Engineering an oilseed crop for hyper-accumulation of carotenoids in the seeds without using a traditional marker gene

Multi-omics-driven advances in the understanding of triacylglycerol biosynthesis in oil seeds

Vegetable oils are rich sources of polyunsaturated fatty acids and energy as well as valuable sources of human food, animal feed, and bioenergy. Triacylglycerols, which are comprised of three fatty acids attached to a glycerol backbone, are the main component of vegetable oils. Here, we review the development and application of multiple-level omics in major oilseeds and emphasize the progress in the analysis of the biological roles of key genes underlying seed oil content and quality in major oilseeds. Finally, we discuss future research directions in functional genomics research based on current omics and oil metabolic engineering strategies that aim to enhance seed oil content and quality, and specific fatty acids components according to either human health needs or industrial requirements.

Engineered Cleistogamy in Camelina sativa for bioconfinement

Camelina sativa is a self-pollinating and facultative outcrossing oilseed crop. Genetic engineering has been used to improve camelina yield potential for altered fatty acid composition, modified protein profiles, improved seed and oil yield, and enhanced drought resistance. The deployment of transgenic camelina in the field posits high risks related to the introgression of transgenes into non-transgenic camelina and wild relatives. Thus, effective bioconfinement strategies need to be developed to prevent pollen-mediated gene flow (PMGF) from transgenic camelina. In the present study, we overexpressed the cleistogamy (i.e. floral petal non-openness)-inducing PpJAZ1 gene from peach in transgenic camelina. Transgenic camelina overexpressing PpJAZ1 showed three levels of cleistogamy, affected pollen germination rates after anthesis but not during anthesis, and caused a minor silicle abortion only on the main branches. We also conducted field trials to examine the effects of the overexpressed PpJAZ1 on PMGF in the field, and found that the overexpressed PpJAZ1 dramatically inhibited PMGF from transgenic camelina to non-transgenic camelina under the field conditions. Thus, the engineered cleistogamy using the overexpressed PpJAZ1 is a highly effective bioconfinement strategy to limit PMGF from transgenic camelina, and could be used for bioconfinement in other dicot species.

Genome-Wide Identification and Expression Analysis of Fatty Acid Desaturase (FAD) Genes in Camelina sativa (L.) Crantz

Camelina sativa (L.) Crantz is an indispensable oilseed crop, and its seeds contain many unsaturated fatty acids. FAD (fatty acid desaturase) regulates the synthesis of unsaturated fatty acids. In this research, we performed CsFAD gene family analysis and identified 24 CsFAD genes in Camelina, which were unevenly distributed on 14 of the 19 total chromosomes. Phylogenetic analysis showed that CsFAD includes four subfamilies, supported by the conserved structures and motifs of CsFAD genes. In addition, we investigated the expression patterns of the FAD family in the different tissues of Camelina. We found that CsFAD family genes were all expressed in the stem, and CsFAD2-2 was highly expressed in the early stage of seed development. Moreover, during low temperature (4 °C) stress, we identified that the expression level of CsFAD2-2 significantly changed. By observing the transient expression of CsFAD2-2 in Arabidopsis protoplasts, we found that CsFAD2-2 was located on the nucleus. Through the detection and analysis of fatty acids, we prove that CsFAD2-2 is involved in the synthesis of linolenic acid (C18:3). In conclusion, we identified CsFAD2-2 through the phylogenetic analysis of the CsFAD gene family and further determined the fatty acid content to find that CsFAD2-2 is involved in fatty acid synthesis in Camelina.