Plasmanylethanolamine desaturase involved in plasmalogen biogenesis in the membrane, required for light-induced carotenogenesis (PubMed:12519205, PubMed:18310035, PubMed:22267513, PubMed:31604315). Plasmalogens are glycerophospholipids with a hydrocarbon chain linked by a vinyl ether bond at the glycerol sn-1 position, and are involved in antioxidative and signaling mechanisms, most precisely in sensing photooxidative stress through singlet oxygen (PubMed:31604315). Participates in the light-dependent inactivation of the antisigma factor CarR (PubMed:12519205, PubMed:18310035). Mediates signaling by singlet oxygen, generated via photoexcited protoporphyrin IX (PubMed:22267513). 1-(1,2-saturated alkyl)-2-acyl-sn-glycero-3-phosphoethanolamine + 2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 = 1-O-(1Z-alkenyl)-2-acyl-sn-glycero-3-phosphoethanolamine + 2 Fe(III)-[cytochrome b5] + 2 H2O 1-O-(13-methyltetradecyl)-2-(13-methyltetradecanoyl)-sn-glycero-3-phosphoethanolamine + 2 Fe(II)-[cytochrome b5] + 2 H(+) + O2 = 1-O-(1Z-13-methyltetradecenyl)-2-(13-methyltetradecanoyl)-sn-glycero-3-phosphoethanolamine + 2 Fe(III)-[cytochrome b5] + 2 H2O Interacts with CarR. Histidine box-1 and -2 together with other histidine residues are essential for catalytic activity. Deletion prevents the activation of the light inducible promoters of carQ, crtI and carB. Belongs to the fatty acid desaturase CarF family.