scholarly journals Current Approaches for Advancement in Understanding the Molecular Mechanisms of Mycotoxin Biosynthesis

2021 ◽  
Vol 22 (15) ◽  
pp. 7878
Author(s):  
Antonia Gallo ◽  
Giancarlo Perrone

Filamentous fungi are able to synthesise a remarkable range of secondary metabolites, which play various key roles in the interaction between fungi and the rest of the biosphere, determining their ecological fitness. Many of them can have a beneficial activity to be exploited, as well as negative impact on human and animal health, as in the case of mycotoxins contaminating large quantities of food, feed, and agricultural products worldwide and posing serious health and economic risks. The elucidation of the molecular aspects of mycotoxin biosynthesis has been greatly sped up over the past decade due to the advent of next-generation sequencing technologies, which greatly reduced the cost of genome sequencing and related omic analyses. Here, we briefly highlight the recent progress in the use and integration of omic approaches for the study of mycotoxins biosynthesis. Particular attention has been paid to genomics and transcriptomic approaches for the identification and characterisation of biosynthetic gene clusters of mycotoxins and the understanding of the regulatory pathways activated in response to physiological and environmental factors leading to their production. The latest innovations in genome-editing technology have also provided a more powerful tool for the complete explanation of regulatory and biosynthesis pathways. Finally, we address the crucial issue of the interpretation of the combined omics data on the biology of the mycotoxigenic fungi. They are rapidly expanding and require the development of resources for more efficient integration, as well as the completeness and the availability of intertwined data for the research community.

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 244
Author(s):  
Samanta Mecocci ◽  
Ilaria Porcellato ◽  
Federico Armando ◽  
Luca Mechelli ◽  
Chiara Brachelente ◽  
...  

Equine genital squamous cell carcinomas (egSCCs) are among the most common equine tumors after sarcoids, severely impairing animal health and welfare. Equus caballus papillomavirus type 2 (EcPV2) infection is often related to these tumors. The aim of this study was to clarify the molecular mechanisms behind egSCCs associated with EcPV2 infection, investigating receptor activator of nuclear factor-kappa B ligand (RANKL) signaling in NF-kB pathway, together with the Wnt and IL17 signaling pathways. We analyzed the innate immune response through gene expression evaluation of key cytokines and transcription factors. Moreover, Ki67 index was assessed with immunohistochemistry. EcPV2-E6 DNA was checked, and viral presence was confirmed in 21 positive out to 23 cases (91%). Oncogene expression was confirmed in 14 cases (60.8%) for E6 and in 8 (34.7%) for E2. RANKL, nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB)-p50, NFKBp65, interleukin (IL)-6, IL17, IL23p19, IL8, IL12p35, IL12p40, β-catenin (BCATN1), FOS like 1 (FOSL1), and lymphoid enhancer binding factor 1 (LEF1) showed a significant upregulation in tumor samples compared to healthy tissues. Our results describe an inflammatory environment characterized by the activation of RANKL/RANK and IL17 with the relative downstream pathways, and a positive modulation of inflammatory cytokines genes such as IL6 and IL8. Moreover, the increase of BCATN1, FOSL1, and LEF1 gene expression suggests an activation of both canonical and non-canonical Wnt signaling pathway that could be critical for carcinogenesis and tumor progression.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
S. F. Prewitt ◽  
A. Shalit-Kaneh ◽  
S. N. Maximova ◽  
M. J. Guiltinan

Abstract Background In angiosperms the transition to flowering is controlled by a complex set of interacting networks integrating a range of developmental, physiological, and environmental factors optimizing transition time for maximal reproductive efficiency. The molecular mechanisms comprising these networks have been partially characterized and include both transcriptional and post-transcriptional regulatory pathways. Florigen, encoded by FLOWERING LOCUS T (FT) orthologs, is a conserved central integrator of several flowering time regulatory pathways. To characterize the molecular mechanisms involved in controlling cacao flowering time, we have characterized a cacao candidate florigen gene, TcFLOWERING LOCUS T (TcFT). Understanding how this conserved flowering time regulator affects cacao plant’s transition to flowering could lead to strategies to accelerate cacao breeding. Results BLAST searches of cacao genome reference assemblies identified seven candidate members of the CENTRORADIALIS/TERMINAL FLOWER1/SELF PRUNING gene family including a single florigen candidate. cDNA encoding the predicted cacao florigen was cloned and functionally tested by transgenic genetic complementation in the Arabidopsis ft-10 mutant. Transgenic expression of the candidate TcFT cDNA in late flowering Arabidopsis ft-10 partially rescues the mutant to wild-type flowering time. Gene expression studies reveal that TcFT is spatially and temporally expressed in a manner similar to that found in Arabidopsis, specifically, TcFT mRNA is shown to be both developmentally and diurnally regulated in leaves and is most abundant in floral tissues. Finally, to test interspecies compatibility of florigens, we transformed cacao tissues with AtFT resulting in the remarkable formation of flowers in tissue culture. The morphology of these in vitro flowers is normal, and they produce pollen that germinates in vitro with high rates. Conclusion We have identified the cacao CETS gene family, central to developmental regulation in angiosperms. The role of the cacao’s single FT-like gene (TcFT) as a general regulator of determinate growth in cacao was demonstrated by functional complementation of Arabidopsis ft-10 late-flowering mutant and through gene expression analysis. In addition, overexpression of AtFT in cacao resulted in precocious flowering in cacao tissue culture demonstrating the highly conserved function of FT and the mechanisms controlling flowering in cacao.


Author(s):  
Swee-Suak Ko ◽  
Min-Jeng Li ◽  
Yi-Cheng Ho ◽  
Chun-Ping Yu ◽  
Ting-Ting Yang ◽  
...  

Abstract GAMYB, UDT1, TIP2/bHLH142, TDR, and EAT1/DTD are important transcription factors (TFs) that play a crucial role during rice pollen development. This study demonstrates that bHLH142 acts downstream of UDT1 and GAMYB and works as a “hub” in these two pollen pathways. We show that GAMYB modulates bHLH142 expression through specific binding to the MYB motif of bHLH142 promoter during early stage of pollen development; while TDR acts as a transcriptional repressor of the GAMYB modulation of bHLH142 by binding to the E-box close to the MYB motif on the promoter. The altered expression of TFs highlights the importance that a tight, precise, and coordinated regulation among these TFs is essential for normal pollen development. Most notably, this study illustrates the regulatory pathways of GAMYB and UDT1 that rely on bHLH142 in a direct and an indirect manner, respectively, and function in different tissues with distinct biological functions during pollen development. This study advances our understanding of the molecular mechanisms of rice pollen development.


Author(s):  
Paula Andrea Castillo-Sanmiguel ◽  
Laura Rocío Cortés-Sánchez ◽  
Jovanna Acero-Godoy

<p>Tomato plants (<em>Solanum lycopersicum</em>) are susceptible to the infection by diverse pathogens that cause devastating diseases such as vascular wilt, which causes great losses at the production level. The fungus <em>Fusarium oxysporum</em> f. sp. <em>lycopersici</em> (<em>Fol</em>) is one of the etiologic agents of this disease and its control lies in the use of synthetic chemicals which generate a negative impact in both health and the environment; thus, it is necessary to implement biological control as a healthier and more efficient alternative. The fungus <em>Trichoderma</em> spp. is a favorable option to be employed as a biocontroller against this pathogen thanks to its antagonist mechanisms, determined by metabolic and genetic characteristics. On the one hand, for <em>Fol</em> it is indispensable the activation of signaling routes such as MAPK Fmk1, MAPK Mpk1 y HOG, while <em>Trichoderma</em> spp. uses effectors involved in the interaction with the plant such as proteins, enzymes and secondary metabolites that also strengthen its immune response against infection, determined by both Pathogen Associated Molecular Patterns (PAMP) and effectors. Therefore, this article makes a review about the mentioned characteristics and suggests a greater application of tools and molecular markers for the management of this disease.</p>


2014 ◽  
Vol 38 (6) ◽  
pp. 531-537 ◽  
Author(s):  
Rojane de Oliveira Paiva ◽  
Lucimar Ferreira Kneipp ◽  
Carla Marins Goular ◽  
Mariana Almeida Albuquerque ◽  
Aurea Echevarria

Mycotoxigenic fungi can compromise the quality of food, exposing human and animal health at risk. The antifungal activity of eight thiosemicarbazones (1-8) and nine semicarbazones (9-17) was evaluated against Aspergillus flavus, A. nomius, A. ochraceus, A. parasiticus and Fusarium verticillioides. Thiosemicarbazones had MIC values of 125-500 µg/ml. The thiosemicarbazones 1 and 2 exerted fungistatic activity against Aspergillus spp., and thiosemicarbazone 2 exerted fungicidal activity against F. verticillioides. Compound 2 showed an iron chelating effect of 63%. The ergosterol content of A. parasiticus had a decrease of 28 and 71% for the 31.2 and 62.5 µg/ml concentrations of thiosemicarbazone 2 compared to the control. The obtained results of antifungal activity revealed that thiosemicarbazone class was more active when compared to semicarbazone class and, the thiosemicarbazone 2 was the most active compound, specially, against Aspergillus spp.


2009 ◽  
Vol 39 (3) ◽  
pp. 183-194 ◽  
Author(s):  
Gerardo M. Nava ◽  
David Y. Lee ◽  
Javier H. Ospina ◽  
Shi-Ying Cai ◽  
H. Rex Gaskins

The major thiol redox buffer glutathione (l-γ-glutamyl-l-cysteinylglycine, GSH) is central to cell fate determination, and thus, associated metabolic and regulatory pathways are exquisitely sensitive to a wide range of environmental cues. An imbalance of cellular redox homeostasis has emerged as a pathologic hallmark of a diverse range of human gene-environment disorders. Despite the central importance of GSH in cellular homeostasis, underlying genetic regulatory pathways remain poorly defined. This report describes the annotation and expression analysis of genes contributing to GSH homeostasis in the invertebrate chordate Ciona intestinalis . A core pathway comprising 19 genes contributing to the biosynthesis of GSH and its use as both a redox buffer and a conjugate in phase II detoxification as well as known transcriptional regulators were analyzed. These genes exhibit a high level of sequence conservation with corresponding human, rat, and mouse homologs and were expressed constitutively in tissues of adult animals. The GSH biosynthetic genes Gclc and Gclm were also responsive to the prototypical antioxidant tert-butylhydroquinone. The present evidence of a conserved GSH homeostasis pathway in C. intestinalis together with its phylogenetic position as a basal chordate and lifestyle as a filter feeder constantly exposed to natural marine toxins introduces this species as an important animal model for defining molecular mechanisms that potentially underlie genetic susceptibility to environmentally associated stress.


Author(s):  
Daniel P. Depledge ◽  
Tomohiko Sadaoka ◽  
Werner J. D. Ouwendijk

Primary varicella-zoster virus (VZV) infection causes varicella (chickenpox) and the establishment of a lifelong latent infection in ganglionic neurons. VZV reactivates in about one-third of infected individuals to cause herpes zoster, often accompanied by neurological complications. The restricted host range of VZV and, until recently, the lack of suitable in vitro models to study VZV latency have seriously hampered molecular studies of viral latency. Nevertheless, recent technological advances facilitated a series of exciting studies that resulted in the discovery of a VZV latency-associated transcript (VLT) and have redefined our understanding of VZV latency and factors that initiate reactivation. Together, these findings pave the way for a new era of research that may finally unravel the precise molecular mechanisms that govern latency. In this review, we will summarize the implications of recent discoveries in the VZV latency field from both a virus and host perspective and provide a roadmap for future studies.


2022 ◽  
Vol 12 ◽  
Author(s):  
Michelle F. O’Brien ◽  
Sarah Pellett

Gastropods (class Gastropoda) form the largest of the classes in the phylum Mollusca and inhabit terrestrial, fresh water and marine environments. A large number of these species are of major conservation importance and are an essential component of ecosystems. Gastropods may be deemed as pests, having a negative impact in horticulture and agriculture, whereas others may be used as a food source for human consumption and therefore are beneficial. Gastropods are susceptible to primary diseases and also act as intermediate hosts for diseases which affect other animals, including humans. The diseases described include two that are notifiable to the World Organisation for Animal Health (OIE): Xenohaliotis californiensis and Abalone viral ganglioneuritis caused by Haliotid herpesvirus-1 (HaHV-1). Research into the diseases of gastropods has often focused on those species that act as intermediate disease hosts, those that are used in research or those cultured for food. In this paper we review the viral, bacterial, fungal, parasitic and miscellaneous conditions that have been reported in gastropods and mention some of the factors that appear to predispose them to disease. The pathogenicity of a number of these conditions has not been fully ascertained and more research is needed into specifying both the etiological agent and significance in some of the diseases reported.


2022 ◽  
Vol 12 ◽  
Author(s):  
Jiazi Zhang ◽  
Hongchun Xiong ◽  
Huijun Guo ◽  
Yuting Li ◽  
Xiaomei Xie ◽  
...  

The wheat AP2 family gene Q controls domestication traits, including spike morphology and threshability, which are critical for the widespread cultivation and yield improvement of wheat. Although many studies have investigated the molecular mechanisms of the Q gene, its direct target genes, especially those controlling spike morphology, are not clear, and its regulatory pathways are not well established. In this study, we conducted gene mapping of a wheat speltoid spike mutant and found that a new allele of the Q gene with protein truncation played a role in spike morphology variation in the mutant. Dynamic expression levels of the Q gene throughout the spike development process suggested that the transcript abundances of the mutant were decreased at the W6 and W7 scales compared to those of the WT. We identified several mutation sites on the Q gene and showed that mutations in different domains resulted in distinct phenotypes. In addition, we found that the Q gene produced three transcripts via alternative splicing and that they exhibited differential expression patterns in nodes, internodes, flag leaves, and spikes. Finally, we identified several target genes directly downstream of Q, including TaGRF1-2D and TaMGD-6B, and proposed a possible regulatory network. This study uncovered the target genes of Q, and the results can help to clarify the mechanism of wheat spike morphology and thereby improve wheat grain yield.


Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1918
Author(s):  
Aurele Gnetegha Ayemele ◽  
Mekonnen Tilahun ◽  
Sun Lingling ◽  
Samy Abdelaziz Elsaadawy ◽  
Zitai Guo ◽  
...  

This review examines several molecular mechanisms underpinning oxidative stress in ruminants and their effects on blood and milk oxidative traits. We also investigate strategies to alleviate or repair oxidative damages by improving animal immune functions using novel feed additives. Microbial pathogenic cells, feeding management, and body condition score were some of the studied factors, inducing oxidative stress in ruminants. The predominance of Streptococcus spp. (24.22%), Acinetobacter spp. (21.37%), Romboutsia spp. (4.99%), Turicibacter spp., (2.64%), Stenotrophomonas spp. (2.33%), and Enterococcus spp. (1.86%) was found in the microbiome of mastitis cows with a decrease of d-mannose and increase of xanthine:guanine ratio when Streptococcus increased. Diversity of energy sources favoring the growth of Fusobacterium make it a keystone taxon contributing to metritis. Ruminal volatile fatty acids rose with high-concentrate diets that decreased the ruminal pH, causing a lysis of rumen microbes and release of endotoxins. Moreover, lipopolysaccharide (LPS) concentration, malondialdehyde (MDA), and superoxide dismutase (SOD) activities increased in high concentrate cows accompanied by a reduction of total antioxidant capacity (T-AOC), glutathione peroxidase (GPx), and catalase (CAT) activity. In addition, albumin and paraoxonase concentrations were inversely related to oxidative stress and contributed to the protection of low-density and high-density lipoproteins against lipid peroxidation, protein carbonyl, and lactoperoxidase. High concentrate diets increased the expression of MAPK pro-inflammatory genes and decreased the expression of antioxidant genes and proteins in mammary epithelial tissues. The expression levels of NrF2, NQO1, MT1E, UGT1A1, MGST3, and MT1A were downregulated, whereas NF-kB was upregulated with a high-grain or high concentrate diet. Amino-acids, vitamins, trace elements, and plant extracts have shown promising results through enhancing immune functions and repairing damaged cells exposed to oxidative stress. Further studies comparing the long-term effect of synthetic feed additives and natural plant additives on animal health and physiology remain to be investigated.


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