Abstract: 【Aim】 PI3K signaling pathway plays important roles in many organisms involving in carbohydrate and lipid metabolism, cell and tissue growth, life span, etc. This study aims to study the function of phosphatidylinositol 3-kinase in the rice brown planthopper, Nilaparvata lugens. 【Methods】 The full-length cDNA of NlPIK3R1 gene was cloned by rapid-amplification of cDNA ends (RACE) according to its gene sequence information available in N. lugens transcriptome, and this gene encodes the p85α subunit of PI3K (PI3K p85α), with the GenBank accession number of KP635379. Then the real-time quantitative PCR and RNAi by feeding dsNlPIK3R1 to N. lugens adults were conducted to explore the expression pattern and the function of NlPIK3R1, respectively. 【Results】 The real-time quantitative PCR results showed that the NlPIK3R1 gene was slightly expressed in nymphs and male adults of N. lugens, but strongly expressed in gravid female adults. RNAi results showed that the expression of NlPIK3R1 was inhibited in the two dsNlPIK3R1 treatment groups (fed with 0.1 and 0.5 μg/μL dsNlPIK3R1, respectively), especially in the high concentration treatment group. Feeding of dsNlPIK3R1 led to the death of N. lugens adults. The survival rate of N. lugens adults in the high concentration treatment group significantly declined by 37.5% at 7 d after treatment, and showed significant differences (P<0.01) from those in the blank control group (87%) and the dsGFP group (76.67%). RNAi also resulted in a reduced eclosion rate and lighter body weight. 【Conclusion】 The results suggest that the NlPIK3R1 gene is very important for the survival and growth of N. lugens, and may serve as a potential target for controlling the brown planthopper.

Key words: Nilaparvata lugens, phosphatidylinositol 3-kinase, p85α, NlPIK3R1, RNA interference