Expression patterns and functional analysis of the short neuropeptide F and NPF receptor genes in Rhopalosiphum padi

Abstract

The short neuropeptide F (sNPF) and NPF receptor (NPFR) genes play important roles in many physiological processes. However, information on the survival-related functions of sNPF and NPFR under different stress conditions is lacking in aphids. In this study, we cloned sNPF and NPFR, and investigated the expression levels of these genes in different developmental stages, wing morphs, and stress conditions of the bird cherryoat aphid (Rhopalosiphum padi L.), an important agricultural pest. The sNPF and NPFR transcript levels varied among developmental stages, and their expression levels in alate females were significantly higher than those in apterous females. In addition, starvation resulted in significantly increased sNPF expression, which then recovered after refeeding. Heat stress and insecticides significantly affected transcription of both genes. sNPF and NPFR knockdown in R. padi using RNA interference revealed optimal interference efficiency at 48 h post-injection. sNPF knockdown significantly decreased adult longevity, 15-d fecundity, and food intake. Additionally, mortality under starvation, insecticides, and heat stress conditions was significantly higher after injection with double-stranded sNPF in R. padi. NPFR knockdown significantly affected food intake and starvation resistance in R. padi. These results strongly indicate that sNPF plays vital roles in food intake, longevity, and reproduction in R. padi, and it can significantly affect the pest's response to stress conditions.

Identification of the Short Neuropeptide F and Short Neuropeptide F Receptor Genes and Their Roles of Food Intake in Dendroctonus armandi

“…Therefore, sNPF and sNPFR silencing not only suppresses their expression levels but also leads to an increase of mortality. These results were in consonance with previous studies in R. padi, wherein injection with dssNPF led to a high mortality of this species when undergoing prolonged starvation [ 13 ].…”

“…with previous studies in R. padi, wherein injection with dssNPF led to a high mortality of this species when undergoing prolonged starvation [13].…”

“…A similar result was observed in B. dorsalis ; differential transcription profiles of sNPF and sNPFR were found in the different developmental stages [ 10 ]. In addition, the expression levels of these genes were also assessed in different life stages of R. padi [ 13 ]. In this study, sNPF and sNPFR showed high transcription levels in larvae and adults, which could be because they had sensitive responses to host volatiles [ 21 ].…”

“…In D. melanogaster, overexpression of sNPFs regulated body size and promoted food intake [ 12 ]. Additionally, silencing the sNPF of R. padi significantly decreased food uptake by weighing wheat leaves [ 13 ]. However, injection of either of the two sNPF isoforms strongly decreased food intake and silencing sNPF significantly stimulated food intake in S. gregaria [ 20 , 45 ].…”

“…In the bird cherry-oat aphid, Rhopalosiphum padi , starvation caused an increase in sNPF and sNPFR expression, whereas subsequent refeeding caused a tendency toward downregulation of these genes. sNPF knockdown also notably decreased adults’ food intake [ 13 ]. Moreover, when sNPF and sNPFR expression levels were observed in the honey bee, Apis mellifera , they were found to be higher in foragers that engage in food-searching behavior compared to nurses that provide brood care [ 14 ].…”