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Zhang Y, Li H, Lan Q, Liu X, Wu H, Zhang J, Zhao X, Wang Y. Sinuous Is a Claudin Required for Locust Molt in Locusta migratoria. Genes (Basel) 2024; 15:850. [PMID: 39062629 PMCID: PMC11275452 DOI: 10.3390/genes15070850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
The epidermal cells of insects are polarized epithelial cells that play a pivotal role in the insect's molting process. Sinuous, a pivotal structural protein involved in the formation of septate junctions among epithelial cells, is essential for its physiological function. In this study, to determine whether sinuous participates in the regulation of insect molting, we identified the sinuous gene, Lmsinu, in Locusta migratoria, which encodes a protein belonging to the claudin family and shares 62.6% identity with Drosophila's sinuous protein. Lmsinu is expressed in multiple tissues, and its expression level in the integument significantly increases prior to molting. Knockdown of Lmsinu in L. migratoria results in larval mortality during molting. Furthermore, hematoxylin and eosin and chitin staining demonstrate that the downregulation of Lmsinu led to a prolonged degradation process of the old cuticle during the molting process. Electron microscopy analysis further revealed that knockdown of Lmsinu disrupts the formation of septate junctions among epidermal cells, which are a monolayer of polarized epithelial cells, which may hinder the functionality of epidermal cells during the process of molting. In summary, these findings suggest that Lmsinu plays a role in nymph molting by regulating the formation of septate junctions among epidermal cells.
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Affiliation(s)
- Yichao Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
| | - Hongjing Li
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
- College of Life Science, Shanxi University, Taiyuan 030006, China
| | - Qiuyan Lan
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
- College of Life Science, Shanxi University, Taiyuan 030006, China
| | - Xiaoman Liu
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
- College of Life Science, Shanxi University, Taiyuan 030006, China
| | - Haihua Wu
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
| | - Jianzhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
| | - Xiaoming Zhao
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
| | - Yanli Wang
- Institute of Applied Biology, Shanxi University, Taiyuan 030006, China; (Y.Z.); (H.L.); (Q.L.); (X.L.); (H.W.); (J.Z.); (X.Z.)
- Shanxi Key Laboratory of Nucleic Acid Biopesticides, Taiyuan 030006, China
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Yuan H, Zhang W, Qiao H, Jin S, Jiang S, Xiong Y, Gong Y, Fu H. MnHR4 Functions during Molting of Macrobrachium nipponense by Regulating 20E Synthesis and Mediating 20E Signaling. Int J Mol Sci 2022; 23:ijms232012528. [PMID: 36293382 PMCID: PMC9604295 DOI: 10.3390/ijms232012528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 12/05/2022] Open
Abstract
HR4, a member of the nuclear receptor family, has been extensively studied in insect molting and development, but reports on crustaceans are still lacking. In the current study, the MnHR4 gene was identified in Macrobrachium nipponense. To further improve the molting molecular mechanism of M. nipponense, this study investigated whether MnHR4 functions during the molting process of M. nipponense. The domain, phylogenetic relationship and 3D structure of MnHR4 were analyzed by bioinformatics. Quantitative real-time PCR (qRT-PCR) analysis showed that MnHR4 was highly expressed in the ovary. In different embryo stages, the highest mRNA expression was observed in the cleavage stage (CS). At different individual stages, the mRNA expression of MnHR4 reached its peak on the fifteenth day after hatching (L15). The in vivo injection of 20-hydroxyecdysone (20E) can effectively promote the expression of the MnHR4 gene, and the silencing of the MnHR4 gene increased the content of 20E in M. nipponense. The regulatory role of MnHR4 in 20E synthesis and 20E signaling was further investigated by RNAi. Finally, the function of the MnHR4 gene in the molting process of M. nipponense was studied by counting the molting frequency. After knocking down MnHR4, the molting frequency of M. nipponense decreased significantly. It was proved that MnHR4 plays a pivotal role in the molting process of M. nipponense.
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Affiliation(s)
- Huwei Yuan
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Shubo Jin
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Yongsheng Gong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Hongtuo Fu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
- Correspondence: ; Tel.: +86-510-8555-8835
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Shen CH, Jin L, Fu KY, Guo WC, Li GQ. RNA interference targeting Ras GTPase gene Ran causes larval and adult lethality in Leptinotarsa decemlineata. PEST MANAGEMENT SCIENCE 2022; 78:3849-3858. [PMID: 35104039 DOI: 10.1002/ps.6822] [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: 10/27/2021] [Revised: 01/06/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND RNA interference (RNAi) is a breakthrough technology in pest control. It is highly efficient to Coleopteran pests such as the Colorado potato beetle Leptinotarsa decemlineata, a serious pest defoliator mainly attacking potatoes worldwide. The first step for effective pest control by RNAi is the development of effective and reliable target genes. RESULTS Our results revealed that continuous ingestion of dsLdRan for 3 days successfully silenced the target gene, inhibited larval growth and killed 100% L. decemlineata larvae. When the bioassay began at the second-, third/fourth-instar larval stages, the larval lethality mainly occurred at the fourth larval instar and prepupal stages, respectively. Importantly, consumption of dsLdRan for 3 days by the newly-emerged males and females effectively knocked down the target transcript, reduced fresh weights and caused 100% of lethality within a week. The LdRan females possessed underdeveloped ovaries. CONCLUSION Considering that the larvae, adults and eggs are simultaneously sited on the potato plants, bacterially-expressed dsLdRan is a potential RNAi-based strategy for managing L. decemlineata in the potato field. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Chen-Hui Shen
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Kai-Yun Fu
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China
- Key Laboratory of Intergraded Management of Harmful Crop Vermin of China North-western Oasis, Ministry of Agriculture, Urumqi, China
| | - Wen-Chao Guo
- Institute of Microbiological Application, Xinjiang Academy of Agricultural Science, Urumqi, China
| | - Guo-Qing Li
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Liu X, Li J, Sun Y, Liang X, Zhang R, Zhao X, Zhang M, Zhang J. A nuclear receptor HR4 is essential for the formation of epidermal cuticle in the migratory locust, Locusta migratoria. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 143:103740. [PMID: 35183732 DOI: 10.1016/j.ibmb.2022.103740] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 02/07/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Nuclear receptors (NRs) function as key factors in diverse signaling and metabolic pathways. Previous studies have focused on the roles of a nuclear receptor, hormone receptor 4 (HR4), mainly in holometabolous insects, while current knowledge of its function in hemimetabolous insects is still limited. In this study, we identified a HR4 gene in the orthopteran species Locusta migratoria. The full-length open reading frame of LmHR4 comprises 2694-nucleotides encoding a polypeptide of 897 amino acids, which contained a DNA-binding and a ligand-binding domain. Analyzing LmHR4 expression by quantitative reverse-transcription PCR (RT-qPCR) revealed that LmHR4 was highly expressed in integument, hindgut and fat body. During development from 3rd and 5th nymphal instars, the expression of LmHR4 reached maximal levels before ecdysis. We further demonstrated that LmHR4 expression is induced by 20-hydroxyecdysone (20E) and suppressed by silencing LmEcR, suggesting that LmHR4 expression is controlled by 20E signaling. The dsLmHR4-injected nymphs failed to molt and remained in the nymphal stage until death. Hematoxylin and eosin staining of the integument indicated that apolysis in the dsLmHR4-injected insects was delayed compared to that in control insects. Chitin staining and ultra-structural analysis showed that both the synthesis of the new cuticle and the degradation of the old cuticle were blocked in dsLmHR4-injected insects. Silencing LmHR4 decreased 20E titer and down-regulated the transcript levels of genes involved in chitin synthesis and degradation. Taken together, these results suggest that LmHR4 is essential for the formation of epidermal cuticle by mediating the 20E signaling to regulate the expression of chitin synthesis and degradation genes.
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Affiliation(s)
- Xiaojian Liu
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Juan Li
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Yawen Sun
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Xiaoyu Liang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Rui Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Xiaoming Zhao
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Min Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China.
| | - Jianzhen Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, 030006, China.
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Jia ZQ, Zhan EL, Zhang SG, Jones AK, Zhu L, Wang YN, Huang QT, Han ZJ, Zhao CQ. Sublethal doses of broflanilide prevents molting in the fall armyworm, Spodoptera frugiperda via altering molting hormone biosynthesis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 181:105017. [PMID: 35082040 DOI: 10.1016/j.pestbp.2021.105017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 11/26/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Broflanilide is a novel insecticide with a unique mode of action on the insect GABA receptor and is registered worldwide for the control of agricultural pests. It shows high efficacy in controlling the fall armyworm (FAW) Spodoptera frugiperda, which is a destructive pest to various crops. FAW was exposed to sublethal concentrations of broflanilide to determine its impact on insect development. Sublethal doses (LD10 and LD30) caused failure of ecdysis, reduced body length of larvae, malformation of pupae, and vestigial wing formation in adults. Also, broflanilide at LD30 significantly reduced the amount of molting hormone (MH). After exposure to LD10 or LD30 broflanilide, expression of five Halloween genes, which participate in MH biosynthesis, were found to be altered. Specifically, the transcript levels of SfrCYP307A1 (Spook), SfrCYP314A1 (Shade) and SfrCYP315A1 (Shadow) in 3rd day larvae were significantly decreased as well as SfrCYP302A1 (Disembodied) and SfrCYP306A1 (Phantom) in 5th day pupae. In contrast, the transcript levels of SfrCYP302A1 in 3rd day larvae, SfrCYP307A1 and SfrCYP314A1 in 5th day pupae, and SfrCYP306A1, SfrCYP307A1 and SfrCYP315A1 in 0.5th day adults were significantly increased. Our results demonstrate that broflanilide caused the failure of ecdysis in FAW possibly by influencing the intake of cholesterol through inhibition of feeding and also via altering expression of genes important for MH biosynthesis.
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Affiliation(s)
- Zhong Qiang Jia
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - En Ling Zhan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Su Gui Zhang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Andrew K Jones
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
| | - Lin Zhu
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Ying Nan Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Qiu Tang Huang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zhao Jun Han
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Chun Qing Zhao
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, PR China.
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Zhang Z, Ma Y, Ma X, Hu H, Wang D, Song X, Ren X, Ma Y. Combined Transcriptomic Analysis and RNA Interference Reveal the Effects of Methoxyfenozide on Ecdysone Signaling Pathway of Spodoptera exigua. Int J Mol Sci 2021; 22:ijms22169080. [PMID: 34445782 PMCID: PMC8396458 DOI: 10.3390/ijms22169080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/05/2022] Open
Abstract
Spodoptera exigua is a worldwide pest afflicting edible vegetables and has developed varying levels of resistance to insecticides. Methoxyfenozide (MET), an ecdysteroid agonist, is effective against lepidopteran pests such as S. exigua. However, the mechanism of MET to S. exigua remains unclear. In this study, we analyzed the expression patterns of genes related to the ecdysone signaling pathway in transcriptome data treated with sublethal doses of MET and analyzed how expression levels of key genes affect the toxicity of MET on S. exigua. Our results demonstrated that 2639 genes were up-regulated and 2512 genes were down-regulated in S. exigua treated with LC30 of MET. Of these, 15 genes were involved in the ecdysone signaling pathway. qPCR results demonstrated that ecdysone receptor A (EcRA) expression levels significantly increased in S. exigua when treated with different doses of MET, and that the RNAi-mediated silencing of EcRA significantly increased mortality to 55.43% at 72 h when L3 S. exigua larvae were exposed to MET at the LC30 dose. Additionally, knocking down EcRA suppressed the most genes expressed in the ecdysone signaling pathway. The combination of MET and dsEcRA affected the expression of E74 and enhanced the expression of TREA. These results demonstrate that the adverse effects of sublethal MET disturb the ecdysone signaling pathway in S. exigua, and EcRA is closely related to MET toxic effect. This study increases our collective understanding of the mechanisms of MET in insect pests.
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Affiliation(s)
- Zhixian Zhang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Yajie Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xiaoyan Ma
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Hongyan Hu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Dan Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xianpeng Song
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xiangliang Ren
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
- Correspondence: (X.R.); or (Y.M.)
| | - Yan Ma
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
- Correspondence: (X.R.); or (Y.M.)
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Wu JJ, Mu LL, Kang WN, Ze LJ, Shen CH, Jin L, Anjum AA, Li GQ. RNA interference targeting ecdysone receptor blocks the larval-pupal transition in Henosepilachna vigintioctopunctata. INSECT SCIENCE 2021; 28:419-429. [PMID: 32162469 DOI: 10.1111/1744-7917.12777] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/19/2020] [Accepted: 03/08/2020] [Indexed: 05/10/2023]
Abstract
Henosepilachna vigintioctopunctata is a serious insect pest which attacks a large number of nightshades and cucurbits in Asian countries, Brazil and Australia. Prolonged application of traditional pesticides has caused environmental pollution and exerted deleterious effects on human health. Finding new approaches with high target specificity and low environmental contamination has become an urgent task. RNA interference (RNAi) induced by double-stranded RNA (dsRNA) is expected to be applicable to managing this pest. Here we evaluated the effects of Escherichia coli-expressed dsRNAs targeting ecdysone receptor (EcR) gene via dietary delivery in laboratory and foliar spraying in a greenhouse. The target transcript was successfully knocked down when the 4th-instar larvae had fed on potato foliage dipped with dsEcR in a laboratory bioassay. Around 85% of the HvEcR RNAi larvae remained as prepupae or became abnormal pupae, and failed to emerge into adults. Ingestion of dsEcR-immersed foliage by the 3rd-instar larvae effectuated a comparable RNAi response and brought about more severe defects: all the resultant larvae arrested development, remained as prepupae and finally died. For assay in the greenhouse, a dsEcR-contained E. coli suspension was directly sprayed to the foliage of greenhouse-growing potato plants and the 3rd- and 4th-instar larvae were transferred to the leaves. High RNAi efficacy was obtained and identical RNAi phenotypes were observed in treated larvae. In addition, spraying dsEcR reduced leaf damage. Our results indicate a possibility of practical application of dsEcR as an environmentally friendly RNA pesticide to control H. vigintioctopunctata larvae.
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Affiliation(s)
- Jian-Jian Wu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Li-Li Mu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Wei-Nan Kang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Long-Ji Ze
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Chen-Hui Shen
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ahmad Ali Anjum
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Shen CH, Xu QY, Fu KY, Guo WC, Jin L, Li GQ. Two Splice Isoforms of Leptinotarsa Ecdysis Triggering Hormone Receptor Have Distinct Roles in Larva-Pupa Transition. Front Physiol 2020; 11:593962. [PMID: 33335488 PMCID: PMC7736071 DOI: 10.3389/fphys.2020.593962] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/11/2020] [Indexed: 12/13/2022] Open
Abstract
Insect ecdysis triggering hormone (ETH) receptors (ETHRs) are rhodopsin-like G protein-coupled receptors. Upon binding its ligand ETH, ETHR initiates a precisely programed ecdysis behavior series and physiological events. In Drosophila melanogaster, the ethr gene produces two functionally distinct splicing isoforms, ethra and ethrb. ETH/ETHRA activates eclosion hormone (EH), kinin, crustacean cardioactive peptide (CCAP), and bursicon (burs and pburs) neurons, among others, in a rigid order, to elicit the behavioral sequences and physiological actions for ecdysis at all developmental stages, whereas ETH/ETHRB is required at both pupal and adult ecdysis. However, the role of ETHRB in regulation of molting has not been clarified in any non-drosophila insects. In the present paper, we found that 20-hydroxyecdysone (20E) signaling triggers the expression of both ethra and ethrb in a Coleopteran insect pest, the Colorado potato beetle Leptinotarsa decemlineata. RNA interference (RNAi) was performed using double-stranded RNAs (dsRNAs) targeting the common (dsethr) or isoform-specific (dsethra, dsethrb) regions of ethr. RNAi of dsethr, dsethra, or dsethrb by the final-instar larvae arrested larva development. The arrest was not rescued by feeding 20E. All the ethra depleted larvae stopped development at prepupae stage; the body cavity was expanded by a large amount of liquid. Comparably, more than 80% of the ethrb RNAi larvae developmentally halted at the prepupae stage. The remaining Ldethrb hypomorphs became pupae, with blackened wings and highly-expressed burs, pburs and four melanin biosynthesis genes. Therefore, ETHRA and ETHRB play isoform-specific roles in regulation of ecdysis during larva-pupa transition in L. decemlineata.
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Affiliation(s)
- Chen-Hui Shen
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qing-Yu Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Kai-Yun Fu
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China
| | - Wen-Chao Guo
- Institute of Microbiological Application, Xinjiang Academy of Agricultural Science, Urumqi, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Petek M, Coll A, Ferenc R, Razinger J, Gruden K. Validating the Potential of Double-Stranded RNA Targeting Colorado Potato Beetle Mesh Gene in Laboratory and Field Trials. FRONTIERS IN PLANT SCIENCE 2020; 11:1250. [PMID: 32973826 PMCID: PMC7466441 DOI: 10.3389/fpls.2020.01250] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/29/2020] [Indexed: 05/25/2023]
Abstract
Colorado potato beetle (CPB) is an agricultural pest of solanaceous crops, notorious for its rapid resistance development to chemical pesticides. Foliar spraying of dsRNA formulations is a promising innovative technology providing highly specific and environmentally acceptable option for CPB management. We designed dsRNA to silence CPB mesh gene (dsMESH) and performed laboratory feeding trials to assess impacts on beetle survival and development. We compared the effectiveness of in vivo and in vitro produced dsRNA in a series of laboratory experiments. We additionally performed a field trial in which the efficacy of dsRNA sprayed onto potato foliage was compared to a spinosad-based insecticide. We showed that dsMESH ingestion consistently and significantly impaired larval growth and decreased larval survival in laboratory feeding experiments. In vivo produced dsRNA performed similarly as in vitro synthesized dsRNA in laboratory settings. In the field trial, dsMESH was as effective in controlling CPB larvae as a commercial spinosad insecticide, its activity was however slower. We discuss limitations and benefits of a potential dsMESH-based CPB management strategy and list some important RNAi based CPB research topics, which will have to be addressed in future.
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Affiliation(s)
- Marko Petek
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Anna Coll
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Rok Ferenc
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Jaka Razinger
- Plant Protection Department, Agricultural Institute of Slovenia, Ljubljana, Slovenia
| | - Kristina Gruden
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
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Shen CH, Xu QY, Mu LL, Fu KY, Guo WC, Li GQ. Involvement of Leptinotarsa hormone receptor 38 in the larval-pupal transition. Gene 2020; 751:144779. [DOI: 10.1016/j.gene.2020.144779] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/16/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022]
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11
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Xu Q, Deng P, Zhang Q, Li A, Fu K, Guo W, Li G. Ecdysone receptor isoforms play distinct roles in larval-pupal-adult transition in Leptinotarsa decemlineata. INSECT SCIENCE 2020; 27:487-499. [PMID: 30688001 PMCID: PMC7277042 DOI: 10.1111/1744-7917.12662] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/31/2018] [Accepted: 01/22/2019] [Indexed: 05/25/2023]
Abstract
A heterodimer of two nuclear receptors, ecdysone receptor (EcR) and ultraspiracle, mediates 20-hydroxyecdysone (20E) signaling to modulate many aspects in insect life, such as molting and metamorphosis, reproduction, diapause and innate immunity. In the present paper, we intended to determine the isoform-specific roles of EcR during larval-pupal-adult transition in the Colorado potato beetle. Double-stranded RNAs (dsRNAs) were prepared using the common (dsEcR) or isoform-specific (dsEcRA, dsEcRB1) regions of EcR as templates. Ingestion of either dsEcR or dsEcRA, rather than dsEcRB1, by the penultimate (3rd) and final (4th) instar larvae caused failure of larval-pupal and pupal-adult ecdysis. The RNA interference (RNAi) larvae remained as prepupae, or became deformed pupae and adults. Determination of messenger RNA (mRNA) levels of EcR isoforms found that LdEcRA regulates the expression of LdEcRB1. Moreover, silencing the two EcR transcripts, LdEcRA or LdEcRB1 reduced the mRNA levels of Ldspo and Ldsad, and lowered 20E titer. In contrast, the expression levels of HR3, HR4, E74 and E75 were significantly decreased in the LdEcR or LdEcRA RNAi larvae, but not in LdEcRB1 depleted specimens. Dietary supplement with 20E did not restore the expression of five 20E signaling genes (USP, HR3, HR4, E74 and E75), and only partially alleviated the pupation defects in dsEcR- or dsEcRA-fed beetles. These data suggest that EcR plays isoform-specific roles in the regulation of ecdysteroidogenesis and the transduction of 20E signal in L. decemlineata.
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Affiliation(s)
- Qing‐Yu Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Pan Deng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Qiong Zhang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Ang Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Kai‐Yun Fu
- Institute of Plant ProtectionXinjiang Academy of Agricultural SciencesUrumqiChina
| | - Wen‐Chao Guo
- Institute of Microbiological ApplicationXinjiang Academy of Agricultural ScienceUrumqiChina
| | - Guo‐Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
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12
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Xu QY, Deng P, Li A, Zhang Q, Mu LL, Fu KY, Guo WC, Li GQ. Functional characterization of ultraspiracle in Leptinotarsa decemlineata using RNA interference assay. INSECT MOLECULAR BIOLOGY 2019; 28:676-688. [PMID: 30834617 DOI: 10.1111/imb.12580] [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
A heterodimer of ultraspiracle (USP) and ecdysone receptor (EcR) mediates 20-hydroxyecdysone (20E) signalling cascade to regulate insect moulting and metamorphosis. However, at least two questions remain to be addressed in terms of the molecular importance of USP in insect species. First, is USP involved in both regulation of ecdysteroidogenesis and mediation of 20E signalling in non-drosophilid insects, as in Drosophila melanogaster? Second, does USP play any role in larval metamorphosis except as the partner of heterodimeric receptor to activate the downstream 20E signalling genes? In this paper, we found that RNA interference (RNAi) of LdUSP in the final (fourth) instar larvae reduced the messenger RNA levels of four ecdysteroidogenesis genes (Ldspo, Ldphm, Lddib and Ldsad) and 20E titre, and repressed the expression of five 20E signal genes (EcRA, HR3, HR4, E74 and E75) in Leptinotarsa decemlineata. The LdUSP RNAi larvae remained as prepupae, with developing antennae, legs and discs of forewings and hindwings. Dietary supplement with 20E restored the expression of the five 20E signal genes, but only partially alleviated the decreased pupation rate in LdUSP RNAi beetles. Knockdown of LdUSP at the penultimate (third) instar larvae did not affect third-fourth instar moulting. However, silencing LdUSP caused similar but less severe impairments on pupation. Accordingly, we propose that USP is undoubtedly necessary for ecdysteroidogenesis, for mediation of 20E signalling and for initiation of metamorphosis in L. decemlineata.
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Affiliation(s)
- Q-Y Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - P Deng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - A Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Q Zhang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - L-L Mu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - K-Y Fu
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China
- Key Laboratory of Integrated Management of Harmful Crop Vermin of China North-western Oasis, Ministry of Agriculture, Urumqi, China
| | - W-C Guo
- Institute of Microbiological Application, Xinjiang Academy of Agricultural Science, Urumqi, China
| | - G-Q Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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13
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Xu QY, Meng QW, Deng P, Fu KY, Guo WC, Li GQ. Impairment of pupation by RNA interference-aided knockdown of Broad- Complex gene in Leptinotarsa decemlineata (Say). BULLETIN OF ENTOMOLOGICAL RESEARCH 2019; 109:659-668. [PMID: 30704539 DOI: 10.1017/s0007485318001050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dietary delivery of bacterially expressed double-stranded RNA (dsRNA) has a great potential for management of Leptinotarsa decemlineata. An important first step is to discover possible RNA-interference (RNAi)-target genes effective against larvae, especially the old larvae. In the present paper, five putative Broad-Complex (BrC) cDNAs (Z1-Z4, and Z6) were identified in L. decemlineata. The expression of the five LdBrC isoforms was suppressed by juvenile hormone signaling, whereas the transcription was upregulated by 20-hydroxyecdysone signaling at the fourth (final) instar larval stage. Feeding of bacterially expressed dsBrC (derived from a common fragment of the five LdBrC variants) in the third- and fourth-instar larvae successfully knocked down the target mRNAs. For the fourth-instar LdBrC RNAi hypomorphs, they had a higher larval mortality compared with the controls. Moreover, most dsBrC-fed beetles did not pupate normally. After removal of the apolysed larval cuticle, a miniature adult was found. The adult head, compound eyes, prothorax, mesothorax, metathorax were found on the dorsal view. Distinct adult cuticle pigmentation was seen on the prothorax. The mouthparts, forelegs, midlegs, and hindlegs could be observed on the ventral view of the miniature adults. For the third-instar LdBrC RNAi specimens, around 20% moribund beetles remained as prepupae and finally died. Therefore, LdBrC is among the most attractive candidate genes for RNAi to control the fourth-instar larvae in L. decemlineata.
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Affiliation(s)
- Q-Y Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Q-W Meng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - P Deng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - K-Y Fu
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - W-C Guo
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - G-Q Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
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14
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Xu QY, Deng P, Mu LL, Fu KY, Guo WC, Li GQ. Silencing Taiman impairs larval development in Leptinotarsa decemlineata. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 160:30-39. [PMID: 31519255 DOI: 10.1016/j.pestbp.2019.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/19/2019] [Accepted: 06/23/2019] [Indexed: 06/10/2023]
Abstract
An exploration of novel control strategies for Leptinotarsa decemlineata is becoming more pressing given rapid evolution of insecticide resistance and rise of production loss of potato. Dietary delivery of bacterially expressed double-stranded RNA (dsRNA) is a promising alternative for management. An important first step is to uncover possible RNA-interference (RNAi)-target genes effective against both young and old larvae. Taiman (Tai) is a basic-helix-loop-helix/Per-Arnt-Sim transcription factor that is involved in the mediation of both juvenile hormone (JH) and 20-hydroxyecdysone (20E) signaling. In the present paper, we found that continuous ingestion of dsTai for three days by third (penultimate)-instar larvae caused approximately 20% larval mortality and 80% pupation failure. The larval lethality resulted from failed cuticle and tracheae shedding, which subsequently reduced foliage consumption and nutrient absorption, and depleted lipid stores. In contrast, pupation failure derived from disturbed JH and 20E signals, and disordered nutrient homeostasis including, among others, inhibition of trehalose metabolism and reduction of chitin content. Knockdown of LdTai caused similar larval lethality and pupation impairment in second and fourth (final) larval instars. Therefore, LdTai is among the most attractive candidate genes for RNAi to control L. decemlineata larvae.
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Affiliation(s)
- Qing-Yu Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Pan Deng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Li-Li Mu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Kai-Yun Fu
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; Key Laboratory of Intergraded Management of Harmful Crop Vermin of China North-western Oasis, Ministry of Agriculture, China
| | - Wen-Chao Guo
- Institute of Microbiological Application, Xinjiang, Academy of Agricultural Science; Urumqi, 830091, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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15
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Xu QY, Du JL, Mu LL, Guo WC, Li GQ. Importance of Taiman in Larval-Pupal Transition in Leptinotarsa decemlineata. Front Physiol 2019; 10:724. [PMID: 31263425 PMCID: PMC6584964 DOI: 10.3389/fphys.2019.00724] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 05/27/2019] [Indexed: 02/01/2023] Open
Abstract
Insect Taiman (Tai) binds to methoprene-tolerant to form a heterodimeric complex, mediating juvenile hormone (JH) signaling to regulate larval development and to prevent premature metamorphosis. Tai also acts as a steroid receptor coactivator of 20-hydroxyecdysone (20E) receptor heterodimer, ecdysone receptor (EcR) and Ultraspiracle (USP), to control the differentiation of early germline cells and the migration of specific follicle cells and border cells in ovaries in several insect species. In holometabolous insects, however, whether Tai functions as the coactivator of EcR/USP to transduce 20E message during larval-pupal transition is unknown. In the present paper, we found that the LdTai mRNA levels were positively correlated with circulating JH and 20E titers in Leptinotarsa decemlineata; and ingestion of either JH or 20E stimulated the transcription of LdTai. Moreover, RNA interference (RNAi)-aided knockdown of LdTai at the fourth (final) instar stage repressed both JH and 20E signals, inhibited larval growth and shortened larval developing period. The knockdown caused 100% larval lethality due to failure of larval-pupal ecdysis. Under the apolysed larval cuticle, the LdTai RNAi prepupae possessed pupal thorax. In contrast, the process of tracheal ecdysis was uncompleted. Neither JH nor 20E rescued the aforementioned defectives in LdTai RNAi larvae. It appears that Tai mediates both JH and 20E signaling. Our results uncover a link between JH and 20E pathways during metamorphosis in L. decemlineata.
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Affiliation(s)
- Qing-Yu Xu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jun-Li Du
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.,College of Agriculture, Anhui Science and Technology University, Fengyang, China
| | - Li-Li Mu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Wen-Chao Guo
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China.,Key Laboratory of Intergraded Management of Harmful Crop Vermin of China North-Western Oasis, Ministry of Agriculture, Urumqi, China
| | - Guo-Qing Li
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Wu JJ, Chen ZC, Wang YW, Fu KY, Guo WC, Li GQ. Silencing chitin deacetylase 2 impairs larval-pupal and pupal-adult molts in Leptinotarsa decemlineata. INSECT MOLECULAR BIOLOGY 2019; 28:52-64. [PMID: 30058750 DOI: 10.1111/imb.12524] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Insect chitin deacetylases (CDAs) are carbohydrate esterases that catalyze N-deacetylation of chitin to generate chitosan, a process essential for chitin organization and compactness during the formation of extracellular chitinous structure. Here we identified two CDA2 splice variants (LdCDA2a and LdCDA2b) in Leptinotarsa decemlineata. Both splices were abundantly expressed in larval foregut, rectum, and epidermis; their levels peaked immediately before ecdysis within each instar. In vivo results revealed that the two isoforms transcriptionally responded, positively and negatively respectively, to 20-hydroxyecdysone and juvenile hormone signaling pathways. RNA interference (RNAi)-aided knockdown of the two LdCDA2 variants (hereafter LdCDA2) or LdCDA2b, rather than LdCDA2a, resulted in three negative effects. First, foliage consumption was significantly reduced, larval developing period was lengthened, and larval growth was retarded. Second, chitin contents were reduced, whereas glucose, trehalose, and glycogen contents were increased in the LdCDA2 and LdCDA2b RNAi larvae. Third, approximately 20% of LdCDA2 and LdCDA2b RNAi larvae were trapped within the exuviae and finally died. About 60% of the abnormal pupae died as pharate adults. Around 20% of the RNAi pupae emerged as deformed adults, with small size and wrinkled wings. These adults eventually died within 1 week after molting. Our results reveal that knockdown of CDA2 affects chitin accumulation. Consequently, LdCDA2 may be a potential target for control of L. decemlineata larvae.
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Affiliation(s)
- J-J Wu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Z-C Chen
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Y-W Wang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - K-Y Fu
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China
| | - W-C Guo
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China
- Xinjiang Laboratory of Special Environmental Microbiology, Institute of Microbiology, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China
| | - G-Q Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
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Deng P, Xu QY, Fu KY, Guo WC, Li GQ. RNA interference against the putative insulin receptor substrate gene chico affects metamorphosis in Leptinotarsa decemlineata. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 103:1-11. [PMID: 30296480 DOI: 10.1016/j.ibmb.2018.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 09/30/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
It is noted that insect insulin/insulin-like growth factor/target of rapamycin signaling is critical for the regulation of metamorphosis in holometabolous insects. However, the molecular mechanism remains undetermined. Our previous findings reveal that RNA interference (RNAi)-mediated knockdown of an insulin gene (LdILP2) in Leptinotarsa decemlineata disturbs both 20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling, and impairs pupation. In the present paper, we further observed that the expression of the insulin receptor substrate gene chico (Ldchico) and the phosphoinositide-3-kinase gene pi3k (Ldpi3k92E) was repressed in LdILP2 depleted larvae. Moreover, RNAi of Ldchico or Ldpi3k92E decreased food consumption, affected absorption and metabolism of amino acids and sugars, and reduced expression of several 20E (LdEcR, LdHR3 and LdE75) and JH (LdJHAMT, LdKr-h1 and LdHairy) signaling genes. As a result, larval development was postponed and larval growth was inhibited. Intriguingly, knockdown of Ldchico, rather than Ldpi3k92E, impaired larval-pupal and pupal-adult ecdysis, and specifically repressed transcription of another 20E signaling gene LdUSP. Ingestion of 20E rescued the expression of LdEcR, LdHR3 and LdE75, whereas 20E feeding restored neither the decreased LdUSP mRNA level, nor the reduced pupation and adult emergence rates in Ldchico RNAi larvae. Therefore, Chico is critical for the regulation of larval-pupal-adult transition by a PI3K-independent pathway, perhaps through activation of USP in L. decemlineata.
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Affiliation(s)
- Pan Deng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Qing-Yu Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Kai-Yun Fu
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China.
| | - Wen-Chao Guo
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China; Xinjiang Laboratory of Special Environmental Microbiology, Institute of Microbiology, Xinjiang Academy of Agricultural Sciences, Urumqi, 830091, China.
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
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