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Lean CH. Navigating the 'moral hazard' argument in synthetic biology's application. Synth Biol (Oxf) 2024; 9:ysae008. [PMID: 38828013 PMCID: PMC11141592 DOI: 10.1093/synbio/ysae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 05/07/2024] [Accepted: 05/21/2024] [Indexed: 06/05/2024] Open
Abstract
Synthetic biology has immense potential to ameliorate widespread environmental damage. The promise of such technology could, however, be argued to potentially risk the public, industry or governments not curtailing their environmentally damaging behavior or even worse exploit the possibility of this technology to do further damage. In such cases, there is the risk of a worse outcome than if the technology was not deployed. This risk is often couched as an objection to new technologies, that the technology produces a moral hazard. This paper describes how to navigate a moral hazard argument and mitigate the possibility of a moral hazard. Navigating moral hazard arguments and mitigating the possibility of a moral hazard will improve the public and environmental impact of synthetic biology.
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Affiliation(s)
- Christopher Hunter Lean
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia
- Department of Philosophy, Faculty of Arts, Macquarie University, Sydney, NSW, Australia
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2
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Kerr SC, Shehnaz S, Paudel L, Manivannan MS, Shaw LM, Johnson A, Velasquez JTJ, Tanurdžić M, Cazzonelli CI, Varkonyi-Gasic E, Prentis PJ. Advancing tree genomics to future proof next generation orchard production. FRONTIERS IN PLANT SCIENCE 2024; 14:1321555. [PMID: 38312357 PMCID: PMC10834703 DOI: 10.3389/fpls.2023.1321555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 12/26/2023] [Indexed: 02/06/2024]
Abstract
The challenges facing tree orchard production in the coming years will be largely driven by changes in the climate affecting the sustainability of farming practices in specific geographical regions. Identifying key traits that enable tree crops to modify their growth to varying environmental conditions and taking advantage of new crop improvement opportunities and technologies will ensure the tree crop industry remains viable and profitable into the future. In this review article we 1) outline climate and sustainability challenges relevant to horticultural tree crop industries, 2) describe key tree crop traits targeted for improvement in agroecosystem productivity and resilience to environmental change, and 3) discuss existing and emerging genomic technologies that provide opportunities for industries to future proof the next generation of orchards.
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Affiliation(s)
- Stephanie C Kerr
- School of Biology and Environmental Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Centre for Agriculture and the Bioeconomy, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Saiyara Shehnaz
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Lucky Paudel
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Mekaladevi S Manivannan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Lindsay M Shaw
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
- School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD, Australia
| | - Amanda Johnson
- School of Biology and Environmental Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Centre for Agriculture and the Bioeconomy, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Jose Teodoro J Velasquez
- School of Biology and Environmental Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Centre for Agriculture and the Bioeconomy, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Miloš Tanurdžić
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | | | - Erika Varkonyi-Gasic
- The New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand
| | - Peter J Prentis
- School of Biology and Environmental Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
- Centre for Agriculture and the Bioeconomy, Queensland University of Technology (QUT), Brisbane, QLD, Australia
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3
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Islam-Faridi N, Hodnett GL, Zhebentyayeva T, Georgi LL, Sisco PH, Hebard FV, Nelson CD. Cyto-molecular characterization of rDNA and chromatin composition in the NOR-associated satellite in Chestnut (Castanea spp.). Sci Rep 2024; 14:980. [PMID: 38225361 PMCID: PMC10789788 DOI: 10.1038/s41598-023-45879-6] [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: 10/11/2022] [Accepted: 10/25/2023] [Indexed: 01/17/2024] Open
Abstract
The American chestnut (Castanea dentata, 2n = 2x = 24), once known as the "King of the Appalachian Forest", was decimated by chestnut blight during the first half of the twentieth century by an invasive fungus (Cryphonectria parasitica). The Chinese chestnut (C. mollissima, 2n = 2x = 24), in contrast to American chestnut, is resistant to this blight. Efforts are being made to transfer this resistance to American chestnut through backcross breeding and genetic engineering. Both chestnut genomes have been genetically mapped and recently sequenced to facilitate gene discovery efforts aimed at assisting molecular breeding and genetic engineering. To complement and extend this genomic work, we analyzed the distribution and organization of their ribosomal DNAs (35S and 5S rDNA), and the chromatin composition of the nucleolus organizing region (NOR)-associated satellites. Using fluorescent in situ hybridization (FISH), we have identified two 35S (one major and one minor) and one 5S rDNA sites. The major 35S rDNA sites are terminal and sub-terminal in American and Chinese chestnuts, respectively, originating at the end of the short arm of the chromosome, extending through the secondary constriction and into the satellites. An additional 5S locus was identified in certain Chinese chestnut accessions, and it was linked distally to the major 35S site. The NOR-associated satellite in Chinese chestnut was found to comprise a proximal region packed with 35S rDNA and a distinct distal heterochromatic region. In contrast, the American chestnut satellite was relatively small and devoid of the distal heterochromatic region.
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Affiliation(s)
- Nurul Islam-Faridi
- Forest Tree Molecular Cytogenetics Laboratory, Southern Institute of Forest Genetics, USDA Forest Service, Southern Research Station, Texas A&M University, College Station, TX, 77843, USA.
| | - George L Hodnett
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Tetyana Zhebentyayeva
- The Schatz Center for Tree Molecular Genetics, Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Forestry and Natural Resources, University of Kentucky, Lexington, KY, 40546, USA
| | - Laura L Georgi
- Meadowview Research Farms, The American Chestnut Foundation, 29010 Hawthorne Drive, Meadowview, VA, 24361, USA
| | - Paul H Sisco
- The American Chestnut Foundation, 50 North Merrimon Ave., Suite 115, Asheville, NC, 28804, USA
| | - Frederick V Hebard
- Meadowview Research Farms, The American Chestnut Foundation, 29010 Hawthorne Drive, Meadowview, VA, 24361, USA
| | - C Dana Nelson
- USDA Forest Service, Southern Research Station, Forest Health Research and Education Center, Lexington, KY, 40546, USA
- USDA Forest Service, Southern Institute of Forest Genetics, Harrison Experimental Forest, 23332 Success Road, Saucier, MS, 39574, USA
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4
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Austin AT, Ballaré CL. Attackers gain the upper hand over plants in the face of rapid global change. Curr Biol 2023; 33:R611-R620. [PMID: 37279692 DOI: 10.1016/j.cub.2023.03.082] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Interactions among organisms in natural ecosystems are the foundational underpinnings of nearly all ecological studies. It has never been more important to increase our awareness of how these interactions are altered by human activity, threatening biodiversity and disrupting ecosystem functioning. Much of the historic focus of species conservation has been the preservation of endangered and endemic species at risk from hunting, over-exploitation, and habitat destruction. However, there is increasing evidence that differences between plants and their attacking organisms in the speed and direction of physiological, demographic, and genetic (adaptation) responses to global change are having devastating consequences, resulting in large-scale losses of dominant or abundant plant species, particularly in forest ecosystems. From the elimination in the wild of the American chestnut to the extensive regional damage caused by insect outbreaks in temperate forest ecosystems, these losses of dominant species change the ecological landscape and functioning, and represent important threats to biodiversity at all scales. Introductions due to human activity, range shifts due to climate change, and their combination are the principal drivers behind these profound ecosystem changes. In this Review, we argue that there is an urgent need to increase our recognition and hone our predictive power for how these imbalances may occur. Moreover, we should seek to minimize the consequences of these imbalances in order to ensure the preservation of the structure, function and biodiversity of entire ecosystems, not just rare or highly endangered species.
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Affiliation(s)
- Amy T Austin
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Buenos Aires, Argentina.
| | - Carlos L Ballaré
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE, Buenos Aires, Argentina; IIB-INTECH, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de San Martín, B1650HMP Buenos Aires, Argentina.
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5
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Conn CE, Howie N, Lynch M, Lee S, Young E, Westbrook J, Holliday J, Zhang Q, Cipollini ML. Validation of an Alternative Small Stem Assay for Blight Resistance in Chestnut Seedlings and Recommendations for Broader Use. PLANT DISEASE 2023:PDIS06221489RE. [PMID: 36383986 DOI: 10.1094/pdis-06-22-1489-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We evaluated an alternative small stem assay (AltSSA) for blight resistance in backcross hybrid chestnut trees (Castanea dentata/mollissima). Whereas standard small stem assays (SSAs) are done by inoculating small incisions in stems, in our AltSSA, 4- to 5-mm stems are cut off, and the exposed (living) stem tips are inoculated with discs of Cryphonectria parasitica inoculum and temporarily covered with plastic sleeves. Intended primarily for forward selection, this method was designed to be easy to implement, to consistently induce cankering, and to better enable seedling recovery via the development of lateral shoots from the lower stem. After 90+ days, cankers are evaluated and removed, and seedlings are prepared for out-planting. Previous results showed that AltSSAs performed at least as well as a common SSA method in distinguishing resistant and susceptible types. In this follow-up analysis of 35 lines of backcross seedlings studied in 2020 and 2021, we showed that mean orange zone canker length (OZCL) and a multifactor principal components analysis-based blight resistance index gave results consistent with predictions derived from two methods of blight resistance phenotyping and percentage of American chestnut ancestry of the parents of each line. As expected, based upon the apparent polygenic inheritance of blight resistance in backcross chestnut trees, mean OZCL of backcross families ranged from intermediate (F1 hybrid-level) to low (wild-type American chestnut-level). Consistent with prior results, canker production was near 100%, survivorship after out-planting was very high, and postinoculation stem dieback was not apparently related to the stem tip inoculations. Altogether, these results suggest that the AltSSA is a viable method for early detection of relative blight resistance in seedlings and may enable a reduction in the numbers of trees out-planted and placed under care for long-term evaluation and breeding. Thus, the AltSSA can prevent time, resources, and orchard space from being used on susceptible trees.
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Affiliation(s)
| | - Noah Howie
- Department of Biology, Berry College, Mount Berry, GA
| | | | - Shanna Lee
- Department of Biology, Berry College, Mount Berry, GA
| | - Eden Young
- Department of Biology, Berry College, Mount Berry, GA
| | | | - Jason Holliday
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA
| | - Qian Zhang
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA
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6
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Li P, Liu C, Luo Y, Shi H, Li Q, PinChu C, Li X, Yang J, Fan W. Oxalate in Plants: Metabolism, Function, Regulation, and Application. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:16037-16049. [PMID: 36511327 DOI: 10.1021/acs.jafc.2c04787] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Characterized by strong acidity, chelating ability, and reducing ability, oxalic acid, a low molecular weight dicarboxylic organic acid, plays important roles in the regulation of plant growth and development, the response to both biotic and abiotic stresses such as plant defense and heavy metals detoxification, and food quality. The metabolism of oxalic acid has been well-studied in microorganisms, fungi, and animals but remains less understood in plants. However, excessive accumulation of oxalic acid is detrimental to plants. Therefore, the level of oxalic acid has to be precisely controlled in plant tissues. In this review, we summarize the metabolism, function, and regulation of oxalic acid in plants, and we discuss solutions such as agricultural practices and plant biotechnology to manipulate oxalic acid metabolism to regulate plant responses to both external stimuli and internal developmental cues.
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Affiliation(s)
- Pengfei Li
- State Key Laboratory of Plant Physiology and Biochemistry, Institute of Plant Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chunlan Liu
- College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, China
| | - Yu Luo
- College of Food Science and Technology, Yunnan Agricultural University, Kunming, 650201, China
| | - Huineng Shi
- College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, China
| | - Qi Li
- College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, China
| | - Cier PinChu
- College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, China
| | - Xuejiao Li
- College of Landscape and Horticulture, Yunnan Agricultural University, Kunming 650201, China
| | - Jianli Yang
- State Key Laboratory of Plant Physiology and Biochemistry, Institute of Plant Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wei Fan
- College of Landscape and Horticulture, Yunnan Agricultural University, Kunming 650201, China
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7
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LeBoldus JM, Navarro SM, Kline N, Ritokova G, Grünwald NJ. Repeated Emergence of Sudden Oak Death in Oregon: Chronology, Impact, and Management. PLANT DISEASE 2022; 106:3013-3021. [PMID: 35486603 DOI: 10.1094/pdis-02-22-0294-fe] [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: 06/14/2023]
Abstract
It has been two decades since the first detection of the sudden oak death pathogen Phytophthora ramorum in Oregon forests. Although the epidemic was managed since its first discovery in 2001, at least three invasions of three separate variants (clonal lineages), NA1, EU1, and NA2, are documented to have occurred to date. Control of this epidemic has cost over US$32 million from 2001 to 2020. This is dwarfed by the predicted cost of the closure to the Coos Bay export terminal, estimated at $58 million per year, if the epidemic was allowed to spread unchecked. Management efforts in Oregon have reduced inoculum and limited the spread of the pathogen. An outreach and citizen scientist program has been piloted to help in early detection efforts and search for disease-resistant tanoak. This feature article documents the repeated emergence, impact, costs, and lessons learned from managing this devastating invasive pathogen.
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Affiliation(s)
- Jared M LeBoldus
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR
- Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, OR
| | | | - Norma Kline
- Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, OR
| | | | - Niklaus J Grünwald
- Horticultural Crops Research Laboratory, United States Department of Agriculture-Agricultural Research Service, Corvallis, OR
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8
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Laport RG, Brookover ZS, Christman BD, Julienne NG, Philley K, Craddock JH. Environmental Niche and Demographic Modeling of American Chestnut near its Southwestern Range Limit. AMERICAN MIDLAND NATURALIST 2022. [DOI: 10.1674/0003-0031-188.2.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
| | | | | | - NG Julienne
- Department of Biology, Rhodes College, Memphis, Tennessee 38112
| | - Kevin Philley
- United States Army Corps of Engineers, Engineer Research and Development Center, Vicksburg, Mississippi 39180
| | - J. Hill Craddock
- Department of Biology, Geology, and Environmental Science, University of Tennessee at Chattanooga, Chattanooga 37403
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9
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Fernandes P, Colavolpe MB, Serrazina S, Costa RL. European and American chestnuts: An overview of the main threats and control efforts. FRONTIERS IN PLANT SCIENCE 2022; 13:951844. [PMID: 36092400 PMCID: PMC9449730 DOI: 10.3389/fpls.2022.951844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Chestnuts are multipurpose trees significant for the economy and wildlife. These trees are currently found around the globe, demonstrating their genetic adaptation to different environmental conditions. Several biotic and abiotic stresses have challenged these species, contributing to the decline of European chestnut production and the functional extinction of the American chestnut. Several efforts started over the last century to understand the cellular, molecular, and genetic interactions behind all chestnut biotic and abiotic interactions. Most efforts have been toward breeding for the primary diseases, chestnut blight and ink disease caused by the pathogens, Cryphonectria parasitica and Phytophthora cinnamomi, respectively. In Europe and North America, researchers have been using the Asian chestnut species, which co-evolved with the pathogens, to introgress resistance genes into the susceptible species. Breeding woody trees has several limitations which can be mostly related to the long life cycles of these species and the big genome landscapes. Consequently, it takes decades to improve traits of interest, such as resistance to pathogens. Currently, the availability of genome sequences and next-generation sequencing techniques may provide new tools to help overcome most of the problems tree breeding is still facing. This review summarizes European and American chestnut's main biotic stresses and discusses breeding and biotechnological efforts developed over the last decades, having ink disease and chestnut blight as the main focus. Climate change is a rising concern, and in this context, the adaptation of chestnuts to adverse environmental conditions is of extreme importance for chestnut production. Therefore, we also discuss the abiotic challenges on European chestnuts, where the response to abiotic stress at the genetic and molecular level has been explored.
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Affiliation(s)
- Patrícia Fernandes
- Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal
- Green-It Bioresources for Sustainability, ITQB NOVA, Oeiras, Portugal
- Department of Environmental Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States
| | | | - Susana Serrazina
- BioISI – Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - Rita Lourenço Costa
- Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
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10
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Sandercock AM, Westbrook JW, Zhang Q, Johnson HA, Saielli TM, Scrivani JA, Fitzsimmons SF, Collins K, Perkins MT, Craddock JH, Schmutz J, Grimwood J, Holliday JA. Frozen in time: rangewide genomic diversity, structure, and demographic history of relict American chestnut populations. Mol Ecol 2022; 31:4640-4655. [PMID: 35880415 DOI: 10.1111/mec.16629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 11/30/2022]
Abstract
American chestnut (Castanea dentata) was once the most economically and ecologically important hardwood species in the eastern United States. In the first half of the 20th century, an exotic fungal pathogen - Cryphonectria parasitica - decimated the species, killing billions of chestnut trees. Two approaches to developing blight resistant American chestnut populations show promise, but both will require introduction of adaptive genomic diversity from wild germplasm to produce diverse, locally adapted restoration populations. Here we characterize population structure, demographic history, and genomic diversity in a range-wide sample of 384 wild American chestnuts to inform conservation and breeding with blight resistant varieties. Population structure analyses suggest that the chestnut range can be roughly divided into northeast, central, and southwest populations. Within-population genomic diversity estimates revealed a clinal pattern with the highest diversity in the southwest, which likely reflects bottleneck events associated with Quaternary glaciation. Finally, we identified genomic regions under positive selection within each population, which suggests that defense against fungal pathogens is a common target of selection across all populations. Taken together, these results show that American chestnut underwent a postglacial expansion from the southern portion of its range leading to three extant genetic populations. These populations will serve as management units for breeding adaptive genetic variation into the blight-resistant tree populations for targeted reintroduction efforts.
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Affiliation(s)
| | | | - Qian Zhang
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA, USA
| | - Hayley A Johnson
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA, USA
| | | | | | | | | | - M Taylor Perkins
- Department of Biology, Geology, and Environmental Science, The University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - J Hill Craddock
- Department of Biology, Geology, and Environmental Science, The University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Jeremy Schmutz
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Jason A Holliday
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA, USA
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11
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Carlson E, Stewart K, Baier K, McGuigan L, Culpepper T, Powell W. Pathogen-induced expression of a blight tolerance transgene in American chestnut. MOLECULAR PLANT PATHOLOGY 2022; 23:370-382. [PMID: 34841616 PMCID: PMC8828690 DOI: 10.1111/mpp.13165] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
American chestnut (Castanea dentata) is a susceptible host of the invasive necrotrophic fungus Cryphonectria parasitica, which causes chestnut blight disease. The fungal pathogen attacks chestnut stems by invading wounded tissue and secreting oxalate. This process leads to the death of infected host cells and the formation of cankers, eventually girdling stems and killing the tree above the infections. To reduce damage caused by fungal oxalate, American chestnut has been genetically engineered to express a wheat oxalate oxidase (OxO). This enzyme degrades the oxalate produced by the pathogen and confers elevated tolerance to Cryphonectria parasitica infection. We report new lines of transgenic American chestnut that have been developed with the win3.12 inducible promoter from poplar (Populus deltoides) driving OxO expression. This promoter is responsive to both wounding and pathogen infection, with a low level of baseline expression. Targeted expression of OxO to wounded and infected tissue is sought as an alternative to constitutive expression for potential metabolic resource conservation and transgene stability over the long lifetime of a tree and over successive generations of breeding. Transgenic Castanea dentata lines harbouring the win3.12-OxO construct were evaluated for transgene expression patterns and tolerance to chestnut blight infection. OxO transcript levels were low in uninfected plants, but robust infection-induced expression levels were observed, with one transgenic line reaching levels comparable to those of previously characterized CaMV35S-OxO lines. In chestnut blight infection bioassays, win3.12-OxO lines showed elevated disease tolerance similar to blight-resistant Chinese chestnut (Castanea mollissima) controls.
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Affiliation(s)
- Erik Carlson
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
| | - Kristen Stewart
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
| | - Kathleen Baier
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
| | - Linda McGuigan
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
| | - Tobi Culpepper
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
| | - William Powell
- Department of Environmental BiologySUNY College of Environmental Science and ForestrySyracuseNew YorkUSA
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12
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Genetic approaches for increasing fitness in endangered species. Trends Ecol Evol 2022; 37:332-345. [PMID: 35027225 DOI: 10.1016/j.tree.2021.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022]
Abstract
The global rate of wildlife extinctions is accelerating, and the persistence of many species requires conservation breeding programs. A central paradigm of these programs is to preserve the genetic diversity of the founder populations. However, this may preserve original characteristics that make them vulnerable to extinction. We introduce targeted genetic intervention (TGI) as an alternative approach that promotes traits that enable species to persist in the face of threats by changing the incidence of alleles that impact on fitness. The TGI toolkit includes methods with established efficacy in model organisms and agriculture but are largely untried for conservation, such as synthetic biology and artificial selection. We explore TGI approaches as a species-restoration tool for intractable threats including infectious disease and climate change.
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13
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New developments in the field of genomic technologies and their relevance to conservation management. CONSERV GENET 2021. [DOI: 10.1007/s10592-021-01415-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AbstractRecent technological advances in the field of genomics offer conservation managers and practitioners new tools to explore for conservation applications. Many of these tools are well developed and used by other life science fields, while others are still in development. Considering these technological possibilities, choosing the right tool(s) from the toolbox is crucial and can pose a challenging task. With this in mind, we strive to inspire, inform and illuminate managers and practitioners on how conservation efforts can benefit from the current genomic and biotechnological revolution. With inspirational case studies we show how new technologies can help resolve some of the main conservation challenges, while also informing how implementable the different technologies are. We here focus specifically on small population management, highlight the potential for genetic rescue, and discuss the opportunities in the field of gene editing to help with adaptation to changing environments. In addition, we delineate potential applications of gene drives for controlling invasive species. We illuminate that the genomic toolbox offers added benefit to conservation efforts, but also comes with limitations for the use of these novel emerging techniques.
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Newhouse AE, Allwine AE, Oakes AD, Matthews DF, McArt SH, Powell WA. Bumble bee (Bombus impatiens) survival, pollen usage, and reproduction are not affected by oxalate oxidase at realistic concentrations in American chestnut (Castanea dentata) pollen. Transgenic Res 2021; 30:751-764. [PMID: 34110572 PMCID: PMC8580921 DOI: 10.1007/s11248-021-00263-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 05/29/2021] [Indexed: 12/04/2022]
Abstract
Transgenic American chestnut trees expressing a wheat gene for oxalate oxidase (OxO) can tolerate chestnut blight, but as with any new restoration material, they should be carefully evaluated before being released into the environment. Native pollinators such as bumble bees are of particular interest: Bombus impatiens use pollen for both a source of nutrition and a hive building material. Bees are regular visitors to American chestnut flowers and likely contribute to their pollination, so depending on transgene expression in chestnut pollen, they could be exposed to this novel source of OxO during potential restoration efforts. To evaluate the potential risk to bees from OxO exposure, queenless microcolonies of bumble bees were supplied with American chestnut pollen containing one of two concentrations of OxO, or a no-OxO control. Bees in microcolonies exposed to a conservatively estimated field-realistic concentration of OxO in pollen performed similarly to no-OxO controls; there were no significant differences in survival, bee size, pollen use, hive construction activity, or reproduction. A ten-fold increase in OxO concentration resulted in noticeable but non-significant decreases in some measures of pollen usage and reproduction compared to the no-OxO control. These effects are similar to what is often seen when naturally produced secondary metabolites are supplied to bees at unrealistically high concentrations. Along with the presence of OxO in many other environmental sources, these data collectively suggest that oxalate oxidase at field-realistic concentrations in American chestnut pollen is unlikely to present substantial risk to bumble bees.
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Affiliation(s)
- Andrew E Newhouse
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13210, USA.
| | - Anastasia E Allwine
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - Allison D Oakes
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - Dakota F Matthews
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - Scott H McArt
- Department of Entomology, Cornell University, 2130 Comstock Hall, Ithaca, NY, 14853, USA
| | - William A Powell
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13210, USA
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15
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Abstract
CRISPR-Cas gene editing tools have brought us to an era of synthetic biology that will change the world. Excitement over the breakthroughs these tools have enabled in biology and medicine is balanced, justifiably, by concern over how their applications might go wrong in open environments. We do not know how genomic processes (including regulatory and epigenetic processes), evolutionary change, ecosystem interactions, and other higher order processes will affect traits, fitness, and impacts of edited organisms in nature. However, anticipating the spread, change, and impacts of edited traits or organisms in heterogeneous, changing environments is particularly important with "gene drives on the horizon." To anticipate how "synthetic threads" will affect the web of life on Earth, scientists must confront complex system interactions across many levels of biological organization. Currently, we lack plans, infrastructure, and funding for field science and scientists to track new synthetic organisms, with or without gene drives, as they move through open environments.
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16
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Aucott M, Parker RA. Medical biotechnology as a paradigm for forest restoration and introduction of the transgenic American chestnut. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:190-196. [PMID: 32506503 DOI: 10.1111/cobi.13566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 05/11/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
For over 40 years, biotechnology and genetic engineering (GE) have been used in the development of medicines and biologic agents important in protecting and augmenting human health and have been met with broad public acceptance in the health care arena. GE has also been used to improve and develop plants important to agriculture and forestry, but in these areas, it has often encountered intense opposition that has prevented or delayed the introduction of potentially useful plants. Much of the opposition to GE's application in agriculture and forestry may be driven by concerns that GE plants will serve primarily to encourage the domination of the food and wood products industries by monopolistic corporations or will be disruptive to the environment. But to conflate genetic modifications intended to promote healthy ecosystems or preserve threatened species with GE projects aimed at benefiting corporate agriculture and forestry is misleading and illogical. Further, the pervasive human disruption and damage to forest ecosystems makes it prudent to bring the best that science can offer to the protection and restoration of critical woodland denizens and broader ecosystem health. The notion that minimal human intervention in the forest environment may be the best approach ignores humanity's responsibility to help manage and protect some of the very places that have been most damaged by human intrusion. GE intended to improve forest health should be afforded the same consideration, acceptance, and support as GE intended to improve human health. These efforts should include the use of GE technology such as carefully developed transgenic trees to cure ongoing forest pathogenesis, such as the chestnut blight (Cryphonectria parasitica), which threatens to drive the American chestnut (Castanea dentata) to extinction.
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Affiliation(s)
- Michael Aucott
- Department of Chemistry, The College of New Jersey, PO Box 7718, Ewing, New Jersey, 08629, U.S.A
| | - Rex A Parker
- Research & Development, Bristol-Myers Squibb (retired), Lawrenceville, NJ, 08648, U.S.A
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17
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Newhouse AE, Powell WA. Intentional introgression of a blight tolerance transgene to rescue the remnant population of American chestnut. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.348] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Andrew E. Newhouse
- Department of Environmental and Forest Biology SUNY College of Environmental Science and Forestry Syracuse New York USA
| | - William A. Powell
- Department of Environmental and Forest Biology SUNY College of Environmental Science and Forestry Syracuse New York USA
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18
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Transformation of American Chestnut (Castanea dentata (Marsh.) Borkh) Using RITA® Temporary Immersion Bioreactors and We Vitro Containers. FORESTS 2020. [DOI: 10.3390/f11111196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
American chestnut (Castanea dentata (Marsh.) Borkh) was almost completely wiped out by the fungal pathogen, Cryphonectria parasitica (Murrill) M.E. Barr. Another invasive pathogen, Phytophthora cinnamomi Rands, is devastating American chestnuts in the southern region of the United States. An alternative approach for controlling these pathogens is to use genetic engineering or gene editing. We successfully transformed American chestnut with a detoxifying enzyme, oxalate oxidase, to enhance blight tolerance and more recently with the Cast_Gnk2-like gene, which encodes for an antifungal protein, to be tested for P. cinnamomi putative tolerance. Eight somatic embryo lines were transformed using three methods of selection: semisolid medium in Petri plates, liquid medium in RITA® temporary immersion bioreactors, or liquid medium in We Vitro containers. No significant differences were found between the treatments. These methods will allow for further testing of transgenes and the development of enhanced pathogen resistance in chestnut. It can serve as a model for other tree species threatened by invasive pests and pathogens.
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19
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Microhaplotype genotyping-by-sequencing of 98 highly polymorphic markers in three chestnut tree species. CONSERV GENET RESOUR 2020. [DOI: 10.1007/s12686-020-01157-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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20
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Westbrook JW, Zhang Q, Mandal MK, Jenkins EV, Barth LE, Jenkins JW, Grimwood J, Schmutz J, Holliday JA. Optimizing genomic selection for blight resistance in American chestnut backcross populations: A trade-off with American chestnut ancestry implies resistance is polygenic. Evol Appl 2020; 13:31-47. [PMID: 31892942 PMCID: PMC6935594 DOI: 10.1111/eva.12886] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 01/04/2023] Open
Abstract
American chestnut was once a foundation species of eastern North American forests, but was rendered functionally extinct in the early 20th century by an exotic fungal blight (Cryphonectria parasitica). Over the past 30 years, the American Chestnut Foundation (TACF) has pursued backcross breeding to generate hybrids that combine the timber-type form of American chestnut with the blight resistance of Chinese chestnut based on a hypothesis of major gene resistance. To accelerate selection within two backcross populations that descended from two Chinese chestnuts, we developed genomic prediction models for five presence/absence blight phenotypes of 1,230 BC3F2 selection candidates and average canker severity of their BC3F3 progeny. We also genotyped pure Chinese and American chestnut reference panels to estimate the proportion of BC3F2 genomes inherited from parent species. We found that genomic prediction from a method that assumes an infinitesimal model of inheritance (HBLUP) has similar accuracy to a method that tends to perform well for traits controlled by major genes (Bayes C). Furthermore, the proportion of BC3F2 trees' genomes inherited from American chestnut was negatively correlated with the blight resistance of these trees and their progeny. On average, selected BC3F2 trees inherited 83% of their genome from American chestnut and have blight resistance that is intermediate between F1 hybrids and American chestnut. Results suggest polygenic inheritance of blight resistance. The blight resistance of restoration populations will be enhanced through recurrent selection, by advancing additional sources of resistance through fewer backcross generations, and by potentially by breeding with transgenic blight-tolerant trees.
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Affiliation(s)
| | - Qian Zhang
- Department of Forest Resources and Environmental ConservationVirginia TechBlacksburgVAUSA
| | | | | | | | | | - Jane Grimwood
- HudsonAlpha Institute for BiotechnologyHuntsvilleALUSA
| | | | - Jason A. Holliday
- Department of Forest Resources and Environmental ConservationVirginia TechBlacksburgVAUSA
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