Long-term high-light exposure does not impair growth while photosynthesis is affected in GlcT-complemented transformants. A, Chlorophyll a + b content of mutant plants exposed to high light (600 μmol m−2 s−1) for 4 d is reduced. B, PSII quantum efficiency is strongly decreased in DGD-deficient plants exposed to high light (600 μmol m−2 s−1) for 4 d. C, Growth at high light (3 weeks at 600 μmol m−2 s−1) of the wild type and DGD-deficient lines complemented with the GlcT gene. FW, Fresh weight; PAR, photosynthetic active radiation; WT, wild type.