scholarly journals Knockdown of TRPV Genes Affects the Locomotion and Feeding Behavior of Nilaparvata lugens (Hemiptera: Delphacidae)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jinghua Zhu ◽  
Xiaoqing Liu ◽  
Kunmiao Zhu ◽  
Hanyu Zhou ◽  
Liang Li ◽  
...  

Abstract The vanilloid-type transient receptor potential (TRPV) channel is reported to be the molecular target of the commercial insecticide pymetrozine, which specifically disrupts the feeding of plant sap-sucking insects. However, the functions of TRPV channels in plant sap-sucking insects have not been fully elucidated. In the present study, RNA interference was used to investigate the effects of the knockdown of TRPV genes (Nan and Iav) on the mortality, locomotion, and feeding behavior of an important plant-feeding insect pest in rice, the brown planthopper, Nilaparvata lugens. Injecting dsRNA of Nan and Iav into fourth-instar nymphs significantly knocked down the target genes. The injection of dsNan or dsIav did not affect any morphological phenotype (including leg extension) of N. lugens nymphs and adults. Knockdown of Nan or Iav resulted in significantly decreased climbing activity against top plants but did not influence the leg-griping strength of adults. Knockdown of Nan resulted in a significantly elevated mortality of N. lugens in the observation period of 7 d after injection, whereas no significant difference in survival rates 7 d after injection was found between dsIav-injected and dsGFP-injected insects. Electropenetrographic (EPG) recordings indicated that knockdown of Nan and Iav reduced the ingestion activity in the rice phloem tissues of N. lugens. Knockdown of Nan and Iav significantly reduced the amount of honeydew excreted by N. lugens. Our findings indicated a relationship between TRPV and N. lugens locomotion and feeding behavior, which may help to fully elucidate the functions of TRPV in insects.

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2044
Author(s):  
Xiubing Gao ◽  
Can Guo ◽  
Ming Li ◽  
Rongyu Li ◽  
Xiaomao Wu ◽  
...  

The brown planthopper (BPH), Nilaparvata lugens (Stål), is the most notorious rice insect pest. In order to repel BPH effectively while being environmentally friendly, a new film based on guar gum incorporated with citral (GC film) was formulated. A toxicity bioassay of citral and guar gum at different proportions (ratios of 3:1, 2:1, 1:1, 1:2, and 1:3 in w/w) of GC film-forming emulsion to BPH was performed with the rice stem dipping method. Results showed that the most effective ratio of citral to guar gum was 1:1 with the median lethal concentration (LC50) of 4.30 mg/mL, far below the LC50 of guar gum (GG)/citral individual (141.51 and 44.38 mg/mL, respectively). The mortality of BPH adults and nymphs in the third instar treated with different dilution multiples of GC film-forming emulsion ranged from 46.67% to 82.22% and from 37.78% to 71.11%, respectively. These indicated that GC film-forming emulsion had a direct toxicity on BPH, and the mixture of citral and GG had synergistic interactions. Subsequently, Fourier-transform infrared spectroscopy showed that the incorporation of guar gum with citral was successful and did not result in the formation of new chemical bonds. The GC film exhibited a darker color and rougher surface topography with larger apertures and deeper gullies (Ra = 1.42 nm, Rq = 2.05 nm, and Rmax = 25.40 nm) compared to the guar gum film (GG film) (Ra = 1.00 nm, Rq = 1.33 nm, and Rmax = 16.40 nm), as determined by transmission electron microscopy and atomic force microscopy. The GC film exhibited a 50.4% lower solubility in water (30.30% vs. 15.00%) and 71.3% oxygen permeability (8.26 × 10−9 vs. 2.37 × 10−9 cm3/m2·d·Pa) (p < 0.05) but did not demonstrate any significant difference in mechanical properties, such as thickness (39.10 vs. 41.70 mm), tensile strength (41.89 vs. 38.30 N/mm2), and elongation at break (1.82% vs. 2.03%) (p < 0.05) compared to the GG film. Our findings established a link between physicochemical properties and bioactivity, which can provide useful information on developing and improving GC films and may offer an alternative approach for the control of BPH in the near future.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1202
Author(s):  
Bello Sani Haliru ◽  
Mohd Y. Rafii ◽  
Norida Mazlan ◽  
Shairul Izan Ramlee ◽  
Isma’ila Muhammad ◽  
...  

Brown planthopper (BPH; Nilaparvata lugens Stal) is considered the main rice insect pest in Asia. Several BPH-resistant varieties of rice have been bred previously and released for large-scale production in various rice-growing regions. However, the frequent surfacing of new BPH biotypes necessitates the evolution of new rice varieties that have a wide genetic base to overcome BPH attacks. Nowadays, with the introduction of molecular approaches in varietal development, it is possible to combine multiple genes from diverse sources into a single genetic background for durable resistance. At present, above 37 BPH-resistant genes/polygenes have been detected from wild species and indica varieties, which are situated on chromosomes 1, 3, 4, 6, 7, 8, 9, 10, 11 and 12. Five BPH gene clusters have been identified from chromosomes 3, 4, 6, and 12. In addition, eight BPH-resistant genes have been successfully cloned. It is hoped that many more resistance genes will be explored through screening of additional domesticated and undomesticated species in due course.


Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 57
Author(s):  
Xu Ding ◽  
Xi Huang ◽  
Litong Sun ◽  
Jincai Wu ◽  
Jinglan Liu

Fluridone (FLU) was a pyrrolidone herbicide that was used for selective weeding in wheat, rice, corn and pasture and was also a biosynthesis inhibitor of abscisic acid (ABA), a significant plant hormone. ABA-promoted callose deposition facilitates rice resistance to pests but whether FLU had the opposite influence was unknown. The effects of FLU on the feeding behavior of the brown planthopper (Nilaparvata lugens Stål; BPH), after feeding with rice plants treated with FLU, were studied, using an electrical penetration graph (EPG). For susceptible rice cultivar (TN1), the duration for which BPH sucked phloem sap (N4 wave duration) after 15 μmol/L of FLU treatment was longer than that of the control but decreased after 30 and 60 μmol/L FLU treatments. Fecundity of BPH treated with 15 μmol/L FLU had no significant change, while the deposition area of callose was significantly decreased. For moderately-resistant rice cultivar (IR42), no differences in BPH feeding behavior and fecundity were observed but the deposition area of callose declined after treated with 15 μmol/L of FLU. These findings suggested that a low concentration of FLU (15 μmol/L) promoted BPH feeding behavior in TN1 but not in IR42 and the response in IR42 appeared to be more complicated, which provided supplementary evidence that ABA promoted plant resistance to BPH.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Xin-Qiu Wang ◽  
Jian-sheng Guo ◽  
Dan-Ting Li ◽  
Yang Yu ◽  
Jaco Hagoort ◽  
...  

Using serial block-face scanning electron microscopy, we report on the internal 3D structures of the brown planthopper,Nilaparvata lugens(Hemiptera: Delphacidae) at nanometer resolution for the first time. Within the reconstructed organs and tissues, we found many novel and fascinating internal structures in the planthopper such as naturally occurring three four-way rings connecting adjacent spiracles to facilitate efficient gas exchange, and fungal endosymbionts in a single huge insect cell occupying 22% of the abdomen volume to enable the insect to live on plant sap. To understand the muscle and stylet movement during phloem sap-sucking, the cephalic skeleton and muscles were reconstructed in feeding nymphs. The results revealed an unexpected contraction of the protractors of the stylets and suggested a novel feeding model for the phloem sap-sucking.


2020 ◽  
Author(s):  
Abhishek Ojha ◽  
Wenqing Zhang

AbstractInsect pests consume tastants as their necessary energy and nutrient sources. Gustatory receptors play important roles in insect life and can form within an extremely complicated regulatory network. However, there are still many gustatory genes that have a significant impact on insect physiology, but their functional mechanism is still unknown. Here, we purified and characterized a gustatory receptor (protein) coding gene, NlGr7, from the brown planthopper (BPH) Nilaparvata lugens, which is an important insect pest of rice. Our results revealed that NlGr7 has an active association with various ligands, such as lectins, lipids (phospho- and sphingolipid) and copper. The mass-spectrometry result showed that NlGr7 is a sugar receptor, and NlGr7 is validated by different types of insoluble polysaccharides and a varied range of tastants. Furthermore, we observed that NlGr7-bound ATP hydrolysed on the ATPase activity assay, which indicated that NlGr7 may be associated with important biological functions in the BPH. The important NlGr7 for chemoreception has now been characterized in the BPH. We showed that NlGr7 in the BPH is required for various protein-ligands, as well as protein-sugars interactions, to play crucial roles in this pest. This study will provide valuable information for further functional studies of chemoreception mechanisms in this important agricultural pest.


Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 642
Author(s):  
Lu-Yao Peng ◽  
Zhen-Wei Dai ◽  
Rui-Rui Yang ◽  
Zhen Zhu ◽  
Wei Wang ◽  
...  

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.


2014 ◽  
Vol 6 (2) ◽  
pp. 409-415 ◽  
Author(s):  
A. S. Tetarwal ◽  
Lakhi Ram ◽  
Ram Singh ◽  
Manoj Kumar Jat

The present study on the effect of variety and planting date of rice on population of natural enemies of brown planthopper, Nilaparvata lugens (Stal) showed that during August, the mean population of spiders was statistically on par on CSR 30 and PR 114. The population differed with dates and was significantly (p=0.05) higher (9.0/10 hills) in D2 during 2011 only. There was no significant difference in the population of spiders on two varieties and dates of transplanting during September 2011 only. However, significantly higher population of spiders was recorded in variety PR 114 (21.65/10 hills) and D2 (20.52/10 hills) than on CSR 30 (13.67/10 hills) and D1 (14.80/10 hills) during September, 2012. The mean population of spiders did not differ significantly with the dates during October, 2011 and 2012. However, it was significantly higher on variety PR 114 (27.65/10 hills) than on CSR 30 during both the crop seasons. Mirid bugs did not appear in the month of August, 2011 and 2012 whereas during September 2011, the variety CSR 30 and D1 registered significantly higher population than other variety and date. However, a reverse trend was observed with varieties and dates during 2012. The mean population of coccinelid, carabid and staphylinid beetles remained very low on both the varieties in the month of August during 2011 and 2012. However, the population of these predators was influenced significantly by the varieties and dates during 2012. The population of nymphal-adult parasitoids also remained very low during both years and was not influenced by varieties and dates.


2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Tri A. Mokodompit ◽  
Roni Koneri ◽  
Parluhutan Siahaan ◽  
Agustina M Tangapo

AbstrakWereng Batang Coklat (WBC) (Nilaparvata lugens Stal.) merupakan serangga hama yang dapat merusak tanaman padi (Oryza sativa L.). Tanaman kipait (Tithonia diversifolia) berpotensi sebagai insektisida nabati karena memiliki senyawa toksik terhadap serangga. Penelitian ini bertujuan untuk mengkaji aktifitas makan akibat pemberian ekstrak daun kipait. Konsentrasi ekstrak daun kipait yang digunakan adalah 0% (kontrol), 1%, 3%,5% dan 7% dalam RAL (Rancangan Acak Lengkap) dengan 5 kali ulangan. Hasil penelitian menunjukkan bahwa pemberian ekstrak daun kipait berpengaruh terhadap penghambatan daya makan WBC. Penghambatan makan tertinggi terjadi pada konsentrasi 7% setelah 24 jam.Kata kunci : penghambatan daya makan, Nilaparvata lugens Stal., Tithonia diversifoliaAbstractBrown planthopper (BPH) (Nilaparvata lugens Stal.) Is an insect pest that can damage rice plants (Oryza sativa L.). Kipait (Tithonia diversifolia) is potential as a bioinsecticide because it is toxic to insects. This study aimed to evaluate the feeding activity that was influenced by kipait leaf extract. The concentration of kipait leaf extract were 0% (control), 1%, 3%, 5% and 7%. The experiment design was CRD (completely randomized design) with 5 replications. The results showed that the kipait leaf extract influenced the feeding inhibition of BHP. The highest inhibition occurred in the concentration of 7% after 24 hours treatment.Keywords : brown planthopper, feeding inhibition, Tithonia diversifolia


2019 ◽  
Author(s):  
Liangmiao Qiu ◽  
Wuqi Wang ◽  
Longqing Shi ◽  
Qiquan Liu ◽  
Zhixiong Zhan

The brown planthopper (BPH), Nilaparvata lugens, is the most destructive insect pest in rice production worldwide. The development and cultivation of BPH-resistant varieties is the most economical and efficient strategy to overcome the destruction caused by BPH. In this study, the modified bulk seedling test method was used to identify the BPH resistance level and host feeding choice of rice lines of Liangyou8676 (Bph14/Bph15), Bph68S (Bph14/Bph15), RHT (Bph3), Fuhui676, and TN1 on BPH. Meanwhile, the population, survival and emergence rate, developmental duration, honeydew excretion, female ratio and brachyptery ratio of adults were used as indicators to detect the antibiosis effects of the different rice lines. The results showed that the resistance levels of Rathu Heenati (RHT), Bph68S, Liangyou8676, Fuhui676, and TN1 to BPH were HR, R, MR, S and HS, respectively. The host choice implied that BPH was more inclined to feeding on rice plants with a lower resistance. An analysis of the antibiosis activity of rice lines RHT, BPh68S, and Liangyou8676 carrying resistance genes indicated a significant reduction in the population growth rate, survival and emergence rate of BPH nymphs, significant delay in the developmental duration of nymphs, reduced honeydew excretion of females, decreased female ratio, and a decreased brachyptery ratio of females and males, when compared with rice carrying no BPH-resistant genes.


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