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.

Soil salinization poses a major environmental threat to global agriculture, affecting approximately 20% of cultivated land and 50% of irrigated land worldwide. Developing salt–alkali tolerant plant varieties represents a sustainable strategy for utilizing these marginal lands. Phosphatidylinositol-specific phospholipase C (PI-PLC) is a key enzyme in the phosphoinositide signaling system and has been implicated in plant stress responses; however, its function under salt–alkali stress remains poorly understood. In this study, the function of AtPLC1 in salt–alkali tolerance was investigated, and only the atplc1 mutant exhibited a pronounced stress-sensitive phenotype, with AtPLC1 being predominantly expressed in roots and leaves, with peak expression at 6 h of treatment. Compared with wild-type, atplc1 mutants displayed significantly reduced seedling survival, retarded root growth, decreased biomass, water content, chlorophyll, and soluble sugar contents, yet accumulated higher levels of Na⁺, malondialdehyde, H₂O₂, and superoxide anions under salt–alkali stress. Notably, atplc1 mutants showed increased stomatal conductance and decreased leaf surface temperature, as detected by thermal imaging, indicating impaired water regulation. Collectively, our findings demonstrate that AtPLC1 positively regulates salt–alkali tolerance and provides a candidate gene for molecular breeding of stress-resistant crops.