors.affiliation: a Saskatoon Research Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7J 0X2, Canada.|b Department of Computing Science, University of Alberta, 2-21 Athabasca Hall, Edmonton, AB T6G 2R3, Canada.
authors.forename: M Y
authors.initials: MY
authors.lastname: Gruber
authors.affiliation: b Department of Computing Science, University of Alberta, 2-21 Athabasca Hall, Edmonton, AB T6G 2R3, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Xia
authors.affiliation: a Saskatoon Research Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7J 0X2, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Yu
authors.affiliation: c Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, P.O. Box 1030, Swift Current, SK S9H 3X2, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Steppuhn
authors.affiliation: c Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, P.O. Box 1030, Swift Current, SK S9H 3X2, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Wall
authors.affiliation: c Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, P.O. Box 1030, Swift Current, SK S9H 3X2, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Messer
authors.affiliation: d National Research Council, 110 Gymnasium Pl., Saskatoon, SK S7N 0W9, Canada.
authors.forename: A G
authors.initials: AG
authors.lastname: Sharpe
authors.affiliation: e AAFC Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403 - 1st Avenue S., Lethbridge, AB T1J 4B1, Canada.
authors.forename: S N
authors.initials: SN
authors.lastname: Acharya
authors.affiliation: b Department of Computing Science, University of Alberta, 2-21 Athabasca Hall, Edmonton, AB T6G 2R3, Canada.|f Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2R3, Canada.
authors.forename: D S
authors.initials: DS
authors.lastname: Wishart
authors.affiliation: g Alforex Seeds, an affiliate of Dow AgroSciences, N4505 CTH M, West Salem, WI 54669, USA.
authors.forename: D
authors.initials: D
authors.lastname: Johnson
authors.affiliation: g Alforex Seeds, an affiliate of Dow AgroSciences, N4505 CTH M, West Salem, WI 54669, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Miller
authors.affiliation: a Saskatoon Research Centre, Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7J 0X2, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Taheri
mesh_terms: D001947:Breeding; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D059014:High-Throughput Nucleotide Sequencing; D007477:Ions / Q000378:metabolism; D000455:Medicago sativa / Q000235:genetics* / Q000378:metabolism*; D008903:Minerals / Q000378:metabolism; D058977:Molecular Sequence Annotation; D010937:Plant Growth Regulators / Q000235:genetics; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome
chemical_list: D007477:Ions; D008903:Minerals; D010937:Plant Growth Regulators
keywords: RNA-Seq; abiotic stress; alfalfa; luzerne; salinity; salinité; stress abiotique; transcriptome