Involved in the synthesis of both tocopherols and tocotrienols (vitamin E), which presumably protect photosynthetic complexes from oxidative stress. Catalyzes the conversion of 2-methyl-6-phytyl-1,4-hydroquinone and 2,3-dimethyl-5-phytyl-1,4-hydroquinone (DMPQ) to delta- and gamma-tocopherol respectively. Converts also 2,3-dimethyl-5-geranylgeranyl-1,4-hydroquinone (DMGQ) to gamma-tocotrienol. delta-tocopherol = 2-methyl-6-phytyl-1,4-benzene-1,4-diol gamma-tocopherol = 2,3-dimethyl-6-phytylbenzene-1,4-diol delta-tocotrienol = 6-geranylgeranyl-2-methylbenzene-1,4-diol gamma-tocotrienol = 6-geranylgeranyl-2,3-dimethylbenzene-1,4-diol Cofactor biosynthesis; tocopherol biosynthesis.