Genome‐wide identification, characterization and functional analysis of the chitianse and chitinase‐like gene family in Diaphorina citri

Abstract

BACKGROUND Insect chitinases play vital roles in postembryonic development, especially during the molting process, and are potential targets for the RNA interference (RNAi)‐based insecticidal strategy. Systematic functional analyses of chitinase genes have already been conducted on numerous insect pests, but similar analyses have not been carried out on Diaphorina citri. RESULTS Eleven chitinase/chitinase‐like genes and one endo‐β‐N‐acetylglucosaminidase (ENGase) gene were identified in the Diaphorina citri genome using various bioinformatic tools. Transcriptomes of the integument and midgut from fifth‐instar nymphs and freshly‐emerged adults of Diaphorina citri were generated and sequenced. Potential functions of 12 chitinase/chitinase‐like genes were examined during nymph–adult transitions. Four chitinase genes, including DcCht5, DcCht7, DcCht10‐1 and DcCht10‐2, were mainly expressed in the integument of fifth‐instar nymphs. These four genes were also up‐regulated significantly under 20‐hydroxyecdysone (20E) treatments. RNAi‐mediated knockdown of these four genes suggests that they are essential for nymph–adult transition. CONCLUSION Our results demonstrated essential roles of the chitinase/chitinase‐like genes during the nymph–adult transition in Diaphorina citri, which are potentially useful targets for controlling the Diaphorina citri pest. © 2022 Society of Chemical Industry

Manual curation and phylogenetic analysis of chitinase family genes in the Asian citrus psyllid, Diaphorina citri

“…Knockdown of the other chitinase genes will probably have only subtle effects, possibly because of redundancy, and understanding the function of these genes will require more extensive analysis. While this manuscript was under review, Wu et al [33] published an independent characterization of D. citri chitinase genes with very similar results. They performed RNAi with each of the genes and, as we predicted, found that only DcCht5, DcCht7, DcCht10-1 and DcCht10-2 affected molting.…”

“…While this manuscript was under review, Wu et al. [ 33 ] published an independent characterization of D. citri chitinase genes with very similar results. They performed RNAi with each of the genes and, as we predicted, found that only DcCht5 , DcCht7 , DcCht10-1 and DcCht10-2 affected molting.…”

Identification of chitinase genes and roles in the larval–pupal transition of Leptinotarsa decemlineata

“…An analysis of chitinase counts in various insects revealed an interesting finding (Table S4). Hemimetabolous insects, such as Diaphorina citri , 20 N. lugens , 24 Bemisia tabaci , 14 and Acyrthosiphon pisum 45 possess fewer chitinase‐like genes. This can be attributed to their reduced need for enzymes and energy during integument reconstruction.…”

“…Insect chitinases, specifically those belonging to groups I (Cht5), II (Cht10), and III (Cht7), play crucial roles in the degradation of old exoskeletons 19,20,22 . Previous studies have demonstrated the involvement of Cht5 in the pupal‐to‐adult eclosion process.…”

“…To classify insect chitinases, ten distinct groups have been identified based on the analysis of amino acid sequence similarity and phylogenetic analysis of the catalytic structural domains. Additionally, a new group h has been discovered in Lepidoptera 19–21 …”