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

Abstract

<i>Camelina sativa</i> (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 <i>CsFAD</i> gene family analysis and identified 24 <i>CsFAD</i> genes in Camelina, which were unevenly distributed on 14 of the 19 total chromosomes. Phylogenetic analysis showed that <i>CsFAD</i> includes four subfamilies, supported by the conserved structures and motifs of <i>CsFAD</i> genes. In addition, we investigated the expression patterns of the <i>FAD</i> family in the different tissues of Camelina. We found that <i>CsFAD</i> family genes were all expressed in the stem, and <i>CsFAD2-2</i> was highly expressed in the early stage of seed development. Moreover, during low temperature (4 °C) stress, we identified that the expression level of <i>CsFAD2-2</i> 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 <i>CsFAD2-2</i> through the phylogenetic analysis of the <i>CsFAD</i> gene family and further determined the fatty acid content to find that <i>CsFAD2-2</i> is involved in fatty acid synthesis in Camelina.