Proteins produced in response to salt induction in several strains. Lanes: 1, PCC 7120; 2, 3, and 4, salt-treated PCC 7120, AB5, and SA6, respectively. ∗, proteins of ca. 40 and 67 kDa induced in PCC 7120 in response to salinization and whose production in salt-treated strain AB5 is blocked by the orrA mutation in SA6.