Functional characterization of three trehalase genes regulating the chitin metabolism pathway in rice brown planthopper using RNA interference

Abstract

RNA interference (RNAi) is an effective gene-silencing tool, and double stranded RNA (dsRNA) is considered a powerful strategy for gene function studies in insects. In the present study, we aimed to investigate the function of trehalase (TRE) genes (TRE 1-1, TRE 1-2, and TRE-2) isolated from the brown planthopper Nilaparvata lugens, a typical piercing-sucking insect in rice, and investigate their regulating roles in chitin synthesis by injecting larvae with dsRNA. The results showed that TRE1 and TRE2 had compensatory function, and the expression of each increased when the other was silenced. The total rate of insects with phenotypic deformities ranged from 19.83 to 24.36% after dsTRE injection, whereas the mortality rate ranged from 14.16 to 31.78%. The mRNA levels of genes involved in the chitin metabolism pathway in RNA-Seq and DGEP, namely hexokinase (HK), glucose-6-phosphate isomerase (G6PI) and chitinase (Cht), decreased significantly at 72 h after single dsTREs injection, whereas two transcripts of chitin synthase (CHS) genes decreased at 72 h after dsTRE1-1 and dsTREs injection. These results demonstrated that TRE silencing could affect the regulation of chitin biosynthesis and degradation, causing moulting deformities. Therefore, expression inhibitors of TREs might be effective tools for the control of planthoppers in rice.

Effect of long-term cold storage on trehalose metabolism of pre-wintering Harmonia axyridis adults and changes in morphological diversity before and after wintering

“…In black males, the expressions of TRE1-1, TRE1-2 and TRE1-3 were higher and increased TRE1 activity, while expressions of both TRE2 genes increased contributing to TRE2 activity (Figs 4 and 5D). These results are consistent with other research findings that TRE1 and TRE2 have different functions [14,23,71], and that these functions may be complementary, with the expression of one TRE gene increasing, while the expression of the other was inhibited [73]. Many insects undergo a cold-acclimatization process before winter, thereby increasing their cold tolerance and ability to maintain themselves under low temperature stress [74].…”

Knockdown of five trehalase genes using RNA interference regulates the gene expression of the chitin biosynthesis pathway in Tribolium castaneum

“…3e) have compensatory function at some extent when other TcTre was knockdown. The seeming cross silences similar with TPS genes function study also been found [63], while it is also reported that N. lugens soluble trehalases ( NlTre1 - 1 and NlTre1 - 2 ) and membrane-bound trehalase ( NlTre2 ) also have the compensatory function [64]. The good inhibited effects and stronger phenotype were found when two Tre1 and one Tre2 gene in N. lugens was knockdown simultaneously [64].…”

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

“…Our results showed that glycogen decreased 48 h after dsTPS, dsTRE, and validamycin injection (Figs. 4 and 6C), whereas trehalose content increased 48 and 72 h after dsTPSs, dsTRE1-1, and validamycin injection (Zhao et al 2016, Tang et al 2016, Yang et al 2017). Similarly, glycogen content increased 72 h after dsTRE1-1 and dsTRE2 were injected (Fig.…”

“…Our previous studies showed that RNAi inhibited the expression of trehalase ( TRE or Treh ) or TPS in the chitin synthesis pathway, leading to molting deformities in most tested N. lugens and to their death (Zhao et al 2016, Yang et al 2017). These results suggested that inhibiting the expression of TPS and TRE might also affect the metabolism and the utilization of carbohydrates.…”