scholarly journals Phytotoxins, Elicitors and Other Secondary Metabolites from Phytopathogenic “Blackleg” Fungi: Structure, Phytotoxicity and Biosynthesis

2009 ◽  
Vol 4 (9) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
M. Soledade C. Pedras ◽  
Yang Yu

The metabolites produced by the fungal species Leptosphaeria maculans and L. biglobosa under different culture conditions, together with their phytotoxic activities are reviewed. In addition, the biosynthetic studies of blackleg metabolites carried out to date are described and suggestions for species reclassification are provided.

2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600
Author(s):  
M. Soledade C. Pedras ◽  
Paulos B. Chumala

The phytotoxins and other metabolites produced by isolates L2/M2 of the fungal species Leptosphaeria maculans under different culture conditions, together with those of two new, but related isolates are disclosed. The common metabolic characteristics suggest a phylogenetic similarity between these isolates with potential to become widespread in mustard growing areas.


mSystems ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Jens Christian Nielsen ◽  
Sylvain Prigent ◽  
Sietske Grijseels ◽  
Mhairi Workman ◽  
Boyang Ji ◽  
...  

ABSTRACTFilamentous fungi possess great potential as sources of medicinal bioactive compounds, such as antibiotics, but efficient production is hampered by a limited understanding of how their metabolism is regulated. We investigated the metabolism of six secondary metabolite-producing fungi of thePenicilliumgenus during nutrient depletion in the stationary phase of batch fermentations and assessed conserved metabolic responses across species using genome-wide transcriptional profiling. A coexpression analysis revealed that expression of biosynthetic genes correlates with expression of genes associated with pathways responsible for the generation of precursor metabolites for secondary metabolism. Our results highlight the main metabolic routes for the supply of precursors for secondary metabolism and suggest that the regulation of fungal metabolism is tailored to meet the demands for secondary metabolite production. These findings can aid in identifying fungal species that are optimized for the production of specific secondary metabolites and in designing metabolic engineering strategies to develop high-yielding fungal cell factories for production of secondary metabolites.IMPORTANCESecondary metabolites are a major source of pharmaceuticals, especially antibiotics. However, the development of efficient processes of production of secondary metabolites has proved troublesome due to a limited understanding of the metabolic regulations governing secondary metabolism. By analyzing the conservation in gene expression across secondary metabolite-producing fungal species, we identified a metabolic signature that links primary and secondary metabolism and that demonstrates that fungal metabolism is tailored for the efficient production of secondary metabolites. The insight that we provide can be used to develop high-yielding fungal cell factories that are optimized for the production of specific secondary metabolites of pharmaceutical interest.


Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 673
Author(s):  
Kattia Núñez-Montero ◽  
Damián Quezada-Solís ◽  
Zeinab G. Khalil ◽  
Robert J. Capon ◽  
Fernando D. Andreote ◽  
...  

Concern about finding new antibiotics against drug-resistant pathogens is increasing every year. Antarctic bacteria have been proposed as an unexplored source of bioactive metabolites; however, most biosynthetic gene clusters (BGCs) producing secondary metabolites remain silent under common culture conditions. Our work aimed to characterize elicitation conditions for the production of antibacterial secondary metabolites from 34 Antarctic bacterial strains based on MS/MS metabolomics and genome mining approaches. Bacterial strains were cultivated under different nutrient and elicitation conditions, including the addition of lipopolysaccharide (LPS), sodium nitroprusside (SNP), and coculture. Metabolomes were obtained by HPLC-QTOF-MS/MS and analyzed through molecular networking. Antibacterial activity was determined, and seven strains were selected for genome sequencing and analysis. Biosynthesis pathways were activated by all the elicitation treatments, which varies among strains and dependents of culture media. Increased antibacterial activity was observed for a few strains and addition of LPS was related with inhibition of Gram-negative pathogens. Antibiotic BGCs were found for all selected strains and the expressions of putative actinomycin, carotenoids, and bacillibactin were characterized by comparison of genomic and metabolomic data. This work established the use of promising new elicitors for bioprospection of Antarctic bacteria and highlights the importance of new “-omics” comparative approaches for drug discovery.


2010 ◽  
Vol 5 (6) ◽  
pp. 1934578X1000500
Author(s):  
M. Soledade C. Pedras ◽  
Ryan B. Snitynsky

The biotransformation of brassilexin, a potent phytoalexin produced by brown mustard (Brassica juncea L.), in the presence of various cruciferous phytoalexins was investigated. An important group of isolates of the fungal species Leptosphaeria maculans (Laird 2 and Mayfair 2), which is virulent to brown mustard, but not to canola, was used in this investigation. Brassilexin was detoxified by the fungus, but none of the phytoalexins seemed to affect substantially the rate of brassilexin detoxification; after 12 h of incubation, the amounts of brassilexin remaining in culture were as low as in controls, except in co-incubations with cyclobrassinin and sinalexin, which afforded intermediates that in solution oxidized spontaneously to brassilexin.


2000 ◽  
Vol 122 (2) ◽  
pp. 420-421 ◽  
Author(s):  
Paul Spencer ◽  
Fabio Agnelli ◽  
Howard J. Williams ◽  
Nancy P. Keller ◽  
Gary A. Sulikowski

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