scholarly journals Salicylic acid effect on the mechanism of Lelliottia amnigena causing potato soft rot

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Richard Osei ◽  
Chengde Yang ◽  
Lingxiao Cui ◽  
Lijuan Wei ◽  
Mengjun Jin ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Bacterial Infections ◽  
Extracellular Enzymes ◽  
Antioxidant Activities ◽  
Soft Rot ◽  
Pectin Lyase ◽  
Plant Diseases ◽  
Natural Resistance ◽  
Biotic Stresses ◽  
Four Levels

Abstract Salicylic acid (SA) plays an important role in protecting plants from biotic stresses. Lelliottia amnigena is a newly identified potato soft rot pathogen and there are no adequate studies on this soft rot pathogen. Therefore, this paper focussed on the effect of SA on the mechanism under which L. amnigena causes potato soft rot. L. amnigena was examined and detected to secrete pectinase, proteases, pectin lyase and cellulase, which are the most important pathogenic enzymes involved in the production of plant diseases. Sterilised healthy potato tubers were inoculated with 0.2 mL of L. amnigena suspension (3.69 CFU · mL−1 × 107 CFU · mL−1). After 24 h, 200 μL of four different SA concentrations (0.5 mM, 1.0 mM, 1.5 mM and 2.0 mM) were used to treat the tubers. Co-culture of L. amnigena and SA significantly reduced the activity of pectinase, protease, pectin lyase and cellulase by an average of 33.8%, 43.4%, 67.7% and 46.9%, across the four concentrations (0.5 mM, 1.0 mM, 1.5 mM and 2.0 mM), respectively, compared to the control. The average disease index was reduced by 54.7% across the four SA concentrations. Treatment with SA induced transcriptional levels of the superoxide dismutase, peroxide, catalase and glutathione S-transferase across the four levels by an average of 3.87, 3.25, 3.97 and 3.94-fold, respectively, compared to control. Based on our results, we could state that SA could reduce the activities of these extracellular enzymes produced by L. amnigena by modulating both enzymatic and non-enzymatic antioxidant activities and gene expression that induce natural resistance in plants against bacterial infections.

scholarly journals Efficacy of KNO3, SiO2 and SA priming for improving emergence, seedling growth and antioxidant enzymes of rice (Oryza sativa), under drought

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lawan Gana Ali ◽  
Rosimah Nulit ◽  
Mohd Hafiz Ibrahim ◽  
Christina Yong Seok Yien
Keyword(s):  
Salicylic Acid ◽  
Seedling Growth ◽  
Antioxidant Activities ◽  
Soluble Sugar ◽  
Seed Priming ◽  
Potassium Nitrate ◽  
Total Soluble Protein ◽  
Rice Seedlings ◽  
Chlorophyll Contents ◽  
Randomized Design

AbstractRice is an important staple crop produced and consumed worldwide. However, poor seed emergence is one of the main impediments to obtaining higher yield of rice especially in hot and dry ecosystems of the world that are ravaged by drought. Therefore, this study was carried out to evaluate the effects of potassium nitrate (KNO3), salicylic acid (SA) and silicon dioxide (SiO2) priming in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44 rice under drought conditions. Rice seedlings primed with 2.5% and 5% KNO3, 3% and 3.5% SiO2, and 1 mM and 2.5 mM SA were subjected to three drought levels of low, moderate and severe under the greenhouse. Seed emergence, seedling growth, biochemical attributes and antioxidant activities were thereafter evaluated. Seed priming experiments were laid in a completely randomized design with five replicates per treatment. The results found that rice seedlings responded differently to different priming treatments. However, all primed rice seedlings had significantly (P ≤ 0.05) improved emergence percentage (72–92%), seedling growth, seedling vigor, seedling fresh and dry biomass and shorter emergence time compared with controls. Likewise, total soluble protein content, activities of catalase, ascorbate peroxidase and superoxide dismutase, carbohydrate, soluble sugar and total chlorophyll contents of rice seedlings were increased by more than two-folds by seed priming compared with control. Salicylic acid showed less effect in increasing emergence, seedling growth, antioxidant activities and biochemical attributes of rice. Thus, this study established that seed priming with KNO3 (2.5% and 5%) and SiO2 (3% and 3.5%) were more effective in improving emergence, seedling growth, biochemical attributes and antioxidant activities of FARO44. Thus, priming of FARO44 rice with this chemical is recommended for fast emergence, seedling growth and drought resistance in dry ecosystems.

scholarly journals Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Crop Protection ◽  
Soft Rot ◽  
Causal Agent ◽  
Plant Diseases ◽  
Ecological Niches ◽  
Pectobacterium Carotovorum ◽  
Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

scholarly journals ‘Candidatus Liberibacter asiaticus’ Encodes a Functional Salicylic Acid (SA) Hydroxylase That Degrades SA to Suppress Plant Defenses

2017 ◽  
Vol 30 (8) ◽  
pp. 620-630 ◽  
Author(s):  
Jinyun Li ◽  
Zhiqian Pang ◽  
Pankaj Trivedi ◽  
Xiaofeng Zhou ◽  
Xiaobao Ying ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Enzymatic Activity ◽  
Plant Defenses ◽  
Plant Diseases ◽  
Transgenic Tobacco Plants ◽  
Candidatus Liberibacter Asiaticus ◽  
Tobacco Plants ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Management Approaches

Pathogens from the fastidious, phloem-restricted ‘Candidatus Liberibacter’ species cause the devastating Huanglongbing (HLB) disease in citrus worldwide and cause diseases on many solanaceous crops and plants in the Apiaceae family. However, little is known about the pathogenic mechanisms due to the difficulty in culturing the corresponding ‘Ca. Liberibacter’ species. Here, we report that the citrus HLB pathogen ‘Ca. L. asiaticus’ uses an active salicylate hydroxylase SahA to degrade salicylic acid (SA) and suppress plant defenses. Purified SahA protein displays strong enzymatic activity to degrade SA and its derivatives. Overexpression of SahA in transgenic tobacco plants abolishes SA accumulation and hypersensitive response (HR) induced by nonhost pathogen infection. By degrading SA, ‘Ca. L. asiaticus’ not only enhances the susceptibility of citrus plants to both nonpathogenic and pathogenic Xanthomonas citri but also attenuates the responses of citrus plants to exogenous SA. In addition, foliar spraying of 2,1,3-benzothiadiazole and 2,6-dichloroisonicotinic acid, SA functional analogs not degradable by SahA, displays comparable (and even better) effectiveness with SA in suppressing ‘Ca. L. asiaticus’ population growth and HLB disease progression in infected citrus trees under field conditions. This study demonstrates one or more pathogens suppress plant defenses by degrading SA and establish clues for developing novel SA derivatives-based management approaches to control the associated plant diseases.

Impact of Global Climate Change on Potato Diseases and Strategies for Their Mitigation

2017 ◽  
pp. 205-227
Author(s):  
Mehi Lal ◽  
Saurabh Yadav ◽  
Rajendra Prasad Pant ◽  
Vijay Kumar Dua ◽  
B. P. Singh ◽  
...  
Keyword(s):  
Climatic Factors ◽  
Global Climate ◽  
Soft Rot ◽  
Potato Production ◽  
Potato Industry ◽  
Climatic Conditions ◽  
Mitigation Strategies ◽  
Viral Diseases ◽  
Biotic Stresses ◽  
Potato Diseases

The quality and quantity of the potatoes produced is directly affected by the climatic factors that prevailed during the crop season. It is also well established that abiotic and biotic stresses cause tremendous losses to the crop. Host plants and their pathogens are prone to various climatic factors like temperature, relative humidity, rainfall and CO2 which are behaving in erratic manner. Phytophthora infestans has adapted itself at higher temperature so there are chances to spread at a larger area. The other potato diseases like early blight, bacterial wilt, soft rot and viral diseases may also behave differently at elevated temperature and high rainfall. Viral diseases of potato are serious threat to potato industry as most of the viruses are transmitted by vectors and vector populations are bound to increase with these changed climatic conditions. Therefore, potato researchers need to simulate these conditions and devise mitigation strategies for sustained potato production.

scholarly journals Effect of exogenous salicylic acid on some physiological parameters and alleviation of drought stress in Nigella sativa plant under hydroponic culture 

2014 ◽  
Vol 50 (No. 1) ◽  
pp. 43-51 ◽  
Author(s):  
R. Kabiri ◽  
F. Nasibi ◽  
H. Farahbakhsh
Keyword(s):  
Salicylic Acid ◽  
Drought Stress ◽  
Nigella Sativa ◽  
Soluble Sugar ◽  
Hydroponic Culture ◽  
Black Cumin ◽  
Lyase Activity ◽  
Four Levels ◽  
Phenylalanine Ammonia Lyase Activity ◽  
Experimental Treatments

To study the effect of salicylic acid on photosynthetic pigments (chlorophyll&nbsp;a,&nbsp;b, total chlorophyll, and carotenoids), polyphenol compounds, anthocyanin, flavonoids, phenylalanine ammonia-lyase activity, malondialdehyde, lipoxygenase activity, electrolyte leakage, relative water content, soluble sugar contents, and protein content of black cumin (Nigella sativa) under drought stress in hydroponic culture, an experiment was conducted as a completely randomised design in a factorial arrangement with three replicates. Experimental treatments included salicylic acid at three levels (0, 5, and 10&micro;M) and drought stress (induced by polyethylene glycol 6000) at four levels (0, &ndash;0.2, &ndash;0.4, and &ndash;0.6 MPa). Results showed that salicylic acid application through the root medium increased drought tolerance of black cumin seedlings. Plants pre-treated with salicylic acid exhibited slight injury symptoms whereas those not pre-treated with salicylic acid had moderate damage and lost considerable portions of their foliage. In conclusion, salicylic acid could protect the&nbsp;Nigella&nbsp;plant against drought stress through increasing of all the mentioned traits, and 10&micro;M salicylic acid was the most effective level under both conditions.

scholarly journals Phyllosphere Colonization by a Soil Streptomyces sp. Promotes Plant Defense Responses Against Fungal Infection

2020 ◽  
Vol 33 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Sophie Vergnes ◽  
Damien Gayrard ◽  
Marine Veyssière ◽  
Justine Toulotte ◽  
Yves Martinez ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Fungal Pathogens ◽  
Plant Root ◽  
Defense Responses ◽  
Plant Diseases ◽  
Alternaria Brassicicola ◽  
Size Exclusion ◽  
Plant Defense Responses ◽  
Antifungal Metabolites ◽  
Root Microbiota

Streptomycetes are soil-dwelling, filamentous actinobacteria and represent a prominent bacterial clade inside the plant root microbiota. The ability of streptomycetes to produce a broad spectrum of antifungal metabolites suggests that these bacteria could be used to manage plant diseases. Here, we describe the identification of a soil Streptomyces strain named AgN23 which strongly activates a large array of defense responses when applied on Arabidopsis thaliana leaves. AgN23 increased the biosynthesis of salicylic acid, leading to the development of salicylic acid induction deficient 2 (SID2)-dependent necrotic lesions. Size exclusion fractionation of plant elicitors secreted by AgN23 showed that these signals are tethered into high molecular weight complexes. AgN23 mycelium was able to colonize the leaf surface, leading to plant resistance against Alternaria brassicicola infection in wild-type Arabidopsis plants. AgN23-induced resistance was found partially compromised in salicylate, jasmonate, and ethylene mutants. Our data show that Streptomyces soil bacteria can develop at the surface of plant leaves to induce defense responses and protection against foliar fungal pathogens, extending their potential use to manage plant diseases.

scholarly journals The Effect of Applying Exogenous Salicylic Acid on Aphid Infection and its Influence on Histo-Physiological Traits and Thermal Imaging of Canola

2016 ◽  
Vol 49 (2) ◽  
pp. 67-85 ◽  
Author(s):  
M.A.M. Elhamahmy ◽  
M.F. Mahmoud ◽  
T.Y. Bayoumi
Keyword(s):  
Salicylic Acid ◽  
Foliar Application ◽  
Growth And Yield ◽  
Brassica Napus L ◽  
Aphid Infestation ◽  
Aphid Control ◽  
Xylem Tissue ◽  
Secretory Tissue ◽  
Four Levels ◽  
Aphid Populations

Abstract Insect damage in canola adversely affects its productivity andquality and is considered one of the most important degrading factors in Egypt. The effect of foliar application of salicylic acid (SA) on aphid populations, growth and yield of canola (Brassica napus, L.) cv. serw 4 was the major goal of this study. Two experiments were conducted at the farm of Faculty of Agriculture, Suez Canal University, Ismailia, Egypt, during 2014 and 2015 seasons, to achieve this target. Each experiment included four levels of SA (0, 50, 100, 200 mg 1-1). The experimental results revealed that SA, at low concentration (50 mg 1-1), was an effective treatment for reduction the number of aphid populations and colony depth on the main inflorescence, contributed with reducing the thickness of secretory tissue of flower pedicel. The level of 50 mg 1-1 of SA-treated canola had the highest number of stomata cm-2, along with the lowest width of both stoma and its aperture. Thickness of xylem tissue and the number of xylem vessels bundle-1 in leaf midrib, reducing sugars and free amino acids was increased at 50 mg 1-1 SA, but free phenolics content did not affected significantly. Under controlled conditions, changes in temperature of infected leaves allowed the discrimination between healthy and infected areas in thermo-image, even before visible symptoms of aphid infestation appeared. The detection of modifications in plants or canopies, associated with low insect severity in the early stages of infestation, was crucial for the targeted, site-specific or on demand application of integrated aphid control. Canola, which was treated with 50 mg 1-1 of SA, gave 30.5 and 27.9 kg of oil ha-1 over the control. It was concluded that spraying of SA at 50 mg 1-1 was an effective elicitor to diminish the aphid numbers on canola inflorescence and improve its yield.

scholarly journals Actinomycetes, promising tools to control plant diseases and to promote plant growth

2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu
Keyword(s):  
Plant Growth ◽  
Plant Pathogens ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Control Plant ◽  
Plant Diseases ◽  
Soil Microbial ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.

scholarly journals Effects of Jasmonic Acid, Ethylene, and Salicylic Acid Signaling on the Rhizosphere Bacterial Community of Arabidopsis thaliana

2011 ◽  
Vol 24 (4) ◽  
pp. 395-407 ◽  
Author(s):  
Rogier F. Doornbos ◽  
Bart P. J. Geraats ◽  
Eiko E. Kuramae ◽  
L. C. Van Loon ◽  
Peter A. H. M. Bakker
Keyword(s):  
Salicylic Acid ◽  
Bacterial Community ◽  
Induced Resistance ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Systemic Resistance ◽  
Culturable Bacteria ◽  
Wild Type ◽  
Defense Signaling ◽  
Rhizosphere Bacterial Community

Systemically induced resistance is a promising strategy to control plant diseases, as it affects numerous pathogens. However, since induced resistance reduces one or both growth and activity of plant pathogens, the indigenous microflora may also be affected by an enhanced defensive state of the plant. The aim of this study was to elucidate how much the bacterial rhizosphere microflora of Arabidopsis is affected by induced systemic resistance (ISR) or systemic acquired resistance (SAR). Therefore, the bacterial microflora of wild-type plants and plants affected in their defense signaling was compared. Additionally, ISR was induced by application of methyl jasmonate and SAR by treatment with salicylic acid or benzothiadiazole. As a comparative model, we also used wild type and ethylene-insensitive tobacco. Some of the Arabidopsis genotypes affected in defense signaling showed altered numbers of culturable bacteria in their rhizospheres; however, effects were dependent on soil type. Effects of plant genotype on rhizosphere bacterial community structure could not be related to plant defense because chemical activation of ISR or SAR had no significant effects on density and structure of the rhizosphere bacterial community. These findings support the notion that control of plant diseases by elicitation of systemic resistance will not significantly affect the resident soil bacterial microflora.

Pasteurella multocidaand bovine respiratory disease

2007 ◽  
Vol 8 (2) ◽  
pp. 129-150 ◽  
Author(s):  
S. M. Dabo ◽  
J. D. Taylor ◽  
A. W. Confer
Keyword(s):  
Respiratory Disease ◽  
Bacterial Infections ◽  
Pasteurella Multocida ◽  
Extracellular Enzymes ◽  
Bovine Respiratory Disease ◽  
High Serum ◽  
Stress Factors ◽  
Field Efficacy ◽  
Shipping Fever ◽  
Colonization Factors

AbstractPasteurella multocidais a pathogenic Gram-negative bacterium that has been classified into three subspecies, five capsular serogroups and 16 serotypes.P. multocidaserogroup A isolates are bovine nasopharyngeal commensals, bovine pathogens and common isolates from bovine respiratory disease (BRD), both enzootic calf pneumonia of young dairy calves and shipping fever of weaned, stressed beef cattle.P. multocidaA:3 is the most common serotype isolated from BRD, and these isolates have limited heterogeneity based on outer membrane protein (OMP) profiles and ribotyping. Development ofP. multocida-induced pneumonia is associated with environmental and stress factors such as shipping, co-mingling, and overcrowding as well as concurrent or predisposing viral or bacterial infections. Lung lesions consist of an acute to subacute bronchopneumonia that may or may not have an associated pleuritis. Numerous virulence or potential virulence factors have been described for bovine respiratory isolates including adherence and colonization factors, iron-regulated and acquisition proteins, extracellular enzymes such as neuraminidase, lipopolysaccharide, polysaccharide capsule and a variety of OMPs. Immunity of cattle against respiratory pasteurellosis is poorly understood; however, high serum antibodies to OMPs appear to be important for enhancing resistance to the bacterium. Currently availableP. multocidavaccines for use in cattle are predominately traditional bacterins and a live streptomycin-dependent mutant. The field efficacy of these vaccines is not well documented in the literature.

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