Alpha-dioxygenase that catalyzes the primary oxygenation step of a variety of 14-20 carbon fatty acids, containing up to three unsaturated bonds, into their corresponding 2R-hydroperoxides (PubMed:9724698). Involved in the production of oxylipins that function in cell signaling, wound healing, and protection from infection (PubMed:9724698). a 1,2-saturated fatty acid + O2 = a (2R)-2-hydroperoxy fatty acid (9Z,12Z,15Z)-octadecatrienoate + O2 = (R)-2-hydroperoxy-(9Z,12Z,15Z)-octadecatrienoate (9Z,12Z)-octadecadienoate + O2 = (2R,9Z,12Z)-2-hydroperoxyoctadecadienoate Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit. Binds 1 calcium ion per subunit. Induced by the elicitor harpin (HrpN) from Erwinia amylovora and infection with E.amylovora (PubMed:9724698). Induced by infection with the bacterial pathogens Pseudomonas syringae pv syringae and Pseudomonas syringae pv tabaci (PubMed:9724698). Induced by salicylate (SA), wounding, jasmonate (JA), paraquat and 3-amino-1,2,4-triazole (3AT) (PubMed:9724698). Belongs to the peroxidase family.