scholarly journals Bacillus amyloliquefaciens MBI600 differentially induces tomato defense signaling pathways depending on plant part and dose of application

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anastasia Dimopoulou ◽  
Ioannis Theologidis ◽  
Burghard Liebmann ◽  
Kriton Kalantidis ◽  
Nikon Vassilakos ◽  
...  
Keyword(s):  
Plant Defense ◽  
Stress Responses ◽  
Bacillus Amyloliquefaciens ◽  
Plant Pathogens ◽  
Biological Control Agent ◽  
Induced Defense ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Dependent Manner ◽  
Plant Host

AbstractThe success of Bacillus amyloliquefaciens as a biological control agent relies on its ability to outgrow plant pathogens. It is also thought to interact with its plant host by inducing systemic resistance. In this study, the ability of B. amyloliquefaciens MBI600 to elicit defense (or other) responses in tomato seedlings and plants was assessed upon the expression of marker genes and transcriptomic analysis. Spray application of Serifel, a commercial formulation of MBI600, induced responses in a dose-dependent manner. Low dosage primed plant defense by activation of SA-responsive genes. Suggested dosage induced defense by mediating synergistic cross-talk between JA/ET and SA-signaling. Saturation of tomato roots or leaves with MBI600 elicitors activated JA/ET signaling at the expense of SA-mediated responses. The complex signaling network that is implicated in MBI600-tomato seedling interactions was mapped. MBI600 and flg22 (a bacterial flagellin peptide) elicitors induced, in a similar manner, biotic and abiotic stress responses by the coordinated activation of genes involved in JA/ET biosynthesis as well as hormone and redox signaling. This is the first study to suggest the activation of plant defense following the application of a commercial microbial formulation under conditions of greenhouse crop production.

scholarly journals Transcriptome Reprogramming of Tomato Orchestrate the Hormone Signaling Network of Systemic Resistance Induced by Chaetomium globosum

2021 ◽  
Vol 12 ◽  
Author(s):  
Jagmohan Singh ◽  
Rashmi Aggarwal ◽  
Bishnu Maya Bashyal ◽  
K. Darshan ◽  
Pooja Parmar ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Plant Pathogens ◽  
Biological Control Agent ◽  
Induced Defense ◽  
Chaetomium Globosum ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Hormone Signaling ◽  
Signaling Transduction ◽  
Chlorophyll Metabolism

Chaetomium globosum is a potential biological control agent effective against various plant pathogens. Several reports are available on the mycoparastism and antibiosis mechanisms of C. globosum against plant pathogenic fungi, whereas a few states induced resistance. The potential induced defense component of C. globosum (Cg-2) was evaluated against early blight disease of tomato (Solanum lycopersicum) and further, global RNA sequencing was performed to gain deep insight into its mechanism. The expression of marker genes of hormone signaling pathways, such as PR1, PiII, PS, PAL, Le4, and GluB were analyzed using real-time quantitative reverse transcription PCR (qRT-PCR) to determine the best time point for RNA sequencing. The transcriptome data revealed that 22,473 differentially expressed genes (DEGs) were expressed in tomato at 12 h post Cg-2 inoculation as compared with control plants and among these 922 DEGs had a fold change of −2 to +2 with p < 0.05. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that most of the DEGs were belonging to metabolic pathways, biosynthesis of secondary metabolites, plant–pathogen interaction, chlorophyll metabolism, and plant hormone signal transduction. Gene Ontology (GO) analysis revealed that DEGs were enriched mainly related to binding activity (GO:0005488), catalytic activity (GO:0003824), metabolic process (GO:0008152), cellular process (GO:0009987), response to stimulus (GO:0050896), biological regulation (GO:0065007), and transcription regulator activity (GO:0140110). The gene modulations in hormone signaling transduction, phenylpropanoid biosynthesis, and mitogen-activated protein kinases (MPK) signaling indicated the upregulation of genes in these pathways. The results revealed active participation of jasmonic acid (JA) and salicylic acid (SA) signaling transduction pathways which further indicated the involvement of induced systemic resistance (ISR) and systemic acquired resistance (SAR) in the systemic resistance induced by Cg-2 in tomato.

scholarly journals Characterization of Migration and Induced Resistance of Rhizobium Vitis Strain ARK-1, a Biological Control Agent Against Grapevine Crown Gall Disease

2020 ◽  
Author(s):  
Akira Kawaguchi ◽  
Yoshiteru Noutoshi
Keyword(s):  
Crown Gall ◽  
Temporal Dynamics ◽  
Biological Control Agent ◽  
Control Agent ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Cell Detection ◽  
Induced Expression ◽  
Crown Gall Disease ◽  
Grapevine Crown Gall

Abstract A nonpathogenic strain ARK-1 of Rhizobium vitis has an antagonistic activity toward tumorigenic (Ti) strain of R. vitis, a causal agent of grapevine crown gall disease, and works as a biocontrol agent. We have demonstrated that the gall formation was fully suppressed when ARK-1 was co-inoculated with Ti into the grapevine stem at a 1:1 ratio. For practical use of ARK-1 in agriculture, understanding the temporal dynamics of the bacterial habitat on host plants and the biocontrol property are needed in order to develop proper application methods. Here we demonstrated that the gall incidence by Ti was reduced to about 50% when ARK-1 was pre-inoculated at both upper and lower positions on the grapevine stem 3 cm away from the Ti-inoculation point 5 days before. The bacterial cell detection assay in the grapevine tissue revealed that ARK-1 could migrate at least 3 cm in 5 days. Inoculations of ARK-1 or Ti induced expression of marker genes for defense-related phytohormones such as salicylic acid, jasmonic acid, and ethylene in grapevine within 3 days but they were diminished by 6 days. Inoculation of Ti 5 days after ARK-1 pre-inoculation induced expression of the marker genes except for the LOX-9 gene in a basically similar way to those without the pre-inoculation, suggesting that ARK-1 did not induce typical acquired systemic resistance or induced systemic resistance in grapevine, while the transcript of LOX-9 was detected at 24 and 48 hours after the Ti inoculation when ARK-1 was pre-inoculated, unlike the un-inoculated condition. ARK-1 primed the induction of certain defense genes and it may take part in its biocontrol activity.

scholarly journals Seaweed-Based Compounds and Products for Sustainable Protection against Plant Pathogens

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 59
Author(s):  
Pushp Sheel Shukla ◽  
Tudor Borza ◽  
Alan T. Critchley ◽  
Balakrishnan Prithiviraj
Keyword(s):  
Plant Defense ◽  
Plant Pathogens ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Crop Protection ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Environmental Damage ◽  
Plant Defense Responses ◽  
Seaweed Extracts

Sustainable agricultural practices increasingly demand novel, environmentally friendly compounds which induce plant immunity against pathogens. Stimulating plant immunity using seaweed extracts is a highly viable strategy, as these formulations contain many bio-elicitors (phyco-elicitors) which can significantly boost natural plant immunity. Certain bioactive elicitors present in a multitude of extracts of seaweeds (both commercially available and bench-scale laboratory formulations) activate pathogen-associated molecular patterns (PAMPs) due to their structural similarity (i.e., analogous structure) with pathogen-derived molecules. This is achieved via the priming and/or elicitation of the defense responses of the induced systemic resistance (ISR) and systemic acquired resistance (SAR) pathways. Knowledge accumulated over the past few decades is reviewed here, aiming to explain why certain seaweed-derived bioactives have such tremendous potential to elicit plant defense responses with considerable economic significance, particularly with increasing biotic stress impacts due to climate change and the concomitant move to sustainable agriculture and away from synthetic chemistry and environmental damage. Various extracts of seaweeds display remarkably different modes of action(s) which can manipulate the plant defense responses when applied. This review focuses on both the similarities and differences amongst the modes of actions of several different seaweed extracts, as well as their individual components. Novel biotechnological approaches for the development of new commercial products for crop protection, in a sustainable manner, are also suggested.

scholarly journals RpoS Contributes to Successful Opportunistic Colonization by Human Enteric Pathogens during Plant Disease

2020 ◽  
Author(s):  
Amelia H. Lovelace ◽  
Sangwook Lee ◽  
Diana M. Downs ◽  
Ziad Soufi ◽  
Pedro Bota ◽  
...  
Keyword(s):  
Stress Responses ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Fresh Produce ◽  
Enteric Pathogens ◽  
In Planta ◽  
Foodborne Illnesses ◽  
Plant Host ◽  
E Coli ◽  
Endophytic Colonization

AbstractWith an increase in foodborne illnesses associated with the consumption of fresh produce, it is important to understand the interactions between human bacterial enteric pathogens and plants. It was previously established that diseased plants can create a permissive environment for opportunistic endophytic colonization of enteric pathogens. However, the factors that contribute to the colonization of enteric pathogens during plant disease are largely unknown. Here, we show that both strain and plant host factors contribute to significantly increased populations of enteric pathogens when co-inoculated with the plant pathogen, P. syringae pv. tomato. The two Salmonella enterica strains DM10000 and 14028S, differ in their ability to metabolize host-derived apoplastic carbohydrates dependent on the sigma factor RpoS. The rpoS gene is an important strain factor for endophytic colonization by S. enterica during plant disease. Our results suggest that rpoS plays a crucial role during in planta colonization, balancing nutrient metabolism and stress responses.ImportanceFoodborne illnesses caused by the bacterial human enteric pathogens, E. coli O157:H7 and S. enterica, often results in vomiting and diarrhea. If left untreated, this illness can cause dehydration and sometimes death of a patient. Both E. coli O157:H7 and S. enterica have caused repeated fresh produce-associated epidemics. Crop disease could promote the ability of plants to act as reservoirs for produce-borne outbreaks. Plant pathogens dampen plant immunity, which allows for a more permissive environment for human enteric pathogens to grow. These internalized enteric pathogen populations are especially dangerous since they cannot be removed by washing alone. Therefore, the need to understand the factors that contribute to the opportunistic colonization of human enteric pathogens during plant disease is apparent. Our research has identified host and strain factors that contribute to opportunistic colonization of diseased plants, which will inform the development of future management strategies to mitigate future outbreaks.

scholarly journals Spermine Is a Potent Plant Defense Activator Against Gray Mold Disease on Solanum lycopersicum, Phaseolus vulgaris, and Arabidopsis thaliana

2019 ◽  
Vol 109 (8) ◽  
pp. 1367-1377 ◽  
Author(s):  
Hamed S. Seifi ◽  
Adel Zarei ◽  
Tom Hsiang ◽  
Barry J. Shelp
Keyword(s):  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Phaseolus Vulgaris ◽  
Plant Defense ◽  
Solanum Lycopersicum ◽  
Stress Responses ◽  
Systemic Acquired Resistance ◽  
Defense Responses ◽  
Gray Mold ◽  
Systemic Resistance

Polyamines (PAs) are ubiquitous aliphatic amines that play important roles in growth, development, and environmental stress responses in plants. In this study, we report that exogenous application of spermine (Spm) is effective in the induction of resistance to gray mold disease, which is caused by the necrotrophic fungal pathogen Botrytis cinerea, on tomato (Solanum lycopersicum), bean (Phaseolus vulgaris), and Arabidopsis thaliana. High throughput transcriptome analysis revealed a priming role for the Spm molecule in the genus Arabidopsis, resulting in strong upregulation of several important defense-associated genes, particularly those involved in systemic-acquired resistance. Microscopic analysis confirmed that Spm application potentiates endogenous defense responses in tomato leaves through the generation of reactive oxygen species and the hypersensitive response, which effectively contained B. cinerea growth within the inoculated area. Moreover, co-application of Spm and salicylic acid resulted in a synergistic effect against the pathogen, leading to higher levels of resistance than those induced by separate applications of the two compounds. The Spm plus salicylic acid treatment also reduced infection in systemic nontreated leaves of tomato plants. Our findings suggest that Spm, particularly when applied in combination with salicylic acid, functions as a potent plant defense activator that leads to effective local and systemic resistance against B. cinerea.

scholarly journals Suppression of Sclerotinia sclerotiorum by the Induction of Systemic Resistance and Regulation of Antioxidant Pathways in Tomato Using Fengycin Produced by Bacillus amyloliquefaciens FZB42

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 613 ◽  
Author(s):  
Ayaz Farzand ◽  
Anam Moosa ◽  
Muhammad Zubair ◽  
Abdur Rashid Khan ◽  
Venance Colman Massawe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sclerotinia Sclerotiorum ◽  
Bacillus Amyloliquefaciens ◽  
Plant Pathogens ◽  
Systemic Resistance ◽  
Bacillus Species ◽  
Fungal Mycelium ◽  
Post Inoculation ◽  
Ros Scavenging ◽  
Control Activity

Lipopeptides from Bacillus species exhibit promising biological control activity against plant pathogens. This study aimed to explore the potential of purified fengycin to induce systemic resistance in tomato against Sclerotinia sclerotiorum. Bacillus amyloliquefaciens FZB42, its mutant AK1S, and their corresponding metabolites showed in vitro inhibition of S. sclerotiorum mycelium. Fengycin derived from an AK1S mutant was purified and identified through HPLC and MALDI-TOF-MS, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed structural deformities in the fungal mycelium. Moreover, fengycin induced the accumulation of reactive oxygen species (ROS) in S. sclerotiorum mycelium and downregulated the expression of ROS-scavenging genes viz., superoxide dismutase (SsSOD1), peroxidase (SsPO), and catalase (SsCAT1) compared to the untreated control. Furthermore, the lesion size was dramatically reduced in fengycin-treated tomato plants compared to plants infected with S. sclerotiorum only in a greenhouse experiment. Additionally, the transcriptional regulation of defense-related genes GST, SOD, PAL, HMGR, and MPK3 showed the highest upsurge in expression at 48 h post-inoculation (hpi). However, their expression was subsequently decreased at 96 hpi in fengycin + S. sclerotiorum treatment compared to the plants treated with fengycin only. Conversely, the expression of PPO increased in a linear manner up to 96 hpi.

scholarly journals Ectomycorrhizal fungi induce systemic resistance against insects on a non-mycorrhizal plant in a CERK1-dependent manner

2019 ◽  
Author(s):  
Kishore Vishwanathan ◽  
Krzysztof Zienkiewicz ◽  
Yang Liu ◽  
Dennis Janz ◽  
Ivo Feussner ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Trichoplusia Ni ◽  
Bacterial Pathogen ◽  
Systemic Resistance ◽  
Dependent Manner ◽  
Induce Systemic Resistance ◽  
Mycorrhizal Plant ◽  
Plant Host ◽  
Mediated Effects ◽  
Ja Signaling

ABSTRACTBelow-ground microbes can induce systemic resistance (ISR) against foliar pests and pathogens on diverse plant hosts. The prevalence of ISR among plant-microbe-pest systems raises the question of host specificity in microbial induction of ISR. To test whether ISR is limited by plant host range, we tested the ISR-inducing ectomycorrhizal (ECM) fungus Laccaria bicolor on the non-mycorrhizal plant Arabidopsis. We found that root inoculation with L. bicolor triggered ISR against the insect herbivore Trichoplusia ni and induced systemic susceptibility (ISS) against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pto). We found that L. bicolor-triggered ISR against T. ni was dependent on jasmonic acid (JA) signaling and salicylic acid (SA) biosynthesis and signaling. We found that heat killed L. bicolor and chitin are sufficient to trigger ISR against T. ni and ISS against Pto and that the chitin receptor CERK1 is necessary for L. bicolor-mediated effects on systemic immunity. Collectively our findings suggest that some ISR responses might not require intimate co-evolution of host and microbe, but rather might be the result of root perception of conserved microbial signals.

scholarly journals Tea Tree Oil Induces Systemic Resistance against Fusarium wilt in Banana and Xanthomonas Infection in Tomato Plants

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1137
Author(s):  
Ronaldo J. D. Dalio ◽  
Heros J. Maximo ◽  
Rafaela Roma-Almeida ◽  
Janaína N. Barretta ◽  
Eric M. José ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Priming Effect ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Tea Tree Oil ◽  
Tomato Plants ◽  
Resistance Induction ◽  
Tea Tree

The essential tea tree oil (TTO) derived from Melaleuca alternifolia plant is widely used as a biopesticide to protect crops from several plant-pathogens. Its activity raised queries regarding its ability to, not only act as a bio-fungicide or bio-bactericide, but also systemically inducing resistance in plants. This was examined by TTO application to banana plants challenged by Fusarium oxysporum f. sp. cubense (Foc, Race 1) causing Fusarium wilt and to tomato plants challenged by Xanthomonas campestris. Parameters to assess resistance induction included: disease development, enzymatic activity, defense genes expression correlated to systemic acquired resistance (SAR) and induced systemic resistance (ISR) and priming effect. Spraying TTO on field-grown banana plants infected with Foc and greenhouse tomato plants infected with Xanthomonas campestris led to resistance induction in both hosts. Several marker genes of salicylic acid, jasmonic acid and ethylene pathways were significantly up-regulated in parallel with symptoms reduction. For tomato plants, we have also recorded a priming effect following TTO treatment. In addition to fungicidal and bactericidal effect, TTO can be applied in more sustainable strategies to control diseases by enhancing the plants ability to defend themselves against pathogens and ultimately diminish chemical pesticides applications.

scholarly journals Arginine Decarboxylase Is Essential for Pneumococcal Stress Responses

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 286
Author(s):  
Mary Frances Nakamya ◽  
Moses B. Ayoola ◽  
Leslie A. Shack ◽  
Mirghani Mohamed ◽  
Edwin Swiatlo ◽  
...  
Keyword(s):  
Stress Responses ◽  
Critical Role ◽  
Acid Stress ◽  
Arginine Decarboxylase ◽  
Arginine Deiminase ◽  
Dependent Manner ◽  
Cellular Processes ◽  
Opportunistic Human Pathogen ◽  
Thiol Peroxidase ◽  
The Impact

Polyamines such as putrescine, cadaverine, and spermidine are small cationic molecules that play significant roles in cellular processes, including bacterial stress responses and host–pathogen interactions. Streptococcus pneumoniae is an opportunistic human pathogen, which causes several diseases that account for significant morbidity and mortality worldwide. As it transits through different host niches, S. pneumoniae is exposed to and must adapt to different types of stress in the host microenvironment. We earlier reported that S. pneumoniae TIGR4, which harbors an isogenic deletion of an arginine decarboxylase (ΔspeA), an enzyme that catalyzes the synthesis of agmatine in the polyamine synthesis pathway, has a reduced capsule. Here, we report the impact of arginine decarboxylase deletion on pneumococcal stress responses. Our results show that ΔspeA is more susceptible to oxidative, nitrosative, and acid stress compared to the wild-type strain. Gene expression analysis by qRT-PCR indicates that thiol peroxidase, a scavenger of reactive oxygen species and aguA from the arginine deiminase system, could be important for peroxide stress responses in a polyamine-dependent manner. Our results also show that speA is essential for endogenous hydrogen peroxide and glutathione production in S. pneumoniae. Taken together, our findings demonstrate the critical role of arginine decarboxylase in pneumococcal stress responses that could impact adaptation and survival in the host.

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