Preliminary Study on the Resistance of RNAi-mediated BtPMaT1 Transgenic Tobacco to Bemisia tabaci

Purpose To construct tobacco plants with a silenced BtPMaT1 gene in Bemisia tabaci, evaluating their resistances to B. tabaci.

Methods B. tabaci were collected from 11 main tobacco fields in Yunnan, and the BtPMaT1 gene, known for detoxifying phenolic sugars, was cloned. An RNAi vector expressing the BtPMaT1 gene in tobacco was constructed and introduced into tobacco plants, and the resistance was evaluated.

Results 1) The BtPMaT1 gene sequences from B. tabaci collected from 11 tobacco fields in Yunnan exhibited differences, and distantly related to the tobacco NtPMaT1 gene sequence. 2) Sequence alignment revealed an RNAi target fragment specific to B. tabaci from all 11 fields. The RNAi vector was successfully constructed and introduced into tobacco plants, and there was no significant difference in agronomic traits between RNAi tobacco and control tobacco. 3) After inoculation with B. tabaci for 14 to 35 days, the number of insects on transgenic tobacco plants carrying BtPMaT1 gene RNAi vector was extremely significantly lower than on control tobacco plants (P<0.01).

Conclusion The tobacco plants constructed with the silenced BtPMaT1 gene in the B. tabaci exhibit good resistance.