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Chen C, Hu Z, Zheng X, Yuan J, Zou R, Wang Y, Peng X, Xie C. The essential role of arginine biosynthetic genes in lunate conidia formation, conidiation, mycelial growth, and virulence of nematophagous fungus, Esteya vermicola CBS115803. PEST MANAGEMENT SCIENCE 2024; 80:786-796. [PMID: 37781870 DOI: 10.1002/ps.7809] [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: 06/16/2023] [Revised: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 10/03/2023]
Abstract
BACKGROUND The pinewood nematode (Bursaphelenchus xylophilus) causes severe damage to pine trees. The nematophagous fungus, Esteya vermicola, exhibits considerable promise in the biological control of Bursaphelenchus xylophilus due to its infectivity. Notably, the lunate conidia produced by E. vermicola can infect Bursaphelenchus xylophilus. In the study, we aim to investigate the genes involved in the formation of the lunate conidia of E. vermicola CBS115803. RESULTS Esteya vermicola CBS115803 yielded 95% lunate conidia on the complete medium (CM) and 86% bacilloid conidia on the minimal medium (MM). Transcriptomic analysis of conidia from both media revealed a significant enrichment of differentially expressed genes in the pathway related to 'cellular amino acid biosynthesis and metabolism'. Functional assessment showed that the knockout of two arginine biosynthesis genes (EV232 and EV289) resulted in defects in conidia germination, mycelial growth, lunate conidia formation, and virulence of E. vermicola CBS115803 in Bursaphelenchus xylophilus. Remarkably, the addition of arginine to the MM improved mycelial growth, conidiation and lunate conidia formation in the mutants and notably increased conidia yield and the lunate conidia ratio in the wild-type E. vermicola CBS115803. CONCLUSION This investigation confirms the essential role of two arginine biosynthesis genes in lunate conidia formation in E. vermicola CBS115803. The findings also suggest that the supplementation of arginine to the culture medium can enhance the lunate conidia yield. These insights contribute significantly to the application of E. vermicola CBS115803 in managing Bursaphelenchus xylophilus infections. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Chi Chen
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Zhijuan Hu
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Xinyao Zheng
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Jingjie Yuan
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Run Zou
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Yilan Wang
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Xuan Peng
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
| | - Chengjian Xie
- Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, China
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Li D, Li Y, Wang X, Zhang W, Wen X, Liu Z, Feng Y, Zhang X. Engineered pine endophytic Bacillus toyonensis with nematocidal and colonization abilities for pine wilt disease control. Front Microbiol 2023; 14:1240984. [PMID: 38125565 PMCID: PMC10731049 DOI: 10.3389/fmicb.2023.1240984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 11/07/2023] [Indexed: 12/23/2023] Open
Abstract
Introduction The pinewood nematode (PWN) is responsible for causing pine wilt disease (PWD), which has led to the significant decline of conifer species in Eurasian forests and has become a globally invasive quarantine pest. Manipulating plant-associated microbes to control nematodes is an important strategy for sustainable pest management. However, it has proven difficult to find pine-associated bacteria that possess both nematocidal activity and the ability to colonize pine tissues. Methods The stress experiments with turpentine and pine tissue extract were carried out to screen for the desired target strain that could adapt to the internal environment of pine trees. This strain was used to construct an engineered nematocidal strain. Additionally, a fluorescent strain was constructed to determine its dispersal ability in Pinus massoniana seedlings through plate separation, PCR detection, and fluorescence microscopy observations. The engineered nematocidal strain was tested in the greenhouse experiment to assess its ability to effectively protect P. massoniana seedlings from nematode infection. Results This study isolated a Bacillus toyonensis strain Bxy19 from the healthy pine stem, which showed exceptional tolerance in stress experiments. An engineered nematocidal strain Bxy19P3C6 was constructed, which expressed the Cry6Aa crystal protein and exhibited nematocidal activity. The fluorescent strain Bxy19GFP was also constructed and used to test its dispersal ability. It was observed to enter the needles of the seedlings through the stomata and colonize the vascular bundle after being sprayed on the seedlings. The strain was observed to colonize and spread in the tracheid after being injected into the stems. The strain could colonize the seedlings and persist for at least 50 days. Furthermore, the greenhouse experiments indicated that both spraying and injecting the engineered strain Bxy19P3C6 had considerable efficacy against nematode infection. Discussion The evidence of the colonization ability and persistence of the strain in pine advances our understanding of the control and prediction of the colonization of exogenously delivered bacteria in pines. This study provides a promising approach for manipulating plant-associated bacteria and using Bt protein to control nematodes.
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Affiliation(s)
- Dongzhen Li
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yongxia Li
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Xuan Wang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Wei Zhang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Xiaojian Wen
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Zhenkai Liu
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yuqian Feng
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Xingyao Zhang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
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Hu Z, Chen C, Zheng X, Yuan J, Zou R, Xie C. Establishing Gene Expression and Knockout Methods in Esteya vermicola CBS115803. Mol Biotechnol 2023:10.1007/s12033-023-00898-6. [PMID: 37777998 DOI: 10.1007/s12033-023-00898-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023]
Abstract
Pine wilt disease, which is caused by the nematode Bursaphelenchus xylophilus, is one of the most destructive forest diseases worldwide. Esteya vermicola, a nematophagous fungus, has emerged as a promising biological control agent. However, the limited availability of gene function analysis techniques hinders further genetic modification of this fungus. In this study, we employed a combination of enzymes (driselase, snailase, and cellulase) to enzymatically degrade the cell wall of the fungus, resulting in a high yield of protoplasts. Furthermore, by utilizing 0.6 M sucrose as an osmotic pressure stabilizer, we achieved a significant protoplast regeneration rate of approximately 31%. Subsequently, we employed the polyethylene glycol-mediated protoplast transformation method to successfully establish a genetic transformation technique for E. vermicola CBS115803. Additionally, through our investigation, we identified the Olic promoter from Aspergillus nidulans, which effectively enhanced the expression of the DsRed gene encoding a red fluorescent protein in E. vermicola CBS115803. Moreover, we successfully implemented a split-marker strategy to delete the EvIPMD gene in E. vermicola CBS115803. In summary, our findings present valuable experimental methodologies for gene function analysis in E. vermicola CBS115803.
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Affiliation(s)
- Zhijuan Hu
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Chi Chen
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Xinyao Zheng
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Jingjie Yuan
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Run Zou
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China
| | - Chengjian Xie
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations, Chongqing Normal University, Chongqing, 401331, China.
- Chongqing Engineering Research Center of Specialty Crop Resources and the College of Life Science, Chongqing Normal University, Chongqing, 401331, China.
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Wang R, Li Y, Li D, Zhang W, Wang X, Wen X, Liu Z, Feng Y, Zhang X. Identification of the Extracellular Nuclease Influencing Soaking RNA Interference Efficiency in Bursaphelenchus xylophilus. Int J Mol Sci 2022; 23:ijms232012278. [PMID: 36293134 PMCID: PMC9603779 DOI: 10.3390/ijms232012278] [Citation(s) in RCA: 2] [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: 09/23/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/28/2022] Open
Abstract
RNA interference (RNAi) efficiency dramatically varies among different nematodes, which impacts research on their gene function and pest control. Bursaphelenchus xylophilus is a pine wood nematode in which RNAi-mediated gene silencing has unstable interference efficiency through soaking in dsRNA solutions, the factors of which remain unknown. Using agarose gel electrophoresis, we found that dsRNA can be degraded by nematode secretions in the soaking system which is responsible for the low RNAi efficiency. Based on the previously published genome and secretome data of B. xylophilus, 154 nucleases were screened including 11 extracellular nucleases which are potential factors reducing RNAi efficacy. To confirm the function of nucleases in RNAi efficiency, eight extracellular nuclease genes (BxyNuc1-8) were cloned in the genome. BxyNuc4, BxyNuc6 and BxyNuc7 can be upregulated in response to dsGFP, considered as the major nuclease performing dsRNA degradation. After soaking with the dsRNA of nucleases BxyNuc4/BxyNuc6/BxyNuc7 and Pat10 gene (ineffective in RNAi) simultaneously for 24 h, the expression of Pat10 gene decreased by 23.25%, 26.05% and 11.29%, respectively. With soaking for 36 h, the expression of Pat10 gene decreased by 43.25% and 33.25% in dsBxyNuc6+dsPat10 and dsBxyNuc7+dsPat10 groups, respectively. However, without dsPat10, dsBxyNuc7 alone could cause downregulation of Pat10 gene expression, while dsBxyNuc6 could not disturb this gene. In conclusion, the nuclease BxyNuc6 might be a major barrier to the RNAi efficiency in B. xylophilus.
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Affiliation(s)
- Ruijiong Wang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Yongxia Li
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
- Correspondence: ; Tel.: +86-010-62888578
| | - Dongzhen Li
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Wei Zhang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Xuan Wang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Xiaojian Wen
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Zhenkai Liu
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Yuqian Feng
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Xingyao Zhang
- Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing l00091, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
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The Fight against Plant-Parasitic Nematodes: Current Status of Bacterial and Fungal Biocontrol Agents. Pathogens 2022; 11:pathogens11101178. [PMID: 36297235 PMCID: PMC9606992 DOI: 10.3390/pathogens11101178] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/24/2022] Open
Abstract
Plant-parasitic nematodes (PPNs) are among the most notorious and underrated threats to food security and plant health worldwide, compromising crop yields and causing billions of dollars of losses annually. Chemical control strategies rely heavily on synthetic chemical nematicides to reduce PPN population densities, but their use is being progressively restricted due to environmental and human health concerns, so alternative control methods are urgently needed. Here, we review the potential of bacterial and fungal agents to suppress the most important PPNs, namely Aphelenchoides besseyi, Bursaphelenchus xylophilus, Ditylenchus dipsaci, Globodera spp., Heterodera spp., Meloidogyne spp., Nacobbus aberrans, Pratylenchus spp., Radopholus similis, Rotylenchulus reniformis, and Xiphinema index.
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Two Nematicidal Compounds from Lysinimonas M4 against the Pine Wood Nematode, Bursaphelenchus xylophilus. FORESTS 2022. [DOI: 10.3390/f13081191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A rich source of bioactive secondary metabolites from microorgannisms are widely used to control plant diseases in an eco-friendly way. To explore ideal candidates for prevention of pine wilt disease (PWD), a bacterial strain from rhizosphere of Pinus thunbergii, Lysinimonas M4, with nematicidal activity against pine wood nematode (PWN), Bursaphelenchus xylophilus, was isolated. Two nematicidal compounds were obtained from the culture of Lysinimonas M4 by silica gel chromatography based on bioactivity-guided fractionation and were subsequently identified as 2-coumaranone and cyclo-(Phe-Pro) by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The 2-coumaranone and cyclo-(Phe-Pro) showed significant nematicidal activity against PWN, with LC50 values at 24 h of 0.196 mM and 0.425 mM, respectively. Both compounds had significant inhibitory effects on egg hatching, feeding, and reproduction. The study on nematicidal mechanisms revealed that 2-coumaranone and cyclo-(Phe-Pro) caused the accumulation of reactive oxygen species (ROS) in nematodes, along with a notable decrease in CAT and POS activity and an increase in SOD activity in nematodes, which might contribute to the death of pine wood nematodes. Bioassay tests demonstrated that the two compounds could reduce the incidence of wilting in Japanese black pine seedlings. This research offers a new bacterial strain and two metabolites for biocontrol against PWN.
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Pires D, Vicente CSL, Inácio ML, Mota M. The Potential of Esteya spp. for the Biocontrol of the Pinewood Nematode, Bursaphelenchus xylophilus. Microorganisms 2022; 10:microorganisms10010168. [PMID: 35056617 PMCID: PMC8781088 DOI: 10.3390/microorganisms10010168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 01/21/2023] Open
Abstract
The pinewood nematode (PWN), Bursaphelenchus xylophilus, is the causal agent of pine wilt disease (PWD) and a quarantine organism in many countries. Managing PWD involves strict regulations and heavy contingency plans, and present climate change scenarios predict a spread of the disease. The urgent need for sustainable management strategies has led to an increasing interest in promising biocontrol agents capable of suppressing the PWN, like endoparasitic nematophagous fungi of the Esteya genus. Here, we review different aspects of the biology and ecology of these nematophagous fungi and provide future prospects.
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Affiliation(s)
- David Pires
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), 2780-159 Oeiras, Portugal;
- Mediterranean Institute for Agriculture, Environment and Development (MED), University of Évora, Pólo da Mitra, Apartado 94, 7006-554 Evora, Portugal;
| | - Cláudia S. L. Vicente
- Mediterranean Institute for Agriculture, Environment and Development (MED), University of Évora, Pólo da Mitra, Apartado 94, 7006-554 Evora, Portugal;
- Correspondence: (C.S.L.V.); (M.L.I.)
| | - Maria L. Inácio
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), 2780-159 Oeiras, Portugal;
- GREEN-IT Bioresources for Sustainability, ITQB NOVA, Av. da República, 2780-157 Oeiras, Portugal
- Correspondence: (C.S.L.V.); (M.L.I.)
| | - Manuel Mota
- Mediterranean Institute for Agriculture, Environment and Development (MED), University of Évora, Pólo da Mitra, Apartado 94, 7006-554 Evora, Portugal;
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