SCIENTISTS RESTRICT BT GENE EXPRESSION IN INSECT BITING SITES
Most of the Bt cotton varieties express Bt genes in all whole-plant tissues. Scientists from Ankara University in Turkey and partners developed a triple-gene construct for the confined expression of GNA, cry1Ac, and cp4 epsps genes to targeted insect biting sites instead of whole-plant tissues. They cloned it at downstream of a wound-inducible promoter isolated from Asparagus officinalis (AoPR1). Furthermore, to widen the range of resistance, GNA was driven by the 35S promoter to target the sap-sucking insects such as aphids which impose large losses in cotton production. To select the transformants in selection medium and for glyphosate tolerance, cp4 epsps gene was included with GNA and cry1Ac genes.
Results showed that the introduction of cry1Ac and GNA to cotton plant conferred resistance to Spodoptera littoralis (African cotton leafworm) and Aphis gossypii Glover (cotton aphid). The results indicate that the restriction of cry1Ac protein to insect biting sites along with a plant lectin attributes significantly contribute to insect pest management strategies.
Read the research article in Plant Biotechnology Reports.