scholarly journals Differential regulation and production of secondary metabolites among isolates of the fungal wheat pathogen Zymoseptoria tritici

2021 ◽  
Author(s):  
M. Amine Hassani ◽  
Ernest Oppong-Danquah ◽  
Alice Feurty ◽  
Deniz Tasdemir ◽  
Eva H Stukenbrock

The genome of the wheat pathogenic fungus, Zymoseptoria tritici, represents extensive presence-absence variation in gene content. Here, we addressed variation in biosynthetic gene clusters (BGCs) content and biochemical profiles among three isolates. We analysed secondary metabolite properties based on genome, transcriptome and metabolome data. The isolates represent highly distinct genome architecture, but harbor similar repertoire of BGCs. Expression profiles for most BGCs show comparable patterns of regulation among the isolates, suggesting a conserved 'biochemical infection program'. For all three isolates, we observed a strong up-regulation of an abscisic acid (ABA) gene cluster during biotrophic host colonization, indicating that Z. tritici potentially interfere with host defenses by the biosynthesis of this phytohormone. Further, during in vitro growth the isolates show similar metabolomes congruent with the predicted BGC content. We assessed if secondary metabolite production is regulated by histone methylation using a mutant impaired in formation of facultative heterochromatin (H3K27me3). In contrast to other ascomycete fungi, chromatin modifications play a less prominent role in regulation of secondary metabolites. In summary, we show that Z. tritici has a conserved program of secondary metabolite production contrasting the immense variation in effector expression, some of these metabolites might play a key role during host colonization.

Author(s):  
Tuncay Çalışkan ◽  
Rüştü Hatipoğlu ◽  
Saliha Kırıcı

Plant secondary metabolites are a group of organic compounds produced by plants to interact with biotic and abiotic factors and for the establishment of defence mechanism. Secondary metabolites are classified based on their biosynthetic origin and chemical structure. They have been used as pharmaceutical, agrochemical, flavours, fragrances, colours and food additives. Secondary metabolites are traditionally produced from the native grown or field grown plants. However, this conventional approach has some disadvantages such as low yield, instability of secondary metabolite contents of the plants due to geographical, seasonal and environmental variations, need for land and heavy labour to grow plants. Therefore, plant cell and organ cultures have emerged as an alternative to plant growing under field conditions for secondary metabolite production. In this literature review, present state of secondary metabolite production through plant cell and organ cultures, its problems as well as solutions of the problems were discussed.


2014 ◽  
Vol 9 (7) ◽  
pp. 686-698 ◽  
Author(s):  
Vijay Kumar ◽  
Shailesh Singh ◽  
Rajib Bandopadhyay ◽  
Madan Sharma ◽  
Sheela Chandra

AbstractAn efficient protocol of plant regeneration through direct and indirect organogenesis in Swertia chirayita was developed. Explants cultured on Murashige and Skoog medium supplemented with 2,4-D (0.5 mg L−1) with combination of Kinetin (0.5 mg L−1) showed the highest frequency (84%) of callusing and 1.0mg L−1 6-benzyladenine (BA) in combination with (100 mg L−1) Adenine sulphate (Ads) + (0.1 mg L−1) Indole acetic acid (IAA) was excellent for maximum adventitious shoot (12.69 ± 1.30) formation in four week of culture. A maximum number of (7.14 ± 0.99) shoots were developed per leaf explants through direct organogenesis. The highest frequency of rooting (11.46 ± 1.56) was observed on MS medium augmented with IAA (1.0 mg L−1). Well-rooted shoots transferred to plastic pots containing a soilrite: sand mix and then moved to the greenhouse for further growth and development. Four major secondary metabolites were analyzed and quantified using high performance liquid chromatography. Amount of secondary metabolites was found significantly higher, in in vitro plantlets compared to in vivo plantlets and callus raised from S. chirayita. Higher heavy metal accumulation in in vitro as compared to in vivo plantlets correlates higher secondary metabolite production supporting that they play regulatory role in influencing the plant secondary metabolism.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ulysses Amancio de Frias ◽  
Greicy Kelly Bonifacio Pereira ◽  
María-Eugenia Guazzaroni ◽  
Rafael Silva-Rocha

Bacteria are a source of a large number of secondary metabolites with several biomedical and biotechnological applications. In recent years, there has been tremendous progress in the development of novel synthetic biology approaches both to increase the production rate of secondary metabolites of interest in native producers and to mine and reconstruct novel biosynthetic gene clusters in heterologous hosts. Here, we present the recent advances toward the engineering of novel microbial biosensors to detect the synthesis of secondary metabolites in bacteria and in the development of synthetic promoters and expression systems aiming at the construction of microbial cell factories for the production of these compounds. We place special focus on the potential of Gram-negative bacteria as a source of biosynthetic gene clusters and hosts for pathway assembly, on the construction and characterization of novel promoters for native hosts, and on the use of computer-aided design of novel pathways and expression systems for secondary metabolite production. Finally, we discuss some of the potentials and limitations of the approaches that are currently being developed and we highlight new directions that could be addressed in the field.


Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 864
Author(s):  
Woori Kim ◽  
Namil Lee ◽  
Soonkyu Hwang ◽  
Yongjae Lee ◽  
Jihun Kim ◽  
...  

Streptomyces venezuelae is well known to produce various secondary metabolites, including chloramphenicol, jadomycin, and pikromycin. Although many strains have been classified as S. venezuelae species, only a limited number of strains have been explored extensively for their genomic contents. Moreover, genomic differences and diversity in secondary metabolite production between the strains have never been compared. Here, we report complete genome sequences of three S. venezuelae strains (ATCC 10712, ATCC 10595, and ATCC 21113) harboring chloramphenicol and jadomycin biosynthetic gene clusters (BGC). With these high-quality genome sequences, we revealed that the three strains share more than 85% of total genes and most of the secondary metabolite biosynthetic gene clusters (smBGC). Despite such conservation, the strains produced different amounts of chloramphenicol and jadomycin, indicating differential regulation of secondary metabolite production at the strain level. Interestingly, antagonistic production of chloramphenicol and jadomycin was observed in these strains. Through comparison of the chloramphenicol and jadomycin BGCs among the three strains, we found sequence variations in many genes, the non-coding RNA coding regions, and binding sites of regulators, which affect the production of the secondary metabolites. We anticipate that these genome sequences of closely related strains would serve as useful resources for understanding the complex secondary metabolism and for designing an optimal production process using Streptomyces strains.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 332
Author(s):  
Dini Hu ◽  
Simon Ming-Yuen Lee ◽  
Kai Li ◽  
Kai Meng Mok

Mangroves are intertidal extreme environments with rich microbial communities. Actinobacteria are well known for producing antibiotics. The search for biosynthetic potential of Actinobacteria from mangrove environments could provide more possibilities for useful secondary metabolites. In this study, whole genome sequencing and MS/MS analysis were used to explore the secondary metabolite production potential of one actinobacterial strain of Streptomyces olivaceus sp., isolated from a mangrove in Macau, China. The results showed that a total of 105 gene clusters were found in the genome of S. olivaceus sp., and 53 known secondary metabolites, including bioactive compounds, peptides, and other products, were predicted by genome mining. There were 28 secondary metabolites classified as antibiotics, which were not previously known from S. olivaceus. ISP medium 2 was then used to ferment the S. olivaceus sp. to determine which predicted secondary metabolite could be truly produced. The chemical analysis revealed that ectoine, melanin, and the antibiotic of validamycin A could be observed in the fermentation broth. This was the first observation that these three compounds can be produced by a strain of S. olivaceus. Therefore, it can be concluded that Actinobacteria isolated from the mangrove environment have unknown potential to produce bioactive secondary metabolites.


Author(s):  
Shyam L. Kandel ◽  
Rubaiya Jesmin ◽  
Brian M. Mack ◽  
Rajtilak Majumdar ◽  
Matthew K. Gilbert ◽  
...  

Aspergillus flavus is an opportunistic pathogen of oilseed crops such as maize, peanut, cottonseed, and tree nuts and produces carcinogenic secondary metabolites known as aflatoxins during seed colonization. Aflatoxin contamination not only reduces the value of the produce but also is a health hazard to humans and animals. Previously, we observed inhibition of A. flavus aflatoxin biosynthesis upon exposure to the marine bacterium, Vibrio gazogenes (Vg). In this study, we used RNA sequencing to examine the transcriptional profiles of A. flavus treated with both live and heat-inactivated dead Vg and control samples. Fungal biomass, total accumulated aflatoxins, and expression profiles of genes constituting secondary metabolite biosynthetic gene clusters were determined at 24, 30, and 40 h after treatment. Statistically significant reductions in total aflatoxins were detected in Vg-treated samples as compared to control samples at 40 h. But no statistical difference in fungal biomass was observed upon these treatments. The Vg treatments were most effective on aflatoxin biosynthesis as was reflected in significant downregulation of majority of the genes in the aflatoxin gene cluster including the aflatoxin pathway regulator gene, aflR. Along with aflatoxin genes, we also observed significant downregulation in some other secondary metabolite gene clusters including cyclopiazonic acid and aflavarin, suggesting that the treatment may inhibit other secondary metabolites as well. Finally, a weighted gene correlation network analysis identified an upregulation of ten genes that were most strongly associated with Vg-dependent aflatoxin inhibition and provide a novel start-point in understanding the mechanisms that result in this phenomenon.


2012 ◽  
Vol 10 (2) ◽  
pp. 120 ◽  
Author(s):  
Risa Nofiani

Marine microorganism is one of biologically active potential resources of secondary metabolites. Its potency areso promising that the knowledge of how its secondary metabolite occured need to be studied and collected. Thoseknowledges will enable further study is improving secondary metabolite production in the laboratory. In nature,secondary metabolites synthesis occur when there are effect of both biotic and abiotic factors such as sea waterand microbe symbiosis with other living materials. When this is explained in metabolic pathways, secondarymetabolite synthesis affected by available nutrient and regulated by autoinducer molecules through quorum sensingmechanism


mSystems ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kat Steinke ◽  
Omkar S. Mohite ◽  
Tilmann Weber ◽  
Ákos T. Kovács

ABSTRACT Microbes produce a plethora of secondary (or specialized) metabolites that, although not essential for primary metabolism, benefit them to survive in the environment, communicate, and influence cell differentiation. Biosynthetic gene clusters (BGCs), responsible for the production of these secondary metabolites, are readily identifiable on bacterial genome sequences. Understanding the phylogeny and distribution of BGCs helps us to predict the natural product synthesis ability of new isolates. Here, we examined 310 genomes from the Bacillus subtilis group, determined the inter- and intraspecies patterns of absence/presence for all BGCs, and assigned them to defined gene cluster families (GCFs). This allowed us to establish patterns in the distribution of both known and unknown products. Further, we analyzed variations in the BGC structures of particular families encoding natural products, such as plipastatin, fengycin, iturin, mycosubtilin, and bacillomycin. Our detailed analysis revealed multiple GCFs that are species or clade specific and a few others that are scattered within or between species, which will guide exploration of the chemodiversity within the B. subtilis group. Surprisingly, we discovered that partial deletion of BGCs and frameshift mutations in selected biosynthetic genes are conserved within phylogenetically related isolates, although isolated from around the globe. Our results highlight the importance of detailed genomic analysis of BGCs and the remarkable phylogenetically conserved erosion of secondary metabolite biosynthetic potential in the B. subtilis group. IMPORTANCE Members of the B. subtilis species complex are commonly recognized producers of secondary metabolites, among those, the production of antifungals, which makes them promising biocontrol strains. While there are studies examining the distribution of well-known secondary metabolites in Bacilli, intraspecies clade-specific distribution has not been systematically reported for the B. subtilis group. Here, we report the complete biosynthetic potential within the B. subtilis group to explore the distribution of the biosynthetic gene clusters and to reveal an exhaustive phylogenetic conservation of secondary metabolite production within Bacillus that supports the chemodiversity within this species complex. We identify that certain gene clusters acquired deletions of genes and particular frameshift mutations, rendering them inactive for secondary metabolite biosynthesis, a conserved genetic trait within phylogenetically conserved clades of certain species. The overview guides the assignment of the secondary metabolite production potential of newly isolated Bacillus strains based on genome sequence and phylogenetic relatedness.


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