Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase gene are resistant to diphenyl ether herbicide oxyfluorfen

• Published in: Plant and cell physiology 2000-06, Vol.41 (6), p.743-749
• Main Authors: Lee, H.J. (Chonnam National Univ., Kwangju (Korea R.)), Lee, S.B, Chung, J.S, Han, S.U, Han, O, Guh, J.O, Jeon, J.S, An, G, Back, K
• Format: Article
• Language: English
• Subjects: Agrobacterium tumefaciens - genetics; Amino Acid Sequence; BACILLUS SUBTILIS; Bacillus subtilis - enzymology; Bacillus subtilis - genetics; Base Sequence; diphenyl ether; DNA Primers; Drug Resistance - genetics; GENE TRANSFER; Genetic Vectors; Halogenated Diphenyl Ethers; HERBICIDAS; HERBICIDE; Herbicide resistance; HERBICIDES; Herbicides - pharmacology; Key words: Diphenyl ether herbicides; Kinetics; Molecular Sequence Data; Oryza - drug effects; Oryza - genetics; Oryza - physiology; ORYZA SATIVA; OXIDOREDUCTASES; Oxidoreductases - genetics; Oxidoreductases - metabolism; Oxidoreductases Acting on CH-CH Group Donors; OXIDORREDUCTASAS; OXYDOREDUCTASE; Oxyfluorfen; Phenyl Ethers - pharmacology; Plant Leaves - drug effects; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants, Genetically Modified; Promoter Regions, Genetic; Protoporphyrinogen Oxidase; Protox gene; Recombinant Proteins - metabolism; RESISTANCE AUX PRODUITS CHIMIQUES; RESISTANCE TO CHEMICALS; RESISTENCIA A PRODUCTOS QUIMICOS; TRANSFERENCIA DE GENES; TRANSFERT DE GENE; TRANSGENIC PLANTS; Transgenic rice plants
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/41.6.743

Protoporphyrinogen oxidase (Protox), the penultimate step enzyme of the branch point for the biosynthetic pathway of Chi 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 To generation were found to be resistant to oxyfluorfen when judged by cellular damage with respect to cellular leakage, Chi 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.