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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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Jansson JK, McClure R, Egbert RG. Soil microbiome engineering for sustainability in a changing environment. Nat Biotechnol 2023; 41:1716-1728. [PMID: 37903921 DOI: 10.1038/s41587-023-01932-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 08/01/2023] [Indexed: 11/01/2023]
Abstract
Recent advances in microbial ecology and synthetic biology have the potential to mitigate damage caused by anthropogenic activities that are deleteriously impacting Earth's soil ecosystems. Here, we discuss challenges and opportunities for harnessing natural and synthetic soil microbial communities, focusing on plant growth promotion under different scenarios. We explore current needs for microbial solutions in soil ecosystems, how these solutions are being developed and applied, and the potential for new biotechnology breakthroughs to tailor and target microbial products for specific applications. We highlight several scientific and technological advances in soil microbiome engineering, including characterization of microbes that impact soil ecosystems, directing how microbes assemble to interact in soil environments, and the developing suite of gene-engineering approaches. This Review underscores the need for an interdisciplinary approach to understand the composition, dynamics and deployment of beneficial soil microbiomes to drive efforts to mitigate or reverse environmental damage by restoring and protecting healthy soil ecosystems.
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Affiliation(s)
- Janet K Jansson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
| | - Ryan McClure
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Robert G Egbert
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
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Pantoja Angles A, Valle-Pérez AU, Hauser C, Mahfouz MM. Microbial Biocontainment Systems for Clinical, Agricultural, and Industrial Applications. Front Bioeng Biotechnol 2022; 10:830200. [PMID: 35186907 PMCID: PMC8847691 DOI: 10.3389/fbioe.2022.830200] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
Many applications of synthetic biology require biological systems in engineered microbes to be delivered into diverse environments, such as for in situ bioremediation, biosensing, and applications in medicine and agriculture. To avoid harming the target system (whether that is a farm field or the human gut), such applications require microbial biocontainment systems (MBSs) that inhibit the proliferation of engineered microbes. In the past decade, diverse molecular strategies have been implemented to develop MBSs that tightly control the proliferation of engineered microbes; this has enabled medical, industrial, and agricultural applications in which biological processes can be executed in situ. The customization of MBSs also facilitate the integration of sensing modules for which different compounds can be produced and delivered upon changes in environmental conditions. These achievements have accelerated the generation of novel microbial systems capable of responding to external stimuli with limited interference from the environment. In this review, we provide an overview of the current approaches used for MBSs, with a specific focus on applications that have an immediate impact on multiple fields.
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Affiliation(s)
- Aaron Pantoja Angles
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Alexander U. Valle-Pérez
- Laboratory for Nanomedicine, Division of Biological Sciences, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Charlotte Hauser
- Laboratory for Nanomedicine, Division of Biological Sciences, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- *Correspondence: Magdy M. Mahfouz, ; Charlotte Hauser,
| | - Magdy M. Mahfouz
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- *Correspondence: Magdy M. Mahfouz, ; Charlotte Hauser,
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Zeng Y, Liu H, Zhu T, Han S, Li S. Preparation of Nanomaterial Wettable Powder Formulations of Antagonistic Bacteria from Phellodendron chinense and the Biological Control of Brown Leaf Spot Disease. THE PLANT PATHOLOGY JOURNAL 2021; 37:215-231. [PMID: 34111912 PMCID: PMC8200580 DOI: 10.5423/ppj.oa.02.2021.0020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/15/2021] [Accepted: 03/22/2021] [Indexed: 06/02/2023]
Abstract
Brown leaf spot disease caused by Nigrospora guilinensis on Phellodendron chinense occurs in a large area in Dayi County, Chengdu City, Sichuan Province, China each year. This outbreak has severely reduced the production of Chinese medicinal plants P. chinense and caused substantial economic losses. The bacterial isolate JKB05 was isolated from the healthy leaves of P. chinense, exhibited antagonistic effects against N. guilinensis and was identified as Bacillus megaterium. The following fermentation medium and conditions improved the inhibitory effect of B. megaterium JKB05 on N. guilinensis: 2% glucose, 0.1% soybean powder, 0.1% KCl, and 0.05% MgSO4; initial concentration 6 × 106 cfu/ml, and a 42-h optimal fermentation time. A composite of 0.1% nano-SiO2 JKB05 improved the thermal stability, acid-base stability and ultraviolet resistance by 16%, 12%, and 38.9%, respectively, and nano-SiO2 was added to the fermentation process. The best formula for the wettable powder was 35% kaolin, 4% polyethylene glycol, 8% Tween, and 2% humic acid. The following quality test results for the wettable powder were obtained: wetting time 87.0 s, suspension rate 80.33%, frequency of microbial contamination 0.08%, pH 7.2, fineness 95.8%, drying loss 1.47%, and storage stability ≥83.5%. A pot experiment revealed that the ability of JKB05 to prevent fungal infections on P. chinense increased considerably and achieved levels of control as high as 94%. The use of nanomaterials significantly improved the ability of biocontrol bacteria to control this disease.
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Affiliation(s)
- Yanling Zeng
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Han Liu
- Ganzi Institute of Forestry Research, Kangding 626001, China
| | - Tianhui Zhu
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Shan Han
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Shujiang Li
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
- Key Laboratory of National Forestry & Grassland Administration on Forest Resources Conservation and Ecological Safety in the Upper Reaches of the Yangtze River, College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
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Abstract
Surrogate microorganisms, in short surrogates, are an essential part of pathogen research. Compared to surrogates used in controlled laboratory environments, surrogates for field release are restricted by concerns about human and environmental safety. For field research of food-borne pathogens, strains of an attenuated pathogen or strains of genetically close non-pathogenic species have been used as surrogates. Genetic modification is usually performed to attenuate virulence, through for examples deletion of genes of virulence and transcriptional regulators and removal of virulence plasmids, and to facilitate detection and monitoring through observing antibiotic resistance, fluorescence, and bioluminescence. For field research of a biological warfare agent Bacillus anthracis, strains of genetically close non-pathogenic species or strains of genetically distant non-pathogenic species have been used, mostly without any genetic modification. Recently, we constructed strains of Bacillus thuringiensis as surrogates for B. anthracis, demonstrating that strain engineering could significantly enhance the utility of surrogates, and that the application of a simple genetic circuit could significantly impact surrogate safety. Thus far, enormous potential of biotechnology has not been exploited enough due to safety concerns regarding the field release of genetically engineered microorganisms. However, synthetic biology is rapidly developing, providing new concepts for biocontainment as well as ingenious genetic circuits and devices, which should be applied in future research of field-use surrogates.
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Affiliation(s)
- Sangjin Park
- a Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology , Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon , Republic of Korea.,b The 5th R&D Institute, Agency for Defense Development (ADD) , Daejeon , Republic of Korea
| | - Chang-Hwan Kim
- b The 5th R&D Institute, Agency for Defense Development (ADD) , Daejeon , Republic of Korea
| | - Seong Tae Jeong
- b The 5th R&D Institute, Agency for Defense Development (ADD) , Daejeon , Republic of Korea
| | - Sang Yup Lee
- a Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology , Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon , Republic of Korea
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