Antennae-abundant expression of candidate cytochrome P450 genes associated with odorant degradation in the asian citrus psyllid, Diaphorina citri

Abstract

The Asian citrus psyllid, Diaphorina citri, is a notorious pest that is an efficient vector for Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus huanglongbing (HLB). The olfactory system of insects is crucial for foraging and mating behavior. Antennae-abundant odorant degrading enzymes (ODEs), including cytochrome P450 (CYPs), are important in degrading redundant odorant molecules to recover the insect olfactory. In this study, to isolate the antennal CYP genes of D. citri, we generated four transcriptomes from female/male antennae and body through deep sequencing of RNA libraries. Seven DcCYP genes preferentially expressed in antennae were first identified by comparing the antennal and body transcriptomes. Phylogenetic analysis grouped four DcCYPs (DcCYP6a13, DcCYP6j1, DcCYP6k1, and DcCYP6a2) into the CYP3 class, whereas DcCYP4d2, DcCYP4c62, and DcCYP4d8 were clustered in the CYP4 clade. qRT-PCR analyses across developmental stages and tissues showed they were antennae-abundant in both genders and constantly expressed from the first instar nymph to the adult. The results presented here highlight the isolation and expression of CYP genes in D. citri antennae, providing valuable insights into their putative role in odorant degradation.

Antennae-enriched expression of candidate odorant degrading enzyme genes in the turnip aphid, Lipaphis erysimi

“…In this study, a total of seven antennae enriched LeCYP genes were identified. Our number of antennal CYP genes in L. erysimi is comparable to those found in other insect species, such as seven antennae-abundant CYPs were documented in D. citri (Kuang et al, 2022), as well as four CYPs (CYP4L4, CYP4S4, CYP9A13, and CYP4G20) of Mamestra brassicae and four CYPs (CYP6DE1, CYP6DJ1, CYP6BW1, and CYP6BW3) of D. ponderosae have been found to be highly expressed in the antennae (Maïbèche-Coisne et al, 2002;Maïbèche-Coisne et al, 2005;Chiu et al, 2019a;Chiu et al, 2019b;Chiu et al, 2019c). Insect P450 genes are commonly divided into four clades, which include CYP2, CYP3, CYP4, and the mitochondrial CYP.…”

“…The dataset submitted for phylogenetic analysis comprised the candidate CXE, CYP, GST, and UGT genes of L. erysimi in this study, their homologs from Acyrthosiphon pisum ( Ramsey et al, 2010 ), Aphis craccivora ( Yang et al, 2021 ), Aphis gossypii ( Pan et al, 2018 ), Myzus persicae ( Pan et al, 2019 ), Nilaparvata lugens ( Vontas et al, 2002 ; Zhou et al, 2013 ), Diaphorina citri ( Yu and Killiny, 2018 ; Tian et al, 2019 ; Wu et al, 2020 ; Kuang et al, 2022 ), Anopheles gambiae ( Ding et al, 2003 ), and Bombyx mori ( Yu et al, 2008 ); in addition to some well-identified ODE genes, including the studied antennal CXEs ( Ishida and Leal, 2005 ; 2008 ; Durand et al, 2010 ; Durand et al, 2011 ; He et al, 2015 ; Wei et al, 2021 ), CYPs ( Keeling et al, 2013 ; Chiu et al, 2019a ), GSTs ( Rogers et al, 1999 ; Li et al, 2018 ; Liu et al, 2021 ; Xia et al, 2022 ), and UGTs ( Wang et al, 1999 ; Bozzolan et al, 2014 ). The protein sequences were first aligned using CLUSTAL_X version 1.83.…”

Candidate odorant‐binding protein and chemosensory protein genes in the turnip aphidLipaphis erysimi

“…The sequencing data was filtered to obtain clean reads with SOAPnuke (v1.5.2) by removing low‐quality reads (i.e., low‐quality base ratio >20%) and reads with adaptor sequences and/or unknown nucleotides (>5%). Transcriptome de novo assembly was conducted as previously described (Kuang et al, 2022). The unigenes were annotated using BLAST search against public databases including Nr, Nt, Swiss‐Prot, KEGG, KOG, Pfam, and GO, with a cut‐off E ‐value of 10 −5 .…”

“…The sequencing data was filtered to obtain clean reads with SOAPnuke (v1.5.2) by removing low-quality reads (i.e., low-quality base ratio >20%) and reads with adaptor sequences and/or unknown nucleotides (>5%). Transcriptome de novo assembly was conducted as previously described (Kuang et al, 2022).…”