Biotech Updates

Pyramiding Bt Genes for Increasing Insect Resistance of Cotton

August 6, 2014

To improve insect pest resistance of cotton, scientists at Huazhong Agricultural University in China used gene stacking strategy. First, they introduced Cry9C from Bacillus thuringiensis into cotton (cultivar Simian-3) through Agrobacterium-mediated transformation. The intergration and expression of the gene were confirmed by PCR and RT-PCR. The transgenic plants exhibited moderate toxicity to cotton bollworm (Heliothis armigera) but strong toxicity to cotton leafworm (Spodoptera litura) compared with the transgenic plants expressing Cry 1Ac. Then they pyramided Cry9C gene and Cry 2A or Cry 1Ac, respectively by sexual crossing.

Results showed that the expression of Cry9C protein in the progenies of the first generation had a similar level as the parent plants indicating the high heritability of Bt genes. Progenies from both Cry9CxCry 2A and Cry9CxCry 1Ac showed better resistance to cotton leafworm than their parents. Based on the results, successful incorporation of gene pyramiding technology can provide a new solution of developing multiple resistance management strategies.

Get a copy of the paper at http://link.springer.com/article/10.1007/s11738-014-1642-5.