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Arad N, Paredes-Montero JR, Mondal MH, Ponvert N, Brown JK. RNA interference-mediated knockdown of genes involved in sugar transport and metabolism disrupts psyllid Bactericera cockerelli (Order: Hemiptera) gut physiology and results in high mortality. FRONTIERS IN INSECT SCIENCE 2023; 3:1283334. [PMID: 38469486 PMCID: PMC10926392 DOI: 10.3389/finsc.2023.1283334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/02/2023] [Indexed: 03/13/2024]
Abstract
Introduction The causal agent of zebra chip of potato and vein-greening diseases of tomato is "Candidatus Liberibacter solanacearum" (CLso), a fastidious bacterium transmitted by the potato psyllid. In the absence of disease-resistant cultivars, disease management has relied on minimizing vector population size to reduce CLso transmission, which requires frequent insecticide applications. There is growing interest in the use of RNA interference (RNAi) technology to supplant traditional insecticides with biopesticides. This requires knowledge of genes essential for insect livelihood whose knockdown leads to significant mortality or other phenotypes. Such candidate genes can be evaluated by reverse genetics approaches to further corroborate predicted gene function. Methods Here, five potato psyllid genes involved in sugar homeostasis in the potato psyllid gut, α-glucosidase1 (AGLU1), aquaporin2 (AQP2), facilitated trehalose transporter1 (TRET1), Trehalase1 (TRE1), and Trehalase2 (TRE2), were investigated as candidates for effective gene silencing. Potato psyllid dsRNAs were designed to optimize knockdown of gene targets. Third instar PoP nymphs were given a 48-hr ingestion-access period (IAP) on individual or groups of dsRNA in 20% sucrose. Mortality was recorded 0, 3, 5, 7, and 9 days post-IAP. Gene knockdown was analyzed 9 days post-IAP by quantitative real-time reverse-transcriptase polymerase chain reaction amplification. Results The individual or stacked dsRNA combinations resulted in 20-60% and 20-40% knockdown, respectively, while subsequent psyllid mortality ranged from 20-40% to >60% for single and stacked dsRNA combinations, respectively. Reverse genetics analysis showed that simultaneous knockdown of the five selected candidate genes with predicted functions in pathways involved in sugar-homeostasis, metabolism, and -transport yielded the highest mortality, when compared with single or combinations of targets. Discussion Results confirmed the functions afforded by psyllid gut genes responsible for osmotic homeostasis and sugar metabolism/transport are essential for livelihood, identifying them as potentially lucrative RNAi biopesticide targets and highlighted the translational relevance of targeting multiple nodes in a physiological pathway simultaneously.
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Affiliation(s)
- Neda Arad
- School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
| | - Jorge R. Paredes-Montero
- School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
- Facultad de Ciencias de la Vida, Escuela Superior Politécnica del Litoral, ESPOL, Guayaquil, Guayas, Ecuador
| | | | - Nathaniel Ponvert
- School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
| | - Judith K. Brown
- School of Plant Sciences, The University of Arizona, Tucson, AZ, United States
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Jiang X, Zhong F, Chen Y, Shi D, Chao L, Yu L, He B, Xu C, Wu Y, Tang B, Duan H, Wang S. Novel compounds ZK-PI-5 and ZK-PI-9 regulate the reproduction of Spodoptera frugiperda (Lepidoptera: Noctuidae), with insecticide potential. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:1850-1861. [PMID: 37478561 DOI: 10.1093/jee/toad140] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 06/20/2023] [Accepted: 07/13/2023] [Indexed: 07/23/2023]
Abstract
Trehalase inhibitors prevent trehalase from breaking down trehalose to provide energy. Chitinase inhibitors inhibit chitinase activity affecting insect growth and development. This is an important tool for the investigation of regulation of trehalose metabolism and chitin metabolism in insect reproduction. There are few studies on trehalase or chitinase inhibitors' regulation of insect reproduction. In this study, ZK-PI-5 and ZK-PI-9 were shown to have a significant inhibitory effect on the trehalase, and ZK-PI-9 significantly inhibited chitinase activity in female pupae. We investigated the reproduction regulation of Spodoptera frugiperda using these new inhibitors and evaluated their potential as new insecticides. Compounds ZK-PI-5 and ZK-PI-9 were injected into the female pupae, and the control group was injected with solvent (2% DMSO). The results showed that the emergence failure rate for pupae treated with inhibitors increased dramatically and aberrant phenotypes such as difficulty in wings spreading occurred. The oviposition period and longevity of female adults in the treated group were significantly shorter than those in the control group, and the ovaries developed more slowly and shrank earlier. The egg hatching rate was significantly reduced by treatment with the inhibitor. These results showed that the two new compounds had a significant impact on the physiological indicators related to reproduction of S. frugiperda, and have pest control potential. This study investigated the effect of trehalase and chitin inhibitors on insect reproduction and should promote the development of green and efficient insecticides.
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Affiliation(s)
- Xinyi Jiang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Fan Zhong
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Yan Chen
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Dongmei Shi
- Department of Applied Chemistry, Innovation Center of Pesticide Research, College of Science, China Agricultural University, Beijing 100193, P.R. China
| | - Lei Chao
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Liuhe Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Biner He
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Caidi Xu
- Jing Hengyi School of Education, HangzhouNormal University, Hangzhou, Zhejiang 311121, P.R.China
| | - Yan Wu
- Key Laboratory of Surveillance and Management of Invasive Alien Species in Guizhou Education Department ,Guiyang University, Guiyang 550005, P.R.China
| | - Bin Tang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
| | - Hongxia Duan
- Department of Applied Chemistry, Innovation Center of Pesticide Research, College of Science, China Agricultural University, Beijing 100193, P.R. China
| | - Shigui Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, P.R. China
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Turner M, Van Hulzen L, Peta V, Pietri JE. Survival of Salmonella Typhimurium in the hemolymph of the German cockroach vector is limited by both humoral immune factors and hemocytes but not by trehalose metabolism. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:875-883. [PMID: 37348971 PMCID: PMC10496438 DOI: 10.1093/jme/tjad076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 05/15/2023] [Accepted: 06/08/2023] [Indexed: 06/24/2023]
Abstract
The German cockroach (Blattella germanica) has been linked to transmission of Salmonella enterica serovar Typhimurium (S. Typhimurium), but infection dynamics within this vector are poorly characterized. Our recent work has focused on S. Typhimurium infection in the cockroach gut. However, microbial dissemination to the hemolymph is an essential aspect of many vector-borne pathogen transmission cycles and could potentially contribute to S. Typhimurium colonization of cockroaches. Therefore, the goal of this study was to examine the ability of S. Typhimurium to disseminate, survive, and proliferate in the hemolymph of cockroaches after oral infection. We detected only low numbers of bacteria in the hemolymph of a minority of insects (~26%) after oral infection. Further, S. Typhimurium was unable to survive overnight in cell-free hemolymph. Several hypotheses to explain the inability of S. Typhimurium to colonize hemolymph were tested. First, we investigated the ability of S. Typhimurium to metabolize trehalose, the primary sugar in hemolymph. S. Typhimurium grew efficiently in vitro using trehalose as a sole carbon source and mutant strains lacking trehalose metabolism genes exhibited no growth deficiencies in media mimicking the composition of hemolymph, suggesting that trehalose metabolism ability is not a factor involved in restricting survival in hemolymph. On the other hand, heat-inactivated cell-free hemolymph was permissive of S. Typhimurium growth, demonstrating that survival in hemolymph is limited specifically by heat-labile humoral factors. The involvement of cellular immune responses was also investigated and cockroach hemocytes in culture were observed to internalize S. Typhimurium within 1 h of exposure. Most hemocytes harbored few to no bacteria after 24 h, indicating that hemocyte responses are additionally involved in clearing infection from the hemolymph. However, dense intracellular clusters of S. Typhimurium were observed sporadically, suggesting a small subset of hemocytes may serve as reservoirs for bacterial replication. Together, our results reveal that a minute proportion of ingested S. Typhimurium is able to escape the cockroach gut and enter the hemolymph, but this systemic population is limited by both humoral effectors and hemocytes. Thus, we conclude that invasion of the hemolymph appears minimally important for colonization of the cockroach vector and that colonization of the gut is the main driver of vector-borne transmission. Our insight into the antimicrobial mechanisms of cockroach hemolymph also highlights the strong ability of these prevalent pests/vectors to cope with frequent infectious challenges in septic habitats.
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Affiliation(s)
- Matthew Turner
- Sanford School of Medicine, Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, SD, USA
| | - Landen Van Hulzen
- Sanford School of Medicine, Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, SD, USA
| | - Vincent Peta
- Sanford School of Medicine, Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, SD, USA
| | - Jose E Pietri
- Sanford School of Medicine, Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, SD, USA
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Xu H, Zhang Z, Zhang Z, Peng J, Gao Y, Li K, Chen J, Du J, Yan S, Zhang D, Zhou X, Shi X, Liu Y. Effects of insulin-like peptide 7 in Bemisia tabaci MED on tomato chlorosis virus transmission. PEST MANAGEMENT SCIENCE 2023; 79:1508-1517. [PMID: 36533303 DOI: 10.1002/ps.7329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 12/11/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Tomato chlorosis virus (ToCV) is a semi-persistent plant virus that is primarily transmitted by the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae). It causes a serious disease that lowers tomato yield. Insulin-like peptide (ILP), an insulin homolog, regulates trehalose metabolism in a variety of insects. In a previous study, we discovered that trehalose metabolism is required for whiteflies to transmit ToCV effectively. Furthermore, transcriptome sequencing revealed that the BtILP7 gene was highly expressed in B. tabaci infected with ToCV. Therefore, the whitefly ILP7 gene may facilitate the transmission of ToCV and be an attractive target for the control of whiteflies and subsequently ToCV. RESULTS The ToCV content in B. tabaci MED was found to be correlated with BtILP7 gene expression. Subsequent RNA interference (RNAi) of the BtILP7 gene had a significant impact on B. tabaci MED's trehalose metabolism and reproductive capacity, as well as ability to transmit ToCV. CONCLUSIONS These results indicate that the BtILP7 gene was closely related to ToCV transmission by regulating trehalose metabolism and reproduction behavior, thus providing a secure and environmentally friendly management strategy for the control of whiteflies and ToCV-caused disease. © 2022 Society of Chemical Industry.
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Affiliation(s)
- HuiNan Xu
- Longping Branch, School of Biology, Hunan University, Changsha, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - ZhanHong Zhang
- Institute of Vegetable, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Zhuo Zhang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Jing Peng
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Yang Gao
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - KaiLong Li
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Jianbin Chen
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Jiao Du
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Shuo Yan
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - DeYong Zhang
- Longping Branch, School of Biology, Hunan University, Changsha, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - XuGuo Zhou
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
| | - XiaoBin Shi
- Longping Branch, School of Biology, Hunan University, Changsha, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Yong Liu
- Longping Branch, School of Biology, Hunan University, Changsha, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
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Zhang L, Zhao H, Yang Y, Ge Y, Shi W. Effects of Nutritional Composition of Different Prey Eggs on Development and Reproduction of the Predatory Bug, Orius sauteri (Hemiptera: Anthocoridae). JOURNAL OF ECONOMIC ENTOMOLOGY 2022; 115:1869-1876. [PMID: 36240118 DOI: 10.1093/jee/toac159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Indexed: 06/16/2023]
Abstract
Orius sauteri (Poppius) is an important predator of many economically important insect pests. The mass rearing of O. sauteri is difficult, limiting its application in pest control. Here we assessed the nutritional quality of eggs of Sitotroga cerealella (Olivier), Agrotis ypsilon (Rottemberg), or Spodoptera litura (Fabricius), and their potential for rearing O. sauteri in the laboratory for two generations. Of species tested, S. cerealella eggs resulted in the highest survival and reproduction of O. sauteri compared to the other two lepidopteran species. Eggs of A. ypsilon were a suitable diet for the nymphal stage, which developed faster on A. ysilon eggs than those of S. cerealella eggs. Conversely, eggs of S. litura were not a suitable diet for O. sauteri, and they disrupted the development and reproduction of O. sauteri. Sitotroga cerealella eggs showed advantages in all the nutritional components evaluated. Orius sauteri fed S. litura eggs contained significantly lower protein levels than those fed on the other eggs tested. Spodoptera litura eggs significantly enhanced the CAT activity in O. sauteri, which suggests that some components from S. litura eggs harmed the development and reproduction of O. sauteri. Based on these results, we suggest using a combined diet for mass rearing of the pirate bug, feeding the nymphs and adults with A. ypsilon eggs and S. cerealella eggs, respectively. This study contributes to the discovery of artificial diets for mass rearing O. sauteri and other Orius species in the future.
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Affiliation(s)
- Liu Zhang
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Hongyan Zhao
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Yuxi Yang
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Yang Ge
- National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, State Key Laboratory Breeding Base of Dao-di Herbs, Beijing 100700, China
| | - Wangpeng Shi
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
- Sanya Institute of China Agricultural University, Sanya 572019, China
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6
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Fan X, Liu Y, Zhang Z, Zhang Z, Peng J, Gao Y, Zheng L, Chen J, Du J, Yan S, Zhou X, Shi X, Zhang D. Bta06987, Encoding a Peptide of the AKH/RPCH Family: A Role of Energy Mobilization in Bemisia tabaci. INSECTS 2022; 13:834. [PMID: 36135535 PMCID: PMC9502992 DOI: 10.3390/insects13090834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/07/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
A neuropeptide precursor encoded by Bta06987 associates with AKH neuropeptide. In the AKH/RPCH family, these members have been demonstrated to participate in energy mobilization in many insects. In our research, the Bta06987 gene from Bemisia tabaci was cloned, and the amino acid sequence analysis was performed. During the starvation of B. tabaci, the mRNA level of Bta06987 showed a significant elevation. We investigated the functions of Bta06987 in B. tabaci using RNA interference (RNAi), and the adult females of B. tabaci after being fed with dsBta06987 showed a higher glycogen and triglyceride levels and lower trehalose content than the control. Furthermore, in the electrical penetration graph (EPG) experiment, B. tabaci showed changes in feeding behavior after feeding with dsBta06987, such as the reduction in parameters of E waveform percentage and total feeding time. Our findings might be helpful in developing strategies to control pest and plant virus transmission.
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Affiliation(s)
- Xiaofan Fan
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Yong Liu
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Zhuo Zhang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Zhanhong Zhang
- Institute of Vegetable Crops, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Jing Peng
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Yang Gao
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Limin Zheng
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Jianbin Chen
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Jiao Du
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Shuo Yan
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Xuguo Zhou
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA
| | - Xiaobin Shi
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Deyong Zhang
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China
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Zhou H, Lei G, Chen Y, You M, You S. PxTret1-like Affects the Temperature Adaptability of a Cosmopolitan Pest by Altering Trehalose Tissue Distribution. Int J Mol Sci 2022; 23:ijms23169019. [PMID: 36012281 PMCID: PMC9409412 DOI: 10.3390/ijms23169019] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/01/2022] [Accepted: 08/10/2022] [Indexed: 11/18/2022] Open
Abstract
Global warming poses new challenges for insects to adapt to higher temperatures. Trehalose is the main blood sugar in insects and plays an important role in energy metabolism and stress resistance. The transmembrane transport of trehalose mainly depends on the trehalose transporter (TRET1). Plutella xylostella (L.) is a worldwide agricultural pest; however, the effects of the trehalose transport mechanism and trehalose distribution in tissues on the development, reproduction and temperature adaptation of P. xylostella have yet to be reported. In this study, PxTret1-like was cloned and analyzed regarding its expression pattern. It was found that the expression of PxTret1-like was affected by ambient temperature. The knockout mutation of PxTret1-like was generated using a CRISPR/Cas9 system by targeted knockout. The trehalose content and trehalase activity of mutant P. xylostella increased at different developmental stages. The trehalose content increased in the fat body of the fourth-instar P. xylostella, and decreased in the hemolymph, and there was no significant change in glucose in the fat body and hemolymph. Mutant strains of P. xylostella showed a significantly reduced survival rate, fecundity and ability to withstand extreme temperatures. The results showed that PxTret1-like could affect the development, reproduction and temperature adaptability of P. xylostella by regulating the trehalose content in the fat body and hemolymph.
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Affiliation(s)
- Huiling Zhou
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Gaoke Lei
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yanting Chen
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China
| | - Minsheng You
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shijun You
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- BGI-Sanya, BGI-Shenzhen, Sanya 572025, China
- Correspondence:
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Tan YA, Zhao XD, Sun HJ, Zhao J, Xiao LB, Hao DJ, Jiang YP. Phospholipase C gamma (PLCγ) regulates soluble trehalase in the 20E-induced fecundity of Apolygus lucorum. INSECT SCIENCE 2021; 28:430-444. [PMID: 32108427 DOI: 10.1111/1744-7917.12772] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/03/2020] [Accepted: 02/09/2020] [Indexed: 06/10/2023]
Abstract
Apolygus lucorum is the dominant pathogenic insect attacking Bacillus thuringiensis (Bt) cotton in China. Additionally, 20-hydroxyecdysone (20E) has important functions in many biological processes, including insect reproduction. Phospholipase C (PLC), which is an essential enzyme for phosphoinositide metabolism, is involved in 20E signal transduction, but its function in 20E-mediated reproduction in A. lucorum remains unclear. In this study, 20E increased AlPLCγ transcription as well as the abundance and activity of the encoded protein during molting and metamorphosis. The 20E treatment also induced the considerable accumulation of two second messengers, inositol triphosphate and diacylglycerol. The expression levels of genes encoding vitellogenin (AlVg) and soluble trehalase (AlTre-1) were similar to those of AlPLCγ, and were upregulated in response to 20E. The silencing of AlPLCγ resulted in downregulated expression of AlTre-1 and AlVg. However, the silencing of AlTre-1 and AlVg did not affect AlPLCγ expression. Moreover, the silencing of AlVg did not alter AlTre-1 expression. Furthermore, an examination of the insect specimens indicated that AlPLCγ is required for female adult reproduction, and that downregulated expression of this gene is associated with decreases in fecundity, adult longevity, and egg hatching rate as well as delayed oocyte maturation. We propose that 20E regulates AlTre-1 expression via AlPLCγ and affects Vg expression as well as ovary development to facilitate the reproductive activities of A. lucorum females.
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Affiliation(s)
- Yong-An Tan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xu-Dong Zhao
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Hou-Jun Sun
- Jiangsu Xuzhou Sweet Potato Research Center, Xuzhou, Jiangsu Province, China
| | - Jing Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Liu-Bin Xiao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - De-Jun Hao
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Yi-Pin Jiang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
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Leyria J, El-Mawed H, Orchard I, Lange AB. Regulation of a Trehalose-Specific Facilitated Transporter (TRET) by Insulin and Adipokinetic Hormone in Rhodnius prolixus, a Vector of Chagas Disease. Front Physiol 2021; 12:624165. [PMID: 33643069 PMCID: PMC7902789 DOI: 10.3389/fphys.2021.624165] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/18/2021] [Indexed: 12/26/2022] Open
Abstract
Using the blood-sucking kissing bug, Rhodnius prolixus as an experimental model, we have studied the involvement of insulin-like peptides (ILPs) and adipokinetic hormone (AKH) signaling in carbohydrate metabolism, focusing on the regulation of the trehalose-specific facilitated transporter (Rhopr-TRET), particularly in the ovaries. We find that trehalose stores in ovaries increase after feeding, synchronously with the beginning of vitellogenesis, but that the transcript expression of enzymes involved in trehalose synthesis show no changes between unfed and blood-fed animals. However, an eightfold increase in Rhopr-TRET transcript expression is observed in the ovaries post-blood meal. In vivo and ex vivo assays using exogenous insulins and Rhopr-AKH, reveal that Rhopr-TRET is up-regulated in ovaries by both peptide families. In accordance with these results, when ILP and AKH signaling cascades are impaired using RNA interference, Rhopr-TRET transcript is down-regulated. In addition, trehalose injection induces an up-regulation of Rhopr-TRET transcript expression and suggests an activation of insulin signaling. Overall, the results support the hypothesis of a direct trehalose uptake by ovaries from the hemolymph through Rhopr-TRET, regulated by ILP and/or AKH. We also show that Rhopr-TRET may work cooperatively with AKH signaling to support the release of trehalose from the ovaries into the hemolymph during the unfed (starved) condition. In conclusion, the results indicate that in females of R. prolixus, trehalose metabolism and its hormonal regulation by ILP and AKH play critical roles in adapting to different nutritional conditions and physiological states.
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Affiliation(s)
- Jimena Leyria
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Hanine El-Mawed
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Ian Orchard
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Angela B Lange
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
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10
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Li Y, Wang S, Liu Y, Lu Y, Zhou M, Wang S, Wang S. The Effect of Different Dietary Sugars on the Development and Fecundity of Harmonia axyridis. Front Physiol 2020; 11:574851. [PMID: 33041872 PMCID: PMC7522449 DOI: 10.3389/fphys.2020.574851] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/25/2020] [Indexed: 11/13/2022] Open
Abstract
The aim of this study was to screen synergistic substances included in existing artificial feeds in order to improve the fertility and survival rate of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an efficient pest predator. To this end, we analyzed the potential effects of glucose and trehalose on the growth, development, and reproduction of H. axyridis and evaluated the effect of three different artificial feeds on the energy stress of H. axyridis. The artificial diets contained fresh pork liver, honey, sucrose, vitamin C, and royal jelly, which was marked it as Diet1. The glucose was added to diet1, which was marked it as diet2, while adding trehalose to diet1 was marked as diet3. The pre-oviposition period of H. axyridis on Diet 1 was slower than that of Diet 2 and Diet 3. Additionally, the spawning quantity and incubation rate of insects on Diet 2 and Diet 3 were significantly higher than that of those on Diet 1. Finally, the larval developmental time on Diet 1 was significantly slower than that of Diet 2 and Diet 3. These results indicate that the addition of an appropriate amount of glucose or trehalose may affect positively the growth, development, and reproduction of H. axyridis. In addition, further studies showed that ATP, amino acids and fatty acids content in the H. axyridis also increased after the addition of the synergistic substance. All these results show that proper adjustment of stored energy anabolic and catabolism is important to maintain the metabolic balance of the insect’s entire life cycle and the addition of glucose or trehalose has a certain effect on the life indicators of H. axyridis.
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Affiliation(s)
- Yan Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Shasha Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yongkang Liu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yuting Lu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Min Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Su Wang
- Institute of Plant and Environment Protection, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Shigui Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
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11
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Abstract
The RNA interference (RNAi) triggered by short/small interfering RNA (siRNA) was discovered in nematodes and found to function in most living organisms. RNAi has been widely used as a research tool to study gene functions and has shown great potential for the development of novel pest management strategies. RNAi is highly efficient and systemic in coleopterans but highly variable or inefficient in many other insects. Differences in double-stranded RNA (dsRNA) degradation, cellular uptake, inter- and intracellular transports, processing of dsRNA to siRNA, and RNA-induced silencing complex formation influence RNAi efficiency. The basic dsRNA delivery methods include microinjection, feeding, and soaking. To improve dsRNA delivery, various new technologies, including cationic liposome-assisted, nanoparticle-enabled, symbiont-mediated, and plant-mediated deliveries, have been developed. Major challenges to widespread use of RNAi in insect pest management include variable RNAi efficiency among insects, lack of reliable dsRNA delivery methods, off-target and nontarget effects, and potential development of resistance in insect populations.
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Affiliation(s)
- Kun Yan Zhu
- Department of Entomology, Kansas State University, Manhattan, Kansas 66506, USA;
| | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, Kentucky 40546, USA;
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12
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Rauf I, Asif M, Amin I, Naqvi RZ, Umer N, Mansoor S, Jander G. Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata. INSECT MOLECULAR BIOLOGY 2019; 28:785-797. [PMID: 30980445 DOI: 10.1111/imb.12589] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Gut-expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, which encodes a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant-mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein and/or free amino acids in their honeydew. Larvae of Coccinella septempunctata (seven-spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi-mediated pest control.
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Affiliation(s)
- I Rauf
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
- Pakistan Institute of Engineering & Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
- Boyce Thompson Institute, Ithaca, NY, USA
| | - M Asif
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
| | - I Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
| | - R Z Naqvi
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
| | - N Umer
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
- Pakistan Institute of Engineering & Applied Sciences (PIEAS), Nilore, Islamabad, Pakistan
- Boyce Thompson Institute, Ithaca, NY, USA
| | - S Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
| | - G Jander
- Boyce Thompson Institute, Ithaca, NY, USA
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13
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Lu K, Wang Y, Chen X, Zhang X, Li W, Cheng Y, Li Y, Zhou J, You K, Song Y, Zhou Q, Zeng R. Adipokinetic Hormone Receptor Mediates Trehalose Homeostasis to Promote Vitellogenin Uptake by Oocytes in Nilaparvata lugens. Front Physiol 2019; 9:1904. [PMID: 30687120 PMCID: PMC6338042 DOI: 10.3389/fphys.2018.01904] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022] Open
Abstract
Adipokinetic hormones (AKHs) are well known to mobilize lipids and carbohydrates for energy-consuming activities in insects. These neuropeptides exert their functions by interacting with AKH receptors (AKHRs) located on the plasma membrane of fat body cells, which regulates energy mobilization by stimulating lipolysis of triacylglycerols (TAG) to diacylglycerols (DAG) and conversion of glycogen into trehalose. Here, we investigated the roles of AKH/AKHR signaling system in trehalose metabolism and vitellogenesis during female reproduction in the brown planthopper, Nilaparvata lugens. Knockdown of AKHR expression by RNA interference (RNAi) resulted in a decrease of the circulating trehalose in hemolymph and significantly increased levels of two trehalases in fat bodies, indicating that the modulation of hemolymph trehalose levels by AKHR may be mediated by regulating trehalose degradation. In addition, adult females that had been injected with double-stranded RNA (dsRNA) for AKHR exhibited delayed oocyte maturation, prolonged pre-oviposition period, as well as decline in egg number and reduction in fecundity. Considering that these phenotypes resulting from AKHR silencing are similar to those of vitellogenin receptor (VgR) RNAi, we further analyzed a possible connection between AKHR and vitellogenesis. Knockdown of AKHR showed no effects on the Vg synthesis in fat bodies, whereas it significantly reduced the levels of VgR in ovaries. With RNAi-females, we observed an increase of Vg accumulation in hemolymph and a decrease of Vg deposition in ovaries. Moreover, the decrease in VgR expression and Vg incorporation by developing oocytes could be partially rescued by injection of trehalose into AKHR RNAi females. The present study has implicated trehalose in the AKH/AKHR signaling-mediated control of reproduction and provided new insight into mechanisms of AKH/AKHR regulation of trehalose metabolism in insect vitellogenesis, oocyte maturation and fecundity.
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Affiliation(s)
- Kai Lu
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ying Wang
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xia Chen
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xinyu Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wenru Li
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yibei Cheng
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yue Li
- College of Crop Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jinming Zhou
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Keke You
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yuanyuan Song
- College of Crop Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qiang Zhou
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Rensen Zeng
- College of Crop Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
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14
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Cao M, Gatehouse JA, Fitches EC. A Systematic Study of RNAi Effects and dsRNA Stability in Tribolium castaneum and Acyrthosiphon pisum, Following Injection and Ingestion of Analogous dsRNAs. Int J Mol Sci 2018; 19:E1079. [PMID: 29617308 PMCID: PMC5979293 DOI: 10.3390/ijms19041079] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 03/28/2018] [Accepted: 03/30/2018] [Indexed: 01/29/2023] Open
Abstract
RNA interference (RNAi) effects in insects are highly variable and may be largely dependent upon the stability of introduced double-stranded RNAs to digestion by nucleases. Here, we report a systematic comparison of RNAi effects in susceptible red flour beetle (Tribolium castaneum) and recalcitrant pea aphid (Acyrthosiphon pisum) following delivery of dsRNAs of identical length targeting expression of V-type ATPase subunit E (VTE) and inhibitor of apoptosis (IAP) genes. Injection and ingestion of VTE and IAP dsRNAs resulted in up to 100% mortality of T. castaneum larvae and sustained suppression (>80%) of transcript levels. In A. pisum, injection of VTE but not IAP dsRNA resulted in up to 65% mortality and transient suppression (ca. 40%) of VTE transcript levels. Feeding aphids on VTE dsRNA reduced growth and fecundity although no evidence for gene suppression was obtained. Rapid degradation of dsRNAs by aphid salivary, haemolymph and gut nucleases contrasted with stability in T. castaneum larvae where it appears that exo-nuclease activity is responsible for relatively slow digestion of dsRNAs. This is the first study to directly compare RNAi effects and dsRNA stability in receptive and refractory insect species and provides further evidence that dsRNA susceptibility to nucleases is a key factor in determining RNAi efficiency.
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Affiliation(s)
- Min Cao
- Department of Biosciences, Durham University, Durham DH1 3LE, UK.
| | - John A Gatehouse
- Department of Biosciences, Durham University, Durham DH1 3LE, UK.
| | - Elaine C Fitches
- Department of Biosciences, Durham University, Durham DH1 3LE, UK.
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15
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Kumar D, Gong C. Insect RNAi: Integrating a New Tool in the Crop Protection Toolkit. TRENDS IN INSECT MOLECULAR BIOLOGY AND BIOTECHNOLOGY 2017. [PMCID: PMC7121382 DOI: 10.1007/978-3-319-61343-7_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protecting crops against insect pests is a major focus area in crop protection. Over the past two decades, biotechnological interventions, especially Bt proteins, have been successfully implemented across the world and have had major impacts on reducing chemical pesticide applications. As insects continue to adapt to insecticides, both chemical and protein-based, new methods, molecules, and modes of action are necessary to provide sustainable solutions. RNA interference (RNAi) has emerged as a significant tool to knock down or alter gene expression profiles in a species-specific manner. In the past decade, there has been intense research on RNAi applications in crop protection. This chapter looks at the current state of knowledge in the field and outlines the methodology, delivery methods, and precautions required in designing targets. Assessing the targeting of specific gene expression is also an important part of a successful RNAi strategy. The current literature on the use of RNAi in major orders of insect pests is reviewed, along with a perspective on the regulatory aspects of the approach. Risk assessment of RNAi would focus on molecular characterization, food/feed risk assessment, and environmental risk assessment. As more RNAi-based products come through regulatory systems, either via direct application or plant expression based, the impact of this approach on crop protection will become clearer.
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Affiliation(s)
- Dhiraj Kumar
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Chengliang Gong
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
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16
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Lin YH, Huang JH, Liu Y, Belles X, Lee HJ. Oral delivery of dsRNA lipoplexes to German cockroach protects dsRNA from degradation and induces RNAi response. PEST MANAGEMENT SCIENCE 2017; 73:960-966. [PMID: 27470169 DOI: 10.1002/ps.4407] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 06/09/2016] [Accepted: 07/25/2016] [Indexed: 05/28/2023]
Abstract
BACKGROUND In the past years, the concept of RNAi application for insect pest control has been proposed, considering the disruption of vital genes. However, the efficiency of RNAi is variable between different insect groups, especially by oral delivery of dsRNA. The purpose of this study is to assess the possibilities of RNAi as a tool for pest control using oral delivery of the dsRNAs encapsulated by liposome in the German cockroach Blattella germanica, which is highly sensitive to RNAi by injection of dsRNAs. RESULTS Injecting dsRNA into the abdomen of B. germanica caused dramatic depletion of essential α-tubulin gene and mortality. In contrast, oral delivery of the naked dsRNA resulted in lower RNAi efficiency, accounting for rapid degradation of the dsRNA in the midgut of B. germanica. Notably, we have further demonstrated that continuous ingestion of dsRNA lipoplexes in which dsRNA was encapsulated with a cationic liposome carrier was sufficient to slow down the degradation of dsRNA in the midgut and to increase the mortality of the German cockroach by significantly inhibiting α-tubulin expression in the midgut. CONCLUSION We provide empirical evidence that the formulation of dsRNA lipoplexes could be a plausible approach for insect pest control based on RNAi. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Yu-Hsien Lin
- Department of Entomology, National Taiwan University, Taipei, Taiwan
| | - Jia-Hsin Huang
- Department of Entomology, National Taiwan University, Taipei, Taiwan
| | - Yun Liu
- Department of Entomology, National Taiwan University, Taipei, Taiwan
| | - Xavier Belles
- CSIC-UPF, Institute of Evolutionary Biology, Barcelona, Spain
| | - How-Jing Lee
- Department of Entomology, National Taiwan University, Taipei, Taiwan
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17
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Park Y, Kim Y. Identification of a hypertrehalosemic factor in Spodoptera exigua. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2017; 95:e21386. [PMID: 28440594 DOI: 10.1002/arch.21386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Trehalose is a major blood sugar in insects with a range of physiological functions, including an energy source and a cryoprotectant. Hemolymph trehalose concentrations are tightly regulated according to physiological conditions. An insulin-like peptide, SeILP1, downregulates hemolymph trehalose concentrations in Spodoptera exigua. Here, we identified a factor that upregulates hemolymph trehalose concentration in S. exigua. Hemolymph trehalose concentrations were significantly increased after immune challenge or under starvation in a time-dependent manner. To determine endocrine factors responsible for the upregulation, stress-associated mediators, such as octopamine, serotonin, or eicosanoids were injected, but they did not upregulate hemolymph trehalose. On the other hand, injection with Schistocerca gregaria adipokinetic hormone (AKH) significantly increased hemolymph trehalose concentration in S. exigua. During upregulation of hemolymph trehalose by AKH injection, trehalose degradation appeared to be inhibited because expression of trehalase and SeILP1 were significantly suppressed while that of trehalose phosphate synthase was not significantly changed. Interrogation of a Spodoptera genome database identified an S. exigua AKH-like gene and its expression was confirmed. During starvation, its expression concentrations were increased, although RNA interference specific to the AKH-like hypertrehalosemic factor (SeHTF) gene significantly prevented the upregulation of hemolymph trehalose concentrations during starvation. A synthetic peptide of SeHTF was prepared and injected into S. exigua larvae. At nanomolar concentration, the synthetic SeHTF peptide effectively upregulated hemolymph trehalose concentrations. Here we report a novel hypertrehalosemic factor in S. exigua (SeHTF).
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Affiliation(s)
- Youngjin Park
- Department of Bio-Sciences, Andong National University, Andong, Korea
| | - Yonggyun Kim
- Department of Bio-Sciences, Andong National University, Andong, Korea
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18
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Yogindran S, Rajam MV. Artificial miRNA-mediated silencing of ecdysone receptor (EcR) affects larval development and oogenesis in Helicoverpa armigera. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 77:21-30. [PMID: 27476930 DOI: 10.1016/j.ibmb.2016.07.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 07/24/2016] [Accepted: 07/26/2016] [Indexed: 05/27/2023]
Abstract
The insect pests are real threat to farmers as they affect the crop yield to a great extent. The use of chemical pesticides for insect pest control has always been a matter of concern as they pollute the environment and are also harmful for human health. Bt (Bacillus thuringensis) technology helped the farmers to get rid of the insect pests, but experienced a major drawback due to the evolution of insects gaining resistance towards these toxins. Hence, alternative strategies are high on demand to control insect pests. RNA-based gene silencing is emerging as a potential tool to tackle with this problem. In this study, we have shown the use of artificial microRNA (amiRNA) to specifically target the ecdysone receptor (EcR) gene of Helicoverpa armigera (cotton bollworm), which attacks several important crops like cotton, tomato chickpea, pigeon pea, etc and causes huge yield losses. Insect let-7a precursor miRNA (pre-miRNA) backbone was used to replace the native miRNA with that of amiRNA. The precursor backbone carrying the 21 nucleotide amiRNA sequence targeting HaEcR was cloned in bacterial L4440 vector for in vitro insect feeding experiments. Larvae fed with Escherichia coli expressing amiRNA-HaEcR showed a reduction in the expression of target gene as well as genes involved in the ecdysone signaling pathway downstream to EcR and exhibited mortality and developmental defects. Stem-loop RT-PCR revealed the presence of amiRNA in the insect larvae after feeding bacteria expressing amiRNA-HaEcR, which was otherwise absent in controls. We also found a significant drop in the reproduction potential (oogenesis) of moths which emerged from treated larvae as compared to control. These results demonstrate the successful use of an insect pre-miRNA backbone to express amiRNA for gene silencing studies in insects. The method is cost effective and can be exploited as an efficient and alternative tool for insect pest management.
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Affiliation(s)
- Sneha Yogindran
- Department of Genetics, University of Delhi South Campus, Benito Juarez Marg, New Delhi 110021, India
| | - Manchikatla Venkat Rajam
- Department of Genetics, University of Delhi South Campus, Benito Juarez Marg, New Delhi 110021, India.
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19
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Yu XD, Liu ZC, Huang SL, Chen ZQ, Sun YW, Duan PF, Ma YZ, Xia LQ. RNAi-mediated plant protection against aphids. PEST MANAGEMENT SCIENCE 2016; 72:1090-8. [PMID: 26888776 DOI: 10.1002/ps.4258] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/21/2015] [Accepted: 02/15/2016] [Indexed: 05/10/2023]
Abstract
Aphids (Aphididae) are major agricultural pests that cause significant yield losses of crop plants each year by inflicting damage both through the direct effects of feeding and by vectoring harmful plant viruses. Expression of double-stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant-mediated RNA interference (RNAi). Thus, as a potential alternative and effective strategy for insect pest management in agricultural practice, plant-mediated RNAi for aphid control has received close attention in recent years. In this review, the mechanism of RNAi in insects and the so far explored effective RNAi target genes in aphids, their potential applications in the development of transgenic plants for aphid control and the major challenges in this regard are reviewed, and the future prospects of using plant-mediated RNAi for aphid control are discussed. This review is intended to be a helpful insight into the generation of aphid-resistant plants through plant-mediated RNAi strategy. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Xiu-Dao Yu
- School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan, China
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zong-Cai Liu
- School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan, China
| | - Si-Liang Huang
- School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan, China
| | - Zhi-Qin Chen
- School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan, China
| | - Yong-Wei Sun
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Peng-Fei Duan
- School of Life Science and Technology, Nanyang Normal University, Nanyang, Henan, China
| | - You-Zhi Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lan-Qin Xia
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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20
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Antifreeze proteins govern the precipitation of trehalose in a freezing-avoiding insect at low temperature. Proc Natl Acad Sci U S A 2016; 113:6683-8. [PMID: 27226297 DOI: 10.1073/pnas.1601519113] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The remarkable adaptive strategies of insects to extreme environments are linked to the biochemical compounds in their body fluids. Trehalose, a versatile sugar molecule, can accumulate to high levels in freeze-tolerant and freeze-avoiding insects, functioning as a cryoprotectant and a supercooling agent. Antifreeze proteins (AFPs), known to protect organisms from freezing by lowering the freezing temperature and deferring the growth of ice, are present at high levels in some freeze-avoiding insects in winter, and yet, paradoxically are found in some freeze-tolerant insects. Here, we report a previously unidentified role for AFPs in effectively inhibiting trehalose precipitation in the hemolymph (or blood) of overwintering beetle larvae. We determine the trehalose level (29.6 ± 0.6 mg/mL) in the larval hemolymph of a beetle, Dendroides canadensis, and demonstrate that the hemolymph AFPs are crucial for inhibiting trehalose crystallization, whereas the presence of trehalose also enhances the antifreeze activity of AFPs. To dissect the molecular mechanism, we examine the molecular recognition between AFP and trehalose crystal interfaces using molecular dynamics simulations. The theory corroborates the experiments and shows preferential strong binding of the AFP to the fast growing surfaces of the sugar crystal. This newly uncovered role for AFPs may help explain the long-speculated role of AFPs in freeze-tolerant species. We propose that the presence of high levels of molecules important for survival but prone to precipitation in poikilotherms (their body temperature can vary considerably) needs a companion mechanism to prevent the precipitation and here present, to our knowledge, the first example. Such a combination of trehalose and AFPs also provides a novel approach for cold protection and for trehalose crystallization inhibition in industrial applications.
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21
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Mass spectrometric identification, sequence evolution, and intraspecific variability of dimeric peptides encoded by cockroach akh genes. Anal Bioanal Chem 2014; 407:1685-93. [DOI: 10.1007/s00216-014-8382-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 10/24/2022]
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22
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Süren-Castillo S, Abrisqueta M, Maestro JL. FoxO is required for the activation of hypertrehalosemic hormone expression in cockroaches. Biochim Biophys Acta Gen Subj 2014; 1840:86-94. [DOI: 10.1016/j.bbagen.2013.08.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/09/2013] [Accepted: 08/21/2013] [Indexed: 10/26/2022]
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23
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Park Y, Kim Y. RNA interference of glycerol biosynthesis suppresses rapid cold hardening of the beet armyworm, Spodoptera exigua. ACTA ACUST UNITED AC 2013; 216:4196-203. [PMID: 23948473 DOI: 10.1242/jeb.092031] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The beet armyworm, Spodoptera exigua, is a freeze-susceptible species that overwinters in temperate zones without diapause. A rapid cold hardening (RCH) and supercooling capacity usually play crucial roles in survival during the overwintering period. This study identified a cryoprotectant as a RCH factor of S. exigua. Pre-exposure of S. exigua larvae to 4°C significantly increased survival at -10°C in all developmental stages from egg to adult. RCH was dependent on the duration of the pre-exposure period. RCH also significantly enhanced the supercooling capacity. Cryoprotectant analysis using HPLC showed that the pre-exposure treatment allowed the larvae to accumulate glycerol in the hemolymph. Two genes, glycerol-3-phosphate dehydrogenase (GPDH) and glycerol kinase (GK), were identified as being associated with glycerol biosynthesis, and were cloned from S. exigua larvae. Both GPDH and GK were expressed in all developmental stages of S. exigua. RNA interference (RNAi) of either GPDH or GK significantly inhibited glycerol accumulation in the hemolymph of S. exigua. Larvae treated with RNAi for GPDH or GK exhibited a significant decrease in RCH capacity. The glycerol accumulation in response to 4°C appeared to be under the control of a humoral signal, because a ligation experiment prevented glycerol accumulation in the other half of the body. This study indicates that glycerol is a RCH factor of S. exigua and its synthesis is in response to low temperature via humoral mediation.
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Affiliation(s)
- Youngjin Park
- Department of Bioresource Sciences, Andong National University, Andong 760-749, Korea
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24
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Zhang H, Li HC, Miao XX. Feasibility, limitation and possible solutions of RNAi-based technology for insect pest control. INSECT SCIENCE 2013; 20:15-30. [PMID: 23955822 DOI: 10.1111/j.1744-7917.2012.01513.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Numerous studies indicate that target gene silencing by RNA interference (RNAi) could lead to insect death. This phenomenon has been considered as a potential strategy for insect pest control, and it is termed RNAi-mediated crop protection. However, there are many limitations using RNAi-based technology for pest control, with the effectiveness target gene selection and reliable double-strand RNA (dsRNA) delivery being two of the major challenges. With respect to target gene selection, at present, the use of homologous genes and genome-scale high-throughput screening are the main strategies adopted by researchers. Once the target gene is identified, dsRNA can be delivered by micro-injection or by feeding as a dietary component. However, micro-injection, which is the most common method, can only be used in laboratory experiments. Expression of dsRNAs directed against insect genes in transgenic plants and spraying dsRNA reagents have been shown to induce RNAi effects on target insects. Hence, RNAi-mediated crop protection has been considered as a potential new-generation technology for pest control, or as a complementary method of existing pest control strategies; however, further development to improve the efficacy of protection and range of species affected is necessary. In this review, we have summarized current research on RNAi-based technology for pest insect management. Current progress has proven that RNAi technology has the potential to be a tool for designing a new generation of insect control measures. To accelerate its practical application in crop protection, further study on dsRNA uptake mechanisms based on the knowledge of insect physiology and biochemistry is needed.
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Affiliation(s)
- Hao Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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Garbutt JS, Bellés X, Richards EH, Reynolds SE. Persistence of double-stranded RNA in insect hemolymph as a potential determiner of RNA interference success: evidence from Manduca sexta and Blattella germanica. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:171-8. [PMID: 22664137 DOI: 10.1016/j.jinsphys.2012.05.013] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 05/17/2012] [Accepted: 05/22/2012] [Indexed: 05/03/2023]
Abstract
RNA interference (RNAi) is a specific gene silencing mechanism mediated by double-stranded RNA (dsRNA), which has been harnessed as a useful reverse genetics tool in insects. Unfortunately, however, this technology has been limited by the variable sensitivity of insect species to RNAi. We propose that rapid degradation of dsRNA in insect hemolymph could impede gene silencing by RNAi and experimentally investigate the dynamics of dsRNA persistence in two insects, the tobacco hornworm, Manduca sexta, a species in which experimental difficulty has been experienced with RNAi protocols and the German cockroach, Blattella germanica, which is known to be highly susceptible to experimental RNAi. An ex vivo assay revealed that dsRNA was rapidly degraded by an enzyme in M. sexta hemolymph plasma, whilst dsRNA persisted much longer in B. germanica plasma. A quantitative reverse transcription PCR-based assay revealed that dsRNA, accordingly, disappeared rapidly from M. sexta hemolymph in vivo. The M. sexta dsRNAse is inactivated by exposure to high temperature and is inhibited by EDTA. These findings lead us to propose that the rate of persistence of dsRNA in insect hemolymph (mediated by the action of one or more nucleases) could be an important factor in determining the susceptibility of insect species to RNAi.
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Affiliation(s)
- Jennie S Garbutt
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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Yu N, Christiaens O, Liu J, Niu J, Cappelle K, Caccia S, Huvenne H, Smagghe G. Delivery of dsRNA for RNAi in insects: an overview and future directions. INSECT SCIENCE 2013; 20:4-14. [PMID: 23955821 DOI: 10.1111/j.1744-7917.2012.01534.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
RNA interference (RNAi) refers to the process of exogenous double-stranded RNA (dsRNA) silencing the complementary endogenous messenger RNA. RNAi has been widely used in entomological research for functional genomics in a variety of insects and its potential for RNAi-based pest control has been increasingly emphasized mainly because of its high specificity. This review focuses on the approaches of introducing dsRNA into insect cells or insect bodies to induce effective RNAi. The three most common delivery methods, namely, microinjection, ingestion, and soaking, are illustrated in details and their advantages and limitations are summarized for purpose of feasible RNAi research. In this review, we also briefly introduce the two possible dsRNA uptake machineries, other dsRNA delivery methods and the history of RNAi in entomology. Factors that influence the specificity and efficiency of RNAi such as transfection reagents, selection of dsRNA region, length, and stability of dsRNA in RNAi research are discussed for further studies.
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Affiliation(s)
- Na Yu
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
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De Loof A, Lindemans M, Liu F, De Groef B, Schoofs L. Endocrine archeology: do insects retain ancestrally inherited counterparts of the vertebrate releasing hormones GnRH, GHRH, TRH, and CRF? Gen Comp Endocrinol 2012; 177:18-27. [PMID: 22402582 DOI: 10.1016/j.ygcen.2012.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 01/20/2012] [Accepted: 02/03/2012] [Indexed: 11/28/2022]
Abstract
Vertebrate releasing hormones include gonadotropin releasing hormone (GnRH), growth hormone releasing hormone (GHRH), corticotropin releasing hormone (CRF), and thyrotropin-releasing hormone (TRH). They are synthesized in the hypothalamus and stimulate the release of pituitary hormones. Here we review the knowledge on hormone releasing systems in the protostomian lineage. We address the question: do insects have peptides that may be phylogenetically related to an ancestral GnRH, GHRH, TRH, and CRF? Such endocrine archeology has become possible thanks to the growing list of fully sequenced genomes as well as to the continuously improving bioinformatic tool set. It has recently been shown that the ecdysozoan (nematodes and arthropods) adipokinetic hormones (AKHs), the lophotrochozoan (annelids and mollusks) GnRHs as well as the protochordate GnRHs are structurally related. The adipokinetic hormone precursor-related peptides (APRPs), in locusts encoded by the same gene that contains the AKH-coding region, have been forwarded as the structural counterpart of GHRH of vertebrates. CRF is relatively well conserved in insects, in which it functions as a diuretic hormone. Members of TRH-receptor family seem to have been conserved in some arthropods, but other elements of the thyroid hormone signaling system are not. A challenging idea is that in insects the functions of the thyroid hormones were taken over by juvenile hormone (JH). Our reconstruction suggests that, perhaps, the ancestral releasing hormone precursors played a role in controlling energy metabolism and water balance, and that releasing hormone functions as present in extant vertebrates were probably secondarily acquired.
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Affiliation(s)
- Arnold De Loof
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven-University of Leuven, Belgium.
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Jedlička P, Steinbauerová V, Simek P, Zahradníčková H. Functional characterization of the adipokinetic hormone in the pea aphid, Acyrthosiphon pisum. Comp Biochem Physiol A Mol Integr Physiol 2012; 162:51-8. [PMID: 22357169 DOI: 10.1016/j.cbpa.2012.02.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 12/22/2022]
Abstract
Aphids are important plant phloem-sucking pests and detailed knowledge about the hormonal control of their metabolism can potentially contribute to the development of methods for their management. The insect metabolism is predominantly controlled by neuropeptides belonging to the adipokinetic hormone/red pigment-concentrating hormone family (AKH/RPCH). The main goal of this study was to obtain the sequence of AKH transcripts and analyze its expression in all polyphenic female forms of the pea aphid, Acyrthosiphon pisum. The neuropeptide is expressed in the brain of all female forms and in the ovaries of the both (wingless and winged) parthenogenetic forms. The form of active Acypi-AKH decapeptide was confirmed by the LC/MS and +ESI tandem mass spectrometry. The highest relative amount of Acypi-AKH was recorded in winged virginoparae. Furthermore, a potential role of this hormone when directly applied to the aphid was studied as well. Interestingly, no significant increase of trehalose in the wingless virginoparae after application of synthetic Acypi-AKH was detected. Yet this treatment did affect the level of protective polyol (mannitol) and furthermore led to increased activity of the detoxification enzyme glutathione S-transferase. The possible physiological function of AKH in A. pisum under the stress conditions is discussed.
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Affiliation(s)
- P Jedlička
- Institute of Entomology, Biology Centre AS CR, University of South Bohemia, Republic.
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Huang JH, Bellés X, Lee HJ. Functional Characterization of Hypertrehalosemic Hormone Receptor in Relation to Hemolymph Trehalose and to Oxidative Stress in the Cockroach Blattella germanica. Front Endocrinol (Lausanne) 2011; 2:114. [PMID: 22649400 PMCID: PMC3355951 DOI: 10.3389/fendo.2011.00114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 12/20/2011] [Indexed: 11/29/2022] Open
Abstract
Hypertrehalosemic hormone (HTH) is a peptide hormone that belongs to the adipokinetic hormone/red pigment concentrating hormone (AKH/RPCH) family, which exerts pleiotropic actions related to catabolic reaction and stress response. AKH peptides have been demonstrated to participate in stress response including oxidative stress in several insects. In order to study the signaling pathway of HTH involved in anti-oxidative stress, we have characterized a HIH receptor cDNA in Blattella germanica (Blage-HTHR) in structural and in functional terms using RNA interference (RNAi). Blage-HTHR is expressed in various female adult tissues (brain-CC-CA, ventral nerve cord, midgut, fat body, oviduct), but maximal expression is observed in the fat body. RNAi-mediated knockdown of Blage-HTHR expression results in a significantly lower level of hemolymph trehalose, even though HTH is exogenously administered. Paraquat elicits lethal oxidative stress in B. germanica, and co-injection of paraquat and HTH reduces this detrimental effect and extends the median survival time. Interestingly, the "rescue" effect of HTH on mortality caused by paraquat is diminished in specimens with depleted expression of Blage-HTH and Blage-HTHR. Finally, lipid peroxidation in the hemolymph increases 4 h after paraquat treatment, in comparison with control specimens or with HTH-treated specimens. However, lipid peroxidation induced by paraquat was not "rescued" by HTH in Blage-HTH and Blage-HTHR knockdown specimens. Our results demonstrate that HTH acts as a stress hormone mediating anti-oxidative protection in B. germanica, and that its receptor, Blage-HTHR, is essential for this action.
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Affiliation(s)
- Jia-Hsin Huang
- Department of Entomology, National Taiwan UniversityTaipei, Taiwan
| | - Xavier Bellés
- CSIC-UPF, Institute of Evolutionary BiologyBarcelona, Spain
| | - How-Jing Lee
- Department of Entomology, National Taiwan UniversityTaipei, Taiwan
- *Correspondence: How-Jing Lee, Department of Entomology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan. e-mail:
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