• Plant Biotechnology Reports
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• v.4 no.4
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• pp.293-301
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• 2010

The feasibility of two strategies for transgene pyramiding using Agrobacterium-mediated transformation was investigated to develop a transgenic potato (Solanum tuberosum L. cv. Iwa) with resistance to potato tuber moth (PTM) (Phthorimaea operculella (Zeller)). In the first approach, cry1Ac9 and cry9Aa2 genes were introduced simultaneously using a kanamycin (nptII) selectable marker gene. The second approach involved the sequential introduction (re-transformation) of a cry1Ac9 gene, using a hygromycin resistance (hpt) selectable marker gene, into an existing line transgenic for a cry9Aa2 gene and a kanamycin resistance (nptII) selectable marker gene. Multiplex polymerase chain reaction (PCR) confirmed the presence of the specific selectable marker gene and both cry genes in all regenerated lines. The relative steady-state level of the cry gene transcripts in leaves was quantified in all regenerated lines by real-time PCR analysis. Re-transformation proved to be a flexible approach to effectively pyramid genes for PTM resistance in potato, since it allowed the second gene to be added to a line that was previously identified as having a high level of resistance. Larval growth of PTM was significantly inhibited on excised greenhouse-grown leaves in all transgenic lines, although no lines expressing both cry genes exhibited any greater resistance to PTM larvae over that previously observed for the individual genes. It is anticipated that these lines will permit more durable resistance by delaying the opportunities for PTM adaptation to the individual cry genes.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.535-537
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• 2023

We report the draft genome sequence of Bacillus thuringiensis serovar aizawai AS23, an insecticidal strain targeting lepidopteran pests, which was isolated from the rhizosphere of Korean melon (Cucumis melo L.). The genome of strain AS23 comprising 6,846,584 bp with a G + C content of 34.83% was assembled to 11 contigs obtained using hybrid assembly. Additionally, we mined the genome for pesticidal genes, identifying several insecticidal genes, including Cry1Aa3, Cry1Ca9, Cry1Da2, Cry1Ia44, Cry2Ab41, Cry9Ea9, Spp1Aa1, and Vip3Aa86.