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-ß-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.