title: Transgenic cotton expressing Cry10Aa toxin confers high resistance to the cotton boll weevil.
abstract: Genetically modified (GM) cotton plants that effectively control cotton boll weevil (CBW), which is the most destructive cotton insect pest in South America, are reported here for the first time. This work presents the successful development of a new GM cotton with high resistance to CBW conferred by Cry10Aa toxin, a protein encoded by entomopathogenic Bacillus thuringiensis (Bt) gene. The plant transformation vector harbouring cry10Aa gene driven by the cotton ubiquitination-related promoter uceA1.7 was introduced into a Brazilian cotton cultivar by biolistic transformation. Quantitative PCR (qPCR) assays revealed high transcription levels of cry10Aa in both T0GM cotton leaf and flower bud tissues. Southern blot and qPCR-based 2-ΔΔCtanalyses revealed that T0GM plants had either one or two transgene copies. Quantitative and qualitative analyses of Cry10Aa protein expression showed variable protein expression levels in both flower buds and leaves tissues of T0GM cotton plants, ranging from approximately 3.0 to 14.0 μg g-1fresh tissue. CBW susceptibility bioassays, performed by feeding adults and larvae with T0GM cotton leaves and flower buds, respectively, demonstrated a significant entomotoxic effect and a high level of CBW mortality (up to 100%). Molecular analysis revealed that transgene stability and entomotoxic effect to CBW were maintained in T1generation as the Cry10Aa toxin expression levels remained high in both tissues, ranging from 4.05 to 19.57 μg g-1fresh tissue, and the CBW mortality rate remained around 100%. In conclusion, these Cry10Aa GM cotton plants represent a great advance in the control of the devastating CBW insect pest and can substantially impact cotton agribusiness.
authors.affiliation: Brasilia Federal University (UnB), Brasília, DF, Brazil.|Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Thuanne Pires
authors.initials: TP
authors.lastname: Ribeiro
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.|Rio Grande do Sul Federal University, Porto Alegre, RS, Brazil.
authors.forename: Fabricio Barbosa Monteiro
authors.initials: FBM
authors.lastname: Arraes
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Isabela Tristan
authors.initials: IT
authors.lastname: Lourenço-Tessutti
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Marilia Santos
authors.initials: MS
authors.lastname: Silva
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.|Agricultural Research Company of Minas Gerais State, Uberaba, MG, Brazil.
authors.forename: Maria Eugênia
authors.initials: ME
authors.lastname: Lisei-de-Sá
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.|Embrapa Cotton, Campina Grande, PB, Brazil.
authors.forename: Wagner Alexandre
authors.initials: WA
authors.lastname: Lucena
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Leonardo Lima Pepino
authors.initials: LLP
authors.lastname: Macedo
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Janaina Nascimento
authors.initials: JN
authors.lastname: Lima
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Regina Maria
authors.initials: RM
authors.lastname: Santos Amorim
authors.affiliation: Rio de Janeiro Federal University, Rio de Janeiro, RJ, Brazil.
authors.forename: Sinara
authors.initials: S
authors.lastname: Artico
authors.affiliation: Rio de Janeiro Federal University, Rio de Janeiro, RJ, Brazil.
authors.forename: Márcio
authors.initials: M
authors.lastname: Alves-Ferreira
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Mattar Silva
authors.affiliation: Embrapa Genetic Resources and Biotechnology, Brasília, DF, Brazil.|Catholic University of Brasilia, Brasília, DF, Brazil.
authors.forename: Maria Fatima
authors.initials: MF
authors.lastname: Grossi-de-Sa
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism*; D003368:Gossypium / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology*; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism*; D057865:Plant Immunity / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D048889:Weevils / Q000472:pathogenicity*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: 
  Anthonomus grandis
  ; 
  Gossypium hirsutum
  ; Bt toxin; genetic transformation; insect pest; plant resistance