FOLIAR APPLICATION OF PSEUDOMONAS METABOLITE PROTECTS CAPSICUM ANNUM (CHILLI) FROM FUNGAL PHYTOPATHOGENS (original) (raw)
Related papers
Natural Product Research, 2012
Pseudomonas chlororaphis subsp. aureofaciens strain M71 produced two phenazine compounds as main secondary metabolites. These metabolites were identified as phenazine-1-carboxylic acid (PCA) and 2-hydroxyphenazine (2-OH P). In this study, the spectrum of the activity of PCA and 2-OH P was evaluated against a group of crop and forestal plant pathogenic fungi by an agar plate bioassay. PCA was active against most of the tested plant pathogens, while 2-OH P slightly inhibited a few fungal species. Furthermore, four semisynthesised derivatives of PCA (phenazine-1-carboxymethyl, phenazine-1-carboxamide, phenazine-1-hydroxymethyl and phenazine-1-acetoxymethyl) were assayed for their antifungal activity against 11 phytopathogenic species. Results showed that the carboxyl group is a structural feature important for the antifungal activity of PCA. Since the activity of phenazine-1-carboxymethyl and phenazine-1-carboxamide, the two more lipophilic and reversible PCA derivatives remained substantially unaltered compared with PCA.
Biomolecules
Pseudomonas fluorescens 9 and Bacillus subtilis 54, proposed as biofungicides to control Macrophomina phaseolina, a dangerous pathogen of soybean and other crops, were grown in vitro to evaluate their ability to produce metabolites with antifungal activity. The aim of the manuscript was to identify the natural compounds responsible for their antifungal activity. Only the culture filtrates of P. fluorescens 9 showed strong antifungal activity against M. phaseolina. Its organic extract contained phenazine and mesaconic acid (1 and 2), whose antifungal activity was tested against M. phaseolina, as well as Cercospora nicotianae and Colletotrichum truncatum, other pathogens of soybean; however, only compound 1 exhibited activity. The antifungal activity of compound 1 was compared to phenazine-1-carboxylic acid (PCA, 3), 2-hydroxyphenazine (2-OH P, 4), and various semisynthetic phenazine nitro derivatives in order to perform a structure–activity relationship (SAR) study. PCA and phenazine...
2018
Control of Taro Leaf Blight (TLB) by chemical pesticides remains ineffective in Cameroon. Alternative methods of control are required to fight against the causative agent of this epidemy. Fluorescent Pseudomonas is the main rhizobacteria widely used against plant pathogens because they produce a broad range of antimicrobial secondary metabolites (including phenazines) involved in the biocontrol mechanism. However many ecological factors could influence the production of compounds involved in biocontrol. In the present study, we evaluated the abiotic conditions of P. fluorescens DS17R growth, phenazine production and antimicrobial activity against Phytophthora colocasiae the causal agent of TLB. The abiotic factors were pH, temperature, carbon and nitrogen sources, and osmotic stress. The bacterium was grown on King B medium and monitored by spectrophotometer. The secondary metabolites were extracted with chloroform and the phenazines content estimated by the MnO 2-based reduction assay. The antimicrobial activity of each extracts was evaluated by the well diffusion method. Results showed that the growth, phenazine production and the antimicrobial activity of secondary metabolites extracted from P. fluorescens DS17R was influenced by different abiotic conditions. Overall, glycerol was the best carbon source while peptone and NH 4 Cl were the best nitrogen sources. These best sources of growth promoted significant phenazine production in correlation with the antimicrobial activity observed. In addition the optimum pH and temperature for phenazine production was 6 and 28°C respectively. On other hand, the positive correlation between growth, antimicrobial activity and phenazines production of the extract was observed at 2.5% NaCl. These findings show that Pseudomonas fluorescens DS17R extract could be positively optimized by certain abiotic factors and has the potential to be further developed as natural antimicrobial agent against P. colocasiae.
The present investigation aims at throughing light on isolation and identification of phenazine-1-carboxylic acid from different isolates and its biological activity against Alternaria solani. Thirteen bacterial strains were isolated from different growing parts of plant material. Parallel, in the same time collections of Pseudomonas spp. from different local geographical area were identified by biochemical and molecular genetic tools. Data indicates that all of Pseudomonas isolates caused direct effect on Alternaria solani and inhibited its growth. The best separation of phenazine-1-carboxylic acid by TLC was obtained by using the solvent system ethylacetate : chloroform (5:5, v /v). Moreover, F biological activity was found in band no. 8 having R of 0.63. Chemical structure of phenazine-1carboxylic acid was determined by LC-MS. Concern of the production of phenazine-1-carboxylic acid on YM media inoculated with 13 Pseudomonas isolates, the obtained results indicated that the production of Phenazine-1-carboxylic acid reached its maximum rate in isolate no. 103 (P. putida, 40ug/ml) followed by isolate no 102 (P. putida, 35.8 ug/ml). The other isolates achieved from lower to medium level of Phenazine-1-carboxylic acid production.
Frontiers in Microbiology, 2021
Gray blight disease is one of the most destructive diseases of tea plants and occurs widely in the tea-growing areas of the world. It is caused by several fungal phytopathogens, of which Pseudopestalotiopsis camelliae-sinensis is the main pathogen in China. The environmentally friendly antimicrobial, phenazine-1-carboxylic acid (PCA), a metabolite of the natural soil-borne bacteria Pseudomonas spp., can inhibit a range of fungal crop diseases. In this study, we determined that PCA was active against Ps. camelliae-sinensis in vitro. We studied the mode of action of PCA on hyphae using a microscopic investigation, transcriptomics, biochemical methods, and molecular docking. The results of scanning and transmission electron microscopy indicated that PCA caused developmental deformity of mycelia and organelle damage, and it significantly decreased the accumulation of exopolysaccharides on the hyphal surface. The transcriptome revealed that 1705 and 1683 differentially expressed genes of...
Molecular Plant-microbe Interactions, 1998
Seventy bacterial isolates from the rhizosphere of tomato were screened for antagonistic activity against the tomato foot and root rot-causing fungal pathogen Fusarium oxysporum f. sp. radicis-lycopersici. One isolate, strain PCL1391, appeared to be an efficient colonizer of tomato roots and an excellent biocontrol strain in an F. oxysporum/tomato test system. Strain PCL1391 was identified as Pseudomonas chlororaphis and further characterization showed that it produces a broad spectrum of antifungal factors (AFFs), including a hydrophobic compound, hydrogen cyanide, chitinase(s), and protease(s). Through mass spectrometry and nuclear magnetic resonance, the hydrophobic compound was identified as phenazine-1-carboxamide (PCN). We have studied the production and action of this AFF both in vitro and in vivo. Using a PCL1391 transposon mutant, with a lux reporter gene inserted in the phenazine biosynthetic operon (phz), we showed that this phenazine biosynthetic mutant was substantially decreased in both in vitro antifungal activity and biocontrol activity. Moreover, with the same mutant it was shown that the phz biosynthetic operon is expressed in the tomato rhizosphere. Comparison of the biocontrol activity of the PCN-producing strain PCL1391 with those of phenazine-1-carboxylic acid (PCA)producing strains P. fluorescens 2-79 and P. aureofaciens 30-84 showed that the PCN-producing strain is able to suppress disease in the tomato/F. oxysporum system, whereas the PCA-producing strains are not. Comparison of in vitro antifungal activity of PCN and PCA showed that the antifungal activity of PCN was at least 10 times higher at neutral pH, suggesting that this may contribute to the superior biocontrol performance of strain PCL1391 in the tomato/F. oxysporum system.
Bioactive metabolite from Pseudomonas
Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media New York. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Frontiers in microbiology, 2017
One of the most important postharvest plant pathogens that affect strawberries, grapes and tomatoes is Botrytis cinerea, known as gray mold. The fungus remains in latent form until spore germination conditions are good, making infection control difficult, causing great losses in the whole production chain. This study aimed to purify and identify phenazine-1-carboxylic acid (PCA) produced by the Pseudomonas aeruginosa LV strain and to determine its antifungal activity against B. cinerea. The compounds produced were extracted with dichloromethane and passed through a chromatographic process. The purity level of PCA was determined by reversed-phase high-performance liquid chromatography semi-preparative. The structure of PCA was confirmed by nuclear magnetic resonance and electrospray ionization mass spectrometry. Antifungal activity was determined by the dry paper disk and minimum inhibitory concentration (MIC) methods and identified by scanning electron microscopy and confocal micros...
Phenazines and their role in biocontrol by Pseudomonas bacteria
New Phytologist, 2003
Various rhizosphere bacteria are potential (micro)biological pesticides which are able to protect plants against diseases and improve plant yield. Knowledge of the molecular mechanisms that govern these beneficial plant-microbe interactions enables optimization, enhancement and identification of potential synergistic effects in plant protection. The production of antifungal metabolites, induction of systemic resistance, and the ability to compete efficiently with other resident rhizobacteria are considered to be important prerequisites for the optimal performance of biocontrol agents. Intriguing aspects in the molecular mechanisms of these processes have been discovered recently. Phenazines and phloroglucinols are major determinants of biological control of soilborne plant pathogens by various strains of fluorescent Pseudomonas spp. This review focuses on the current state of knowledge on biocontrol by phenazine-producing Pseudomonas strains and the action, biosynthesis, and regulation mechanisms of the production of microbial phenazines.