• Citer

A subset of chemosensory genes differs between two populations of a specialized leaf beetle after host plant shift

par Wang, Ding;Pentzold, Stefan;Kunert, Maritta;Groth, Marco;Brandt, Wolfgang;Pasteels, Jacques ;Boland, Wilhelm;Burse, Antje
Référence International Journal of Business Innovation and Research, 17, 3, page (8055-8075)
Publication Publié, 2018

Article révisé par les pairs

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Due to its fundamental role in shaping host selection behavior, we have analyzed thechemosensory repertoire of Chrysomela lapponica. This specialized leaf beetleevolved distinct populations which shifted from the ancestral host plant, willow (Salixsp., Salicaceae), to birch (Betula rotundifolia, Betulaceae). We identified 114 chemosensory candidate genes in adult C. lapponica: 41 olfactory receptors (ORs), eightgustatory receptors, 17 ionotropic receptors, four sensory neuron membrane proteins, 32 odorant binding proteins (OBPs), and 12 chemosensory proteins (CSP) byRNA-seq. Differential expression analyses in the antennae revealed significant upregulation of one minus-C OBP (ClapOBP27) and one CSP (ClapCSP12) in the willowfeeders. In contrast, one OR (ClapOR17), four minus-C OBPs (ClapOBP02, 07, 13, 20),and one plus-C OBP (ClapOBP32) were significantly upregulated in birch feeders.The differential expression pattern in the legs was more complex. To narrow downputative ligands acting as cues for host discrimination, the relative abundanceand diversity of volatiles of the two host plant species were analyzed. In additionto salicylaldehyde (willow-specific), both plant species differed mainly in theiremission rate of terpenoids such as (E,E)-a-farnesene (high in willow) or4,8-dimethylnona-1,3,7-triene (high in birch). Qualitatively, the volatiles were similarbetween willow and birch leaves constituting an "olfactory bridge" for the beetles.Subsequent structural modeling of the three most differentially expressed OBPs anddocking studies using 22 host volatiles indicated that ligands bind with varying affinity. We suggest that the evolution of particularly minus-C OBPs and ORs in C. lapponica facilitated its host plant shift via chemosensation of the phytochemicals frombirch as novel host plant.