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Vanacore MFG, Sartori M, Giordanino F, Barros G, Nesci A, García D. Physiological Effects of Microbial Biocontrol Agents in the Maize Phyllosphere. PLANTS (BASEL, SWITZERLAND) 2023; 12:4082. [PMID: 38140407 PMCID: PMC10747270 DOI: 10.3390/plants12244082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 12/24/2023]
Abstract
In a world with constant population growth, and in the context of climate change, the need to supply the demand of safe crops has stimulated an interest in ecological products that can increase agricultural productivity. This implies the use of beneficial organisms and natural products to improve crop performance and control pests and diseases, replacing chemical compounds that can affect the environment and human health. Microbial biological control agents (MBCAs) interact with pathogens directly or by inducing a physiological state of resistance in the plant. This involves several mechanisms, like interference with phytohormone pathways and priming defensive compounds. In Argentina, one of the world's main maize exporters, yield is restricted by several limitations, including foliar diseases such as common rust and northern corn leaf blight (NCLB). Here, we discuss the impact of pathogen infection on important food crops and MBCA interactions with the plant's immune system, and its biochemical indicators such as phytohormones, reactive oxygen species, phenolic compounds and lytic enzymes, focused mainly on the maize-NCLB pathosystem. MBCA could be integrated into disease management as a mechanism to improve the plant's inducible defences against foliar diseases. However, there is still much to elucidate regarding plant responses when exposed to hemibiotrophic pathogens.
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Affiliation(s)
- María Fiamma Grossi Vanacore
- PHD Student Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina;
| | - Melina Sartori
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina; (M.S.); (G.B.); (A.N.)
| | - Francisco Giordanino
- Microbiology Student Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina;
| | - Germán Barros
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina; (M.S.); (G.B.); (A.N.)
| | - Andrea Nesci
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina; (M.S.); (G.B.); (A.N.)
| | - Daiana García
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601, Río Cuarto 5800, Córdoba, Argentina; (M.S.); (G.B.); (A.N.)
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Plant-Pathogenic Fusarium Species. J Fungi (Basel) 2022; 9:jof9010013. [PMID: 36675834 PMCID: PMC9866786 DOI: 10.3390/jof9010013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Fusarium species are ubiquitous fungi, both saprotrophic and pathogenic to plants, animals and humans. They are also potent mycotoxin producers which makes them one of the most devastating plant pathogens. Mycotoxin biosynthesis and regulation has recently become one of the mainstream research topics, since knowledge concerning individual metabolic pathways became available and modern 'omics' techniques allowed us to expand this even further. Independently, high-throughput sequencing methodology helped researchers gain insight into the complex phylogenetic relationships among closely related genotypes comprising Fusarium populations, species and species complexes. Molecular tools have so far been very powerful in species identification and phylogeny, as the great diversity of the Fusarium genus has forced scientists to continuously revise previously described taxons.
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Mycotoxin risks are lower in biotech corn. Curr Opin Biotechnol 2022; 78:102792. [PMID: 36088737 DOI: 10.1016/j.copbio.2022.102792] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 12/14/2022]
Abstract
Mycotoxins are food contaminants that occur when toxigenic fungi colonize crops. Unfortunately, corn, a major staple crop worldwide, is highly susceptible to mycotoxin contamination. Some mycotoxins, most notably aflatoxin, cause human cancer and other harmful effects such as immunotoxicity and growth impairment. Hence, many nations have set food-safety standards on mycotoxins. Aside from regulations, good agricultural and manufacturing practices lower mycotoxin risks. Agricultural biotechnology has made notable advances in reducing mycotoxins recently. While transgenic Bt corn has been known for years to reduce the mycotoxin fumonisin, new studies have shown its benefit in reducing aflatoxin as well. Other transgenic and RNA-interference corn hybrids target mycotoxin reduction specifically, and gene editing through clustered regularly interspaced short palindromic repeat systems has focused on preventing mycotoxin biosynthesis.
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Shabana YM, Ghoneem KM, Rashad YM, Arafat NS, Fitt BDL, Richard B, Qi A. Distribution and Biodiversity of Seed-Borne Pathogenic and Toxigenic Fungi of Maize in Egypt and Their Correlations with Weather Variables. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11182347. [PMID: 36145747 PMCID: PMC9506050 DOI: 10.3390/plants11182347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 05/23/2023]
Abstract
Studies of the biodiversity of plant pathogenic and toxigenic fungi are attracting great attention to improve the predictability of their epidemics and the development of their control programs. Two hundred maize grain samples were gathered from 25 maize-growing governorates in Egypt and 189 samples were processed for the isolation and identification of seed-borne fungal microbiome. Twenty-six fungal genera comprising 42 species were identified according to their morphological characteristics and ITS DNA sequence analysis. Occurrence and biodiversity indicators of these fungal species were calculated. Ustilago maydis, Alternaria alternata, Aspergillus flavus, A. niger, Penicillium spp., Cladosporium spp. and Fusarium verticillioides were the highly frequent (>90% for each), recording the highest relative abundance (˃50%). Al-Menia governorate showed the highest species diversity and richness, followed by Sohag, Al-Nobaria and New Valley governorates. Correlations of 18 fungal species with temperature, relative humidity, precipitation, wind speed, and solar radiation were analyzed using canonical correspondence analysis. Results showed that relative humidity, temperature, and wind speed, respectively, were the most impactful weather variables. However, the occurrence and distribution of these fungi were not clearly grouped into the distinctive climatic regions in which maize crops are grown. Monitoring the occurrence and distribution of the fungal pathogens of maize grains in Egypt will play an important role in predicting their outbreaks and developing appropriate future management strategies. The findings in this study may be useful to other maize-growing countries that have similar climatic conditions.
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Affiliation(s)
- Yasser M. Shabana
- Plant Pathology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
| | - Khalid M. Ghoneem
- Department of Seed Pathology Research, Plant Pathology Research Institute, Agricultural Research Center, Giza 12112, Egypt
| | - Younes M. Rashad
- Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications, Alexandria 21500, Egypt
| | - Nehal S. Arafat
- Plant Pathology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
| | - Bruce D. L. Fitt
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, Hertfordsire, UK
| | - Benjamin Richard
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, Hertfordsire, UK
| | - Aiming Qi
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, Hertfordsire, UK
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Al-Askar AA, Ghoneem KM, Hafez EE, Saber WIA. A Case Study in Saudi Arabia: Biodiversity of Maize Seed-Borne Pathogenic Fungi in Relation to Biochemical, Physiological, and Molecular Characteristics. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11060829. [PMID: 35336711 PMCID: PMC8954539 DOI: 10.3390/plants11060829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 05/02/2023]
Abstract
Microbiodiversity is usually correlated with environmental conditions. This investigation is a case study to cover the lack of knowledge on the correlation of biochemical, physiological, and molecular attributes with the distribution of seed-borne pathogenic fungi of maize under the environmental conditions of the Kingdom of Saudi Arabia to help forecast any destructive epidemics. Forty-one fungal species belonging to 24 genera were detected using standard moist blotter (SMB), deep freezing blotter (DFB), and agar plate (AP) techniques. SMB was superior in detecting the maximum numbers (36 species) of seed-borne mycoflora. The pathogenicity assay revealed that, among 18 seed-borne fungal pathogens used, 12 isolates caused high percentages of rotted seeds and seedling mortality symptoms, which were identified molecularly using an internal transcribed spacer sequence. Two Curvularia spp. and Sarocladium zeae were reported for the first time in KSA. The strains showed various enzymatic activities and amino acid profiles under different environmental setups. Temperature and humidity were the environmental variables influencing the fungal pathogenicity. The highest pathogenicity was correlated with the presence and concentration of threonine, alanine, glutamic, aspartic acids, and protein. The study concluded with the discovery of four new phytopathogens in KSA and, further, evidenced a marked correlation among the investigated variables. Nevertheless, more studies are encouraged to include additional physiological properties of the phytopathogens, such as toxigenic activity, as well as extend the fungal biodiversity study to other plants.
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Affiliation(s)
- Abdulaziz A. Al-Askar
- Botany and Microbiology Department, Faculty of Science, King Saud University, Riyadh 11451, Saudi Arabia
- Correspondence: (A.A.A.-A.); (W.I.A.S.); Tel.: +20-111-173-1062 (W.I.A.S.)
| | - Khalid M. Ghoneem
- Seed Pathology Research Department, Plant Pathology Research Institute, Agricultural Research Center, Giza 12619, Egypt;
| | - Elsayed E. Hafez
- Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications, New Borg El-Arab City 21934, Egypt;
| | - WesamEldin I. A. Saber
- Microbial Activity Unit, Microbiology Department, Soils, Water and Environment Research Institute, Agricultural Research Center, Giza 12619, Egypt
- Correspondence: (A.A.A.-A.); (W.I.A.S.); Tel.: +20-111-173-1062 (W.I.A.S.)
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Influence of Endosperm Starch Composition on Maize Response to Fusarium temperatum Scaufl. & Munaut. Toxins (Basel) 2022; 14:toxins14030200. [PMID: 35324697 PMCID: PMC8951129 DOI: 10.3390/toxins14030200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 02/24/2022] [Accepted: 03/04/2022] [Indexed: 11/17/2022] Open
Abstract
Fusarium temperatum Scaufl. & Munaut is a newly described taxon belonging to the Fusarium fujikuroi species complex (FFSC) and a frequent causative factor of maize ear rot. The aim of the present study was to determine the responses to the disease in maize populations differing in endosperm features that were classified to flint, dent, and a group of plants with intermediate kernel characteristics. In inoculation studies, substantial variation of host response to the fungus was found among the tested maize types. The dent-type kernels contained significantly less amylose (28.27%) and exhibited significantly higher rates of infection (IFER = 2.10) and contamination by beauvericin (7.40 mg kg−1) than plants of the flint maize subpopulation. The study documents a significant positive correlation between the Fusarium ear rot intensity (IFER) and ergosterol content (the R value ranged from 0.396 in 2015 to 0.735 in 2018) and between IFER and the presence of beauvericin (the R value ranged from 0.364 in 2015 to 0.785 in 2017). The negative correlation between (IFER) and amylose content (ranging from R = −0.303 to R= −0.180) stresses the role of the endosperm starch composition in the kernel resistance to Fusarium ear rot. The conducted study indicated that the risk of kernel infection and contamination with fungal metabolites (beauvericin and ergosterol) was associated with the maize type kernels.
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Tran TM, Ameye M, Devlieghere F, De Saeger S, Eeckhout M, Audenaert K. Streptomyces Strains Promote Plant Growth and Induce Resistance Against Fusarium verticillioides via Transient Regulation of Auxin Signaling and Archetypal Defense Pathways in Maize Plants. FRONTIERS IN PLANT SCIENCE 2021; 12:755733. [PMID: 34899781 PMCID: PMC8655691 DOI: 10.3389/fpls.2021.755733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/01/2021] [Indexed: 06/14/2023]
Abstract
Driven by climate change, Fusarium ear rot (FER) caused by Fusarium verticillioides occurs frequently in maize worldwide. In parallel, legislative regulations and increasing environmental awareness have spurred research on alternative FER biocontrol strategies. A promising group of bacterial control agents is Streptomyces species due to their metabolic versatility. However, insights into the molecular modes of action of these biocontrol agents are often lacking. This study aims at unraveling the biocontrol efficacy of Streptomyces rhizobacterial strains against F. verticillioides. We first assessed the direct antagonism of four Streptomyces strains ST02, ST03, ST07, and ST08. Then, a profile of 16 genes associated with intrinsic plant defense signaling was assessed in maize plants. Both in vitro and in vivo data showed that the biocontrol strain ST03 perfectly suppressed the growth of F. verticillioides. High inhibition efficacy was also observed for extracellular compounds in the supernatant secreted by this strain. Especially, for maize cobs, the biocontrol strain ST03 not only inhibited the proliferation of F. verticillioides but also significantly repressed fungal fumonisin production 7 days after inoculation. On maize plants, the direct antagonism was confirmed by a significant reduction of the fungal DNA level in soils when co-applied with F. verticillioides and strain ST03. In terms of its action on plants, strain ST03 induced downregulation of auxin responsive genes (AUX1, ARF1, and ARF2) and gibberellic acid (GA)-related gene AN1 even in the absence of F. verticillioides at early time points. In leaves, the biocontrol strain induced the expression of genes related to salicylic acid (SA), and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA)-mediated pathways, and pathogenesis-related proteins in the presence or absence of the pathogen. Interestingly, the biocontrol strain significantly promoted plant growth even in the presence of F. verticillioides. All of which demonstrated that the Streptomyces strain ST03 is a promising FER biocontrol and a growth-promoting candidate.
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Affiliation(s)
- Trang Minh Tran
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
- Laboratory of Applied Mycology, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Maarten Ameye
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Frank Devlieghere
- Research Unit Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sarah De Saeger
- Center of Excellence in Mycotoxicology and Public Health, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Mia Eeckhout
- Laboratory of Applied Mycology, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Research Unit of Cereal and Feed Technology, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Kris Audenaert
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Faculty Bioscience Engineering, Ghent University, Ghent, Belgium
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