Updated project metadata. Typically, when fully developed leaves of Arabidopsis thaliana are exposed to an increase in light intensity, they are able to increase their photosynthetic capacity in a process known as dynamic acclimation. Fully developed leaves of Arabidopsis thaliana were exposed to a fourfold increase in light intensity for 7 days to induce high light acclimation. This treatment was subjected to wild-type and a non-acclimating mutant lacking the gpt2 gene. The proteomic responses of the leaves were investigated using label-free mass spectrometry. A large reorganisation of the proteome was shown, with increases in the abundance of proteins of photosynthesis and carbon metabolism. Subtle differences were seen between the WT and gpt2 mutant: in the mutant, an increased stress response was seen, and some differences in the responses of metabolism. Proteomic responses generally correlated with physiological responses.