The Relationship Between Two Genes Of TRPV Channel Substypes Of Nilaparvata Lugens(Hemiptera: Delphacidae)and Feeding Behavior

Brown planhopper(BPH)Nilaparvata lugens(St?l)is one of the most destructive insect with piercing-sucking mouthpart on rice plants.Pymetrozine is one of the frequently used insecticides in the field for BPHs' control,which kills BPHs by inhibiting their feeding in phloem.Recent study showed the target of pymetrozine in insects is TRPV channel.This present study demonstrates the close relationship between TRPV channel and feeding behavior of BPHs by decreasing the expression of Iav and Nan gene with RNA interference.The results showed as follow:1.After cloning the Iav and Nan gene of BPH,the sequence alignment with Acythosiphon pisum and Drosophia melanogaster suggested that the cloned gene sequences are BPHs' Iav and Nan,in which the identity of BPH's gene of Iav with Acythosiphon pisum and Drosophia melanogaster separately are 83% and 85%,while the identity of BPH's gene of Nan separately are 85% and 83%.2.After RNAi,the survival rates of the 3rd day and the 4th day are lower than control but other survival rates of BPHs have no different significance between the control and the ones interfered with dsRNA of Iav,while the survival rate of BPHs after RNA interfered with ds Nan for 7 days is 26.67%,which is lower than the survival rate of control.The BPHs didn't show different phenotypes after RNAi of Iav and Nan.3.Using EPG equipment to record the adults' feeding behavior after RNAi,it demonstrated that the feeding behavior blocked in phloem after the RNAi of Iav and Nan.Compared to the control,the number of probe and the duriation of pathway incresed while the duriation of feeding in phloem and number of probe phloem decreased after the RNAi of Iav.After the RNAi of Nan,the BPHs' feeding duriation in xylem and the duriation of unprobe extended,yet duriation of feeding in phloem and number of probe phloem decreased.4.We recorded BPHs' feeding on sucrose solution with EPG equipment,which suggests there is no significant difference between the control and treatment.So the RNAi of Iav and Nan has no effect on BPHs' capacity of active ingestion.Accordingly,TRPV channel has a close relationship with BPHs' feeding behavior and the lower expression of TRPV channels can restrict the BPHs' feeding on rice plants,while the restriction works without by inhibiting the capacity of BPHs' active ingestion.It needs futher study to demonstrate whether the TRPV channels engaged in the insect-plant interaction.This study demonstrated that TRPV channels has a close relationship with BPHs' feeding behavior which provides fundamental basis for the study of BPHs' feeding behavior,the target of pymetrozine in insects and the control of BPHs.