Provided are plants comprising wild type or mutated Alopecurus PPO enzymes and methods of obtaining such plants. Also provided is a method for controlling weeds at a plant cultivation site the method comprising the steps of providing at said site a plant that comprises at least one nucleic acid comprising a nucleotide sequence encoding a wild type or a mutated Alopecurus PPO enzyme which is resistant or tolerant to a PPO inhibiting herbicide by applying to said site an effective amount of said herbicide.
