Abstract: The present invention provides methods to confer resistance to protoporphyrinogen-inhibiting herbicides onto crop plants. Resistance is conferred by genetically engineering the plants to express cloned DNA encoding a protoporphyrinogen oxidase resistant to porphyric herbicides. If such resistant crop plants are cultivated, utilization of these herbicides on fields of these crop plants becomes feasible. This should allow for simpler and more effective weed management, and increase the value of these herbicides for agricultural use. Furthermore, the present invention provides plants, algae, plant cells, and algal cells which have been made resistant to protoporphyrinogen oxidase-inhibiting herbicides by the subject methods using a herbicide-resistant protoporphyrinogen oxidase gene that has been prepared by genetic engineering methods.

Abstract: Provided are methods for conferring resistance to porphyrin-accumulating type herbicides upon plant or algal cells using DNA fragments or biologically functional equivalents thereof isolated from Chlamydomonas reinhardtii, and herbicide-resistant plants or algae into which these DNA fragments or biologically functional equivalents thereof have been introduced and in which they are expressed.

Abstract: Provided are DNA fragments and biologically functional equivalents thereof that confer resistance to porphyrin-accumulating type herbicides upon plant and algal cells, plasmids containing these DNA fragments or biologically functional equivalents thereof, microorganisms containing these DNA fragments or biologically functional equivalents thereof, methods for conferring resistance to porphyrin-accumulating type herbicides upon plant or algal cells using these DNA fragments or biologically functional equivalents thereof, and herbicide-resistant plants or algae into which these DNA fragments or biologically functional equivalents thereof have been introduced and in which they are expressed.