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 (By similarity). Cofactor biosynthesis; tocopherol biosynthesis. Expressed in the roots, stems, leaves and spikelets. By salt and drougt stresses, H(2)O(2), salicylic acid (SA) and abscisic acid (ABA). Plants overexpressing VTE1 show increased tolerance to salt stress with reduced H(2)O(2) levels. Plants silencing VTE1 show enhanced sensitivity to salt stress with increased H(2)O(2) levels.