AUTHOR=Zhu Haowen , Zheng Sui , Xu Jinming , Wu Qing , Song Qisheng , Ge Linquan 

TITLE=The Amino Acid-Mediated TOR Pathway Regulates Reproductive Potential and Population Growth in Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae)

JOURNAL=Frontiers in Physiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.617237

DOI=10.3389/fphys.2020.617237

ISSN=1664-042X

ABSTRACT=<p>The predatory mirid bug, <italic>Cyrtorhinus lividipennis</italic> Reuter, feeds on brown planthopper (BPH) eggs that are deposited on rice and gramineous plants surrounding rice fields. The development and reproduction of <italic>C. lividipennis</italic> are inhibited by feeding on BPH eggs from gramineous species, and the underlining regulatory mechanism for this phenomenon is unclear. In the present study, HPLC-MS/MS analysis revealed that the concentrations of six amino acids (AAs:Ala, Arg, Ser, Lys, Thr, and Pro) were significantly higher in rice than in five gramineous species. When <italic>C. lividipennis</italic> fed on gramineous plants with BPH eggs, expression of several genes in the target of rapamycin (TOR) pathway (<italic>Rheb</italic>, <italic>TOR</italic>, and <italic>S6K</italic>) were significantly lower than that in the insects fed on rice plants with BPH eggs. Treatment of <italic>C. lividipennis</italic> females with rapamycin, dsRheb, dsTOR, or dsS6K caused a decrease in <italic>Rheb</italic>, <italic>TOR</italic>, and <italic>S6K</italic> expression, and these effects were partially rescued by the juvenile hormone (JH) analog, methoprene. Dietary dsTOR treatment significantly influenced a number of physiological parameters and resulted in impaired predatory capacity, fecundity, and population growth. This study indicates that these six AAs play an important role in the mediated-TOR pathway, which in turn regulates vitellogenin (Vg) synthesis, reproduction, and population growth in <italic>C. lividipennis</italic>.</p>