Nicotine‐mediated dopamine regulates short neuropeptide F to inhibit brown planthopper feeding behavior in tobacco‐rice rotation cropping

Abstract

BACKGROUND The tobacco‐rice rotation cropping (TRRC) is an ecologically friendly system that can both alleviate soil nicotine pollution and decrease the brown planthopper (BPH, Nilaparvata lugens Stål) fitness on rice. However, few studies on this green and effective rotational cropping system have been reported. In particular, the underlying mechanisms of TRRC on the significant reduction of field pest population at the molecular level is still unknown. RESULTS Field investigation showed that BPH population decreased significantly in TRRC than in rice‐rice successive cropping (RRSC) field. In addition, the short neuropeptide F (NlsNPF) and its receptor NlA7 of BPH had half‐times lower levels in the TRRC field. Behavioral bioassay indicated a 1.93‐fold increase in the number of salivary flanges of the dsNlsNPF group, while BPH fitness parameters, such as honeydew, weight gain, and mortality decreased significantly. Dopamine (DA) content in BPH decreased by ~11.1% under the influence of nicotine, and its presence increased the expression levels of NlsNPF and NlA7. Exogenous DA application eliminated the inhibitory effects of nicotine on BPH feeding and restored the fitness levels of its parameters. Independent application of either a mixture of dsNlsNPF with a nanocarrier or nicotine to the normal rice field revealed that the latter could produce better effects in combination with dsRNA. CONCLUSION These findings confirmed that DA regulated NlsNPF to inhibit the BPH feeding behavior in TRRC. The results not only provided novel findings on the mechanism of pest‐host interactions, but also presented new method for integrated pest management. © 2023 Society of Chemical Industry.

2-Ethylhexyl Diphenyl Phosphate Causes Obesity in Zebrafish by Stimulating Overeating via Inhibition of Dopamine Receptor D2

“…For example, delayed or reduced reward signaling in the brain caused by high-sugar foods was evidenced to stimulate appetite in flies . Yuan et al reported that the use of exogenous DA restored the nicotine-induced DA reduction and eliminated the inhibitory effect related to feeding in brown planthoppers . Steele et al revealed that similar to drug addiction, obesity patients showed a decrease in the effective DRD2 level in the DA system, but it increased in those who underwent gastric bypass surgery .…”

“…55 Yuan et al reported that the use of exogenous DA restored the nicotine-induced DA reduction and eliminated the inhibitory effect related to feeding in brown planthoppers. 56 Steele et al revealed that similar to drug addiction, obesity patients showed a decrease in the effective DRD2 level in the DA system, but it increased in those who underwent gastric bypass surgery. 57 These results suggest that overeating is induced by an impaired DA signaling pathway via a compensatory mechanism.…”