The invention relates to methods of increasing the photosynthesis rate of a plant cell and/or the production of biomass in a plant, as well as to plant cells and plants with increased photosynthesis rate/production of biomass. The present invention also relates to a phosphatase of the light-harvesting complex of photosystem II, to nucleic acids coding for such phosphatase, and to mutants of such nucleic acids. Moreover, the present invention relates to plant cells and plants, wherein the activity of said phosphatase is inhibited in particular the present invention relates to plant cells and plants comprising the mutant nucleic acids.
