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Shi JF, Cheng MH, Zhou W, Zeng MZ, Chen Y, Yang JX, Wu H, Ye QH, Tang H, Zhang Q, Fu KY, Guo WC. Crucial roles of specialized chitinases in elytral and hindwing cuticles construction in Leptinotarsa decemlineata. PEST MANAGEMENT SCIENCE 2024; 80:4437-4449. [PMID: 38656531 DOI: 10.1002/ps.8141] [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: 01/15/2024] [Revised: 03/25/2024] [Accepted: 04/24/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND The Colorado potato beetle (CPB), Leptinotarsa decemlineata, is a major potato (Solanum tuberosum) pest, infesting over 16 million km2 and causing substantial economic losses. The insect cuticle forms an apical extracellular matrix (ECM) envelope covering exposed organs to direct morphogenesis and confer structural protection. While select chitinase (Cht) genes have proven essential for larval development, their potential activities directing ECM remodeling underlying adult wing maturation remain undefined. RESULTS We investigated the expression patterns and performed an oral RNA interference (RNAi) screen targeting 19 LdChts in late-instar L. decemlineata larvae. Subsequently, we assessed their effects on adult eclosion and wing characteristics. Knockdown of LdCht5, LdCht7, LdCht10, LdIDGF2, and LdIDGF4, as well as others from Group IV (LdCht15, LdCht12, LdCht17, and LdCht13) and Groups VII-X (LdCht2, LdCht11, LdCht1, and LdCht3), resulting in shrunken, misshapen elytra with reduced areal density, as well as transverse wrinkling and impaired wing-tip folding in hindwings. Scanning electron micrographs revealed eroded elytral ridges alongside thinned, ruptured hindwing veins, indicative of mechanical fragility post-LdCht suppression. Spectroscopic analysis uncovered biomolecular alterations underlying the elytral anomalies, including decreases in peaks representing chitin, proteins, and lipids. This loss of essential ECM components provides evidence for the fragility, wrinkling, and shrinkage observed in the RNAi groups. CONCLUSION Our findings elucidate the crucial role of chitinases in the turnover of chitinous cuticles on beetle wings, offering insights into RNAi-based control strategies against this invasive pest. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Ji-Feng Shi
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Man-Hong Cheng
- Chongqing College of Humanities, Science and Technology, Chongqing, China
| | - Wei Zhou
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Mu-Zi Zeng
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Yu Chen
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Jia-Xin Yang
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Hao Wu
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Qiu-Hong Ye
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Hong Tang
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Qing Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Kai-Yun Fu
- Ministry of Agriculture/Xinjiang Key Laboratory of Agricultural Biosafety, Institute of Plant Protection Xinjiang Academy of Agricultural Sciences/Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Urumqi, China
| | - Wen-Chao Guo
- Ministry of Agriculture/Xinjiang Key Laboratory of Agricultural Biosafety, Institute of Plant Protection Xinjiang Academy of Agricultural Sciences/Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Urumqi, China
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Zeng QH, Gong MF, Yang H, Chen NN, Lei Q, Jin DC. Effect of four chitinase genes on the female fecundity in Sogatella furcifera (Horváth). PEST MANAGEMENT SCIENCE 2024; 80:1912-1923. [PMID: 38088492 DOI: 10.1002/ps.7933] [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: 06/05/2023] [Revised: 10/18/2023] [Accepted: 12/13/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND The white-backed planthopper (WPH), Sogatella furcifera (Horváth), is a destructive rice pest with strong reproductive capacity. To gain insights into the roles of chitinases in the reproductive process of this insect species, this study represents the first-ever endeavor to conduct an in-depth exploration into the reproductive functions of four chitinase genes. RESULTS In this study, it was observed that four chitinase genes were expressed in female adults, with a relatively high expression level in the ovaries. SfCht2 and SfIDGF1 were highly expressed during later ovarian development. while SfENGase increased and then decreased with ovarian development. SfCht2, SfCht6-2 and SfENGase were highly expressed in fat body on the first and second days after eclosion, whereas SfIDGF1 highest on day 7. Compared with control group, Silencing four chitinase genes inhibited ovarian development and significantly shortened the oviposition period of S. furcifera, reducing egg-laying capacity but not affecting egg hatching. The detection demonstrated that the expression levels of SfVg, SfVgR and 70-90% juvenile hormone (JH) signaling pathway-related reproductive genes was significantly down-regulated. Moreover, SfCht6-2 and SfENGase significantly affected the expression levels of Target of Rapamycin (TOR) signaling pathway genes. SfENGase had the ability to impact nutrient signaling pathways and fatty acid metabolism, repressing vitellogenin synthesis and ultimately influencing ovarian development of S. furcifera. CONCLUSIONS Overall, this study provides insight into the function of chitinases in insect fecundity and is of great significance for enriching the cognition of insect chitinase function. They will become the suitable target genes for controlling the most destructive rice planthoppers. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Qing-Hui Zeng
- Institute of Entomology, Guizhou University, Guiyang, China
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China Guiyang, Guiyang, China
| | - Ming-Fu Gong
- Institute of Entomology, Guizhou University, Guiyang, China
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China Guiyang, Guiyang, China
| | - Hong Yang
- Institute of Entomology, Guizhou University, Guiyang, China
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China Guiyang, Guiyang, China
| | - Ning-Nan Chen
- Plant Protection 2020, Agricultural College of Guizhou University, Guiyang, China
| | - Qing Lei
- Plant Protection 2020, Agricultural College of Guizhou University, Guiyang, China
| | - Dao-Chao Jin
- Institute of Entomology, Guizhou University, Guiyang, China
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous Region, Scientific Observing and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China Guiyang, Guiyang, China
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Chen Y, Tang H, Zhou W, Li C, Chen YN, Zhang Q, Fu KY, Guo WC, Shi JF. Identification of chitinase genes and roles in the larval-pupal transition of Leptinotarsa decemlineata. PEST MANAGEMENT SCIENCE 2024; 80:282-295. [PMID: 37671631 DOI: 10.1002/ps.7754] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/12/2023] [Accepted: 09/06/2023] [Indexed: 09/07/2023]
Abstract
BACKGROUND Insect chitinases play crucial roles in degrading chitin in the extracellular matrix, affecting insect development and molting. However, our understanding of the specific functions of various chitinases in Leptinotarsa decemlineata is limited, hindering the deployment of novel gene-targeting technologies as pest management strategies. RESULTS We identified and characterized 19 full-length complementary DNA (cDNA) sequences of chitinase genes (LdChts) in Leptinotarsa decemlineata. Despite having varying domain architectures, all these chitinases contained at least one chitinase catalytic domain. Phylogenetic analysis classified the chitinase proteins into ten distinct clusters (groups I-X). Expression profiles showed the highest expression in chitin-rich tissues or during specific developmental stages from the larva-to-pupa transition. Gene-specific RNA interference (RNAi) experiments provided valuable insight into chitinase gene function. Silencing of group II LdCht10 prevented larval-larval molting, larval-prepupal, and prepupal-pupal processes. Moreover, our study revealed that LdCht5, LdCht2, LdCht11, LdCht1, and LdCht3 from groups I and VII-X were specifically essential for the transition from prepupal to pupal stage, whereas LdIDGF2 from group V was necessary for the larval-prepupal metamorphic process. The chitinase gene LdCht7 from group III and LdIDGF4 from group V were involved in both the larva-to-prepupa and the prepupa-to-pupa shift. Additionally, our findings also shed light on the exclusive expression of nine chitinase genes within group IV in the digestive system, suggesting their potential role in regulating larval body weight and larva-to-pupa transition. CONCLUSION Our results provide a comprehensive understanding of the functional specialization of chitinase genes during the molting process of various stages and identify potential targets for RNAi-based management of Leptinotarsa decemlineata. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Yu Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Hong Tang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Wei Zhou
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Chang Li
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Yi-Nan Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Qing Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Kai-Yun Fu
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China
| | - Wen-Chao Guo
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China
| | - Ji-Feng Shi
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
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Rabadiya D, Behr M. The biology of insect chitinases and their roles at chitinous cuticles. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 165:104071. [PMID: 38184175 DOI: 10.1016/j.ibmb.2024.104071] [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: 09/29/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024]
Abstract
Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation, and degradation. Sequencing of the Drosophila genome more than twenty years ago revealed that insect genomes contain a number of chitinases, but why insects need so many different chitinases was unclear. Here, we focus on insect GH18 family chitinases and discuss their participation in chitin matrix formation and degradation. We describe their variations in terms of temporal and spatial expression patterns, molecular function, and physiological consequences at chitinous cuticles. We further provide insight into the catalytic mechanisms by discussing chitinase protein domain structures, substrate binding, and enzymatic activities with respect to structural analysis of the enzymatic GH18 domain, substrate-binding cleft, and characteristic TIM-barrel structure.
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Affiliation(s)
- Dhyeykumar Rabadiya
- Cell & Developmental Biology, Institute for Biology, Leipzig University, Philipp-Rosenthal-Str. 55, 04103, Leipzig, Germany
| | - Matthias Behr
- Cell & Developmental Biology, Institute for Biology, Leipzig University, Philipp-Rosenthal-Str. 55, 04103, Leipzig, Germany.
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Lee Y, Muthukrishnan S, Kramer KJ, Sakamoto T, Tabunoki H, Arakane Y, Noh MY. Functional importance of groups I and II chitinases in cuticle chitin turnover during molting in a wood-boring beetle, Monochamus alternatus. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 194:105496. [PMID: 37532355 DOI: 10.1016/j.pestbp.2023.105496] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/05/2023] [Accepted: 06/10/2023] [Indexed: 08/04/2023]
Abstract
Insects must periodically replace their old cuticle/exoskeleton with a new one in a process called molting or ecdysis to allow for continuous growth through sequential developmental stages. Many RNA interference (RNAi) studies have demonstrated that certain chitinases (CHTs) play roles in this vital physiological event because knockdown of these CHT genes resulted in developmental arrest during the ensuing molting period in several insect species. In this research we analyzed the functions of group I (MaCHT5) and group II (MaCHT10) CHT genes in molting of the Japanese pine sawyer, Monochamus alternatus, an important forest pest known as a major vector of the pinewood nematode. Real-time qPCR revealed that these two CHT genes differ in their expression patterns during late stages of development. Depletion of either MaCHT5 or MaCHT10 transcripts by RNAi resulted in lethal larval-pupal and pupal-adult molting defects depending on the double-stranded RNA (dsRNA) injection timing during development. The insects were unable to shed their old cuticle and died. Furthermore, transmission electron microscopic analysis revealed that, unlike dsEGFP-treated controls, dsMaCHT5- and dsMaCHT10-treated pharate adults exhibited a failure of degradation of the endocuticular layer of their old pupal cuticle, retaining nearly intact horizontal chitinous laminae and vertical pore canal fibers. Both enzymes were indispensable for complete turnover of the chitinous old endocuticle, which is critical for insect molting. The possible functions of two spliced variants of MaCHT10, namely, MaCHT10a and MaCHT10b, are also discussed. Our results add to the knowledge base for further functional studies of insect chitin catabolism by revealing the relative importance of both MaCHT5 and MaCHT10 in chitin turnover with subtle differences in their action. These essential genes and their encoded proteins are potential targets to manipulate for controlling populations of M. alternatus and other pest insects.
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Affiliation(s)
- Youngseo Lee
- Department of Forest Resources, AgriBio Institute of Climate Change Management, Chonnam National University, Gwangju 61186, South Korea
| | - Subbaratnam Muthukrishnan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Chalmers Hall, Manhattan, Kansas 66506, USA
| | - Karl J Kramer
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Chalmers Hall, Manhattan, Kansas 66506, USA
| | - Takuma Sakamoto
- Department of Science of Biological Production, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Hiroko Tabunoki
- Department of Science of Biological Production, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Yasuyuki Arakane
- Department of Applied Biology, Chonnam National University, Gwangju 61186, South Korea.
| | - Mi Young Noh
- Department of Forest Resources, AgriBio Institute of Climate Change Management, Chonnam National University, Gwangju 61186, South Korea.
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