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Patel JK, Mistry Y, Soni R, Jha A. Evaluation of Antifungal Activity of Endophytic Bacillus spp. and Identification of Secondary Metabolites Produced Against the Phytopathogenic Fungi. Curr Microbiol 2024; 81:128. [PMID: 38580768 DOI: 10.1007/s00284-024-03652-6] [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: 12/08/2023] [Accepted: 02/26/2024] [Indexed: 04/07/2024]
Abstract
Endophytic bacteria serve as a rich source of diverse antimicrobial compounds. Recently, there has been a growing interest in utilizing endophytic Bacillus spp. as biological agents against phytogenic fungi, owing to their potential to produce a wide range of antimicrobial substances. The objective of this research was to investigate the protective abilities of 15 endophytic Bacillus spp. isolated from previous study from wheat plant, against the phytopathogenic fungi, Fusarium graminearum and Macrophomina phaseolina. A dual culture plate assay was conducted as a preliminary analysis, revealing that 7 out of 15 endophytic Bacillus spp. demonstrated inhibition against one or both of the phytopathogenic fungi used in this study. All seven endophytes were further assessed for the presence of diffusible antifungal metabolites. The cultures were grown in potato dextrose broth for 120 h, and the cell-free supernatant was extracted and analyzed using the cup plate method. The methanolic extract yielded similar results to the dual culture plate analysis, except for WL2-15. Additionally, deformities in the mycelial structure were examined under the light microscope upon exposure to methanolic extract. Furthermore, the analysis and identification of metabolites were carried out via gas chromatography-mass spectrometry of methanolic extract from selected seven endophytic Bacillus spp. The chromatogram revealed the presence of some major peaks such as tridecanoic acid, methyl ester, hydroperoxide, 1-methylbutyl, 9-octadecenamide, (z)-, hexane-1,3,4-triol, 3,5-dimethyl- tetradecanoic acid. To the best of our knowledge, this is the first report of these biocontrol agents in endophytic Bacillus spp. Interestingly, volatile organic compound production was also seen in all the isolates against the phytopathogenic fungi.
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Affiliation(s)
- Janki K Patel
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Changa, Gujarat, 388 421, India.
| | - Yukta Mistry
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Changa, Gujarat, 388 421, India
| | - Riya Soni
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Changa, Gujarat, 388 421, India
| | - Anamika Jha
- Department of Biological Sciences, P. D. Patel Institute of Applied Sciences, Charotar University of Science and Technology, Changa, Gujarat, 388 421, India
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Heo Y, Lee Y, Balaraju K, Jeon Y. Characterization and evaluation of Bacillus subtilis GYUN-2311 as a biocontrol agent against Colletotrichum spp. on apple and hot pepper in Korea. Front Microbiol 2024; 14:1322641. [PMID: 38260885 PMCID: PMC10800898 DOI: 10.3389/fmicb.2023.1322641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
Crop plants are vulnerable to a variety of diseases, including anthracnose, caused by various species of Colletotrichum fungi that damages major crops, including apples and hot peppers. The use of chemical fungicides for pathogen control may lead to environmental pollution and disease resistance. Therefore, we conducted this research to develop a Bacillus subtilis-based biological control agent (BCA). B. subtilis GYUN-2311 (GYUN-2311), isolated from the rhizosphere soil of an apple orchard, exhibited antagonistic activity against a total of 12 fungal pathogens, including eight Colletotrichum species. The volatile organic compounds (VOCs) and culture filtrate (CF) from GYUN-2311 displayed antifungal activity against all 12 pathogens, with 81% control efficiency against Fusarium oxysporum for VOCs and 81.4% control efficacy against Botryosphaeria dothidea for CF. CF also inhibited germination and appressorium formation in Colletotrichum siamense and C. acutatum. The CF from GYUN-2311 showed antifungal activity against all 12 pathogens in different media, particularly in LB medium. It also exhibited plant growth-promoting (PGP) activity, lytic enzyme activity, siderophore production, and the ability to solubilize insoluble phosphate. In trials on apples and hot peppers, GYUN-2311 effectively controlled disease, with 75 and 70% control efficacies against C. siamense in wounded and unwounded apples, respectively. Similarly, the control efficacy of hot pepper against C. acutatum in wounded inoculation was 72%. Combined application of GYUN-2311 and chemical suppressed hot pepper anthracnose to a larger extent than other treatments, such as chemical control, pyraclostrobin, TK®, GYUN-2311 and cross-spraying of chemical and GYUN-2311 under field conditions. The genome analysis of GYUN-2311 identified a circular chromosome comprising 4,043 predicted protein-coding sequences (CDSs) and 4,096,969 bp. B. subtilis SRCM104005 was the strain with the highest average nucleotide identity (ANI) to GYUN-2311. AntiSMASH analysis identified secondary metabolite biosynthetic genes, such as subtilomycin, bacillaene, fengycin, bacillibactin, pulcherriminic acid, subtilosin A, and bacilysin, whereas BAGEL analysis confirmed the presence of competence (ComX). Six secondary metabolite biosynthetic genes were induced during dual culture in the presence of C. siamense. These findings demonstrate the biological control potential of GYUN-2311 against apple and hot pepper anthracnose.
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Affiliation(s)
- Yunjeong Heo
- Department of Plant Medicals, Andong National University, Andong, Republic of Korea
| | - Younmi Lee
- Department of Plant Medicals, Andong National University, Andong, Republic of Korea
| | - Kotnala Balaraju
- Agricultural Science and Technology Research Institute, Andong National University, Andong, Republic of Korea
| | - Yongho Jeon
- Department of Plant Medicals, Andong National University, Andong, Republic of Korea
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Wang Y, Sun Z, Zhao Q, Yang X, Li Y, Zhou H, Zhao M, Zheng H. Whole-genome analysis revealed the growth-promoting and biological control mechanism of the endophytic bacterial strain Bacillus halotolerans Q2H2, with strong antagonistic activity in potato plants. Front Microbiol 2024; 14:1287921. [PMID: 38235428 PMCID: PMC10792059 DOI: 10.3389/fmicb.2023.1287921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 11/21/2023] [Indexed: 01/19/2024] Open
Abstract
Introduction Endophytes are colonizers of healthy plants and they normally exhibit biocontrol activities, such as reducing the occurrence of plant diseases and promoting plant growth. The endophytic bacterium Bacillus halotolerans Q2H2 (Q2H2) was isolated from the roots of potato plants and was found to have an antagonistic effect on pathogenic fungi. Methods Q2H2 was identified by morphological observations, physiological and biochemical identification, and 16S rRNA gene sequence analysis. Genes related to the anti-fungal and growth-promoting effects were analyzed using whole-genome sequencing and comparative genomic analysis. Finally, we analyzed the growth-promoting and biocontrol activities of Q2H2 in potato plants using pot experiments. Results Antagonism and non-volatile substance plate tests showed that Q2H2 had strong antagonism against Fusarium oxysporum, Fusarium commune, Fusarium graminearum, Fusarium brachygibbosum, Rhizoctonia solani and Stemphylium solani. The plate test showed that Q2H2 had the ability to produce proteases, cellulases, β-1,3-glucanase, dissolved organic phosphate, siderophores, indole-3-acetic acid (IAA), ammonia and fix nitrogen. The suitable growth ranges of Q2H2 under different forms of abiotic stress were pH 5-9, a temperature of 15-30°C, and a salt concentration of 1-5%. Though whole-genome sequencing, we obtained sequencing data of approximately 4.16 MB encompassed 4,102 coding sequences. We predicted 10 secondary metabolite gene clusters related to antagonism and growth promotion, including five known products surfactin, bacillaene, fengycin, bacilysin, bacillibactin, and subtilosin A. Average nucleotide identity and comparative genomic analyses revealed that Q2H2 was Bacillus halotolerans. Through gene function annotation, we analyzed genes related to antagonism and plant growth promotion in the Q2H2 genome. These included genes involved in phosphate metabolism (pstB, pstA, pstC, and pstS), nitrogen fixation (nifS, nifU, salA, and sufU), ammonia production (gudB, rocG, nasD, and nasE), siderophore production (fhuC, fhuG, fhuB, and fhuD), IAA production (trpABFCDE), biofilm formation (tasA, bslA, and bslB), and volatile compound production (alsD, ilvABCDEHKY, metH, and ispE), and genes encoding hydrolases (eglS, amyE, gmuD, ganB, sleL, and ydhD). The potato pot test showed that Q2H2 had an obvious growth-promoting effect on potato roots and better control of Fusarium wilt than carbendazim. Conclusion These findings suggest that the strain-specific genes identified in bacterial endophytes may reveal important antagonistic and plant growth-promoting mechanisms.
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Affiliation(s)
- Yuhu Wang
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
| | - Zhenqi Sun
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
| | - Qianqian Zhao
- Institute of Agro-Food Technology, Jilin Academy of Agricultural Sciences, Changchun, China
| | - Xiangdong Yang
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, China
| | - Yahui Li
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
| | - Hongyou Zhou
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
| | - Mingmin Zhao
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
| | - Hongli Zheng
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot, China
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Chen L, Hu Y, Huang L, Luo M, Wang G. Isolation and identification of two pathogens causing leaf spot of Fritillaria taipaiensis P. Y. Li. in China. Arch Microbiol 2023; 206:1. [PMID: 37987846 DOI: 10.1007/s00203-023-03721-7] [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: 05/29/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
Fritillaria taipaiensis P. Y. Li is one of the biological sources for Fritillariae Cirrhosae Bulbus. Its bulbs are widely used for treating respiratory diseases such as pneumonia, bronchitis and influenza. Cultivated F. taipaiensis suffers from many diseases during its growing season. Leaf spot is a destructive disease that is increasingly affecting F. taipaiensis and can cause an incidence of up to 30% in severe cases. Leaf spot inhibits the growth of F. taipaiensis by causing disease spots on the surface of leaves. In severe cases, these spots can result in leaf desiccation and blackspot formation at the lesion site, leading to a decrease in photosynthesis. Leaf spot has shown little benefit, and it can even result in a reduced yield of bulbs and the death of plants. According to previous studies, Alternaria alternata has been identified as the pathogen of leaf spot in many medicinal plants, but the main pathogens of the leaf spot of F. taipeiensis remains uncertain. In this paper, five isolates from diseased leaves of F. taipaiensis were isolated and purified and the pathogenicity test showed that isolates B-5 and B-7 induced leaf spot symptoms on healthy F. taipaiensis leaves. Integrating multiple phylogenetic analyses of rDNA using Internal transcribed spacer region (ITS), Beta-tubulin (TUB2), RNA polymerase II second largest subunit (RPB2) and Translation elongation factor 1-alpha (TEF1-a) primers, strain B-5 and strain B-7 were eventually identified as Didymella segeticola and A. alternata. This is also the first report on the pathogens that cause leaf spot in F. taipaiensis in China.
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Affiliation(s)
- Lijuan Chen
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Yiwen Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Li Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Min Luo
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Guangzhi Wang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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Wei L, Fan L, Yang C, Jin M, Osei R. Analysis of Bioactive Compounds Produced by Bacillus mojavensis ZA1 and Their Antagonistic Effect on Colletotrichum coccodes by GC-MS. Appl Biochem Biotechnol 2023:10.1007/s12010-023-04771-9. [PMID: 37982968 DOI: 10.1007/s12010-023-04771-9] [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] [Accepted: 10/31/2023] [Indexed: 11/21/2023]
Abstract
The plant disease Colletotrichum coccodes, which lowers potato yields, poses a severe danger to the booming potato industry. Isolated plant endophytic bacteria from highland pasture can produce a variety of metabolites that lessen the risk that the pathogen C. coccodes poses to plant growth and development. Therefore, the objective of our work was to assess substances with antipathogenic properties made by the endophytic bacteria Bacillus mojavensis ZA1. Gas chromatography-mass spectrometry (GC-MS) was used in our investigation to accomplish a thorough structural elucidation of the antipathogenic compounds produced by the endophytic bacterial strain B. mojavensis ZA1. The results showed that the metabolites extracted from ethyl acetate as an extractant were the most effective in inhibiting the pathogen C. coccodes, with 60.95% inhibition. Thirty-five distinct chemicals, including acids, esters, ketones, alcohols, amino acid ammonium salts, cyclic ethers, aromatic hydrocarbons, and heterocyclic compounds, were among the metabolites that may inhibit C. coccodes. Further analysis of the chemical groups in the compound structures revealed the potential of driving groups, such as hydroxyl, carbonyl, ester, benzene, carbon-carbon double bonds, and carbon rings, that prevent C. coccodes from performing its function. This study opens up new opportunities for plant protection programs by demonstrating that natural chemicals produced by B. mojavensis ZA1 can be used as candidates for cutting-edge plant disease management treatments.
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Affiliation(s)
- Lijuan Wei
- College of Plant Protection, Gansu Agricultural University, Lanzhou, 730070, China
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou, 730070, China
| | - Lijuan Fan
- College of Plant Protection, Gansu Agricultural University, Lanzhou, 730070, China
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou, 730070, China
| | - Chengde Yang
- College of Plant Protection, Gansu Agricultural University, Lanzhou, 730070, China.
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou, 730070, China.
| | - Mengjun Jin
- College of Plant Protection, Gansu Agricultural University, Lanzhou, 730070, China
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou, 730070, China
| | - Richard Osei
- College of Plant Protection, Gansu Agricultural University, Lanzhou, 730070, China
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, Lanzhou, 730070, China
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Cheng X, Li D, Jiang Z, Qu C, Yan H, Wu Q. Metabolite profiling and transcriptomic analyses demonstrate the effects of biocontrol agents on alkaloid accumulation in Fritillaria thunbergii. BMC PLANT BIOLOGY 2023; 23:435. [PMID: 37723471 PMCID: PMC10506312 DOI: 10.1186/s12870-023-04459-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 09/13/2023] [Indexed: 09/20/2023]
Abstract
BACKGROUND During Fritillaria thunbergii planting, pests and diseases usually invade the plant, resulting in reduced yield and quality. Previous studies have demonstrated that using biocontrol agents can effectively control grubs and affect the steroid alkaloids content in F. thunbergii. However, the molecular regulatory mechanisms underlying the differences in the accumulation of steroid alkaloids in response to biocontrol agents remain unclear. RESULTS Combined transcriptomic and metabolic analyses were performed by treating the bulbs of F. thunbergii treated with biocontrol agents during planting. Otherwise, 48 alkaloids including 32 steroid alkaloids, 6 indole alkaloids, 2 scopolamine-type alkaloids, 1 isoquinoline alkaloid, 1 furoquinoline alkaloid, and 6 other alkaloids were identified. The content of steroidal alkaloids particularly peimine, peiminine, and veratramine, increased significantly in the group treated with the biocontrol agents. Transcriptome sequencing identified 929 differential genes using biocontrol agents, including 589 upregulated and 340 downregulated genes. Putative biosynthesis networks of steroid alkaloids have been established and combined with differentially expressed structural unigenes, such as acetyl-CoA C-acetyl-transferase, acelyl-CoAC-acetyltransferase3-hydroxy-3-methylglutaryl-coenzyme A synthase, 1-deoxy-D-xylulose-5-phosphate reductor-isomerase, 2-C-methyl-D-erythritol-4-phosphate cytidylyltransferase and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase. In addition, biological processes such as amino acid accumulation and oxidative phosphorylation were predicted to be related to the synthesis of steroid alkaloids. Cytochrome P450 enzymes also play crucial roles in the steroid alkaloid synthesis. The transcription factor families MYB and bHLH were significantly upregulated after using biocontrol agents. CONCLUSIONS Biocontrol agents increased the steroid alkaloids accumulation of steroid alkaloids by affecting key enzymes in the steroid alkaloid synthesis pathway, biological processes of oxidative phosphorylation and amino acid synthesis, cytochrome P450 enzymes, and transcription factors. This study revealed the mechanism underlying the difference in steroidal alkaloids in F. thunbergii after using biocontrol agents, laying the groundwork for future industrial production of steroid alkaloids and ecological planting of medicinal materials in the future.
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Affiliation(s)
- Xuemei Cheng
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
| | - Dishuai Li
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
| | - Zheng Jiang
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
| | - Cheng Qu
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China.
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Nanjing, China.
| | - Hui Yan
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Nanjing, China
| | - Qinan Wu
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing, China.
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Nanjing, China.
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Adedire DE, Owoeye TE, Farinu OM, Ogundipe WF, Adedire OM. Management of Fusarium Wilt Disease of Maize (Zea mays L.) with Selected Antimycotic Plant Extracts and Inhibitory Bacillus Strains. Curr Microbiol 2023; 80:204. [PMID: 37149815 DOI: 10.1007/s00284-023-03302-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/14/2023] [Indexed: 05/08/2023]
Abstract
Maize (Zea mays L. var. Everta) is an economically significant crop cultivated worldwide. Unfortunately, microbial diseases, especially, mycopathogens such as Fusarium species, militate against the production of maize. Protective microbial species and bioactive plant extracts have been studied in the control of plant pathogens. However, there is a dearth of information on their comparative efficacy and effect on wilt disease of maize caused by Fusarium solani, as investigated in this study. Using the ITS and 16s rDNA primers for fungal pathogen and bacterial strains, respectively, the mycopathogen was confirmed as Fusarium solani FCI20, while biocontrol Bacillus strains were identified as Bacillus velezensis EBs02 and Bacillus thuringiensis EBs04. Fusarium solani FCI20 successfully infected maize seedlings through rhizosphere inoculation, and caused severe leaf chlorosis, necrosis and wilt in maize seedlings. Bacillus thuringiensis EBs04 expressed the highest in vitro mycelial inhibition (85.20%), followed by Gmelina arborea (78.58%), while Milicia excelsa appeared to express the lowest mycelial inhibition potential (49.95%). Bacillus velezensis EBs02 expressed the highest in vivo disease severity reduction in maize seedlings (with percentage disease control of 84.16), while B. thuringiensis-treated plants had the lowest incidence of wilt disease (4.32%). However, contrary to their in vitro mycelial inhibition potential, B. velezensis EBs02, Gmelina arborea, Milicia excelsa and Cola nitida expressed radically different levels of in vivo wilt disease control in maize seedlings. Consequent upon the biocontrol patterns observed in this study, in vivo assay should be considered in the preliminary selection of promising biocontrol agents against phytopathogens, such as Fusarium species.
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Affiliation(s)
- Deborah Ebunoluwa Adedire
- Department of Genetics, Genomics and Bioinformatics, National Biotechnology Development Agency, Abuja, Nigeria
| | - Temitope Esther Owoeye
- Southwest Center, National Biotechnology Development Agency, University of Ibadan, Ibadan, Nigeria
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Rosić I, Nikolić I, Ranković T, Anteljević M, Medić O, Berić T, Stanković S. Genotyping-driven diversity assessment of biocontrol potent Bacillus spp. strain collection as a potential method for the development of strain-specific biomarkers. Arch Microbiol 2023; 205:114. [PMID: 36907935 DOI: 10.1007/s00203-023-03460-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 02/01/2023] [Accepted: 03/01/2023] [Indexed: 03/14/2023]
Abstract
Bacillus species are among the most researched and frequently applied biocontrol agents. To estimate their potential as environmentally friendly microbial-based products, reliable and rapid plant colonization monitoring methods are essential. We evaluated repetitive element-based (rep) and Random Amplified Polymorphic DNA (RAPD) PCR (Polymerase Chain Reaction) genotyping in a diversity assessment of 251 strains from bulk soil, straw, and manure samples across Serbia, highlighting their discriminative force and the presence of unique bands. RAPD 272, OPG 5, and (GTG)5 primers were most potent in revealing the high diversity of a sizable environmental Bacillus spp. collection. RAPD 272 also amplified a unique band for a proven biocontrol strain, opening the possibility of Sequence Characterized Amplified Region (SCAR) marker design. That will enable colonization studies using the SCAR marker for its specific detection. This study provides a guide for primer selection for diversity and monitoring studies of environmental Bacillus spp. isolates.
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Affiliation(s)
- Iva Rosić
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia.
| | - Ivan Nikolić
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
| | - Tamara Ranković
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
| | - Marina Anteljević
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
| | - Olja Medić
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
| | - Tanja Berić
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
| | - Slaviša Stanković
- University of Belgrade - Faculty of Biology, Center for Biological Control and Plant Growth Promotion, University of Belgrade, Studentski Trg 16, 11000, Belgrade, Serbia
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Pandey C, Prabha D, Negi YK, Maheshwari DK, Dheeman S, Gupta M. Macrolactin a mediated biocontrol of Fusarium oxysporum and Rhizoctonia solani infestation on Amaranthus hypochondriacus by Bacillus subtilis BS-58. Front Microbiol 2023; 14:1105849. [PMID: 36970695 PMCID: PMC10032343 DOI: 10.3389/fmicb.2023.1105849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Plant diseases are one of the main hurdles for successful crop production and sustainable agriculture development world-wide. Though several chemical measures are available to manage crop diseases, many of them have serious side effects on humans, animals and the environment. Therefore, the use of such chemicals must be limited by using effective and eco-friendly alternatives. In view of the same, we found a Bacillus subtilis BS-58 as a good antagonist towards the two most devastating phytopathogens, i.e., Fusarium oxysporum and Rhizoctonia solani. Both the pathogens attack several agricultural crops (including amaranth) and induce a variety of infections in them. The findings of scanning electron microscopy (SEM) in this study suggested that B. subtilis BS-58 could inhibit the growth of both the pathogenic fungi by various means such as perforation, cell wall lysis, and cytoplasmic disintegration in the fungal hyphae. Thin-layer chromatography, LC–MS and FT-IR data revealed the antifungal metabolite to be macrolactin A with a molecular weight of 402 Da. Presence of the mln gene in the bacterial genome further endorsed that the antifungal metabolite produced by BS-58 was macrolactin A. Pot trial conducted in the present study showed that seed treatment by BS-58 effectively reduced seedling mortality (54.00 and 43.76%) in amaranth, when grown in pathogen infested soil (F. oxysporum and R. solani, respectively), when compared to their respective negative controls. Data also revealed that the disease suppression ability of BS-58 was almost equivalent to the recommended fungicide, carbendazim. SEM analysis of roots of the seedlings recovered from pathogenic attack substantiated the hyphal disintegration by BS-58 and prevention of amaranth crop. The findings of this study conclude that macrolactin A produced by B. subtilis BS-58 is responsible for the inhibition of both the phytopathogens and the suppression of the diseases caused by them. Being native and target specific, such strains under suitable conditions, may result in ample production of antibiotic and better suppression of the disease.
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Affiliation(s)
- Chitra Pandey
- Department of Basic Sciences, College of Forestry (VCSG UUHF), Tehri Garhwal, Uttarakhand, India
- Department of Botany and Microbiology, Gurukula Kangri University, Haridwar, Uttarakhand, India
| | - Deepti Prabha
- Department of Seed Science and Technology, School of Agriculture and Allied Sciences, HNB Garhwal University, Srinagar, Pauri Garhwal, Uttarakhand, India
| | - Yogesh Kumar Negi
- Department of Basic Sciences, College of Forestry (VCSG UUHF), Tehri Garhwal, Uttarakhand, India
- *Correspondence: Yogesh Kumar Negi,
| | - Dinesh Kumar Maheshwari
- Department of Botany and Microbiology, Gurukula Kangri University, Haridwar, Uttarakhand, India
| | - Shrivardhan Dheeman
- Department of Botany and Microbiology, Gurukula Kangri University, Haridwar, Uttarakhand, India
| | - Monika Gupta
- Amity Institute of Microbial Technology, Amity University, Noida, Uttar Pradesh, India
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Ku Y, Li W, Mei X, Yang X, Cao C, Zhang H, Cao L, Li M. Biological Control of Melon Continuous Cropping Obstacles: Weakening the Negative Effects of the Vicious Cycle in Continuous Cropping Soil. Microbiol Spectr 2022; 10:e0177622. [PMID: 36301101 PMCID: PMC9769590 DOI: 10.1128/spectrum.01776-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/19/2022] [Indexed: 01/05/2023] Open
Abstract
The continuous cropping obstacles of melons have become increasingly serious in recent years. To investigate this, we explored the effects and mechanisms of Bacillus subtilis C3 in control of the continuous cropping obstacles of melon. We provide a novel interaction model of the occurrence factors of continuous cropping obstacles. The dominant pathogen isolated from melon soil was Fusarium. Their hyphae were used as food to cultivate root-knot nematodes. The main phenolic acids in melon soil promoted the growth of Fusarium and indirectly increased the number of root-knot nematodes, but they also had direct toxic effects on melon root-knot nematodes. The simultaneous inoculation of the three had the strongest inhibitory effect on melon seedlings, while the inhibitory effect of paired inoculation was weaker than that of single inoculation. Therefore, the three balance each other, forming a vicious cycle. Bacillus subtilis C3 weakened the negative effects of this cycle on melon by eliminating phenolic acids and inhibiting the growth of Fusarium and root-knot nematodes. Simultaneously, they also alleviated the continuous cropping obstacles of melon by improving the composition and structure of the rhizosphere microbial community. Our results might be useful for the effective control of the continuous cropping obstacles of melon. IMPORTANCE The soil environment, crop growth and fruit quality of melons are negatively affected by long-term continuous cropping. It is important to study the mechanism of continuous cropping obstacles and their biological control. In this study, we propose a novel interaction model of the occurrence factors of continuous cropping obstacles. The dominant phenolic acids, pathogenic fungi, and root-knot nematodes from melon soil balance each other, forming a vicious cycle. Bacillus subtilis C3 weakened the negative effects of this cycle on melon by eliminating phenolic acids and inhibiting the growth of Fusarium and root-knot nematodes. In addition, C3 also improved the composition and structure of the melon rhizosphere microbial community. These results advance the study of the occurrence mechanism of continuous cropping obstacles and demonstrate an efficient and environmentally friendly biological control scheme.
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Affiliation(s)
- Yongli Ku
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Wenqiang Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xueli Mei
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Xiangna Yang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Cuiling Cao
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Huimei Zhang
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi Province, China
| | - Le Cao
- College of Environment and Life Sciences, Weinan Normal University, Weinan, Shaanxi Province, China
| | - Minglei Li
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi Province, China
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