Abstract
Simple SummaryThe brown planthopper, Nilaparvata lugens, a plant phloem-sucking Hemipteran insect, has become the most destructive pest for rice—the major food source for half of the world’s population. Nilaparvata lugens possess robust fecundity, enabling population densities to increase quickly in a favorable environment. Nilaparvata lugens has also been used as a model system for ecological studies and for developing effective pest management. To better understand the regulation mechanisms of insect reproduction and to provide insights to improve pest control, we searched N. lugens genome and transcriptome databases and identified an NADPH oxidase 5 gene, which was specifically expressed in ovaries of female adults and freshly laid eggs in rice leaf sheaths. Although homologous NADPH oxidase 5 genes have been identified in many insect species, their reproductive functions remain unknown. In this work, our findings initially reveal a functional role of the NADPH oxidase 5 gene in molting and oviposition in N. lugens. This novel finding improves our understanding of the reproductive strategies in insects and provides a potential molecular target for effective pest control of the rice planthopper.The brown planthopper Nilaparvata lugens is a typical monophagous insect herbivore that feeds exclusively on rice sap. This insect pest causes serious damage to rice crops throughout East Asian countries. Chemical control remains the first choice for managing N. lugens populations; however, the use of insecticides has given rise to planthopper resurgence and additional environmental risks. Nilaparvata lugens is a model insect of Hemiptera because its whole genome sequence has been elucidated and is susceptible to RNA interference. In this study, our findings revealed that a superoxide-generating gene, NADPH oxidase 5 (Nox5), is essential for molting and oviposition in a Hemipteran insect Nilaparvata lugens. Knockdown of Nox5 transcript levels by RNA interference in 2nd–5th-instar nymphs results in significantly lethal deficits in the molting transitions from nymph–nymph and nymph–adult. Nox5 knockdown leads to a reduction of hydrogen peroxide in female ovaries and failure of oviposition from the insect ovipositor into the rice leaf sheath. Here, we provide in vivo evidence demonstrating that Nox5 is a key enzyme for regulating molting and oviposition in this insect species.
Highlights
The brown planthopper Nilaparvata lugens (Hemiptera: Delphacidae), a plant phloem-suckingHemipteran insect, has emerged as a major pest affecting rice crops in tropical Asia and southernInsects 2020, 11, 642; doi:10.3390/insects11090642 www.mdpi.com/journal/insectsChina [1]
Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays an essential role in generating superoxide in mature follicles for Drosophila oviposition [4]
We found that knockdown of NADPH oxidase 5 (Nox5) did not affect the release of the mature oocytes from ovarioles to the lateral oviduct, but inhibited the laying of the oocytes from the ovipositor into rice leaf sheaths, which led to the failure of oviposition
Summary
The brown planthopper Nilaparvata lugens (Hemiptera: Delphacidae), a plant phloem-suckingHemipteran insect, has emerged as a major pest affecting rice crops in tropical Asia and southernInsects 2020, 11, 642; doi:10.3390/insects11090642 www.mdpi.com/journal/insectsChina [1]. The brown planthopper Nilaparvata lugens (Hemiptera: Delphacidae), a plant phloem-sucking. Nilaparvata lugens possess robust fecundity, enabling population densities to increase quickly in a favorable environment. Once an eruption of this insect pest occurs, little can be done to control the planthoppers [1]. Fecundity largely depends on oogenesis and oviposition [2]. Oviposition is an important phase for the reproductive success of insects. It has been recognized that some proteins/enzymes play vital roles in insect oviposition through regulating a variety of biological processes. In Drosophila melanogaster, matrix metalloproteinase 2 is required for the release of mature oocytes from follicles [3]. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays an essential role in generating superoxide in mature follicles for Drosophila oviposition [4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
