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Ebadi M, Ebadi A. Genetic diversity and population structure of Alternaria alternata: An endophytic fungus isolated from various hosts. Fungal Biol 2024; 128:2305-2310. [PMID: 39643397 DOI: 10.1016/j.funbio.2024.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 11/08/2024] [Indexed: 12/09/2024]
Abstract
Alternaria alternata is a significant fungal species that can function as both an endophytic fungus and a pathogen in various plant tissues. Unlike pathogenic fungi, endophytic fungi enhance the growth of host plants through different mechanisms. Studying the genetic diversity of endophytic fungi can provide insights into their co-evolution with plants. In this research, the genetic diversity of A. alternata from different hosts was examined using ten pairs of ISSR primers. Seven of the ten primers generated scorable polymorphic bands (total of 65 bands with an average of 9.2 bands per primer) for molecular analysis. Genetic diversity parameters revealed that isolates from Gundelia tournefortii exhibited the highest genetic diversity (Na, Ne, I, and He values of 1.55, 1.45, 0.35, and 0.24, respectively), while isolates from Tamarix ramosissima showed lower diversity (Na, Ne, I, and He values of 1.18, 1.13, 0.11, and 0.07, respectively). Cluster analysis grouped the isolates into four clusters based on Jaccard similarity matrix and UPGMA method. Principal coordinate analysis (PCOA) supported the cluster analysis findings. Analysis of molecular variance (AMOVA) indicated a high level of genetic differentiation within populations (72 %), with only 28 % of diversity between populations. The genetic structure assessment revealed a relatively strong genetic structure among populations, suggesting the presence of a hidden sexual cycle or mitotic recombination as factors contributing to the high genetic differentiation among A. alternata populations.
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Affiliation(s)
- Mostafa Ebadi
- Department of Biology, Faculty of Science, Azarbaijan Shahid Madani University, Tabriz, Iran.
| | - Ali Ebadi
- Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute (NSTRI), Karaj, Iran
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Huang XR, Jiang CN, Wang HS, Gu G, Wang M, Sui XN, Si T, Zhang ZF, Zhang P, Zhao DL. Herbicidal Sorbicillinoid Analogs Cause Lignin Accumulation in Aspergillus aculeatus TE-65L. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:21102-21111. [PMID: 39269321 DOI: 10.1021/acs.jafc.4c06809] [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: 09/15/2024]
Abstract
Five new sorbicillinoid derivatives, including (±)-aspersorbicillin A [(±)-1], a pair of enantiomers at C-9, and aspersorbicillins B-D (2-4), together with two known analogs (5 and 6) were isolated from the endophytic fungus Aspergillus aculeatus TE-65L. Their structures including absolute configurations were determined by detailed spectroscopic analyses and electronic circular dichroism calculations. The herbicidal activity of sorbicillinoids on the germ and radicle elongation of various weed types was reported for the first time. Compound 1 displayed significant herbicidal activity against Eleusine indica germ elongation (IC50 = 28.8 μg/mL), while compound 6 inhibited radicle elongation (IC50 = 25.6 μg/mL). Both were stronger than those of glyphosate (66.2 and 30.9 μg/mL, respectively). Further transcriptomic and LC-MS/MS metabolomic analysis indicated that 6 induced the transcriptional expressions of genes related to the lignin biosynthetic pathway, resulting in lignin accumulation. Transmission electron microscopy confirmed the cell wall thickening of seeds treated with 6, suggesting weed growth inhibition. This study reveals new lead compounds for fabricating natural herbicides and expands the agricultural use of sorbicillinoid analogs.
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Affiliation(s)
- Xin-Rong Huang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Chao-Nan Jiang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Hai-Su Wang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Gan Gu
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Mei Wang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Xiao-Na Sui
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Tong Si
- College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China
| | - Zhong-Feng Zhang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Peng Zhang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Dong-Lin Zhao
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
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Fan W, Tao Y, Jiang C, Huang Q, Li J, Ding W, Li C. Four New Isocoumarins from the Mangrove Fungus Alternaria Malorum with Antimicrobial Activities. Chem Biodivers 2024; 21:e202400327. [PMID: 38446672 DOI: 10.1002/cbdv.202400327] [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: 02/07/2024] [Revised: 03/03/2024] [Accepted: 03/05/2024] [Indexed: 03/08/2024]
Abstract
Four new isocoumarins, alternariethers A-C (1-3) and alternariester (4) were separated from the fermentation of the fungus Alternaria malorum FL39, purified from Myoporum bontioides. Their structures were ascertained using NMR and HR-ESI-MS spectroscopy. For compound 4, the absolute configuration was solved with the help of ECD calculation and the DP4+ method. Compared with the positive control triadimefon, compound 1 showed more potent antifungal effects on Colletotrichum musae. The antifungal effects of compounds 1, 2, and 3 on Fusarium oxysporum and Fusarium graminearum, of compound 4 on F. oxysporum, were equal to those of triadimefon. Except for compound 4 which was inactive against Escherichia coli with O78 serotype, all compounds showed moderate or weak antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli with O6 or O78 serotype.
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Affiliation(s)
- Wei Fan
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
| | - Yiwen Tao
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, 511436, China
| | - Canmin Jiang
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
| | - Qisen Huang
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
| | - Jiacong Li
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
| | - Weijia Ding
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
| | - Chunyuan Li
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China
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Kusmiati K, Fanani A, Nurkanto A, Purnaningsih I, Mamangkey J, Ramadhani I, Nurcahyanto DA, Simanjuntak P, Afiati F, Irawan H, Puteri AL, Ewaldo MF, Juanssilfero AB. Profile and in silico analysis of metabolite compounds of the endophytic fungus Alternaria alternata K-10 from Drymoglossum piloselloides as antioxidants and antibacterials. Heliyon 2024; 10:e27978. [PMID: 38524563 PMCID: PMC10958433 DOI: 10.1016/j.heliyon.2024.e27978] [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: 09/07/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/26/2024] Open
Abstract
Endophytic fungi are known for producing secondary metabolites with valuable biological activities, including antiviral, anticancer, antibacterial, and antioxidant properties. This study aims to evaluate an endophytic fungus from Dragon Scales leaves (Drymoglossum piloselloides) and analyze its metabolites as antioxidants and antibacterials. In this study, an endophytic fungus was isolated from the leaves of Dragon Scales (D. piloselloides) and identified using molecular analysis of the Internal Transcribed Spacer (ITS) ribosomal RNA locus. The fungus was authenticated as Alternaria alternata strain K-10. Crude extracts were obtained using n-hexane and ethyl acetate and analyzed via GC-MS Shimadzu-QP 2010 Ultra with NIST spectral library. Antibacterial activity was observed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa using the paper disc method, showing inhibition zones of 8.7-9.3 mm and 8.8-9.4 mm for ethyl acetate and n-hexane extracts, respectively. Ethyl acetate and n-hexane extracts exhibited strong antioxidant potential against 2,2-diphenyl-1-picrylhydrazil (DPPH) radical (IC50 values of 50.99 μg mL-1 and 74.44 μg mL-1, respectively). GC-MS analysis revealed 40 compounds in both extracts, some of which, including 2-ethylhexyl ester benzoic acid, benzo-b-dihydropyran-6-hydroxy-4-4-5-7-8-pentamethyl, diethyl phthalate, and octadecanoic acid, were identified through in silico analysis and found to possess antioxidant properties. These findings hold implications for potential applications of the plant and its biological constituent to be developed as lead compounds in the medical sector.
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Affiliation(s)
- Kusmiati Kusmiati
- Research Center for Biosystematics and Evolution- Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Asrul Fanani
- Research and Education Center for Bioinformatics, Indonesia Institute of Bioinformatics, Malang, 65162, Indonesia
| | - Arif Nurkanto
- Research Center for Biosystematics and Evolution- Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Ismu Purnaningsih
- Directorate of Scientific Collection Management, The National Research and Innovation Agency (BRIN)- KST Soekarno, Jl Raya Bogor Km 46, Cibinong Bogor, 16911, Indonesia
| | - Jendri Mamangkey
- Department of Biology Education, Faculty of Education and Teacher Training, Universitas Kristen Indonesia, Jakarta, Indonesia
- Research Center for Genetic Engineering, Research Organization for Life Sciences and Environment, National Research and Innovation Agency (BRIN), KST Soekarno, Cibinong, Bogor, Indonesia
| | - Indriati Ramadhani
- Research Center for Biosystematics and Evolution- Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Dian Alfian Nurcahyanto
- Research Center for Biosystematics and Evolution- Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Partomuan Simanjuntak
- Research Center for Pharmaceutical Ingredient and Traditional Medicine, National Research and Innovation Agency (BRIN), Indonesia
| | - Fifi Afiati
- Research Center for Applied Microbiology-Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Herman Irawan
- Research Center for Genetic Engineering, Research Organization for Life Sciences and Environment, National Research and Innovation Agency (BRIN), KST Soekarno, Cibinong, Bogor, Indonesia
| | - Ade Lia Puteri
- Research Center for Biosystematics and Evolution- Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
| | - Muhammad Farrel Ewaldo
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia Jl. Salemba Raya – Jakarta Pusat, Indonesia
| | - Ario Betha Juanssilfero
- Research Center for Applied Microbiology-Research Organization for Life Sciences and Environment, The National Research and Innovation Agency (BRIN), Indonesia
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Mahajan S, Chakraborty A, Bisht MS, Sil T, Sharma VK. Genome sequencing and functional analysis of a multipurpose medicinal herb Tinospora cordifolia (Giloy). Sci Rep 2024; 14:2799. [PMID: 38307917 PMCID: PMC10837142 DOI: 10.1038/s41598-024-53176-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 01/29/2024] [Indexed: 02/04/2024] Open
Abstract
Tinospora cordifolia (Willd.) Hook.f. & Thomson, also known as Giloy, is among the most important medicinal plants that have numerous therapeutic applications in human health due to the production of a diverse array of secondary metabolites. To gain genomic insights into the medicinal properties of T. cordifolia, the genome sequencing was carried out using 10× Genomics linked read and Nanopore long-read technologies. The draft genome assembly of T. cordifolia was comprised of 1.01 Gbp, which is the genome sequenced from the plant family Menispermaceae. We also performed the genome size estimation for T. cordifolia, which was found to be 1.13 Gbp. The deep sequencing of transcriptome from the leaf tissue was also performed. The genome and transcriptome assemblies were used to construct the gene set, resulting in 17,245 coding gene sequences. Further, the phylogenetic position of T. cordifolia was also positioned as basal eudicot by constructing a genome-wide phylogenetic tree using multiple species. Further, a comprehensive comparative evolutionary analysis of gene families contraction/expansion and multiple signatures of adaptive evolution was performed. The genes involved in benzyl iso-quinoline alkaloid, terpenoid, lignin and flavonoid biosynthesis pathways were found with signatures of adaptive evolution. These evolutionary adaptations in genes provide genomic insights into the presence of diverse medicinal properties of this plant. The genes involved in the common symbiosis signalling pathway associated with endosymbiosis (Arbuscular Mycorrhiza) were found to be adaptively evolved. The genes involved in adventitious root formation, peroxisome biogenesis, biosynthesis of phytohormones, and tolerance against abiotic and biotic stresses were also found to be adaptively evolved in T. cordifolia.
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Affiliation(s)
- Shruti Mahajan
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India
| | - Abhisek Chakraborty
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India
| | - Manohar S Bisht
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India
| | - Titas Sil
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India
| | - Vineet K Sharma
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462066, India.
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Li H, Ding J, Liu C, Huang P, Yang Y, Jin Z, Qin W. Carvacrol Treatment Reduces Decay and Maintains the Postharvest Quality of Red Grape Fruits ( Vitis vinifera L.) Inoculated with Alternaria alternata. Foods 2023; 12:4305. [PMID: 38231758 DOI: 10.3390/foods12234305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/18/2023] [Accepted: 11/20/2023] [Indexed: 01/19/2024] Open
Abstract
In this study, we isolated and identified pathogenic fungi from the naturally occurring fruits of red grapes, studied their biological characteristics, screened fifteen essential oil components to find the best natural antibacterial agent with the strongest inhibitory effect, and then compared the incidence of postharvest diseases and storage potential of red grapes treated with two concentrations (0.5 EC50/EC50) of essential oil components (inoculated with pathogenic fungi) during storage for 12 d at room temperature. In our research, Alternaria alternata was the primary pathogenic fungus of red grapes. Specifically, red grapes became infected which caused diseases, regardless of whether they were inoculated with Alternaria alternata in an injured or uninjured state. Our findings demonstrated that the following conditions were ideal for Alternaria alternata mycelial development and spore germination: BSA medium, D-maltose, ammonium nitrate, 28 °C, pH 6, and exposure to light. For the best Alternaria alternata spore production, OA medium, mannitol, urea, 34 °C, pH 9, and dark conditions were advised. Furthermore, with an EC50 value of 36.71 μg/mL, carvacrol demonstrated the highest inhibitory impact on Alternaria alternata among the 15 components of essential oils. In the meantime, treatment with EC50 concentration of carvacrol was found to be more effective than 0.5 EC50 concentration for controlling Alternaria alternata-induced decay disease of red grapes. The fruits exhibited remarkable improvements in the activity of defense-related enzymes, preservation of the greatest hardness and total soluble solids content, reduction in membrane lipid peroxidation in the peel, and preservation of the structural integrity of peel cells. Consequently, carvacrol was able to prevent the Alternaria alternata infestation disease that affects red grapes, and its EC50 concentration produced the greatest outcomes.
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Affiliation(s)
- Hongying Li
- College of Food Science, Sichuan Agricultural University, Ya'an 625014, China
| | - Jie Ding
- College of Food Science, Sichuan Tourism University, Chengdu 610100, China
| | - Chunyan Liu
- Chengdu Kuafu Technology Co., Ltd., Chengdu 610100, China
| | - Peng Huang
- College of Food Science, Sichuan Agricultural University, Ya'an 625014, China
- Department of Quality Management and Inspection and Detection, Yibin University, Yibin 644000, China
| | - Yifan Yang
- College of Food Science, Sichuan Agricultural University, Ya'an 625014, China
| | - Zilu Jin
- College of Food Science, Sichuan Agricultural University, Ya'an 625014, China
| | - Wen Qin
- College of Food Science, Sichuan Agricultural University, Ya'an 625014, China
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Spina R, Ropars A, Bouazzi S, Dadi S, Lemiere P, Dupire F, Khiralla A, Yagi S, Frippiat JP, Laurain-Mattar D. Screening of Anti-Inflammatory Activity and Metabolomics Analysis of Endophytic Fungal Extracts; Identification and Characterization of Perylenequinones and Terpenoids from the Interesting Active Alternaria Endophyte. Molecules 2023; 28:6531. [PMID: 37764307 PMCID: PMC10534442 DOI: 10.3390/molecules28186531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/24/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Patients suffering from inflammatory chronic diseases are classically treated with anti-inflammatory drugs but unfortunately are highly susceptible to becoming resistant to their treatment. Finding new drugs is therefore crucial and urgent and research on endophytic fungi is a promising way forward. Endophytic fungi are microorganisms that colonize healthy plants and live within their intercellular tissues. They are able to produce a large variety of secondary metabolites while allowing their host to stay healthy. A number of these molecules are endowed with antioxidant or antimicrobial as well as cytotoxic properties, making them very interesting/promising in the field of human therapy. The aim of our study was to investigate whether extracts from five endophytic fungi isolated from plants are endowed with anti-inflammatory activity. Extracts of the endophytic fungi Alternaria alternata from Calotropis procera leaves and Aspergillus terreus from Trigonella foenum-graecum seeds were able to counteract the lipopolysaccharide (LPS) pro-inflammatory effect on THP-1 cells differentiated into macrophages. Moreover, they were able to induce an anti-inflammatory state, rendering them less sensitive to the LPS pro-inflammatory stimulus. Taken together, these results show that these both endophytic fungi could be interesting alternatives to conventional anti-inflammatory drugs. To gain more detailed knowledge of their chemical richness, phytochemical analysis of the ethyl acetate extracts of the five endophytic fungi studied was performed using HPTLC, GC-MS and LC-MS with the Global Natural Products Social (GNPS) platform and the MolNetEnhancer tool. A large family of metabolites (carboxylic acids and derivatives, steroid derivatives, alkaloids, hydroxyanthraquinones, valerolactones and perylenequinones) were detected. The purification of endophytic fungus extract of Alternaria alternate, which diminished TNF-α production of 66% at 20 µg/mL, incubated one hour before LPS addition, led to the characterization of eight pure compounds. These molecules are altertoxins I, II, III, tricycloalternarenes 3a, 1b, 2b, anthranilic acid, and o-acetamidobenzoic acid. In the future, all these pure compounds will be evaluated for their anti-inflammatory activity, while altertoxin II has been shown in the literature as the most active mycotoxin in terms of anti-inflammatory activity.
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Affiliation(s)
- Rosella Spina
- Université de Lorraine, INRAE, LAE, F-54000 Nancy, France;
| | - Armelle Ropars
- Université de Lorraine, SIMPA, F-54000 Nancy, France; (A.R.); (J.-P.F.)
| | - Sihem Bouazzi
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France; (S.B.); (S.D.); (P.L.); (F.D.)
| | - Safa Dadi
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France; (S.B.); (S.D.); (P.L.); (F.D.)
| | - Pascal Lemiere
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France; (S.B.); (S.D.); (P.L.); (F.D.)
| | - François Dupire
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France; (S.B.); (S.D.); (P.L.); (F.D.)
| | - Afra Khiralla
- Botany Department, Faculty of Sciences and Technologies, Shendi University, Shendi 11111, Sudan;
| | - Sakina Yagi
- Department of Botany, Faculty of Science, University of Khartoum, Khartoum 11115, Sudan;
| | - Jean-Pol Frippiat
- Université de Lorraine, SIMPA, F-54000 Nancy, France; (A.R.); (J.-P.F.)
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Fan J, Guo F, Zhao C, Li H, Qu T, Xiao L, Du F. Secondary Metabolites with Herbicidal and Antifungal Activities from Marine-Derived Fungus Alternaria iridiaustralis. J Fungi (Basel) 2023; 9:716. [PMID: 37504705 PMCID: PMC10381437 DOI: 10.3390/jof9070716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/24/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023] Open
Abstract
Weed and soil-borne pathogens could synergistically affect vegetable growth and result in serious losses. Investigation of agricultural bioactive metabolites from marine-derived fungus Alternaria iridiaustralis yielded polyketides (1-4), benzopyrones (5-7), meroterpenoid derivatives (8), and alkaloid (9). The structures and absolute configurations of new 1, 3, 5-6, and 8 were elucidated by extensive spectroscopic analyses, as well as comparisons between measured and calculated ECD and 13C NMR data. Compounds 1-4, 6, and 9 showed herbicidal potentials against the radicle growth of Echinochloa crusgalli seedlings. Especially 9 exhibited inhibition rates over 90% at concentrations of 20 and 40 μg/mL, even better than the commonly used chemical herbicide acetochlor. Furthermore, 9 also performed a wide herbicidal spectrum against the malignant weeds Digitaria sanguinalis, Portulaca oleracea, and Descurainia sophia. Compounds 5-8 showed antifungal activities against carbendazim-resistant strains of Botrytis cinerea, with minimum inhibitory concentration (MIC) values ranging from 32 to 128 μg/mL, which were better than those of carbendazim (MIC = 256 μg/mL). Especially 6 exhibited integrated effects against both soil-borne pathogens and weed. Overall, marine-derived fungus A. iridiaustralis, which produces herbicidal and antifungal metabolites 1-9, showed the potential for use as a microbial pesticide to control both weed and soil-borne pathogens.
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Affiliation(s)
- Jinqing Fan
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Fangfang Guo
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Chen Zhao
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Hong Li
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Tianli Qu
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Qingdao 266109, China
| | - Lin Xiao
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Qingdao 266109, China
| | - Fengyu Du
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Qingdao 266109, China
- Shandong Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao 266109, China
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The Potential of Bacilli-Derived Biosurfactants as an Additive for Biocontrol against Alternaria alternata Plant Pathogenic Fungi. Microorganisms 2023; 11:microorganisms11030707. [PMID: 36985279 PMCID: PMC10056989 DOI: 10.3390/microorganisms11030707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Fungal diseases caused by Alternaria alternata constitute a significant threat to the production and quality of a wide range of crops, including beans, fruits, vegetables, and grains. Traditional methods for controlling these diseases involve synthetic chemical pesticides, which can negatively impact the environment and human health. Biosurfactants are natural, biodegradable secondary metabolites of microorganisms that have also been shown to possibly have antifungal activity against plant pathogenic fungi, including A. alternata being sustainable alternatives to synthetic pesticides. In this study, we investigated the potential of biosurfactants of three bacilli (Bacillus licheniformis DSM13, Bacillus subtilis DSM10, and Geobacillus stearothermophilus DSM2313) as a biocontrol agent against A. alternata on beans as a model organism. For this fermentation, we describe using an in-line biomass sensor monitoring both permittivity and conductivity, which are expected to correlate with cell concentration and products, respectively. After the fermentation of biosurfactants, we first characterised the properties of the biosurfactant, including their product yield, surface tension decrement capability, and emulsification index. Then, we evaluated the antifungal properties of the crude biosurfactant extracts against A. alternata, both in vitro and in vivo, by analysing various plant growth and health parameters. Our results showed that bacterial biosurfactants effectively inhibited the growth and reproduction of A. alternata in vitro and in vivo. B. licheniformis manufactured the highest amount of biosurfactant (1.37 g/L) and demonstrated the fastest growth rate, while G. stearothermophilus produced the least amount (1.28 g/L). The correlation study showed a strong positive relationship between viable cell density VCD and OD600, as well as a similarly good positive relationship between conductivity and pH. The poisoned food approach in vitro demonstrated that all three strains suppressed mycelial development by 70–80% when applied with the highest tested dosage of 30%. Regarding in vivo investigations, B. subtilis post-infection treatment decreased the disease severity to 30%, whereas B. licheniformis and G. stearothermophilus post-infection treatment reduced disease severity by 25% and 5%, respectively. The study also revealed that the plant’s total height, root length, and stem length were unaffected by the treatment or the infection.
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