title: Evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects.
abstract: The high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. The genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid Acyrthosiphon pisum: sucrase 1 (SUC1), a sucrase in glycoside hydrolase family 13 (GH13), and aquaporin 1 (AQP1), a member of the Drosophila integral protein (DRIP) family of aquaporins. Here, we describe molecular analysis of GH13 and AQP genes in phloem-feeding representatives of the four phloem-feeding groups: aphids (Myzus persicae), coccids (Planococcus citri), psyllids (Diaphorina citri, Bactericera cockerelli) and whiteflies (Bemisia tabaci MEAM1 and MED). A single candidate GH13-SUC gene and DRIP-AQP gene were identified in the genome/transcriptome of most insects tested by the criteria of sequence motif and gene expression in the gut. Exceptionally, the psyllid Ba. cockerelli transcriptome included a gut-expressed Pyrocoelia rufa integral protein (PRIP)-AQP, but has no DRIP-AQP transcripts, suggesting that PRIP-AQP is recruited for osmoregulatory function in this insect. This study indicates that phylogenetically related SUC and AQP genes may generally mediate osmoregulatory functions in these diverse phloem-feeding insects, and provides candidate genes for empirical validation and development as targets for osmotic disruption of pest species.
authors.affiliation: Department of Entomology, Cornell University, Ithaca, NY, USA.
authors.forename: X
authors.initials: X
authors.lastname: Jing
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, UK.
authors.forename: T A
authors.initials: TA
authors.lastname: White
authors.affiliation: Department of Entomology, Cornell University, Ithaca, NY, USA.
authors.forename: J
authors.initials: J
authors.lastname: Luan
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA.
authors.forename: C
authors.initials: C
authors.lastname: Jiao
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Fei
authors.affiliation: Department of Entomology, Cornell University, Ithaca, NY, USA.|Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Douglas
mesh_terms: D000818:Animals; D020346:Aquaporins / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D017344:Genes, Insect; D005959:Glucosidases / Q000235:genetics*; D006430:Hemiptera / Q000235:genetics*; D064587:Osmoregulation / Q000235:genetics*
chemical_list: D020346:Aquaporins; D005959:Glucosidases
keywords: aphid; aquaporin; osmoregulation; psyllid; sucrase; whitefly; α-glucohydrolase