Abstract: The present invention relates to an isolated nucleic acid comprising a nucleotide sequence encoding a mutated HPPD protein, wherein said mutated HPPD protein has HPPD activity, wherein in said mutated HPPD protein at least one amino acid has been replaced so that the resulting amino acid sequence comprises at least one amino acid selected from certain amino acids at specific positions important for conferring an increased HPPD inhibitor tolerance. The present invention also relates to proteins encoded by the nucleic acid of the invention, to chimeric genes, plant cells comprising the nucleic acid of the invention operably linked to a plant-expressible promoter and optionally a transcription termination and polyadenylation region, plants essentially consisting of the plant cells of the invention and methods of obtaining transgenic plants.