Genetic variation and structural diversity in major seed proteins among and within Camelina species

Dwayne Hegedus; Cathy Coutu; Branimir Gjetvaj; Abdelali Hannoufa; Myrtle Harrington; Sara Martin; Isobel A P Parkin; Suneru Perera; Janitha Wanasundara

doi:10.1007/s00425-022-03998-w

Genetic variation and structural diversity in major seed proteins among and within Camelina species

Planta. 2022 Oct 6;256(5):93. doi: 10.1007/s00425-022-03998-w.

Authors

Dwayne Hegedus^{1

2}, Cathy Coutu³, Branimir Gjetvaj³, Abdelali Hannoufa⁴, Myrtle Harrington³, Sara Martin⁴, Isobel A P Parkin³, Suneru Perera^{3

5}, Janitha Wanasundara^{3

5}

Affiliations

¹ Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada. Dwayne.Hegedus@agr.gc.ca.
² Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada. Dwayne.Hegedus@agr.gc.ca.
³ Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada.
⁴ Agriculture and Agri-Food Canada, London, ON, Canada.
⁵ Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada.

Abstract

Genetic variation in seed protein composition, seed protein gene expression and predictions of seed protein physiochemical properties were documented in C. sativa and other Camelina species. Seed protein diversity was examined in six Camelina species (C. hispida, C. laxa, C. microcarpa, C. neglecta, C. rumelica and C. sativa). Differences were observed in seed protein electrophoretic profiles, total seed protein content and amino acid composition between the species. Genes encoding major seed proteins (cruciferins, napins, oleosins and vicilins) were catalogued for C. sativa and RNA-Seq analysis established the expression patterns of these and other genes in developing seed from anthesis through to maturation. Examination of 187 C. sativa accessions revealed limited variation in seed protein electrophoretic profiles, though sufficient to group the majority into classes based on high MW protein profiles corresponding to the cruciferin region. C. sativa possessed four distinct types of cruciferins, named CsCRA, CsCRB, CsCRC and CsCRD, which corresponded to orthologues in Arabidopsis thaliana with members of each type encoded by homeologous genes on the three C. sativa sub-genomes. Total protein content and amino acid composition varied only slightly; however, RNA-Seq analysis revealed that CsCRA and CsCRB genes contributed > 95% of the cruciferin transcripts in most lines, whereas CsCRC genes were the most highly expressed cruciferin genes in others, including the type cultivar DH55. This was confirmed by proteomics analyses. Cruciferin is the most abundant seed protein and contributes the most to functionality. Modelling of the C. sativa cruciferins indicated that each type possesses different physiochemical attributes that were predicted to impart unique functional properties. As such, opportunities exist to create C. sativa cultivars with seed protein profiles tailored to specific technical applications.

Keywords: Camelina sativa; Cruciferin; Gene expression; Protein functionality; Protein modelling.

MeSH terms

Amino Acids / metabolism
Arabidopsis* / genetics
Brassicaceae* / genetics
Brassicaceae* / metabolism
Genetic Variation
Seeds / genetics
Seeds / metabolism

Substances

Amino Acids