Cerebroside Elicitor Confers Resistance to Fusarium Disease in Various Plant Species

In the rice blast fungus pathosystem, cerebroside, a compound categorized as a sphingolipid, was found in our previous study to be a non-racespecific elicitor, which elicits defense responses in rice. Here we describe that cerebroside C is produced in diverse strains of Fusarium oxysporum, a common soilborne agent of wilt disease affecting a wide range of plant species. In addition, some type of cerebroside elicitor involving cerebroside A, B, or C was detected in other soilborne phytopathogens, such as Pythium and Botrytis. Treatment of lettuce (Lactuca sativa), tomato (Lycopersicon esculentum), melon (Cucumis melo), and sweet potato (Ipomoea batatas) with cerebroside B resulted in resistance to infection by each pathogenic strain of F. oxysporum. Induction of pathogenesis-related genes and H2O2 production by treatment with cerebroside B were observed in tomato root tissues. The cerebroside elicitor showed no antifungal activity against F. oxysporum in vitro, indicating that the cerebroside elicitor activates defense mechanisms to confer resistance to Fusarium disease. These results suggest that cerebroside functions as a non-race-specific elicitor in a wide range of plant-phytopathogenic fungus interactions. Additionally, cerebroside elicitor serves as a potential biologically derived control agent.

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Lactobacillus plantarum Exopolysaccharides Induce Resistance against Tomato Bacterial Spot

Journal of Agricultural Science ◽

10.5539/jas.v9n2p162 ◽

2017 ◽

Vol 9 (2) ◽

pp. 162 ◽

Cited By ~ 2

Author(s):

Juliane Mendes Lemos Blainski ◽

Argus Cezar da Rocha Neto ◽

Caroline Luiz ◽

Márcio José Rossi ◽

Robson Marcelo Di Piero

Keyword(s):

Lactobacillus Plantarum ◽

Defense Mechanisms ◽

Culture Medium ◽

Defense Responses ◽

Total Phenolic ◽

Bacterial Spot ◽

Tomato Plants ◽

Induce Resistance ◽

Severity Of The Disease

Lactic acid bacteria produce several exopolysaccharides (EPS) that may have antimicrobial action and/or induce defense responses in plants. This work aims to evaluate the potential of EPS produced by Lactobacillus plantarum in the protection of tomato plants against bacterial spot caused by Xanthomonas gardneri, as well as to predict the possible mechanisms of action. The EPS were characterized through FTIR and applied at 0; 0.5; 1.5 and 3.0 mg mL-1 in tomato plants with five expanded leaves, followed by the pathogen inoculation after 3 or 7 days. Antimicrobial activity of the biopolymer (1.5 or 10.0 mg mL-1) was evaluated in bioassay when EPS was incorporated into culture medium or embedded in antibiogram disk. The defense mechanisms i.e., total phenolic compounds and flavonoids content, phenylalanine ammonia-lyase (PAL), glutathione reductase (GR) and lipoxygenase (LOX) activities, were measured in tomato plants treated with EPS (1.5 mg mL-1), inoculated or not with X. gardneri. EPS reduced bacterial spot symptoms by up to 72.0% compared to the control. There were no direct effects of EPS on the in vitro growth of X. gardneri. The spectrophotometric profile, ascorbic and ellagic acid concentrations were change in tomato plants after EPS application, in plants challenged with the pathogen. Increases in PAL, GR and LOX activities were observed in plants treated with EPS. Thus, the application of L. plantarum exopolysaccharides can be considered as an effective alternative for controlling bacterial spot in tomato plants. This paper also discusses how these exopolysaccharides reduced the severity of the disease.

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ASEPTIC BROOMRAPE INFECTION OF TOMATO ROOT CULTURE

Israel Journal of Plant Sciences ◽

10.1080/07929978.1996.10676638 ◽

1996 ◽

Vol 44 (2-3) ◽

pp. 89-94 ◽

Cited By ~ 4

Author(s):

Dalia Losner-Goshen ◽

Graham Ben-Hod ◽

M. Alfred Mayer ◽

Daniel Joel M.

Keyword(s):

Culture Media ◽

Root Culture ◽

Petri Dish ◽

The Other ◽

Tomato Root ◽

In Vitro System ◽

Host Root ◽

Biochemical Mechanisms ◽

Root Tissues

The parasitic plants of the genus Orobanche (broomrape) are important pathogens of numerous agricultural crops throughout the world. The understanding of biochemical mechanisms involved in the penetration of Orobanche haustorium into host root tissues faces difficulties due to the presence of microorganisms. Here we describe an aseptic in vitro system, in which normal broomrape seedlings infect host roots grown in culture, instead of the previously reported infection of intact host plants by Orobanche calli. This system is based on divided Petri plates with two different culture media: one part of the dish contains a rich medium suitable for the support of host root culture, the other part contains a medium with no organic nutrients and no hormones and is therefore suitable for infection of host roots by Orobanche. Roots that are supported by the first medium pass to the other side of the petri dish where they stimulate broomrape seed germination and are infected by the emerging broomrape seedlings.

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Antibacterial and Antifungal Activities of Ethiopian Medicinal Plants: A Systematic Review

Frontiers in Pharmacology ◽

10.3389/fphar.2021.633921 ◽

2021 ◽

Vol 12 ◽

Author(s):

Dereje Nigussie ◽

Gail Davey ◽

Takele Beyene Tufa ◽

Malcolm Brewster ◽

Belete Adefris Legesse ◽

...

Keyword(s):

Medicinal Plants ◽

Plant Species ◽

Meta Analysis ◽

Fungal Species ◽

Antifungal Activities ◽

Traditional Medicines ◽

Antibacterial And Antifungal Activities ◽

Wide Range ◽

Antibacterial And Antifungal

Background: Podoconiosis and lymphatic filariasis are the most common causes of lower limb lymphoedema in the tropics. Many sufferers experience frequent painful episodes of acute bacterial infection. Plant based traditional medicines are used to treat infections in many countries and are culturally established in Ethiopia. Ethiopian medicinal plants found to have antibacterial and antifungal activities were reviewed with the aim of increasing information about the treatment of wound infections in patients with lymphoedema.Methods: This study collates data from published articles on medicinal plants with antibacterial and antifungal activities in Ethiopia. A systematic search of Scopus, EMBASE, PUBMED/MEDLINE and Google Scholar was undertaken. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed. The protocol was registered on PROSPERO with registration number CRD42019127471. All controlled studies of in vitro antibacterial and antifungal activities were considered. All articles containing the descriptors published until June 28, 2019 were included. The outcome was measured as percent inhibition of microbial growth. For quality assessment of individual in vitro studies, OECD guidelines and the WHO-Good Laboratory Practice (GLP) handbook were used.Results: Seventy-nine studies met the inclusion criteria. A total of 150 plant species and three compounds had been tested against 42 species of bacteria, while 43 plant species had been tested against 22 species of fungus.Conclusion: Materials derived from several Ethiopian medicinal plants have been shown to have promising activity against a variety of bacteria and fungi. Those derived from Azadiractha indica A. Juss. and Lawsonia inerms L. are the most extensively studied against a wide range of gram-negative and positive bacteria, and fungal species.

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Molecular Characterization and Functional Analysis of a Necrosis- and Ethylene-Inducing, Protein-Encoding Gene Family from Verticillium dahliae

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-11-0319 ◽

2012 ◽

Vol 25 (7) ◽

pp. 964-975 ◽

Cited By ~ 74

Author(s):

Bang-Jun Zhou ◽

Pei-Song Jia ◽

Feng Gao ◽

Hui-Shan Guo

Keyword(s):

Functional Analysis ◽

Amino Acid ◽

Verticillium Dahliae ◽

Defense Responses ◽

Phytopathogenic Fungus ◽

Amino Acid Residues ◽

Wide Range ◽

Protein Encoding ◽

Necrotrophic Stage ◽

Verticillium Dahliae Kleb

Verticillium dahliae Kleb. is a hemibiotrophic, phytopathogenic fungus that causes wilt disease in a wide range of crops, including cotton. Successful host colonization by hemibiotrophic pathogens requires the induction of plant cell death to provide the saprophytic nutrition for the transition from the biotrophic to the necrotrophic stage. In this study, we identified a necrosis-inducing Phytophthora protein (NPP1) domain–containing protein family containing nine genes in a virulent, defoliating isolate of V. dahliae (V592), named the VdNLP genes. Functional analysis demonstrated that only two of these VdNLP genes, VdNLP1 and VdNLP2, encoded proteins that were capable of inducing necrotic lesions and triggering defense responses in Nicotiana benthamiana, Arabidopsis, and cotton plants. Both VdNLP1 and VdNLP2 induced the wilting of cotton seedling cotyledons. However, gene-deletion mutants targeted by VdNLP1, VdNLP2, or both did not affect the pathogenicity of V. dahliae V592 in cotton infection. Similar expression and induction patterns were found for seven of the nine VdNLP transcripts. Through a comparison of the conserved amino acid residues of VdNLP with different necrosis-inducing activities, combined with mutagenesis-based analyses, we identified several novel conserved amino acid residues, in addition to the known conserved heptapeptide GHRHDWE motif and the cysteine residues of the NPP domain–containing protein, that are indispensable for the necrosis-inducing activity of the VdNLP2 protein.

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Expression of a Toll Signaling Regulator Serpin in a Mycoinsecticide for Increased Virulence

Applied and Environmental Microbiology ◽

10.1128/aem.01197-14 ◽

2014 ◽

Vol 80 (15) ◽

pp. 4531-4539 ◽

Cited By ~ 24

Author(s):

Linzhi Yang ◽

Nemat O. Keyhani ◽

Guirong Tang ◽

Chuang Tian ◽

Ruipeng Lu ◽

...

Keyword(s):

Entomopathogenic Fungi ◽

Galleria Mellonella ◽

Lethal Dose ◽

Defense Responses ◽

Content Type ◽

Greater Wax Moth ◽

Wide Range ◽

New Strategy

ABSTRACTSerpins are ubiquitously distributed serine protease inhibitors that covalently bind to target proteases to exert their activities. Serpins regulate a wide range of activities, particularly those in which protease-mediated cascades are active. TheDrosophila melanogasterserpin Spn43Ac negatively controls the Toll pathway that is activated in response to fungal infection. The entomopathogenic fungusBeauveria bassianaoffers an environmentally friendly alternative to chemical pesticides for insect control. However, the use of mycoinsecticides remains limited in part due to issues of efficacy (low virulence) and the recalcitrance of the targets (due to strong immune responses). Since Spn43Ac acts to inhibit Toll-mediated activation of defense responses, we explored the feasibility of a new strategy to engineer entomopathogenic fungi with increased virulence by expression of Spn43Ac in the fungus. Compared to the 50% lethal dose (LD50) for the wild-type parent, the LD50ofB. bassianaexpressing Spn43Ac (strain Bb::S43Ac-1) was reduced ∼3-fold, and the median lethal time against the greater wax moth (Galleria mellonella) was decreased by ∼24%, with the more rapid proliferation of hyphal bodies being seen in the host hemolymph.In vitroandin vivoassays showed inhibition of phenoloxidase (PO) activation in the presence of Spn43Ac, with Spn43Ac-mediated suppression of activation by chymotrypsin, trypsin, laminarin, and lipopolysaccharide occurring in the following order: chymotrypsin and trypsin > laminarin > lipopolysaccharide. Expression of Spn43Ac had no effect on the activity of the endogenousB. bassiana-derived cuticle-degrading protease (CDEP-1). These results expand our understanding of Spn43Ac function and confirm that suppression of insect immune system defenses represents a feasible approach to engineering entomopathogenic fungi for greater efficacy.

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Biological Activities and Contents of Scopolin and Scopoletin in Sweetpotato Clones

HortScience ◽

10.21273/hortsci.38.6.1129 ◽

2003 ◽

Vol 38 (6) ◽

pp. 1129-1133 ◽

Cited By ~ 12

Author(s):

Joseph K. Peterson ◽

Howard F. Harrison ◽

D. Michael Jackson ◽

Maurice E. Snook

Keyword(s):

Mycelial Growth ◽

Fungal Pathogens ◽

Ipomoea Batatas ◽

Biological Activities ◽

Diamondback Moth ◽

Larval Growth ◽

Pathogenic Fungi ◽

Proso Millet ◽

Wide Range

Periderm and cortex tissues of 14 genetically diverse sweetpotato [Ipomoea batatas (L.) Lam.] clones were grown under low stress conditions and analyzed for their content of scopoletin ((7-hydroxy-6-methoxycoumarin) and scopolin (7-glucosylscopoletin). A wide range of concentrations of both compounds was found in both tissues. The two compounds were tested in vitro for their biological activity (concentration-activity relationships) using several bio assays: germination of proso-millet (Panicum milliaceum L.) seed; mycelial growth of the sweetpotato fungal pathogens Fusarium oxysporum Schlecht. f. sp. batatas (Wollenw.) Snyd. & Hans, F. solani (Sacc.) Mart., Lasiodiplodia theobromae (Pat.) Griffon & Maubl., and Rhizopus stolonifer (Ehr. ex Fr.) Lind; and growth and mortality of diamondback moth[Plutella xylostella (L.)] larvae on artificial diet. The glycoside scopolin showed little activity, except moderate inhibition of F. oxysporum. The aglycone scopoletin inhibited seed germination and larval growth; however, at much higher concentrations than were measured in the tissues. Mycelial growth of the four pathogenic fungi, however, was inhibited at concentrations occurring in some sweetpotato clones.

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A Sesquiterpene Synthase from the Endophytic Fungus Serendipita indica Catalyzes Formation of Viridiflorol

Biomolecules ◽

10.3390/biom11060898 ◽

2021 ◽

Vol 11 (6) ◽

pp. 898

Author(s):

Fani Ntana ◽

Wajid W. Bhat ◽

Sean R. Johnson ◽

Hans J. L. Jørgensen ◽

David B. Collinge ◽

...

Keyword(s):

Endophytic Fungus ◽

Synthetic Medium ◽

Phytopathogenic Fungus ◽

Fungal Colonization ◽

Growth Inhibition Assay ◽

Tomato Roots ◽

Wide Range ◽

Colonization Ability ◽

Terpenoid Synthase

Interactions between plant-associated fungi and their hosts are characterized by a continuous crosstalk of chemical molecules. Specialized metabolites are often produced during these associations and play important roles in the symbiosis between the plant and the fungus, as well as in the establishment of additional interactions between the symbionts and other organisms present in the niche. Serendipita indica, a root endophytic fungus from the phylum Basidiomycota, is able to colonize a wide range of plant species, conferring many benefits to its hosts. The genome of S. indica possesses only few genes predicted to be involved in specialized metabolite biosynthesis, including a putative terpenoid synthase gene (SiTPS). In our experimental setup, SiTPS expression was upregulated when the fungus colonized tomato roots compared to its expression in fungal biomass growing on synthetic medium. Heterologous expression of SiTPS in Escherichia coli showed that the produced protein catalyzes the synthesis of a few sesquiterpenoids, with the alcohol viridiflorol being the main product. To investigate the role of SiTPS in the plant-endophyte interaction, an SiTPS-over-expressing mutant line was created and assessed for its ability to colonize tomato roots. Although overexpression of SiTPS did not lead to improved fungal colonization ability, an in vitro growth-inhibition assay showed that viridiflorol has antifungal properties. Addition of viridiflorol to the culture medium inhibited the germination of spores from a phytopathogenic fungus, indicating that SiTPS and its products could provide S. indica with a competitive advantage over other plant-associated fungi during root colonization.

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Molecular Characterization and Pathogenicity of Trichoderma Isolates to Meloidogyne javanica

10.5772/intechopen.99035 ◽

2021 ◽

Author(s):

Ricardo R. Balardin ◽

Cristiano Bellé ◽

Daiane Dalla Nora ◽

Rodrigo F. Ramos ◽

José Carlos V. Rodrigues ◽

...

Keyword(s):

Biological Control ◽

Molecular Characterization ◽

Biological Control Agent ◽

Meloidogyne Javanica ◽

Control Agent ◽

High Potential ◽

Wide Range ◽

Elisa Plate ◽

Trichoderma Isolates

Nematodes are considered a serious problem for agriculture. Nematodes of the Meloidogyne genus can attack a wide range of plants, needing different management methods to decrease its population. Fungi from the Trichoderma genus has been related to have potential as biological control agents. However, before an organism is used as biological control agent, first it is necessary to prospect, characterize and test its potential as biocontrol agent, so the objective of this work was to characterize and test fungi isolates of the Trichoderma genus to control M. javanica. We obtained forty isolate to carry out this experiment. We extracted the DNA of each isolate to discover which species we were testing, by doing a PCR and sequencing. We tested in vitro their parasitism effect using ELISA plate. Also, we extracted their filtrate to see if their metabolites have potential to reduce nematode population by showing a high mortality or inhibiting hatching. The results confirmed the high potential of the fungi of Trichoderma genus as a biological agent to control Meloidogyne javanica.

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Role of Chemotaxis Toward Fusaric Acid in Colonization of Hyphae of Fusarium oxysporum f. sp. radicis-lycopersici by Pseudomonas fluorescens WCS365

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2004.17.11.1185 ◽

2004 ◽

Vol 17 (11) ◽

pp. 1185-1191 ◽

Cited By ~ 48

Author(s):

Sandra de Weert ◽

Irene Kuiper ◽

Ellen L. Lagendijk ◽

Gerda E. M. Lamers ◽

Ben J. J. Lugtenberg

Keyword(s):

Fusarium Oxysporum ◽

Pseudomonas Fluorescens ◽

Fusaric Acid ◽

Chemotactic Response ◽

Phytopathogenic Fungus ◽

Root Tips ◽

Tomato Root ◽

Vitro Assay

Pseudomonas fluorescens WCS365 is an excellent competitive colonizer of tomato root tips after bacterization of seed or seedlings. The strain controls tomato foot and root rot (TFRR) caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici. Under biocontrol conditions, fungal hyphae were shown to be colonized by WCS365 bacteria. Because chemotaxis is required for root colonization by WCS365 cells, we studied whether chemotaxis also is required for hyphae colonization. To that end, an in vitro assay was developed to study hyphae colonization by bacteria. The results indicated that cells of the cheA mutant FAJ2060 colonize hyphae less efficiently than cells of wild-type strain WCS365, when single strains were analyzed as well as when both strains were applied together. Cells of WCS365 show a chemotactic response toward the spent growth medium of F. oxysporum f. sp. radicis-lycopersici, but those of its cheA mutant, FAJ2060, did not. Fusaric acid, a secondary metabolite secreted by Fusarium strains, appeared to be an excellent chemo-attractant. Supernatant fluids of a number of Fusarium strains secreting different levels of fusaric acid were tested as chemo-attractants. A positive correlation was found between chemo-attractant activity and fusaric acid level. No chemotactic response was observed toward the low fusaric acid-producer FO242. Nevertheless, the hyphae of FO242 still were colonized by WCS365, suggesting that other metabolites also play a role in this process. The possible function of hyphae colonization for the bacterium is discussed.

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Callus Culture as an Alternative Source of Secondary Metabolites in Curtailing Malaria Epidemic

Biotechnology Journal International ◽

10.9734/bji/2021/v25i430145 ◽

2021 ◽

pp. 23-31

Author(s):

Daniel Thakuma Tizhe ◽

Gali Adamu Ishaku ◽

Afiniki Yohanna ◽

Dashe Dentsen Fortune ◽

Aisha Salihu Jibrin

Keyword(s):

In Vitro Culture ◽

Plant Species ◽

Callus Culture ◽

Public Healthcare ◽

Natural Habitats ◽

Alternative Source ◽

Natural Form ◽

Continuous Increase ◽

Wide Range

Malaria remains a threat to public healthcare system. In 2018, more than 200 million people were exposed to this disease globally. There have been reports of drug-resistance in the recommended therapy in some endemic regions. This called for relentless efforts in the search for potential antimalarial compounds. An in vitro culture technique has emerged as a promising option for sustainable and industrial propagation of plant bioactive compounds with wide range of medicinal properties. The demand for these invaluable metabolites is witnessing a continuous increase as a folk medicine, hence, endangering their existence in natural habitats. Besides its use in natural form, the nature’s gift to humans seems to be restricted and limited by environmental conditions. An in vitro culture approach remains the most viable and sustainable alternative for the endangered plant species. Here, we present some plant species reported to have potential antimalarial activities and recommend further study through callus culture induction against malaria.

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