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Singh K, Gupta R, Shokat S, Iqbal N, Kocsy G, Pérez-Pérez JM, Riyazuddin R. Ascorbate, plant hormones and their interactions during plant responses to biotic stress. PHYSIOLOGIA PLANTARUM 2024; 176:e14388. [PMID: 38946634 DOI: 10.1111/ppl.14388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/18/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024]
Abstract
Plants can experience a variety of environmental stresses that significantly impact their fitness and survival. Additionally, biotic stress can harm agriculture, leading to reduced crop yields and economic losses worldwide. As a result, plants have developed defense strategies to combat potential invaders. These strategies involve regulating redox homeostasis. Several studies have documented the positive role of plant antioxidants, including Ascorbate (Asc), under biotic stress conditions. Asc is a multifaceted antioxidant that scavenges ROS, acts as a co-factor for different enzymes, regulates gene expression, and facilitates iron transport. However, little attention has been given to Asc and its transport, regulatory effects, interplay with phytohormones, and involvement in defense processes under biotic stress. Asc interacts with other components of the redox system and phytohormones to activate various defense responses that reduce the growth of plant pathogens and promote plant growth and development under biotic stress conditions. Scientific reports indicate that Asc can significantly contribute to plant resistance against biotic stress through mutual interactions with components of the redox and hormonal systems. This review focuses on the role of Asc in enhancing plant resistance against pathogens. Further research is necessary to gain a more comprehensive understanding of the molecular and cellular regulatory processes involved.
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Affiliation(s)
- Kalpita Singh
- Department of Biological Resources, Agricultural Institute, Centre for Agricultural Research, Hungarian Research Network (HUN-REN), Martonvásár, Hungary
- Doctoral School of Plant Sciences, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Ravi Gupta
- College of General Education, Kookmin University, Seoul, Republic of South Korea
| | - Sajid Shokat
- Section for Crop Science, Department of Plant and Environmental Sciences, University of Copenhagen, Taastrup, Denmark
- Plant Breeding and Genetics Laboratory, IAEA Laboratories, Seibersdorf, Austria
| | - Nadeem Iqbal
- Department of Plant Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Doctoral School of Environmental Sciences, University of Szeged, Szeged, Hungary
| | - Gábor Kocsy
- Department of Biological Resources, Agricultural Institute, Centre for Agricultural Research, Hungarian Research Network (HUN-REN), Martonvásár, Hungary
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Shu P, Li Y, Sheng J, Shen L. Recent Advances in Dissecting the Function of Ethylene in Interaction between Host and Pathogen. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:4552-4563. [PMID: 38379128 DOI: 10.1021/acs.jafc.3c07978] [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: 02/22/2024]
Abstract
Pathogens influence the growth and development of plants, resulting in detrimental damage to their yields and quality. Ethylene, a gaseous phytohormone, serves a pivotal function in modulating diverse physiological processes in plants, including defense mechanisms against pathogen invasion. Ethylene biosynthesis is involved in both plants and pathogens. Recent empirical research elucidates the intricate interactions and regulatory mechanisms between ethylene and pathogens across various plant species. In this review, we provide a comprehensive overview of the latest findings concerning ethylene's role and its regulatory networks in host-pathogen interactions. Additionally, we explore the crosstalk between ethylene and other phytohormones. Points regarding ethylene emission and its modulation by pathogens are also emphasized. Moreover, we also discuss potential unresolved issues in the field that warrant further investigation.
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Affiliation(s)
- Pan Shu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, P. R. China
| | - Yujing Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, P. R. China
| | - Jiping Sheng
- School of Agricultural Economics and Rural Development, Renmin University of China, Beijing 100872, P. R. China
| | - Lin Shen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, P. R. China
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Santos MG, Nunes da Silva M, Vasconcelos MW, Carvalho SMP. Scientific and technological advances in the development of sustainable disease management tools: a case study on kiwifruit bacterial canker. FRONTIERS IN PLANT SCIENCE 2024; 14:1306420. [PMID: 38273947 PMCID: PMC10808555 DOI: 10.3389/fpls.2023.1306420] [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: 10/03/2023] [Accepted: 12/21/2023] [Indexed: 01/27/2024]
Abstract
Plant disease outbreaks are increasing in a world facing climate change and globalized markets, representing a serious threat to food security. Kiwifruit Bacterial Canker (KBC), caused by the bacterium Pseudomonas syringae pv. actinidiae (Psa), was selected as a case study for being an example of a pandemic disease that severely impacted crop production, leading to huge economic losses, and for the effort that has been made to control this disease. This review provides an in-depth and critical analysis on the scientific progress made for developing alternative tools for sustainable KBC management. Their status in terms of technological maturity is discussed and a set of opportunities and threats are also presented. The gradual replacement of susceptible kiwifruit cultivars, with more tolerant ones, significantly reduced KBC incidence and was a major milestone for Psa containment - which highlights the importance of plant breeding. Nonetheless, this is a very laborious process. Moreover, the potential threat of Psa evolving to more virulent biovars, or resistant lineages to existing control methods, strengthens the need of keep on exploring effective and more environmentally friendly tools for KBC management. Currently, plant elicitors and beneficial fungi and bacteria are already being used in the field with some degree of success. Precision agriculture technologies, for improving early disease detection and preventing pathogen dispersal, are also being developed and optimized. These include hyperspectral technologies and forecast models for Psa risk assessment, with the latter being slightly more advanced in terms of technological maturity. Additionally, plant protection products based on innovative formulations with molecules with antibacterial activity against Psa (e.g., essential oils, phages and antimicrobial peptides) have been validated primarily in laboratory trials and with few compounds already reaching field application. The lessons learned with this pandemic disease, and the acquired scientific and technological knowledge, can be of importance for sustainably managing other plant diseases and handling future pandemic outbreaks.
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Affiliation(s)
- Miguel G. Santos
- GreenUPorto—Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences of the University of Porto, Vairão, Portugal
| | - Marta Nunes da Silva
- GreenUPorto—Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences of the University of Porto, Vairão, Portugal
- Universidade Católica Portuguesa, CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Marta W. Vasconcelos
- Universidade Católica Portuguesa, CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Susana M. P. Carvalho
- GreenUPorto—Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences of the University of Porto, Vairão, Portugal
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Xu C, Sun L, Mei Y, Sun G, Li W, Wang D, Li X, Wang NN. Domain Swapping between AtACS7 and PpACL1 Results in Chimeric ACS-like Proteins with ACS or C β-S Lyase Single Enzymatic Activity. Int J Mol Sci 2023; 24:ijms24032956. [PMID: 36769285 PMCID: PMC9917878 DOI: 10.3390/ijms24032956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
The gaseous hormone ethylene plays a pivotal role in plant growth and development. In seed plants, the key rate-limiting enzyme that controls ethylene biosynthesis is ACC synthase (ACS). ACS has, for a long time, been believed to be a single-activity enzyme until we recently discovered that it also possesses Cβ-S lyase (CSL) activity. This discovery raises fundamental questions regarding the biological significance of the dual enzymatic activities of ACS. To address these issues, it is highly necessary to obtain ACS mutants with either ACS or CSL single activity. Here, domain swapping between Arabidopsis AtACS7 and moss CSL PpACL1 were performed. Enzymatic activity assays of the constructed chimeras revealed that, R10, which was produced by replacing AtACS7 box 6 with that of PpACL1, lost ACS but retained CSL activity, whereas R12 generated by box 4 substitution lost CSL and only had ACS activity. The activities of both chimeric proteins were compared with previously obtained single-activity mutants including R6, AtACS7Q98A, and AtACS7D245N. All the results provided new insights into the key residues required for ACS and CSL activities of AtACS7 and laid an important foundation for further in-depth study of the biological functions of its dual enzymatic activities.
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Affiliation(s)
- Chang Xu
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Lifang Sun
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Yuanyuan Mei
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Gongling Sun
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Wenjing Li
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Dan Wang
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
| | - Xin Li
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Ning Ning Wang
- College of Life Sciences, College of Agricultural Sciences, Tianjin Key Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
- Correspondence:
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Nerva L, Dalla Costa L, Ciacciulli A, Sabbadini S, Pavese V, Dondini L, Vendramin E, Caboni E, Perrone I, Moglia A, Zenoni S, Michelotti V, Micali S, La Malfa S, Gentile A, Tartarini S, Mezzetti B, Botta R, Verde I, Velasco R, Malnoy MA, Licciardello C. The Role of Italy in the Use of Advanced Plant Genomic Techniques on Fruit Trees: State of the Art and Future Perspectives. Int J Mol Sci 2023; 24:ijms24020977. [PMID: 36674493 PMCID: PMC9861864 DOI: 10.3390/ijms24020977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/07/2023] Open
Abstract
Climate change is deeply impacting the food chain production, lowering quality and yield. In this context, the international scientific community has dedicated many efforts to enhancing resilience and sustainability in agriculture. Italy is among the main European producers of several fruit trees; therefore, national research centers and universities undertook several initiatives to maintain the specificity of the 'Made in Italy' label. Despite their importance, fruit crops are suffering from difficulties associated with the conventional breeding approaches, especially in terms of financial commitment, land resources availability, and long generation times. The 'new genomic techniques' (NGTs), renamed in Italy as 'technologies for assisted evolution' (TEAs), reduce the time required to obtain genetically improved cultivars while precisely targeting specific DNA sequences. This review aims to illustrate the role of the Italian scientific community in the use of NGTs, with a specific focus on Citrus, grapevine, apple, pear, chestnut, strawberry, peach, and kiwifruit. For each crop, the key genes and traits on which the scientific community is working, as well as the technological improvements and advancements on the regeneration of local varieties, are presented. Lastly, a focus is placed on the legal aspects in the European and in Italian contexts.
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Affiliation(s)
- Luca Nerva
- Research Center for Viticulture and Enology, Council for Agricultural Research and Economics, 31015 Conegliano, Italy
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Lorenza Dalla Costa
- Research and Innovation Centre, Foundation Edmund Mach, 38098 San Michele all’Adige, Italy
| | - Angelo Ciacciulli
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 95024 Acireale, Italy
| | - Silvia Sabbadini
- Department of Agricultural, Food, and Environmental Sciences, Marche Polytechnic University, 60131 Ancona, Italy
| | - Vera Pavese
- Department of Agricultural, Forest and Food Sciences, University of Torino, 10095 Torino, Italy
| | - Luca Dondini
- Department of Agricultural and Food Sciences, University of Bologna, 40127 Bologna, Italy
| | - Elisa Vendramin
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 00134 Rome, Italy
| | - Emilia Caboni
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 00134 Rome, Italy
| | - Irene Perrone
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Andrea Moglia
- Department of Agricultural, Forest and Food Sciences, University of Torino, 10095 Torino, Italy
| | - Sara Zenoni
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Vania Michelotti
- Research Center for Genomics and Bioinformatics, Council for Agricultural Research and Economics, 29017 Fiorenzuola D’Arda, Italy
| | - Sabrina Micali
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 00134 Rome, Italy
| | - Stefano La Malfa
- Department of Biotechnology, University of Catania, 95124 Catania, Italy
| | - Alessandra Gentile
- Department of Biotechnology, University of Catania, 95124 Catania, Italy
| | - Stefano Tartarini
- Department of Agricultural and Food Sciences, University of Bologna, 40127 Bologna, Italy
| | - Bruno Mezzetti
- Department of Agricultural, Food, and Environmental Sciences, Marche Polytechnic University, 60131 Ancona, Italy
| | - Roberto Botta
- Department of Agricultural, Forest and Food Sciences, University of Torino, 10095 Torino, Italy
| | - Ignazio Verde
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 00134 Rome, Italy
| | - Riccardo Velasco
- Research Center for Viticulture and Enology, Council for Agricultural Research and Economics, 31015 Conegliano, Italy
| | - Mickael Arnaud Malnoy
- Research and Innovation Centre, Foundation Edmund Mach, 38098 San Michele all’Adige, Italy
- Correspondence: (M.A.M.); (C.L.); Tel.: +39-04-6161-5536 (M.A.M.); +39-09-5765-3104 (C.L.)
| | - Concetta Licciardello
- Research Center for Olive Fruit and Citrus Crops, Council for Agricultural Research and Economics, 95024 Acireale, Italy
- Correspondence: (M.A.M.); (C.L.); Tel.: +39-04-6161-5536 (M.A.M.); +39-09-5765-3104 (C.L.)
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Correia C, Magnani F, Pastore C, Cellini A, Donati I, Pennisi G, Paucek I, Orsini F, Vandelle E, Santos C, Spinelli F. Red and Blue Light Differently Influence Actinidia chinensis Performance and Its Interaction with Pseudomonas syringae pv. Actinidiae. Int J Mol Sci 2022; 23:13145. [PMID: 36361938 PMCID: PMC9658526 DOI: 10.3390/ijms232113145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 03/08/2024] Open
Abstract
Light composition modulates plant growth and defenses, thus influencing plant-pathogen interactions. We investigated the effects of different light-emitting diode (LED) red (R) (665 nm) and blue (B) (470 nm) light combinations on Actinidia chinensis performance by evaluating biometric parameters, chlorophyll a fluorescence, gas exchange and photosynthesis-related gene expression. Moreover, the influence of light on the infection by Pseudomonas syringae pv. actinidiae (Psa), the etiological agent of bacterial canker of kiwifruit, was investigated. Our study shows that 50%R-50%B (50R) and 25%R-75%B (25R) lead to the highest PSII efficiency and photosynthetic rate, but are the least effective in controlling the endophytic colonization of the host by Psa. Monochromatic red light severely reduced ΦPSII, ETR, Pn, TSS and photosynthesis-related genes expression, and both monochromatic lights lead to a reduction of DW and pigments content. Monochromatic blue light was the only treatment significantly reducing disease symptoms but did not reduce bacterial endophytic population. Our results suggest that monochromatic blue light reduces infection primarily by modulating Psa virulence more than host plant defenses.
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Affiliation(s)
- Cristiana Correia
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
- IB2Lab, LAQV-Requimte, Department of Biology, Faculty of Sciences, University of Porto, Rua Campo Alegre, 4169-007 Porto, Portugal
| | - Federico Magnani
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Chiara Pastore
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Antonio Cellini
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Irene Donati
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Giuseppina Pennisi
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Ivan Paucek
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Francesco Orsini
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
| | - Elodie Vandelle
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Conceição Santos
- IB2Lab, LAQV-Requimte, Department of Biology, Faculty of Sciences, University of Porto, Rua Campo Alegre, 4169-007 Porto, Portugal
| | - Francesco Spinelli
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 46, 40127 Bologna, Italy
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Nunes da Silva M, Carvalho SMP, Rodrigues AM, Gómez-Cadenas A, António C, Vasconcelos MW. Defence-related pathways, phytohormones and primary metabolism are key players in kiwifruit plant tolerance to Pseudomonas syringae pv. actinidiae. PLANT, CELL & ENVIRONMENT 2022; 45:528-541. [PMID: 34773419 DOI: 10.1111/pce.14224] [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] [Received: 09/07/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 05/07/2023]
Abstract
The reasons underlying the differential tolerance of Actinidia spp. to the pandemic pathogen Pseudomonas syringae pv. actinidiae (Psa) have not yet been elucidated. We hypothesized that differential plant-defence strategies linked to transcriptome regulation, phytohormones and primary metabolism might be key and that Actinidia chinensis susceptibility results from an inefficient activation of defensive mechanisms and metabolic impairments shortly following infection. Here, 48 h postinoculation bacterial density was 10-fold higher in A. chinensis var. deliciosa than in Actinidia arguta, accompanied by significant increases in glutamine, ornithine, jasmonic acid (JA) and salicylic acid (SA) (up to 3.2-fold). Actinidia arguta showed decreased abscisic acid (ABA) (0.7-fold), no changes in primary metabolites, and 20 defence-related genes that were only differentially expressed in this species. These include GLOX1, FOX1, SN2 and RBOHA, which may contribute to its higher tolerance. Results suggest that A. chinensis' higher susceptibility to Psa is due to an inefficient activation of plant defences, with the involvement of ABA, JA and SA, leading to impairments in primary metabolism, particularly the ammonia assimilation cycle. A schematic overview on the interaction between Psa and genotypes with distinct tolerance is provided, highlighting the key transcriptomic and metabolomic aspects contributing to the different plant phenotypes after infection.
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Affiliation(s)
- Marta Nunes da Silva
- Centro de Biotecnologia e Química Fina (CBQF), Laboratório Associado, Universidade Católica Portuguesa, Escola Superior de Biotecnologia, Porto, Portugal
- GreenUPorto - Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences of University of Porto, Vairão, Portugal
| | - Susana M P Carvalho
- GreenUPorto - Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences of University of Porto, Vairão, Portugal
| | - Ana M Rodrigues
- Plant Metabolomics Laboratory, Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Oeiras, Portugal
| | - Aurelio Gómez-Cadenas
- Departamento de Ciencias Agrarias y del Medio Natural, Universitat Jaume I, Castelló de la Plana, Spain
| | - Carla António
- Plant Metabolomics Laboratory, Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Oeiras, Portugal
| | - Marta W Vasconcelos
- Centro de Biotecnologia e Química Fina (CBQF), Laboratório Associado, Universidade Católica Portuguesa, Escola Superior de Biotecnologia, Porto, Portugal
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Bioassay-Guided Isolation of Broad-Spectrum Fungicidal Active Compound from Artemisia ordosica. Metabolites 2021; 11:metabo11090629. [PMID: 34564445 PMCID: PMC8468595 DOI: 10.3390/metabo11090629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 12/04/2022] Open
Abstract
To avoid the widespread resistance of commercial fungicides, new broad-spectrum botanical fungicides need to be developed. In previous bioactive screening assays, extracts of Artemisia ordosica Krasch. (A. ordosica) had highly antifungal activities, but the responsible phytochemicals were unidentified. In this study, active compounds of A. ordosica extracts were identified using a bioassay-guided method, and antifungal assays were performed in vitro and in vivo. The bioactive compounds were dissolved in petroleum ether, and the best antifungal fraction contained four compounds: trans-dehydromatricaria ester (TDDE), 7, 4-demetylnringenin, capillarin, and stearic acid. Among them, TDDE exhibited the highest antifungal activity against six pathogenic fungi and five bacteria. It exhibited significant fungicidal activity against Thanatephorus cucumeris and Botrytis cinerea with EC50 values of 0.464 μg/mL and 1.4 μg/mL, respectively. The living tissue bioassay results showed that the relative protection effects (RPE) of TDDE on tomato leaves, tomato fruit, and strawberry leaves infected with B. cinerea reached 76.78%, 86.2%, and 80.89%, respectively. In pot experiments, the RPE on tomato and strawberry plants infected with B. cinerea reached 84.11% and 96.37%, respectively. Morphological and physiological examination showed that TDDE had significant inhibitory effects on mycelial growth, including increased top offshoot, contorted hyphal tips, and extravasated cytochylema. Meanwhile, bactericidal activities of TDDE were significantly higher than kanamycin and streptomycin in five bacteria, and the plant tissue experiments further demonstrated that it had an 88.31% RPE on walnut leaves infected with Xanthomonas campestris pv. jugiandis, 72.18% RPE on potato infected with Erwinia carotovora subsp. carotovora, and 82.50% RPE on kiwifruit branches infected with Pseudomonas syringae pv. actinidiae. The active compounds isolated from A. ordosica in this study show great potential value for developing broad-spectrum fungicides, and also provide an important way to identify and isolate new bioactive products from medicinal plants.
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