scholarly journals Plant Bioactive Compounds as an Intrinsic and Sustainable Tool to Enhance the Microbial Safety of Crops

2021 ◽  
Vol 9 (12) ◽  
pp. 2485
Author(s):  
Andree S. George ◽  
Maria T. Brandl
Keyword(s):  
Bioactive Compounds ◽  
Foodborne Pathogens ◽  
Defense Responses ◽  
Antagonistic Activity ◽  
Enteric Pathogens ◽  
Microbial Safety ◽  
In Planta ◽  
Microbial Infection ◽  
Produce Safety

Outbreaks of produce-associated foodborne illness continue to pose a threat to human health worldwide. New approaches are necessary to improve produce safety. Plant innate immunity has potential as a host-based strategy for the deactivation of enteric pathogens. In response to various biotic and abiotic threats, plants mount defense responses that are governed by signaling pathways. Once activated, these result in the release of reactive oxygen and nitrogen species in addition to secondary metabolites that aim at tempering microbial infection and pest attack. These phytochemicals have been investigated as alternatives to chemical sanitization, as many are effective antimicrobial compounds in vitro. Their antagonistic activity toward enteric pathogens may also provide an intrinsic hurdle to their viability and multiplication in planta. Plants can detect and mount basal defenses against enteric pathogens. Evidence supports the role of plant bioactive compounds in the physiology of Salmonella enterica, Escherichia coli, and Listeria monocytogenes as well as their fitness on plants. Here, we review the current state of knowledge of the effect of phytochemicals on enteric pathogens and their colonization of plants. Further understanding of the interplay between foodborne pathogens and the chemical environment on/in host plants may have lasting impacts on crop management for enhanced microbial safety through translational applications in plant breeding, editing technologies, and defense priming.

scholarly journals A peroxisomal β-oxidative pathway contributes to the formation of C6–C1 aromatic volatiles in poplar

2021 ◽  
Author(s):  
Nathalie D Lackus ◽  
Axel Schmidt ◽  
Jonathan Gershenzon ◽  
Tobias G Köllner
Keyword(s):  
Cinnamic Acid ◽  
Aromatic Compounds ◽  
Populus Trichocarpa ◽  
Alternative Pathway ◽  
Gene Families ◽  
Defense Responses ◽  
In Planta ◽  
Black Cottonwood ◽  
Oxidative Pathway

AbstractBenzenoids (C6–C1 aromatic compounds) play important roles in plant defense and are often produced upon herbivory. Black cottonwood (Populus trichocarpa) produces a variety of volatile and nonvolatile benzenoids involved in various defense responses. However, their biosynthesis in poplar is mainly unresolved. We showed feeding of the poplar leaf beetle (Chrysomela populi) on P. trichocarpa leaves led to increased emission of the benzenoid volatiles benzaldehyde, benzylalcohol, and benzyl benzoate. The accumulation of salicinoids, a group of nonvolatile phenolic defense glycosides composed in part of benzenoid units, was hardly affected by beetle herbivory. In planta labeling experiments revealed that volatile and nonvolatile poplar benzenoids are produced from cinnamic acid (C6–C3). The biosynthesis of C6–C1 aromatic compounds from cinnamic acid has been described in petunia (Petunia hybrida) flowers where the pathway includes a peroxisomal-localized chain shortening sequence, involving cinnamate-CoA ligase (CNL), cinnamoyl-CoA hydratase/dehydrogenase (CHD), and 3-ketoacyl-CoA thiolase (KAT). Sequence and phylogenetic analysis enabled the identification of small CNL, CHD, and KAT gene families in P. trichocarpa. Heterologous expression of the candidate genes in Escherichia coli and characterization of purified proteins in vitro revealed enzymatic activities similar to those described in petunia flowers. RNA interference-mediated knockdown of the CNL subfamily in gray poplar (Populus x canescens) resulted in decreased emission of C6–C1 aromatic volatiles upon herbivory, while constitutively accumulating salicinoids were not affected. This indicates the peroxisomal β-oxidative pathway participates in the formation of volatile benzenoids. The chain shortening steps for salicinoids, however, likely employ an alternative pathway.

scholarly journals The In Vitro and In Planta Interspecies Interactions Among Rice-Pathogenic Burkholderia Species

Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 134-143
Author(s):  
Namgyu Kim ◽  
Mohamed Mannaa ◽  
Juyun Kim ◽  
Ji-Eun Ra ◽  
Sang-Min Kim ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Fluorescent Protein ◽  
Antagonistic Activity ◽  
In Vitro Assays ◽  
Interspecies Interactions ◽  
In Planta ◽  
Burkholderia Glumae ◽  
Burkholderia Species ◽  
Green Fluorescent

Burkholderia glumae, B. plantarii, and B. gladioli are responsible for serious diseases in rice crops and co-occurrence among them has been reported. In this study, in vitro assays revealed antagonistic activity among these organisms, with B. gladioli demonstrating strong inhibition of B. glumae and B. plantarii. Strains of B. glumae and B. plantarii that express green fluorescent protein were constructed and used for cocultivation assays with B. gladioli, which confirmed the strong inhibitory activity of B. gladioli. Cell-free supernatants from each species were tested against cultures of counterpart species to evaluate the potential to inhibit bacterial growth. To investigate the inhibitory activity of B. gladioli on B. glumae and B. plantarii in rice, rice plant assays were performed and quantitative PCR (qPCR) assays were developed for in planta bacterial quantification. The results indicated that coinoculation with B. gladioli leads to significantly reduced disease severity and colonization of rice tissues compared with single inoculation with B. glumae or B. plantarii. This study demonstrates the interactions among three rice-pathogenic Burkholderia species and strong antagonistic activity of B. gladioli in vitro and in planta. The qPCR assays developed here could be applied for accurate quantification of these organisms from in planta samples in future studies.

Characterization of an antifungal soil bacterium and its antagonistic activities againstFusariumspecies

2003 ◽  
Vol 49 (4) ◽  
pp. 253-262 ◽  
Author(s):  
Yiu-Kwok Chan ◽  
Wayne A McCormick ◽  
Keith A Seifert
Keyword(s):  
Bacillus Subtilis ◽  
Culture Filtrate ◽  
Fusarium Species ◽  
Hyphal Growth ◽  
Antagonistic Activity ◽  
Plant Diseases ◽  
Ear Rot ◽  
In Planta ◽  
Head Blight

Bacteria were isolated from a cultivated soil and screened for antagonistic activity against Fusarium graminearum, a predominant agent of ear rot and head blight in cereal crops. Based on its in vitro effectiveness, isolate D1/2 was selected for characterization and identified as a strain of Bacillus subtilis by phenotypic tests and comparative analysis of its 16S ribosomal RNA gene (rDNA) sequence. It inhibited the mycelial growth of a collection of common fungal phytopathogens, including eight Fusarium species, three other ascomycetes, and one basidiomycete. The cell-free culture filtrate of D1/2 at different dilutions was active against macroconidium germination and hyphal growth of F. graminearum, depending on the initial macroconidium density. It induced the formation of swollen hyphal cells in liquid cultures of this fungus grown from macroconidia. A bioassay also demonstrated that D1/2 offered in planta protection against the damping-off disease in alfalfa seedlings caused by F. graminearum, while the type strain of B. subtilis was ineffective. Hence, B. subtilis D1/2 or its culture filtrate has potential application in controlling plant diseases caused by Fusarium.Key words: antifungal activity, Bacillus subtilis, biological control, biopesticide, Fusarium species.

scholarly journals Actinomycete as biocontrol agents against tomato gray mold disease caused by Botrytis cinerea

2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Hind Lahmyed ◽  
◽  
Rachid Bouharroud ◽  
Redouan Qessaoui ◽  
Abdelhadi Ajerrar ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Extracellular Enzymes ◽  
Chitinase Activity ◽  
Gray Mold ◽  
Antagonistic Activity ◽  
Future Research ◽  
In Planta ◽  
Tomato Fruits

The present work aims to isolate actinomycete bacteria with antagonistic abilities towards Botrytis cinerea, the causal agent of gray mold, from a soil sample collected from the rhizosphere of a healthy tomato grove. In vitro confrontation led to the isolation of 104 actinomycete isolates; fifteen isolates have shown the most significant mortality rate of the mycelial growth of B. cinerea (>50%). Based on the results of this screening, representative strains were selected to verify their in vivo antagonistic activity on tomato fruits; the reduction of B. cinerea has a percentage ranging from 52.38% to 96.19%. Furthermore, the actinomycete isolates were evaluated for their plant growth-promoting (PGP) properties and their ability to produce biocontrol-related extracellular enzymes viz., amylase, protease, cellulase, chitinase, esterases, and lecithinase. Indeed, Ac70 showed high β-1,3-glucanase activity and siderophore production (17U/ml and 43% respectively), and the highest chitinase activity (39μmol/ml) was observed for Ac24. These results indicated that these actinomycetes might potentially control gray mold caused by B. cinerea on tomato fruits. Investigations on enhancing the efficacy and survival of the biocontrol agent in planta and finding out the best formulation are recommended for future research.

scholarly journals In planta Activity of Novel Copper(II)-Based Formulations to Inhibit the Esca-Associated Fungus Phaeoacremonium minimum in Grapevine Propagation Material

2021 ◽  
Vol 12 ◽  
Author(s):  
Enrico Battiston ◽  
Stéphane Compant ◽  
Livio Antonielli ◽  
Vincenzo Mondello ◽  
Christophe Clément ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Defense Responses ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Fungal Colonization ◽  
Post Inoculation ◽  
In Planta ◽  
Experimental Treatments ◽  
Propagation Material

Grapevine trunk diseases (GTDs) are a serious and growing threat to vineyards worldwide. The need for innovative control tools persists since pesticides used against some GTDs have been banned and only methods to prevent infections or to reduce foliar symptoms have been developed so far. In this context, the application of imaging methods, already applied to study plant–microbe interactions, represents an interesting approach to understand the effect of experimental treatments applied to reduce fungal colonization, on GTD-related pathogens activity. To this aim, trials were carried out to evaluate the efficacy of copper-based treatments, formulated with hydroxyapatite (HA) as co-adjuvant with innovative delivery properties, loaded with two different copper(II) compounds (tribasic sulfate and sulfate pentahydrate), and applied to grapevine propagation material to inhibit fungal wood colonization. The treated rootstock (Vitis berlandieri × Vitis riparia cv. K5BB) and scion cuttings (Vitis vinifera L., cv. Chardonnay) had been inoculated with a strain of Phaeoacremonium minimum (Pmi) compared to uninoculated rootstocks. Experimental treatments were applied during the water-soaking process, comparing the copper(II) compounds pure or formulated with HA, to hydrate the cuttings. After callusing, grafted vines were grown under greenhouse conditions in a nursery and inoculated with Pmi::gfp7 or with Pmi wild-type. Fifteen weeks post-inoculation, woody tissues close to the inoculation site were sampled to evaluate the efficiency of the treatments by studying the plant–microbe interaction by confocal laser scanning microscopy (CLSM). Copper and further elements were also quantified in the same tissues immediately after the treatments and on the CLSM samples. Finally, the grapevine defense responses were studied in the leaves of cuttings treated with the same formulations. The present investigation confirmed the relevant interaction of Pmi and the related transformed strain on the vascular tissues of grafted vines. Furthermore, in vitro assay revealed (i) the fungistatic effect of HA and the reduced effect of Cu fungicide when combined with HA. In planta assays showed (ii) the reduction of Pmi infection in propagation material treated with HA-Cu formulations, (iii) the movement of HA-Cu formulations inside the plant tissues and their persistence over time, and (iv) the plant defense reaction following the treatment with pure HA or Cu, or combined.

scholarly journals Towards Biological Control of Aspergillus carbonarius and Botrytis cinerea in Grapevine Berries and Transcriptomic Changes of Genes Encoding Pathogenesis-Related (PR) Proteins

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 970
Author(s):  
Danai Gkizi ◽  
Eirini G. Poulaki ◽  
Sotirios E. Tjamos
Keyword(s):  
Biological Control ◽  
Botrytis Cinerea ◽  
Defense Responses ◽  
Economic Losses ◽  
Aspergillus Carbonarius ◽  
In Vitro Experiments ◽  
In Planta ◽  
Pathogenesis Related ◽  
Genes Encoding

Grapevine bunch rot, caused by Botrytis cinerea and Aspergillus carbonarius, causes important economic losses every year in grape production. In the present study, we examined the plant protective activity of the biological control agents, Paenibacillus alvei K165, Blastobotrys sp. FP12 and Arthrobacter sp. FP15 against B. cinerea and A. carbonarius on grapes. The in vitro experiments showed that strain K165 significantly reduced the growth of both fungi, while FP15 restricted the growth of A. carbonarius and FP12 was ineffective. Following the in vitro experiments, we conducted in planta experiments on grape berries. It was shown that K165, FP12 and FP15 reduced A. carbonarius rot severity by 81%, 57% and 37%, respectively, compared to the control, whereas, in the case of B. cinerea, the only protective treatment was that with K165, which reduced rot by 75%. The transcriptomic analysis of the genes encoding the pathogenesis-related proteins PR2, PR3, PR4 and PR5 indicates the activation of multiple defense responses involved in the biocontrol activity of the examined biocontrol agents.

scholarly journals Fusarium Oxysporum f. sp. Cannabis Isolated from Cannabis Sativa L.: In Vitro and in Planta Biocontrol by a Plant Growth Promoting-Bacteria Consortium

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2436
Author(s):  
Marika Pellegrini ◽  
Claudia Ercole ◽  
Carmelo Gianchino ◽  
Matteo Bernardi ◽  
Loretta Pace ◽  
...  
Keyword(s):  
Plant Growth ◽  
Fusarium Oxysporum ◽  
Cannabis Sativa ◽  
Antagonistic Activity ◽  
Plant Growth Promoting Bacteria ◽  
Dual Culture ◽  
In Planta ◽  
Plant Growth Promoting ◽  
Growth Promoting

Industrial hemp (Cannabis sativa L.) is a multipurpose plant used in several fields. Several phytopathogens attack hemp crops. Fusarium oxysporum is a common fungal pathogen that causes wilt disease in nurseries and in field cultivation and causes high losses. In the present study, a pathogenic strain belonging to F. oxysporum f. sp. cannabis was isolated from a plant showing Fusarium wilt. After isolation, identification was conducted based on morphological and molecular characterizations and pathogenicity tests. Selected plant growth-promoting bacteria with interesting biocontrol properties—Azospirillum brasilense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae and Burkholderia ambifaria—were tested against this pathogen. In vitro antagonistic activity was determined by the dual culture method. Effective strains (in vitro inhibition > of 50%) G. diazotrophicus, H. seropedicae and B. ambifaria were combined in a consortium and screened for in planta antagonistic activity in pre-emergence (before germination) and post-emergence (after germination). The consortium counteracted Fusarium infection both in pre-emergence and post-emergence. Our preliminary results show that the selected consortium could be further investigated as an effective biocontrol agent for the management of this pathogen.

scholarly journals Antagonistic Activity of Bacillus spp. Against Fire Blight Disease In vitro and In planta

2022 ◽  
Vol 9 (sp) ◽  
pp. 2486-2492
Author(s):  
Haris Butt ◽  
Kubilay Kurtulus Bastas
Keyword(s):  
Fire Blight ◽  
Positive Control ◽  
Antagonistic Activity ◽  
In Vivo Studies ◽  
In Planta ◽  
Bacillus Spp ◽  
Apple Cultivars ◽  
Blight Disease

Fire blight, affecting more than one hundred and thirty species in the Rosaceae, is probably the most destructive disease affecting pear and apple cultivars in many countries. Currently, there are no effective synthetic compounds with systemic properties. Other major problem is the occurrence and spread of strains of Erwinia amylovora with resistance to streptomycin and copper. Taken into consideration the human and environmental health, the use of biocontrol agents either as an alternative or as a supplement within an integrated fire blight management strategy has attracted worldwide attention. In this study, E. amylovora solution of 107 CFU ml-1 was treated with bio-control agents, Bacillus subtilis str. QST 713, B. amyloliquefaciens str. MBI 600 and their mixture (at solution densities of 106, 107 and 108 CFU ml-1 for each one) on Petri dishes, containing King’s B medium and, compared with positive (streptomycin sulphate) and negative (sterile distilled water) controls. In vivo studies were performed on two-year-old apple cv. Gala seedlings grown in 45-cm-diameter pots containing a sterilized mix of soil–sand–peat under controlled greenhouse conditions (85% relative humidity, 25°C temperature and 16h of day light). The plants were irrigated as needed by drip-irrigation and each pot received a mineral solution (NPK: 20–20–20) at 2 g l-1 twice. When plant shoots reached a length of 30-35 cm, bio-control agents, individually and their mixture, were applied to the plants by a hand-sprayer. Obtaining the data, 108 CFU ml-1 of Bacillus spp. suspension mixture showed strongest in vitro antibacterial effect (26mm) among the tested treatments after positive control streptomycin (28.6mm). Parallel to in vitro findings, the mixture was most effective against the pathogen on cv. Gala (66.03%). Findings show that the use of mixture of beneficial microorganisms with individual antagonistic properties against the pathogen can be an effective strategy as a natural alternative to agrochemicals in the scope of good agriculture practices.

scholarly journals DspA/E, a Type III Effector Essential for Erwinia amylovora Pathogenicity and Growth In Planta, Induces Cell Death in Host Apple and Nonhost Tobacco Plants

2006 ◽  
Vol 19 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Tristan Boureau ◽  
Hayat ElMaarouf-Bouteau ◽  
Amélie Garnier ◽  
Marie-Noëlle Brisset ◽  
Claude Perino ◽  
...  
Keyword(s):  
Cell Death ◽  
Type Iii Secretion ◽  
Erwinia Amylovora ◽  
Marker Gene ◽  
Defense Responses ◽  
In Planta ◽  
Callose Deposition ◽  
Type Iii Effector ◽  
Type Iii

Erwinia amylovora is responsible for fire blight, a necrotic disease of apples and pears. E. amylovora relies on a type III secretion system (TTSS) to induce disease on hosts and hypersensitive response (HR) on nonhost plants. The DspA/E protein is essential for E. amylovora pathogenicity and is secreted via the TTSS in vitro. DspA/E belongs to a type III effector family that is conserved in several phytopathogenic bacteria. In E. amylovora, DspA/E has been implicated in the generation of an oxidative stress during disease and the suppression of callose deposition. We investigated the fate of DspA/E in planta. DspA/E delivered artificially to apple or tobacco cells by agroinfection induced necrotic symptoms, indicating that DspA/E was probably injected via the TTSS. We confirmed that DspA/E acts as a major cell-death inducer during disease and HR, because the dspA/E mutant is severely impaired in its ability to induce electrolyte leakage in apple and tobacco leaves. Expression of the defense marker gene PR1 was delayed when dspA/E was transiently expressed in tobacco, suggesting that DspA/E-mediated necrosis may be associated with an alteration of defense responses.

Sign in / Sign up

Export Citation Format

Share Document