The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a widespread
and destructive pest of cruciferous crops. New strategies for controlling it are needed
because it is rapidly developing resistance to conventional pesticides. In insects,
transcription factors (TFs) including broad-complex (Br-C) are thought to be useful
for insecticide development because they are able to regulate the transcription of
functional genes involved in responses to external stimuli including insecticides.
In the present study, we cloned and sequenced the open reading frames (ORFs) of three
BTB-ZF encoding genes from the diamondback moth deposited in the National Center for
Biotechnology Information (NCBI) database under accessions MG753773, MG288674, and
MG753772. The lengths of these ORFs were 1,680, 1,428, and 1,647 bp, respectively.
The phylogenetic analysis based on the predicted amino acid sequences of ZF domains
showed that MG753773 and MG288674 belonged to Z2/Z3 and Z7 of Br-C while MG753772
belonged to Ttk types. In the agreement, the highest expression level of MG753773
occurred during the prepupal stage, MG288674 and MG753772 were expressed during all
stages and peaked in the adult and egg stages, respectively. RNA interference silencing
of MG753773 in the late third instar larvae significantly decreased survival and pupation
of the insects. With precocene II, transcription of MG753773 increased (4x) in the
fourth instar larva 24 hr later; 48 hr later the rate of prepupation and pupation
was significantly higher. These findings will contribute to the development of new
regulators of the growth and development for diamondback moth control.