Pancreatic triglyceride lipase is involved in the virulence of the brown planthopper to rice plants

The brown planthopper(BPH),Nilaparvata lugens,an important rice insect pest,can enhance its virulence to BPH-resistant rice within as short a span as several generations.Here,we cloned a pancreatic triglyceride lipase(PTL)gene(NlPTL)in N.lugens,and found that its mRNA level was higher in the high virulence population(fed on variety Rathu Heenati,P-RH)than in the low virulence population(fed on variety Taichung Native 1,P-TN1).Knocking down NlPTL caused BPH individuals to spend more time in non-penetration and the pathway phases and less time feeding on the phloem of rice plants;these changes consequently decreased food intake,lipid content,survival rate,and fecundity in the insects.These findings reveal for the first time that PTL in BPH is involved in its virulence to rice plants.