title: Development of protoporphyrinogen oxidase as an efficient selection marker for Agrobacterium tumefaciens-mediated transformation of maize.
abstract: In this article, we report the isolation of plant protoporphyrinogen oxidase (PPO) genes and the isolation of herbicide-tolerant mutants. Subsequently, an Arabidopsis double mutant (Y426M + S305L) was used to develop a selectable marker system for Agrobacterium tumefaciens-mediated transformation of maize (Zea mays) and to obtain multiple events tolerant to the PPO family of herbicides. Maize transformants were produced via butafenacil selection using a flexible light regime to increase selection pressure. Butafenacil selection per se did not change transgene copy number distribution relative to other selectable marker systems, but the most tolerant events identified in the greenhouse were more likely to contain multiple copies of the introduced mutant PPO gene. To date, more than 2,500 independent transgenic maize events have been produced using butafenacil selection. The high frequency of A. tumefaciens-mediated transformation via PPO selection enabled us to obtain single-copy transgenic maize lines tolerant to field levels of butafenacil.
authors.affiliation: Syngenta Biotechnology, Inc., P.O. Box 12257, 3054 Cornwallis Road, Research Triangle Park, NC 27709-2257, USA. Xianggan.Li@syngenta.com
authors.forename: Xianggan
authors.initials: X
authors.lastname: Li
authors.forename: Sandy L
authors.initials: SL
authors.lastname: Volrath
authors.forename: David B G
authors.initials: DB
authors.lastname: Nicholl
authors.forename: Charles E
authors.initials: CE
authors.lastname: Chilcott
authors.forename: Marie A
authors.initials: MA
authors.lastname: Johnson
authors.forename: Eric R
authors.initials: ER
authors.lastname: Ward
authors.forename: Marcus D
authors.initials: MD
authors.lastname: Law
mesh_terms: D016960:Agrobacterium tumefaciens / Q000201:enzymology*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D005816:Genetic Complementation Test; D008027:Light; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics; D050768:Protoporphyrinogen Oxidase; D012641:Selection, Genetic; D014170:Transformation, Genetic / Q000528:radiation effects; D003313:Zea mays / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050768:Protoporphyrinogen Oxidase