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Fernández-Calleja L, García-Domínguez M, Redondo BI, Martín JLG, Villar CJ, Lombó F. Isolation of two triterpenoids from Phlomis purpurea, one of them with anti-oomycete activity against Phytophthora cinnamomi, and insights into its biosynthetic pathway. FRONTIERS IN PLANT SCIENCE 2023; 14:1180808. [PMID: 37692445 PMCID: PMC10485375 DOI: 10.3389/fpls.2023.1180808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/27/2023] [Indexed: 09/12/2023]
Abstract
Phytophthora cinnamomi is an important plant pathogen responsible for dieback diseases in plant genera including Quercus, Fagus, Castanea, Eucalyptus, and Pinus, among others, all over the world. P. cinnamomi infection exerts tremendous ecological and economic losses. Several strategies have been developed to combat this pathogenic oomycete, including the search for novel anti-oomycete compounds. In this work, a Mediterranean vascular plant, Phlomis purpurea, has been screened for secondary bioactivity against this pathogen. The genus Phlomis includes a group of herbaceous plants and shrubs described as producers of many different bioactive compounds, including several triterpenoids. Triterpenoids are well-known molecules synthesized by plants and microorganisms with potent antioxidant, antitumoral, and antimicrobial activities. We have isolated by HPLC-DAD and characterized by HPLC-MS and NMR two nortriterpenoid compounds (phlomispentaol A and phlomispurtetraolone) from the root extracts of P. purpurea. One of them (phlomispentaol A) is active against the plant pathogenic oomycete P. cinnamomi (based on in vitro inhibition bioassays). Based on their chemical structure and their relationship to other plant triterpenoids, oleanolic acid is proposed to be the common precursor for these molecules. The anti-oomycete activity shown by phlomispentaol A represents a promising alternative to counteract the worldwide-scale damage caused to forest ecosystems by this pathogen.
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Affiliation(s)
- L. Fernández-Calleja
- Research Unit “Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC”, Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
| | - M. García-Domínguez
- Research Unit “Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC”, Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
| | - B. Isabel Redondo
- Department Animal Science, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - J. L. Gómez Martín
- Research and Development Department, Campojerez SL, Jerez de los Caballeros, Badajoz, Spain
| | - C. J. Villar
- Research Unit “Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC”, Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
| | - F. Lombó
- Research Unit “Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC”, Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
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Stevenson K, Pegg G, Wills J, Herbohn J, Firn J. Impacts of Myrtle Rust Induced Tree Mortality on Species and Functional Richness within Seedling Communities of a Wet Sclerophyll Forest in Eastern Australia. PLANTS (BASEL, SWITZERLAND) 2023; 12:1970. [PMID: 37653886 PMCID: PMC10221985 DOI: 10.3390/plants12101970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/17/2023] [Accepted: 04/27/2023] [Indexed: 09/02/2023]
Abstract
Austropuccinia psidii is an introduced plant pathogen known to have caused significant declines in populations of several Australian native Myrtaceae species. However, limited research has focused on the impacts of the pathogen on plant communities in the aftermath of its invasion. This study investigated the relationship between disease impact level, plant species diversity, and functional richness in seedling communities in a wet sclerophyll forest in southeast Queensland. A clear shift was found from early colonizer Myrtaceae species in the mid- and understory to a more diverse non-Myrtaceae seedling community indicative of secondary succession. Comparisons of key Myrtaceae species and the seedling community suggest that there may also be a shift towards species that produce drupes and larger seeds, and overall, a current reduction in fruit availability due to the dramatic loss of previously dominant species. Seedling diversity showed no significant correlation with tree mortality, possibly due to favorable rainfall conditions during the study period. The more subtle changes in forest composition, such as changes in fruit type and availability due to myrtle rust, however, could affect the visitation of local bird species in the short term and certainly reduce the store of early colonizing native shrub and tree species.
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Affiliation(s)
- Kristy Stevenson
- School of Agriculture and Food Science, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Geoff Pegg
- The Queensland Department of Agriculture and Fisheries, Brisbane, QLD 4001, Australia
| | - Jarrah Wills
- School of Agriculture and Food Science, The University of Queensland, St Lucia, QLD 4072, Australia
- Australian Government Department of Climate Change, Energy, the Environment and Water, Canberra, ACT 2601, Australia
| | - John Herbohn
- Tropical Forests and People Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD 4556, Australia
| | - Jennifer Firn
- School of Biological and Environmental Science, Queensland University of Technology, Brisbane, QLD 4001, Australia;
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Boulle M, Stewart BA, Barrett S. To spray or not to spray: Impact of phosphite spraying for
Phytophthora cinnamomi
control on Proteaceae species in southwestern Australia. CONSERVATION SCIENCE AND PRACTICE 2023. [DOI: 10.1111/csp2.12903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Affiliation(s)
- Michelle Boulle
- School of Agriculture and Environment University of Western Australia Albany Australia
| | - Barbara A. Stewart
- School of Agriculture and Environment University of Western Australia Albany Australia
| | - Sarah Barrett
- Regional services, Department of Biodiversity Conservation and Attraction Albany Australia
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Dann E, McLeod A. Phosphonic acid: a long-standing and versatile crop protectant. PEST MANAGEMENT SCIENCE 2021; 77:2197-2208. [PMID: 33099862 DOI: 10.1002/ps.6156] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/12/2020] [Accepted: 10/25/2020] [Indexed: 06/11/2023]
Abstract
Phosphonic acid-based fungicides, also referred to as phosphonates, have been used extensively as crop protectants in horticulture since the late 1970s, and more recently in native ecosystems and forestry. Discovering that phosphonates are effective against foliar and soilborne oomycete diseases, such as those caused by species of Phytophthora, Pythium and Plasmopara, was a significant breakthrough, especially for soilborne pathogens that are notoriously difficult to manage. Phosphonates have played an important role in protection of forests and sensitive natural ecosystems, under threat from these pathogens. Since introduction, their increased application in management of non-oomycete diseases, along with other functionalities, demonstrates their versatility in agriculture and more broadly. Continued use of phosphonic acid crop protectants will be underpinned by demonstrated efficacy and safety, and a better understanding of specific interactions within the plant, pathogen and environment. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Elizabeth Dann
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Australia
| | - Adéle McLeod
- Department of Plant Pathology, Stellenbosch University, Stellenbosch, South Africa
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Screening a Natural Product-Inspired Library for Anti- Phytophthora Activities. Molecules 2021; 26:molecules26071819. [PMID: 33804938 PMCID: PMC8037946 DOI: 10.3390/molecules26071819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/15/2021] [Accepted: 03/21/2021] [Indexed: 11/17/2022] Open
Abstract
Phytophthora is a genus of microorganisms that cause devastating dieback and root-rot diseases in thousands of plant hosts worldwide. The economic impact of Phytophthora diseases on crops and native ecosystems is estimated to be billions of dollars per annum. These invasive pathogens are extremely difficult to control using existing chemical means, and the effectiveness of the few treatments available is being jeopardized by increasing rates of resistance. There is an urgent need to identify new chemical treatments that are effective against Phytophthora diseases. Natural products have long been regarded as "Nature's medicine chest", providing invaluable leads for developing front-line drugs and agrochemical agents. Here, we have screened a natural product-inspired library of 328 chemicals against two key Phytophthora species: Phytophthora cinnamomi and Phytophthora agathidicida. The library was initially screened for inhibition of zoospore germination. From these screens, we identified twenty-one hits that inhibited germination of one or both species. These hits were further tested in mycelial growth inhibition studies to determine their half-maximal inhibitory concentrations (IC50s). Four compounds had IC50 values of approximately 10 µM or less, and our best hit had IC50s of approximately 3 µM against both Phytophthora species tested. Overall, these hits may serve as promising leads for the development of new anti-Phytophthora agrochemicals.
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Hopper SD, Lambers H, Silveira FAO, Fiedler PL. OCBIL theory examined: reassessing evolution, ecology and conservation in the world’s ancient, climatically buffered and infertile landscapes. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blaa213] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Abstract
OCBIL theory was introduced as a contribution towards understanding the evolution, ecology and conservation of the biological and cultural diversity of old, climatically buffered, infertile landscapes (OCBILs), especially in the Southern Hemisphere. The theory addresses some of the most intransigent environmental and cultural trends of our time – the ongoing decline of biodiversity and cultural diversity of First Nations. Here we reflect on OCBILs, the origins of the theory, and its principal hypotheses in biological, anthropological and conservation applications. The discovery that threatened plant species are concentrated in the Southwest Australian Floristic Region (SWAFR) on infertile, phosphorous-impoverished uplands within 500 km of the coast formed the foundational framework for OCBIL theory and led to the development of testable hypotheses that a growing literature is addressing. Currently, OCBILs are recognized in 15 Global Biodiversity Hotspots and eight other regions. The SWAFR, Greater Cape Floristic Region of South Africa and South America’s campos rupestres (montane grasslands) are those regions that have most comprehensively been investigated in the context of OCBIL theory. We summarize 12 evolutionary, ecological and cultural hypotheses and ten conservation-management hypotheses being investigated as recent contributions to the OCBIL literature.
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Affiliation(s)
- Stephen D Hopper
- Centre of Excellence in Natural Resource Management, School of Agriculture & Environment, The University of Western Australia, Albany, WA, Australia
| | - Hans Lambers
- School of Biological Sciences, The University of Western Australia, Crawley (Perth), WA, Australia
| | - Fernando A O Silveira
- Departmento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, Av. Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Peggy L Fiedler
- Natural Reserve System, University of California, Office of the President, Oakland, CA, USA
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Gosper CR, Kinloch J, Coates DJ, Byrne M, Pitt G, Yates CJ. Differential exposure and susceptibility to threats based on evolutionary history: how OCBIL theory informs flora conservation. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Optimal conservation approaches have been proposed to differ for biota with contrasting evolutionary histories. Natural selection filters the distribution of plant traits over evolutionary time, with the current expression of traits mediating susceptibility to contemporary and often novel threats. We use old, climatically buffered, infertile landscape (OCBIL) theory to compile predictions regarding differences in exposure and susceptibility to key threats between OCBIL and young, often disturbed, fertile landscape (YODFEL) flora. Based on literature and existing data from the Southwest Australian Floristic Region (SWAFR), we evaluate evidence in support of our predictions, finding strong theoretical and empirical support for the proposition that exposure and/or impact of many threats differs between OCBILs and YODFELs. OCBILs have more exposure to land clearance from mining, whereas many YODFELs have greater exposure to land clearance from agriculture, and urban and industrial land uses, and greater overall levels of habitat loss and fragmentation. OCBIL flora are more susceptible to pathogens and extremes of fire interval than YODFEL flora, but conversely may have a greater capacity to persist in smaller populations if small populations featured in the evolutionary history of the species prior to anthropogenic fragmentation, and have substantial resistance to weed invasion. We argue that consideration of evolutionary history has an important role in informing conservation management.
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Affiliation(s)
- Carl R Gosper
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
| | - Janine Kinloch
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
| | - David J Coates
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
| | - Margaret Byrne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
| | - Georgie Pitt
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
| | - Colin J Yates
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, WA, Australia
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Phytopathogenic oomycetes: a review focusing on Phytophthora cinnamomi and biotechnological approaches. Mol Biol Rep 2020; 47:9179-9188. [PMID: 33068230 DOI: 10.1007/s11033-020-05911-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/10/2020] [Indexed: 10/23/2022]
Abstract
The Phytophthora genus is composed, mainly, of plant pathogens. This genus belongs to the Oomycete class, also known as "pseudo-fungi", within the Chromista Kingdom. Phytophthora spp. is highlighted due to the significant plant diseases that they cause, which represents some of the most economically and cultural losses, such as European chestnut ink disease, which is caused by P. cinnamomi. Currently, there have been four genome assemblies placed at the National Center for Biotechnology Information (NCBI), although the progress to understand and elucidate the pathogenic process of P. cinnamomi by its genome is progressing slowly. In this review paper, we aim to report and discuss the recent findings related to P. cinnamomi and its genomic information. Our research is based on paper databases that reported probable functions to P. cinnamomi proteins using sequence alignments, bioinformatics, and biotechnology approaches. Some of these proteins studied have functions that are proposed to be involved in the asexual sporulation and zoosporogenesis leading to the host colonization and consequently associated with pathogenicity. Some remarkable genes and proteins discussed here are related to oospore development, inhibition of sporangium formation and cleavage, inhibition of flagellar assembly, blockage of cyst germination and hyphal extension, and biofilm proteins. Lastly, we report some biotechnological approaches using biological control, studies with genome sequencing of P. cinnamomi resistant plants, and gene silencing through RNA interference (iRNA).
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Development of a high throughput optical density assay to determine fungicide sensitivity of oomycetes. J Microbiol Methods 2018; 154:33-39. [DOI: 10.1016/j.mimet.2018.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 09/26/2018] [Accepted: 10/08/2018] [Indexed: 12/11/2022]
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