The Creation And Molecular Analysis Of Transgenic Cotton Harboring Exogenous Insect-resistant Genes

Cotton is closely related to people's daily life,which is one of major economic crops in China.Recently,with the widespread use of Bacillus thuringiensis?Bt?insect-resistant cotton,the production of insect-resistant cotton has been upgraded to a new level.However,it has been reported that more than ten insects have developed resistance to Bt cotton since 1997.With the greatly reduced of chemical pesticides,the secondary pests such as Lygocoris lucor?m,Bemisia tabaci and aphid,which have emerged as the primary pest at present.The sap-sucking feeding has increased the difficulty of prevention and pest control.Therefore,it is of great significance to introduce the potential exogenous genes for the development of transgenic cotton with multiple insect-resistance.In this study,were selected four exogenous genes were selected as trans genes,namely: Cry51Aa2.834₁6,Cry51Aa2.834_CG,?E?-?-Farnesene,Tma12.Cry51Aa2.834₁6,Cry51Aa2.834_CG is cloned from Bacillus thuringiensis.Tma12 is cloned from an edible fern plant,which encodes a protein has an effect on whitefly.?E?-?-farnesene gene can synthesize sesquiterpene,which are derived from Matricaria recutita and can protect host plants by evading from aphids.In this experiment,69 transgenic positive plants were successfully obtained by Agrobacterium-mediated genetic transformation.After PCR and Southern blot analysis:7 single copy plants were obtained for Cry51Aa2.834₁6 gene;5 single T-DNA copy plants for Cry51Aa2.834_CG gene and 18 positive plants.For the?E?-?-Farnesene,we have 2 single-copy plants from 12 transgenic positive plants.For Tma12 gene,we obtained 6 single T-DNA copy plants from 12 transgenic positive plants.Four plants of Cry51Aa2.834₁6,five plants of Cry51Aa2.834_CG,four transgenic plants of?E?-?-Farnesene and five plants of Tma12 exhibit high transcription level revealed by qRT-PCR.For the insect bio assay,the results showed Cry51Aa2.834₁6,Cry51Aa2.834_CG,Tma12,?E?-?-Farnesene exhibiting significant toxic effects on the corresponding target insect pests.Cry51Aa2.834₁6,Cry51Aa2.834_CG,and Tma12 have no obvious effect to non-target insect speciesaphids.In summary,we created several transgenic cotton lines exhibiting the potential for the insect control,which provided newly theoretical basis as well as candidate plant materials for the cotton molecular breeding for insect-resistance.