scholarly journals Improving the Yield of Xenocoumacin 1 by PBAD Promoter Replacement in Xenorhabdus nematophila CB6

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1251
Author(s):  
Youcai Qin ◽  
Fenglian Jia ◽  
Xiaohui Li ◽  
Beibei Li ◽  
Jie Ren ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Phytophthora Capsici ◽  
Xenorhabdus Nematophila ◽  
Growth Inhibition Assay ◽  
Widespread Application ◽  
Native Promoter ◽  
Promoter Replacement ◽  
Pbad Promoter

Xenocoumacin 1 (Xcn1), which is produced by Xenorhabdus nematophila CB6, exhibits strong inhibition activity against plant pathogens, especially fungi and oomycetes. Therefore, it has attracted interest in developing it into a novel biofungicide applicable for plant protection. However, its low yield with concomitant high cost during the fermentation process limits its widespread application. In this study, we replaced the native promoter of xcnA with the arabinose-inducible araBAD promoter (PBAD), a well-known and widely used promoter for expressing heterologous genes, to evaluate its effects on Xcn1 yield and antimicrobial activity. Compared with wildtype strain, the fermentation yield of Xcn1 was improved from 68.5 mg/L to 249.7 mg/L (3.6-fold) and 234.9 mg/L (3.4-fold) at 0.5% and 1.0% L-arabinose concentration, respectively. We further explored the transcription level of the biosynthesis related genes of Xcn1 and found that their upregulation resulted in the yield improvement of Xcn1. Moreover, the antimicrobial activity of Xcn1 against Bacillus subtilis and Phytophthora capsici was determined by agar diffusion plate and growth inhibition assay, as expected, it was also found to be enhanced. The promoter-replacement strategy utilized here improves the yield of Xcn1 efficiently, which provides a basis for the industrial production of Xcn1.

scholarly journals The carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Matuszewska ◽  
Tomasz Maciąg ◽  
Magdalena Rajewska ◽  
Aldona Wierzbicka ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Carbon Source ◽  
Reference Genes ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Carbon Sources ◽  
Unknown Compound ◽  
Fungal Plant Pathogens ◽  
The Impact

AbstractPseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7-hydroxytropolone (7-HT) and an unknown compound (“cluster 17”) and are responsible for the antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.

scholarly journals De Novo Design of Antimicrobial Peptides With a Special Charge Pattern and Their Application in Combating Plant Pathogens

2021 ◽  
Vol 12 ◽  
Author(s):  
Eric H. -L. Chen ◽  
Cheng-Wei Weng ◽  
Yi-Min Li ◽  
Ming-Chin Wu ◽  
Chien-Chih Yang ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Plant Pathogens ◽  
De Novo ◽  
Plant Protection ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Plant Diseases ◽  
Basic Residue ◽  
Wide Range

Plant diseases are important issues in agriculture, and the development of effective and environment-friendly means of disease control is crucial and highly desired. Antimicrobial peptides (AMPs) are known as potential alternatives to chemical pesticides because of their potent broad-spectrum antimicrobial activity and because they have no risk, or have only a low risk, of developing chemical-resistant pathogens. In this study, we designed a series of amphipathic helical peptides with different spatial distributions of positive charges and found that the peptides that had a special sequence pattern “BBHBBHHBBH” (“B” for basic residue and “H” for hydrophobic residue) displayed excellent bactericidal and fungicidal activities in a wide range of economically important plant pathogens. The peptides with higher helical propensity had lower antimicrobial activity. When we modified the peptides with a long acyl chain at their N-terminus, their plant protection effect improved. Our application of the fatty acyl-modified peptides on the leaves of tomato and Arabidopsis plants lessened the infection caused by Pectobacterium carotovorum subsp. carotovorum and Botrytis cinerea. Our study provides important insights on the development of more potent novel AMPs for plant protection.

scholarly journals Necessity requires no decision: carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482

2021 ◽  
Author(s):  
Marta Matuszewska ◽  
Tomasz Maciag ◽  
Magdalena Rajewska ◽  
Aldona Wierzbicka ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Carbon Source ◽  
Reference Genes ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Carbon Sources ◽  
Unknown Compound ◽  
Fungal Plant Pathogens ◽  
The Impact

Abstract Pseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7‑hydroxytropolone (7-HT) and an unknown compound (“cluster 17”) and are responsible for antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.

scholarly journals Antimicrobial Activity of Essential Oils Against Plant Pathogenic Fungi: A Review

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Uday Kumar
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Insect Pest ◽  
Complex Mixture ◽  
Pathogenic Fungi ◽  
Fungal Diseases ◽  
Herbivorous Insect ◽  
Plant Pathogenic Fungi

Essential oils are obtained from non-woody parts of the plants, particularly foliage, stem or hydrodistillation. They are complex mixture of terpenoids and variety of aromatic phenols, oxides, ethers, alcohols, esters, aldehydes and ketones that determine the characteristics aroma and odour of the donor plants. Presence of volatile monoterpenes or essential oils in the plants provides an important defense strategy to the plants, particularly against herbivorous insect pest and plant pathogenic fungi. Fungi cause huge amount of yield losses due to their ability to cause serious devastating diseases to the crops. Minimizing their effect on the crops need to get a promising way of controlling them. Therefore, the use of essential oils could be a good option to tackle the challenge of fungal diseases. Essential oils are natural products that are extracted from plants by different methods. They have been used for a long history of time for different purposes. Fungicides used in disease management are expensive for resource-poor farmers andnegatively correlation with ecosystems. Nowadays there is a huge interest to use them as plant protection product to be alternative for new agro-chemicals with large antimicrobial spectrum properties. As we observed from the antifungal trials in different literature, the essential oils have a great antifungal effect on many plant pathogens and inhibited most of the tested plant pathogens in the laboratory. Thus, essential oils could be a control agent for plant fungal diseases and further investigation is required to use in the field. This review summarized that the importance, antimicrobial activity and management of fungi.

scholarly journals Synergistic Antifungal Activity of Graphene Oxide and Fungicides against Fusarium Head Blight In Vitro and In Vivo

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2393
Author(s):  
Xiuping Wang ◽  
Fei Peng ◽  
Caihong Cheng ◽  
Lina Chen ◽  
Xuejuan Shi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Plant Pathogens ◽  
Antimicrobial Agents ◽  
Plant Protection ◽  
Disease Incidence ◽  
Agricultural Science ◽  
Plant Diseases ◽  
Synergistic Activity

Plant pathogens constantly develop resistance to antimicrobial agents, and this poses great challenges to plant protection. Therefore, there is a pressing need to search for new antimicrobials. The combined use of antimicrobial agents with different antifungal mechanisms has been recognized as a promising approach to manage plant diseases. Graphene oxide (GO) is a newly emerging and highly promising antimicrobial agent against various plant pathogens in agricultural science. In this study, the inhibitory activity of GO combined with fungicides (Mancozeb, Cyproconazol and Difenoconazole) against Fusarium graminearum was investigated in vivo and in vitro. The results revealed that the combination of GO and fungicides has significant synergistic inhibitory effects on the mycelial growth, mycelial biomass and spore germination of F. graminearum relative to single fungicides. The magnitude of synergy was found to depend on the ratio of GO and fungicide in the composite. In field tests, GO–fungicides could significantly reduce the disease incidence and disease severity, exhibiting a significantly improved control efficacy on F. graminearum. The strong synergistic activity of GO with existing fungicides demonstrates the great application potential of GO in pest management.

scholarly journals In Vitro Antimicrobial Activity of Zodia (Evodia suaveolens) Leaf Extract on Pathogenic Agents Dragon Fruit Plant

Jurnal Biota ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 78-85
Author(s):  
Trio Ageng Prayitno ◽  
Nuril Hidayati
Keyword(s):  
Antimicrobial Activity ◽  
Leaf Extract ◽  
Plant Pathogens ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Leaf Extracts ◽  
Dragon Fruit ◽  
Fruit Plants ◽  
Pathogenic Agents

The use of antimicrobials from plant extracts has not been used optimally to control pathogenic agents in dragon fruit plants. The purpose of this research was to determine the antimicrobial activity of zodia (Evodia suaveolens) leaf extracts on pathogenic agents of dragon fruit plants in vitro. The research method is laboratory research with Completely Randomized Design (CRD). The antimicrobial concentrations of zodia (E. suaveolens) leaf extract used six types including 50%, 60%, 70%, 80%, 90%, and 100% with four replications. The research sample was the leaf of zodia (E. suaveolens), Pseudomonas aeruginosa and Fusarium oxysporum strain Malang. Test the antimicrobial activity of zodia (E. suaveolens) leaf extracts on the growth of P. aeruginosa and F. oxysporum using the disc-diffusion method and wells method. The research instrument was used the observation sheet of the diameter of inhibition zone indicated by the clear zone. The diameter of inhibition zone data were analyzed using the One Way ANOVA test. The results showed that the antimicrobial activity of zodia (E. suaveolens) leaf extract significantly inhibited the growth of P. aeruginosa and F. oxysporum (P <0.05). These results recommend zodia (E. suaveolens) leaf extract as an antimicrobial agent for dragon fruit plant pathogens.

scholarly journals Genetic transformation of the plant pathogens Phytophthora capsici andPhytophthora parasitica

1991 ◽  
Vol 19 (15) ◽  
pp. 4273-4278 ◽  
Author(s):  
Ana M. Bailey ◽  
Gilda L. Mena ◽  
Luis Herrera-Estrella
Keyword(s):  
Genetic Transformation ◽  
Plant Pathogens ◽  
Phytophthora Capsici

RNA Interference Mechanisms and Applications in Plant Pathology

2018 ◽  
Vol 56 (1) ◽  
pp. 581-610 ◽  
Author(s):  
Cristina Rosa ◽  
Yen-Wen Kuo ◽  
Hada Wuriyanghan ◽  
Bryce W. Falk
Keyword(s):  
Plant Pathology ◽  
Rna Interference ◽  
Gene Function ◽  
Small Rnas ◽  
Plant Pathogens ◽  
Common Ancestor ◽  
Plant Protection ◽  
Plant Diseases ◽  
Antiviral Defense ◽  
Endogenous Genes

The origin of RNA interference (RNAi), the cell sentinel system widely shared among eukaryotes that recognizes RNAs and specifically degrades or prevents their translation in cells, is suggested to predate the last eukaryote common ancestor ( 138 ). Of particular relevance to plant pathology is that in plants, but also in some fungi, insects, and lower eukaryotes, RNAi is a primary and effective antiviral defense, and recent studies have revealed that small RNAs (sRNAs) involved in RNAi play important roles in other plant diseases, including those caused by cellular plant pathogens. Because of this, and because RNAi can be manipulated to interfere with the expression of endogenous genes in an intra- or interspecific manner, RNAi has been used as a tool in studies of gene function but also for plant protection. Here, we review the discovery of RNAi, canonical mechanisms, experimental and translational applications, and new RNA-based technologies of importance to plant pathology.

Evaluation of droplet digital PCR for the detection of black canker disease in tomato

Plant Disease ◽  
2021 ◽  
Author(s):  
Li Wang ◽  
Tian Qian ◽  
Pei Zhou ◽  
Wenjun Zhao ◽  
Xianchao Sun
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Detection Threshold ◽  
Digital Pcr ◽  
Taqman Probe ◽  
Tomato Seed ◽  
Canker Disease ◽  
Probe Set

Clavibacter michiganensis subsp. michiganensis (Cmm), the cause of bacterial canker disease, is one of the most destructive pathogens in greenhouse and field tomato. The pathogen is now present in all main production areas of tomato and is quite widely distributed in the EPPO（European and Mediterranean Plant Protection Organization）region. The inspection and quarantine of the plant pathogens relies heavily on accurate detection tools. Primers and probes reported in previous studies do not distinguish the Cmm pathogen from other closely related subspecies of C. michiganensis, especially the non-pathogenic subspecies that were identified from tomato seeds recently. Here, we have developed a droplet digital polymerase chain reaction (ddPCR) method for the identification of this specific bacterium with primers/TaqMan probe set designed based on the pat-1 gene of Cmm. This new primers/probe set has been evaluated by qPCRthe real time PCR（qPCR） and ddPCR. The detection results suggest that the ddPCR method established in this study was highly specific for the target strains. The result showed the positive amplification for all 5 Cmm strains，and no amplification was observed for the other 43 tested bacteria, including the closely related C. michiganensis strains. The detection threshold of ddPCR was 10.8 CFU/mL for both pure Cmm cell suspensions and infected tomato seed, which was 100 times-fold more sensitive than that of the real-time PCR (qPCR ) performed using the same primers and probe. The data obtained suggest that our established ddPCR could detect Cmm even with low bacteria load, which could facilitate both Cmm inspection for pathogen quarantine and the routine pathogen detection for disease control of black canker in tomato.

Nano-Biosensors Tech and IPM in Plant Protection to Respond to Climate Change Challenges in Morocco

2020 ◽  
pp. 114-129
Author(s):  
Wafaa Mokhtari ◽  
Mohamed Achouri ◽  
Abdellah Remah ◽  
Noureddine Chtaina ◽  
Hassan Boubaker
Keyword(s):  
Plant Pathogens ◽  
Ad Hoc ◽  
Plant Protection ◽  
Point Of Care ◽  
Integrated Approach ◽  
Control Measures ◽  
Special Focus ◽  
Green Beans ◽  
Trichoderma Spp ◽  
Diagnostic Sensitivity And Specificity

In this chapter, the authors introduce two research axes: Part A, nano-biosensors as ad-hoc technologies designed to meet plant diagnostic sensitivity and specificity needs at point of care, and Part B, the study of the interaction of drought and infection stresses in crops investigating bio-control potential antagonists in developing integrated approach (IPM) for disease control measures in crops system. The first part will be revising most used nano-biosensors in plant pathogens detection using different platforms in greenhouses, on-field, and during postharvest. A special focus will be on optical and voltametric immuno/DNA sensors application in plant protection. The last part will present case studies of using nanoparticles functionalized with antibody/DNA for detecting pathogenic Pseudomonas sp, mosaic viruses, Botrytis cinereal, and Fusarium mycotoxins (DON). The second part will be interpreting experimental results of a case study on evaluating bio-control efficacy of local Trichoderma spp. using root dips treatment in Fusarium solani-green beans pathosystem as a model.

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