Cleaves a variety of carotenoids symmetrically at both the 9-10 and 9'-10' double bonds. Active on beta,beta-carotene, lutein, zeaxanthin, all-trans-violaxanthin, 9-cis-violaxanthin and 9'-cis-neoxanthin. With most substrates, the carotenoid is symmetrically cleaved. Probably not involved in abscisic acid biosynthesis. all-trans-zeaxanthin + 2 O2 = 2 (3R)-hydroxy-beta-ionone + 4,9-dimethyldodeca-2,4,6,8,10-pentaenedial Binds 1 Fe(2+) ion per subunit. Homodimer. On the exterior surface of the plastids. High expression in flowers and siliques. Also detected in stems, leaves and roots. By drought stress. Plants do not show any phenotype alteration, but leads to higher seed carotenoid content. Belongs to the carotenoid oxygenase family. Truncated N-terminus.