Calcium-dependent NADPH oxidase that generates superoxide. Involved in the massive phase II oxidative burst induced by pathogen infection. Inhibited by diphenylene iodinium (DPI). Monomer and homodimer. By fungal elicitor, arachidonic acid and salicylic acid. Phosphorylation at Ser-82 and Ser-97 is required for full activity of RBOHB. Not phosphorylated at Ser-89. Phosphorylation at Ser-82 is induced by fungal elicitor treatment. K252a and staurosporine, two protein kinase inhibitors, completely block the RBOHB induction by fungal elicitor. Belongs to the RBOH (TC 5.B.1.3) family.