Odorant degrading carboxylesterases regulate larva foraging and adult
mating in Grapholita molesta (Busck)
Abstract
Insect antennal carboxylesterases (CXEs) play key roles in the process
of ester odor degradation. In this study, 23 candidate CXEs were
identified by transcriptome analysis of Grapholita molesta. The GmolCXE1
and GmolCXE5 were highly expressed in the antennae of adults and
significantly up-regulated in the antennae of male moths after exposure
with odors from female moths. GmolCXE7, 10, 13, 14 and 20-22 were
abundantly expressed in the larval heads. The relative expression of
GmolCXE13, 14 and 21 were significantly up-regulated after stimulation
with odors from ripe fuji apples and crown pears. RNA interference
assays demonstrated that the GmolCXE1, 5 and GmolCXE14, 21 may involve
in regulating the adults’ mating and larval foraging respectively. Our
study suggested that GmolCXE1 and GmolCXE5 could degrade the sex
pheromone component (Z/E)-8-dodecenyl acetate to its product
(Z/E)-8-dodecenol with evidence from EAG responses and GC-MS analysis.
GmolCXE14, 21 could degrade odorant volatiles (Ethyl butanoate/ ethyl
hexanoate) of ripe crown pears by GC-MS analysis. These GmolCXEs
mediated foraging and mating would be potential and effective molecular
targets to develop behavioral antagonists against larvae and adults of
G. molesta.