Phosphorylates the second messenger diacylglycerol (DAG) to generate phosphatidic acid (PA), another important signaling molecule. PA is required for plant development and responses to abiotic stress and pathogen attack. May be involved in the accumulation of PA during cold stress (By similarity). a 1,2-diacyl-sn-glycerol + ATP = a 1,2-diacyl-sn-glycero-3-phosphate + ADP + H(+) Monomer. Expressed in roots, shoots, and leaves. By volatile C6-aldehydes ((E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenol), and allo-ocimene. Treatment with (E)-2-hexenal, (Z)-3-hexenal and allo-ocimene increases plant resistance against the necrotrophic fungal pathogen Botrytis cinerea. Belongs to the eukaryotic diacylglycerol kinase family.