Purification and Functional Characterization of a Soluble Trehalase in Lissorhoptrus oryzophilus (Coleoptera: Curculionidae)

Abstract

Trehalase is the only enzyme known for the irreversible splitting of trehalose and plays a major role in insect growth and development. In this report, we describe a basic study of the trehalase gene fragment encoding a soluble trehalase from Lissorhoptrus oryzophilus (LoTRE1). Sequence alignment and phylogenetic analysis suggested that LoTRE1 was similar to some known insect trehalases and belongs to the Coleoptera trehalase group. Additionally, LoTRE1 was expressed mainly in the fat body. Purified protein was obtained using heterologous expression of LoTRE1 in Escherichia coli, and the recombinant protein exhibited the ability to decompose trehalose. Enzyme–substrate docking indicated the potential involvement of other residues in the catalytic activity, in addition to Asp 333. Moreover, feeding of adults on LoTRE1 dsRNA silenced the transcription of LoTRE1 and thereby reduced the activity of trehalase and increased the trehalose content; it also led to a 12% death rate. This study reveals essential molecular features of trehalase and offers insights into the structural aspects of this enzyme, which might be related to its function. Taken together, the findings demonstrate that LoTRE1 is indispensable for adults of this pest and provide a new target for the control of L. oryzophilus.

Response of Odorant Receptors with Phenylacetaldehyde and the Effects on the Behavior of the Rice Water Weevil (Lissorhoptrus oryzophilus)

“…The introduction efficiency was affected by the methods, species, age, and other factors. , Compared with other methods, orally delivered RNAi has great advantages, which avoids unknown injuries caused by injection. It is also a suitable method for RWW, as the interference efficiency of RWW trehalase gene LoTRE1 reduced the expression levels to 40% at 24 h and 56% at 48 h in our previous study . The antennal response of LoryOR20-silenced RWWs showed an extremely significant difference from that of the wild-type RWWs, which not only showed that in RWW the feeding method for RNAi ORs was effective but also indicated that LoryOR20 was the main and even the only PAA receptor.…”

“…It is also a suitable method for RWW, as the interference efficiency of RWW trehalase gene LoTRE1 reduced the expression levels to 40% at 24 h and 56% at 48 h in our previous study. 49 The antennal response of LoryOR20silenced RWWs showed an extremely significant difference from that of the wild-type RWWs, which not only showed that in RWW the feeding method for RNAi ORs was effective but also indicated that LoryOR20 was the main and even the only PAA receptor. As RNAi-based pesticides have exhibited a good prospect in crop pests' suppression, dsRNA-LoryOR20 may be used as an effective component to control RWWs by interfering with host localization.…”

Knockdown of Two Trehalase Genes by RNA Interference Is Lethal to the White-Backed Planthopper Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

“…RNAi can induce targeted gene silencing, and it has successfully been used for evaluating functional genes in various insects [ 55 , 56 , 57 , 58 , 59 , 60 ]. Previous studies have shown that in S. exigua , the knockdown of SeTre1 and SeTre2 increases the mortality and abnormality rates and significantly decreases CHS expression levels and chitin content [ 44 ].…”

Trehalose-6-Phosphate Synthase Contributes to Rapid Cold Hardening in the Invasive Insect Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) by Regulating Trehalose Metabolism

“…For the total RNA extraction and cDNA synthesis, we followed the same method as described in a previous study [43]. Total RNA was extracted from the whole bodies of three L. oryzophilus adults using RNAiso Plus (Takara, Dalian, China), following the manufacturer's instructions.…”