Glufosinate-ammonium-tolerant, Insect-resistant cotton

The modified cotton (Gossypium hirsutum) is a result of a stacked event produced through the cross-breeding of the modified cotton varieties 3006-210-23, 281-24-236 and COT102. The modified cotton expresses the Bacillus thuringiensis insecticidal proteins Cry1Ac, Cry1F, and Vegetative insecticidal protein 3A (VIP3A) to confer resistance to lepidopteran pests, such as cotton bollworm, pink bollworm, tobacco budworm, beet armyworm, and soybean looper. The VIP3A was included to manage resistance to the crystal proteins. The modified plants also express Streptomyces viridochromogenes phosphinothricin N-acetyltransferase to confer tolerance to glufosinate-ammonium herbicides. An Escherichia coli hygromycin B phosphotransferase gene is also present and was utilized as a selection marker during the transformation of the parental line COT102.

3006-210-23: Line 'Germain's Acala GC510'
281-24-236: Line 'Germain's Acala GC510'
COT102: Cultivar: Coker 312

pMYC3006;  pAGM281; pCOT-1

Genetic elements introduced by pMYC3006:
Transcription of the Streptomyces viridochromogenes phosphinothricin N-acetyltransferase (pat) gene starts from the Agrobacterium tumefaciens 4ocs∆Mas2' promoter and the Bacillus thuringiensis cry1Ac (crystal 1Ac) from the Zea mays ubiquitin gene promoter. Transcription of both transcripts terminates at the bidirectional A. tumefaciens ORF25 poly(A) terminator sequence. Coding sequences of cry1Ac and pat were altered for optimal expression in plant cells.

Note:
- Southern blot analysis confirmed a single integration of the transgenic DNA, including one intact copy of the cry1Ac, one intact copy of the pat, and single, intact copies of each of the regulatory elements.
- Analysis also indicated that there was no integration of segments from the erythromycin resistance gene (part of the vector backbone).

Genetic elements introduced by pAGM281:
Transcription of S. viridochromogenes pat starts from the A. tumefaciens 4ocs∆Mas2' promoter and Bacillus thuringiensis var. aizawai cry1F from the Z. mays ubiquitin gene promoter. Transcription of both transcripts terminates at the bidirectional A. tumefaciens ORF25 poly(A) terminator sequence.

Coding sequences of cry1F and pat were altered for optimal expression in plant cells. The Cry1F protoxin is a chimeric, full-length δ-endotoxin comprised of the core toxin of Cry1F from B. thuringiensis var. aizawai strain PS81I and nontoxic portions of Cry1Ca3 and Cry1Ab1 proteins. Together, the portions of Cry1Ca3 and Cry1Ab1 that comprise the chimeric C-terminal domain are approximately those removed by alkaline proteases during the formation of the active Cry1F core toxin.

Genetic elements introduced by pCOT-1:
Transcription of the Escherichia coli hygromycin B phosphotransferase is under control of the Arabidopsis thaliana ubiquitin 3 promoter and the A. tumefaciens nopaline synthase (nos) terminator. The gene cassette is present in the counterclockwise orientation. The hygromycin B phosphotransferase gene is used for selection of transformants.

The expression of B. thuringiensis vegetative insecticidal protein 3A is under control of the A. thaliana actin 2 promoter and the A. tumefaciens nos terminator. Coding sequence of the Vip3A gene was altered for optimal expression in plant cells. 

Note:
- Southern blot analysis of the genomic DNA from COT102 revealed the incorporation of single intact copies of the vip3A(a) and aph4 genes, along with intact copies of their respective regulatory sequences. Results of these analyses also demonstrated that none of the vector backbone sequences, including the streptomycin adenyltransferase (aadA) gene, were incorporated into the genomic DNA.
- Southern blot analysis confirmed the protein expression of VIP3A.

For more information, kindly refer to the parental LMO records.