Metabolic engineering-induced transcriptome reprogramming enhance oil composition and content in oat (Avena sativa L.)

Authors: ZHOU, ZHOU - McGill University - Canada; KAUR, RAJVINDER - McGill University - Canada; DONOSO, THOMAS - McGill University - Canada; Ohm, Jae-Bom; KUSHWAHA, ASHUTOSH - McGill University - Canada; Gupta, Rajeev; LEFSRUD, MARK - McGill University - Canada; SINGH, JASWINDER - McGill University - Canada

Submitted to: Plant Biotechnology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2024
Publication Date: 9/25/2024
Citation: Zhou, Z., Kaur, R., Donoso, T., Ohm, J., Kushwaha, A., Gupta, R., Lefsrud, M., Singh, J. 2024. Metabolic engineering-induced transcriptome reprogramming enhance oil composition and content in oat (Avena sativa L.). Plant Biotechnology Journal. p. 1-14. https://doi.org/10.1111/pbi.14467.
DOI: https://doi.org/10.1111/pbi.14467

Interpretive Summary: Cultivated hexaploid oat (Avena sativa L.) is an emerging cereal crop with multiple uses in animal feeding and human food consumption. Its unique nutritional profile is attributed to a high-soluble dietary fiber content and valuable source of protein, lipid, vitamins, and minerals. The Avena species possess the highest amount of oil among the cereal grains, which negatively correlated with starch content in oat cultivars. Modification of oil composition through enrichment of monounsaturated fatty acids enhances oat’s nutritional value and make oat an ideal crop for human health. Using transgenic and metabolic engineering approaches, we made efforts to improve the fatty acid profile of cultivated oat. Compared to the wild-type, oleic acid content was increased up to 34.33% in oat grains and total oil content have been improved in oat leaves while maintaining homeostasis in oat plants in transgenic lines. These results underpin the application of genetic engineering to manipulate oil composition and contents in oat for human consumption and livestock feeding.

Technical Abstract: Oil composition and content remain important crop breeding traits to date. The Avena species possess the highest amount of oil among the cereal grains, which negatively correlated with starch content in oat cultivars. Modification of oil composition through enrichment of monounsaturated fatty acids enhances oat’s nutritional value and make oat an ideal crop for human health. However, optimization of oat oil traits through conventional breeding is challenging due to its quantitative nature and complexity of the oat genome. Using transgenic and metabolic engineering approaches, we made efforts to improve the fatty acid profile of cultivated oat. In this study, two constructs containing three genes involved in lipid biosynthesis pathway (AtWRI1, AtDGAT, and SiOLEOSIN) were transformed into oat cultivar ‘Park’ to enhance the oil composition and content. Transgene expression contributed to a global transcriptional reprogramming in oat grains and leaves. Endogenous DGAT1, WRI1, and OLEOSIN genes were up regulated while the genes involved in fatty acid biosynthesis expressed in opposite way between oat grains and leaves. Transcriptomic studies revealed differential gene expression mainly enriched in lipid metabolism. Compared to the wild-type, oleic acid content was increased up to 34.33% in oat grains and total oil content have been improved in oat leaves while maintaining homeostasis in oat plants. These results underpin the application of genetic engineering to manipulate oil composition and contents in oat for human consumption and livestock feeding.