Open AccessTransgenic cotton expressing Cry10Aa toxin confers high resistance to the cotton boll weevil
Author(s) -
Ribeiro Thuanne Pires,
Arraes Fabricio Barbosa Monteiro,
LourençoTessutti Isabela Tristan,
Silva Marilia Santos,
LiseideSá Maria Eugênia,
Lucena Wagner Alexandre,
Macedo Leonardo Lima Pepino,
Lima Janaiscimento,
Santos Amorim Regina Maria,
Artico Sinara,
AlvesFerreira Márcio,
Mattar Silva Maria Cristina,
GrossideSa Maria Fatima
Publication year - 2017
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12694
Subject(s) - biology , bacillus thuringiensis , genetically modified crops , transgene , toxin , transformation (genetics) , genetically modified organism , pest analysis , bioassay , cry1ac , gene , horticulture , botany , microbiology and biotechnology , genetics , bacteria
Summary 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 uce A1.7 was introduced into a Brazilian cotton cultivar by biolistic transformation. Quantitative PCR (qPCR) assays revealed high transcription levels of cry10Aa in both T 0 GM cotton leaf and flower bud tissues. Southern blot and qPCR‐based 2 −ΔΔCt analyses revealed that T 0 GM 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 T 0 GM cotton plants, ranging from approximately 3.0 to 14.0 μg g −1 fresh tissue. CBW susceptibility bioassays, performed by feeding adults and larvae with T 0 GM 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 T 1 generation as the Cry10Aa toxin expression levels remained high in both tissues, ranging from 4.05 to 19.57 μg g −1 fresh 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.