Find in Library

Phytochemical toxins are considered a defense measure for herbivore invasion. To adapt this defensive strategy, herbivores use glutathione S-transferases (GSTs) as an important detoxification enzyme to cope with toxic compounds, but the underlying molecular basis for <i>GST</i> genes in this process remains unclear. Here, we investigated the basis of how <i>GST</i> genes in brown planthopper (BPH, <i>Nilaparvata lugens</i> (Stål)) participated in the detoxification of gramine by RNA interference. For BPH, the LC₂₅ and LC₅₀ concentrations of gramine were 7.11 and 14.99 μg/mL at 72 h after feeding, respectively. The transcriptions of seven of eight <i>GST</i> genes in BPH were induced by a low concentration of gramine, and GST activity was activated. Although interferences of seven genes reduced BPH tolerance to gramine, only the expression of <i>NlGST1-1</i>, <i>NlGSTD2</i>, and <i>NlGSTE1</i> was positively correlated with GST activities, and silencing of these three genes inhibited GST activities in BPH. Our findings reveal that two new key genes, <i>NlGSTD2</i> and <i>NlGSTE1</i>, play an essential role in the detoxification of gramine such as <i>NlGST1-1</i> does in BPH, which not only provides the molecular evidence for the coevolution theory, but also provides new insight into the development of an environmentally friendly strategy for herbivore population management.