ROLE OF IRON IN THE SUPPRESSION OF BACTERIAL PLANT PATHOGENS BY FLUORESCENT PSEUDOMONADS

1993 ◽  
pp. 269-281 ◽  
Author(s):  
PETER A.H.M. BAKKER ◽  
JOS M. RAAIJMAKERS ◽  
BOB SCHIPPERS
Keyword(s):  
Plant Pathogens ◽  
Fluorescent Pseudomonads

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

scholarly journals The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

2016 ◽  
Vol 68 (2) ◽  
pp. 451-459
Author(s):  
Urszula Jankiewicz ◽  
Maria Swiontek-Brzezinska
Keyword(s):  
Plant Pathogens ◽  
Chitinase Activity ◽  
Maximum Activity ◽  
Synergistic Action ◽  
Chitinolytic Activity ◽  
Fungistatic Activity ◽  
Rhizosphere Bacterium ◽  
Paenibacillus Sp ◽  
Growth Inhibiting

The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose). The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria.

scholarly journals Comparative Genomics and Functional Studies of Wheat BED-NLR Loci

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1406
Author(s):  
Clemence Marchal ◽  
Georg Haberer ◽  
Manuel Spannagl ◽  
Cristobal Uauy ◽  
Keyword(s):  
Cell Death ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Functional Studies ◽  
Network Analyses ◽  
Binding Factor ◽  
Localization Signal ◽  
Integrated Domains ◽  
Genomic Regions

Nucleotide-binding leucine-rich-repeat (LRR) receptors (NLRs) with non-canonical integrated domains (NLR-IDs) are widespread in plant genomes. Zinc-finger BED (named after the Drosophila proteins Boundary Element-Associated Factor and DNA Replication-related Element binding Factor, named BED hereafter) are among the most frequently found IDs. Five BED-NLRs conferring resistance against bacterial and fungal pathogens have been characterized. However, it is unknown whether BED-NLRs function in a manner similar to other NLR-IDs. Here, we used chromosome-level assemblies of wheat to explore the Yr7 and Yr5a genomic regions and show that, unlike known NLR-ID loci, there is no evidence for a NLR-partner in their vicinity. Using neighbor-network analyses, we observed that BED domains from BED-NLRs share more similarities with BED domains from single-BED proteins and from BED-containing proteins harboring domains that are conserved in transposases. We identified a nuclear localization signal (NLS) in Yr7, Yr5, and the other characterized BED-NLRs. We thus propose that this is a feature of BED-NLRs that confer resistance to plant pathogens. We show that the NLS was functional in truncated versions of the Yr7 protein when expressed in N. benthamiana. We did not observe cell-death upon the overexpression of Yr7 full-length, truncated, and ‘MHD’ variants in N. benthamiana. This suggests that either this system is not suitable to study BED-NLR signaling or that BED-NLRs require additional components to trigger cell death. These results define novel future directions to further understand the role of BED domains in BED-NLR mediated resistance.

scholarly journals The Role of Birch Tar in Changing the Physicochemical and Biocidal Properties of Polylactide-Based Films

2021 ◽  
Vol 23 (1) ◽  
pp. 268
Author(s):  
Agnieszka Richert ◽  
Ewa Olewnik-Kruszkowska ◽  
Grażyna B. Dąbrowska ◽  
Henryk P. Dąbrowski
Keyword(s):  
Polymer Films ◽  
Plant Pathogens ◽  
Vapour Permeability ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Physicochemical And Structural Properties ◽  
Reduced Water

The objective of this study was to produce bactericidal polymer films containing birch tar (BT). The produced polymer films contain PLA, plasticiser PEG (5% wt.) and birch tar (1, 5 and 10% wt.). Compared to plasticised PLA, films with BT were characterised by reduced elongation at break and reduced water vapour permeability, which was the lowest in the case of film with 10% wt. BT content. Changes in the morphology of the produced materials were observed by performing scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis; the addition of BT caused the surface of the film to be non-uniform and to contain recesses. FTIR analysis of plasticised PLA/BT films showed that the addition of birch tar did not change the crystallinity of the obtained materials. According to ISO 22196: 2011, the PLA film with 10% wt. BT content showed the highest antibacterial effect against the plant pathogens A. tumefaciens, X. campestris, P. brassicacearum, P. corrugata, P. syringae. It was found that the introduction of birch tar to plasticised PLA leads to a material with biocidal effect and favourable physicochemical and structural properties, which classifies this material for agricultural and horticultural applications.

scholarly journals Insights into the cell-cell signaling and iron homeostasis in Xanthomonas virulence and lifestyle

2021 ◽  
Author(s):  
Sheo Shankar Pandey ◽  
Subhadeep Chatterjee
Keyword(s):  
Cell Signaling ◽  
Plant Pathogens ◽  
Iron Homeostasis ◽  
Yield Loss ◽  
Iron Availability ◽  
In Planta ◽  
Xanthomonas Species ◽  
Associated Functions ◽  
Cell Cell

The Xanthomonas group of phytopathogens causes economically important diseases, which cause severe yield loss in major crops. Some Xanthomonas species are known to have an epiphytic and in planta lifestyle which are coordinated by several virulence-associated functions, cell-cell signaling (DSF; diffusible signaling factor), and environmental conditions, including iron availability. In this review, we described the role of cell-cell signaling by the DSF molecule and iron in the regulation of virulence-associated functions. Although DSF and iron are involved in the regulation of several virulence-associated functions, members of the Xanthomonas group of plant pathogens exhibit atypical patterns of regulation. Atypical patterns contribute to the adaptation to different lifestyles. Studies on DSF and iron biology indicate that virulence-associated functions can be regulated in completely contrasting fashions by the same signaling system in closely related xanthomonads.

scholarly journals Role of Endophytic Microbes Against Plant Pathogens: A Review

2019 ◽  
Vol 19 (1) ◽  
pp. 54-62
Author(s):  
Pavithra G. ◽  
Sumant Bindal ◽  
Meenakshi Rana ◽  
Seweta Srivastava
Keyword(s):  
Plant Pathogens

scholarly journals Role of Lipid Composition and Lipid Peroxidation in the Sensitivity of Fungal Plant Pathogens to Aluminum Chloride and Sodium Metabisulfite

2007 ◽  
Vol 73 (9) ◽  
pp. 2820-2824 ◽  
Author(s):  
Tyler J. Avis ◽  
Mélanie Michaud ◽  
Russell J. Tweddell
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acid ◽  
Aluminum Chloride ◽  
Plant Pathogens ◽  
Membrane Lipids ◽  
Membrane Integrity ◽  
Sodium Metabisulfite ◽  
Fatty Acid Unsaturation ◽  
Fungal Plant Pathogens

ABSTRACT Aluminum chloride and sodium metabisulfite have shown high efficacy at low doses in controlling postharvest pathogens on potato tubers. Direct effects of these two salts included the loss of cell membrane integrity in exposed pathogens. In this work, four fungal potato pathogens were studied in order to elucidate the role of membrane lipids and lipid peroxidation in the relative sensitivity of microorganisms exposed to these salts. Inhibition of mycelial growth in these fungi varied considerably and revealed sensitivity groups within the tested fungi. Analysis of fatty acids in these fungi demonstrated that sensitivity was related to high intrinsic fatty acid unsaturation. When exposed to the antifungal salts, sensitive fungi demonstrated a loss of fatty acid unsaturation, which was accompanied by an elevation in malondialdehyde content (a biochemical marker of lipid peroxidation). Our data suggest that aluminum chloride and sodium metabisulfite could induce lipid peroxidation in sensitive fungi, which may promote the ensuing loss of integrity in the plasma membrane. This direct effect on fungal membranes may contribute, at least in part, to the observed antimicrobial effects of these two salts.

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