The invention relates to biotechnology and provides novel recombinant DNA molecules and engineered proteins for conferring tolerance to protoporphyrinogen oxidase-inhibitor herbicides. The invention also provides herbicide tolerant transgenic plants, seeds, cells, and plant parts containing the recombinant DNA molecules, as well as methods of using the same.

The present invention relates to the use of a protoporphyrinogen oxidase. A method for controlling weeds comprises applying a herbicide containing an effective dose of a PPO inhibitor to a field in which at least one transgenic plant is present, wherein the transgenic plant comprises, in the genome thereof, a polynucleotide sequence encoding protoporphyrinogen oxidase, and the transgenic plant has reduced plant damage and/or has an increased plant yield compared with other plants that do not have a polynucleotide sequence encoding protoporphyrinogen oxidase. The protoporphyrinogen oxidase PPO1-PPO14 of the present invention has a high tolerance to a PPO inhibitor herbicide. In addition, the plants containing the polynucleotide sequence encoding protoporphyrinogen oxidase have a strong tolerance to the PPO-inhibitor herbicide, and show high-resistance tolerance to almost all of 4-fold field concentration of oxyfluorfen, saflufenacil and flumioxazin and 2-fold field concentration of sulfentrazone. Therefore, the protoporphyrinogen oxidase has broad application prospects in plants.

The invention refers to plants comprising wild-type or mutated Alopecurus PPO enzymes, and methods of obtaining such plants. The present invention further refers to 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.

The present invention provides a method for controlling undesired vegetation at a plant cultivation site, the method comprising the steps of providing a plant that comprises at least one nucleic acid comprising a nucleotide sequence encoding a wild-type or a mutated protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a PPO-inhibiting herbicide by applying to said site an effective amount of said herbicide. The invention also provides plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a PPO-inhibiting herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a benzoxazinone-derivative herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a PPO-inhibiting herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a PPO-inhibiting herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a PPO-inhibiting herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.

The present invention refers to a method for controlling undesired vegetation 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 protoporphyrinogen oxidase (PPO) which is resistant or tolerant to a benzoxazinone-derivative herbicide by applying to said site an effective amount of said herbicide. The invention further refers to plants comprising wild-type or mutated PPO enzymes, and methods of obtaining such plants.