Strong co-suppression impedes an increase in polyunsaturated fatty acids in seeds overexpressing FAD2

From National Research Council Canada

Download	View supplementary information: Strong co-suppression impedes an increase in polyunsaturated fatty acids in seeds overexpressing FAD2 (PDF, 223 KiB)
DOI	Resolve DOI: https://doi.org/10.1093/jxb/ery378
Author	Search for: Du, Chang; Search for: Chen, Yangyang; Search for: Wang, Kai; Search for: Yang, Zheng; Search for: Zhao, Cuizhu; Search for: Jia, Qingli; Search for: Taylor, David C.¹; Search for: Zhang, Meng
Affiliation	National Research Council of Canada. Aquatic and Crop Resource Development
Format	Text, Article
Subject	Arabidopsis; Brassica carinata; Camelina sativa; co-suppression; FAD2; Linum usitatissimum; polyunsaturated fatty acids (PUFAs); RDR6
Abstract	Fatty acid desaturase2 (FAD2) catalyses the conversion of oleic acid to linoleic acid and is the main determinant of the levels of essential poly-unsaturated fatty acids (PUFAs) in seed oils. The very limited number of successful examples of overexpression of FAD2 over the last two decades and a shortage of reports on co-suppression make it uncertain whether FAD2 can increase PUFAs effectively across a broad range of oil crops. In this study, strong co-suppression was observed in about 80% of over 100 transgenic lines when FAD2 was overexpressed in three oilseed crops, namely flax (Linum usitatissimum), carinata (Brassica carinata), and camelina (Camelina sativa), as well as in the model plant Arabidopsis. Further analyses of Arabidopsis transgenic lines revealed both endogenous and transgenic FAD2 gene-silencing. Thus, the commonality and potency of FAD2 co-suppression seemingly imposes an obstacle to engineering oilseed PUFA enhancement by direct FAD2 overexpression. AtFAD2, driven by the 35S promoter, also caused co-suppression in Arabidopsis roots. The FAD2 co-suppression was unstable and PUFA phenotypes of T₄ lines were similar to the wild-type, further indicating that high PUFA content cannot be achieved by screening advanced generations. However, we demonstrate that the obstacle of FAD2 co-suppression can be overcome in the Arabidopsis rdr6 mutant, which is impaired in post-transcriptional gene-silencing, and that lines with high PUFA content are stable through four generations.
Publication date	2018-11-27
Publisher	Oxford University Press Society for Experimental Biology
In	Journal of Experimental Botany 70, no. 3 (27 November 2018): 985–994.
Language	English
Peer reviewed	Yes
Export citation	Export as RIS
Report a correction	Report a correction (opens in a new tab)
Record identifier	de1c08ee-d29e-46b5-99bc-a57a1e378fed
Record created	2020-12-02
Record modified	2021-02-23

Date modified:: 2024-07-21