title: Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase gene are resistant to diphenyl ether herbicide oxyfluorfen.
abstract: Protoporphyrinogen oxidase (Protox), the penultimate step enzyme of the branch point for the biosynthetic pathway of Chl and hemes, is the target site of action of diphenyl ether (DPE) herbicides. However, Bacillus subtilis Protox is known to be resistant to the herbicides. In order to develop the herbicide-resistant plants, the transgenic rice plants were generated via expression of B. subtilis Protox gene under ubiquitin promoter targeted to the cytoplasm or to the plastid using Agrobacterium-mediated gene transformation. The integration and expression of the transgene were investigated at T0 generation by DNA and RNA blots. Most transgenic rice plants revealed one copy transgene insertion into the rice genome, but some with 3 copies. The expression levels of B. subtilis Protox mRNA appeared to correlate with the copy number. Furthermore, the plastidal transgenic lines exhibited much higher expression of the Protox mRNA than the cytoplasmic transgenic lines. The transgenic plants expressing the B. subtilis Protox gene at T0 generation were found to be resistant to oxyfluorfen when judged by cellular damage with respect to cellular leakage, Chl loss, and lipid peroxidation. The transgenic rice plants targeted to the plastid exhibited higher resistance to the herbicide than the transgenic plants targeted to the cytoplasm. In addition, possible resistance mechanisms in the transgenic plants to DPE herbicides are discussed.
authors.affiliation: Biotechnology Research Institute, Chonnam National University, Kwangju, Korea.
authors.forename: H J
authors.initials: HJ
authors.lastname: Lee
authors.forename: S B
authors.initials: SB
authors.lastname: Lee
authors.forename: J S
authors.initials: JS
authors.lastname: Chung
authors.forename: S U
authors.initials: SU
authors.lastname: Han
authors.forename: O
authors.initials: O
authors.lastname: Han
authors.forename: J O
authors.initials: JO
authors.lastname: Guh
authors.forename: J S
authors.initials: JS
authors.lastname: Jeon
authors.forename: G
authors.initials: G
authors.lastname: An
authors.forename: K
authors.initials: K
authors.lastname: Back
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D004351:Drug Resistance / Q000235:genetics; D005822:Genetic Vectors; D055768:Halogenated Diphenyl Ethers; D006540:Herbicides / Q000494:pharmacology*; D007700:Kinetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010647:Phenyl Ethers / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D050768:Protoporphyrinogen Oxidase; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D017931:DNA Primers; D055768:Halogenated Diphenyl Ethers; D006540:Herbicides; D010647:Phenyl Ethers; D011994:Recombinant Proteins; C016027:oxyfluorofen; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050768:Protoporphyrinogen Oxidase