Transgenic expression of a Δ12-epoxygenase gene in Arabidopsis seeds inhibits accumulation of linoleic acid (original) (raw)

Abstract.

The Crepis palaestina cDNA Cpal2 encodes a Δ12-epoxygenase that can catalyse the synthesis of 12,13-epoxy-_cis_-9-octadecenoic acid (18:1E) from linoleic acid (18:2). When the Cpal2 gene was expressed under the control of the napin seed-specific promoter in Arabidopsis thaliana (L.) Heynh., the seed lipids accumulated only low levels of 18:1E and also 12,13-epoxy-_cis_-9,15-octadec-2-enoic acid (18:2E). Despite the fact that the levels of these epoxy fatty acids comprised only up to 6.2% of the total fatty acids, there was a very marked increase in oleic acid (18:1) and decrease in linoleic (18:2) and α-linolenic (18:3) acids in these plants, indicating that endogenous Δ12-desaturation was greatly reduced in these plants. Significant between-line differences in the levels of Cpal2 mRNA were observed during seed development, but were not associated with any major variation in mRNA levels for the endogenous _Arabidopsis_Δ12-desaturase (Fad2). This suggests that if an unfavourable interaction occurs between the transgenic Δ12-epoxygenase and the endogenous Δ12-desaturase, which decreases the level of desaturation, it occurs at either the translational or post-translational level. We further show that the co-expression of a Δ12-desaturase gene from C. palaestina in Cpal2 transgenic Arabidopsis returns the relative proportions of the C18 seed fatty acids to normal levels and results in an almost twofold increase in total epoxy fatty acids.

Access this article

Log in via an institution

Subscribe and save

• Starting from 10 chapters or articles per month
• Access and download chapters and articles from more than 300k books and 2,500 journals
• Cancel anytime View plans

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Author information

Authors and Affiliations

1. CSIRO Plant Industry, GPO Box 1600, Canberra, Australia, , , , , , AU
   Surinder Singh & Allan Green
2. Scandanavian Biotechnology Research AB, SE 268 31, Svalöv, Sweden, , , , , , SE
   Michael Lee
3. Department of Plant Breeding Research, Swedish University of Agricultural Sciences, 268 31 Svalöv, Sweden, , , , , , SE
   Stefan Thomaeus & Sten Stymne

Authors

1. Surinder Singh
2. Stefan Thomaeus
3. Michael Lee
4. Sten Stymne
5. Allan Green

Additional information

Received: 11 August 2000 / Accepted: 7 September 2000

Rights and permissions

About this article

Cite this article

Singh, S., Thomaeus, S., Lee, M. et al. Transgenic expression of a Δ12-epoxygenase gene in Arabidopsis seeds inhibits accumulation of linoleic acid.Planta 212, 872–879 (2001). https://doi.org/10.1007/s004250000456

Download citation

• Issue date: April 2001
• DOI: https://doi.org/10.1007/s004250000456