scholarly journals Characterization of a Ustilago maydisGene Specifically Induced during the Biotrophic Phase: Evidence for Negative as Well as Positive Regulation

2000 ◽  
Vol 20 (1) ◽  
pp. 329-339 ◽  
Author(s):  
Christoph W. Basse ◽  
Stefan Stumpferl ◽  
Regine Kahmann
Keyword(s):  
Gene Expression ◽  
Axenic Culture ◽  
Fungal Growth ◽  
Positive Control ◽  
Sexual Cycle ◽  
In Planta ◽  
Plant Infection ◽  
Molecular Events ◽  
Sequence Elements ◽  
Potential Applications

ABSTRACT The phytopathogenic basidiomycete Ustilago maydisrequires its host plant, maize, for completion of its sexual cycle. To investigate the molecular events during infection, we used differential display to identify plant-induced U. maydis genes. We describe the U. maydis gene mig1 (for “maize-induced gene”), which is not expressed during yeast-like growth of the fungus, is weakly expressed during filamentous growth in axenic culture, but is extensively upregulated during plant infection.mig1 encodes a small, highly charged protein of unknown function which contains a functional N-terminal secretion sequence and is not essential for pathogenic development. Adjacent tomig1 is a second gene (mdu1) related tomig1, which appears to result from a gene duplication.mig1 gene expression during the infection cycle was assessed by fusing the promoter to eGFP. Expression ofmig1 was absent in hyphae growing on the leaf surface but was detected after penetration and remained high during subsequent proliferation of the fungus until teliospore formation. Successive deletions as well as certain internal deletions in the mig1promoter conferred elevated levels of reporter gene expression during growth in axenic culture, indicative of negative regulation. During fungal growth in planta, sequence elements between positions −148 and −519 in the mig1 promoter were specifically required for high levels of induction, illustrating additional positive control. We discuss the potential applications of mig1 for the identification of inducing compounds and the respective regulatory genes.

scholarly journals Characterisation of theFusarium graminearum-Wheat Floral Interaction

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Neil A. Brown ◽  
Chris Bass ◽  
Thomas K. Baldwin ◽  
Huaigu Chen ◽  
Fabien Massot ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fungal Growth ◽  
Ear Blight ◽  
Gus Reporter ◽  
Plant Infection ◽  
Advancing Front ◽  
Colonisation Pattern ◽  
Symptomless Infection ◽  
Ear Infections ◽  
Fungal Gene Expression

Fusarium Ear Blight is a destructive fungal disease of cereals including wheat and can contaminate the crop with various trichothecene mycotoxins. This investigation has produced a newβ-glucuronidase (GUS) reporter strain that facilitates the quick and easy assessment of plant infection. The constitutively expressedgpdA:GUSstrain ofFusarium graminearumwas used to quantify the overall colonisation pattern. Histochemical and biochemical approaches confirmed, in susceptible wheat ear infections, the presence of a substantial phase of symptomless fungal growth. Separate analyses demonstrated that there was a reduction in the quantity of physiologically active hyphae as the wheat ear infection proceeded. A simplified linear system of rachis infection was then utilised to evaluate the expression of severalTRIgenes by RT-qPCR. Fungal gene expression at the advancing front of symptomless infection was compared with the origin of infection in the rachis. This revealed thatTRIgene expression was maximal at the advancing front and supports the hypothesis that the mycotoxin deoxynivalenol plays a role in inhibiting plant defences in advance of the invading intercellular hyphae. This study has also demonstrated that there are transcriptional differences between the various phases of fungal infection and that these differences are maintained as the infection proceeds.

scholarly journals Nucleosome patterns in four plant pathogenic fungi with contrasted genome structures

2021 ◽  
Author(s):  
Colin Clairet ◽  
Nicolas LAPALU ◽  
Adeline Simon ◽  
Jessica L. Soyer ◽  
Muriel Viaud ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fungal Pathogens ◽  
Genome Structure ◽  
Axenic Culture ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Rna Seq ◽  
Cellular Mechanisms ◽  
Environment Control

Fungal pathogens represent a serious threat towards agriculture, health, and environment. Control of fungal diseases on crops necessitates a global understanding of fungal pathogenicity determinants and their expression during infection. Genomes of phytopathogenic fungi are often compartmentalized: the core genome contains housekeeping genes whereas the fast-evolving genome mainly contains transposable elements and species-specific genes. In this study, we analysed nucleosome landscapes of four phytopathogenic fungi with contrasted lifestyles and genome organisations to describe and compare nucleosome repartition patterns in relation with genome structure and gene expression level. We combined MNase-seq and RNA-seq analyses to concomitantly map nucleosome-rich and transcriptionally active regions during fungal growth in axenic culture; we developed the tool MSTS to analyse and visualise data obtained from MNase-seq experiments in combination with other genomic data and notably RNA-seq expression data. We observed different characteristics of nucleosome profiles between species, as well as between genomic regions within the same species. We further linked nucleosome repartition and gene expression. Our findings support that nucleosome positioning and occupancies are subjected to evolution, in relation with underlying genome sequence modifications. Understanding genomic organisation and its role in expression regulation is the next gear to understand complex cellular mechanisms and their evolution.

scholarly journals Centrin-anchored hydrodynamic shape changes underpin active nuclear rerouting in branched hyphae of an oomycete pathogen

2019 ◽  
Author(s):  
Edouard Evangelisti ◽  
Liron Shenhav ◽  
Temur Yunusov ◽  
Marie Le Naour-Vernet ◽  
Philipp Rink ◽  
...  
Keyword(s):  
Axenic Culture ◽  
Computational Modelling ◽  
Time Lapse ◽  
Phytophthora Palmivora ◽  
In Planta ◽  
Nuclear Dynamics ◽  
Nuclear Distribution ◽  
Plant Infection ◽  
Oomycete Pathogen ◽  
Time Lapse Imaging

AbstractPolyenergid fungi and oomycetes are phylogenetically distant but structurally similar. To address whether they share similar nuclear dynamics we carried out time-lapse imaging of fluorescently labelled Phytophthora palmivora nuclei. Nuclei underwent coordinated bi-directional movements during plant infection. Within hyphal networks growing in planta or in axenic culture nuclei are either dragged passively with the cytoplasm or actively become rerouted toward nuclei-depleted hyphal sections and often display a very stretched shape. Benomyl-induced depolymerization of microtubules reduced active movements and the occurrence of stretched nuclei. A centrosome protein localized at the leading end of stretched nuclei, suggesting that like fungi astral microtubule-guided movements contribute to nuclear distribution within oomycete hyphae. The remarkable hydrodynamic shape adaptations of Phytophthora nuclei contrast those in fungi and likely enable them to migrate over longer distances. Therefore, our work summarises mechanisms which enable a near equal nuclear distribution in an oomycete. We provide a basis for computational modelling of hydrodynamic nuclear deformation within branched tubular networks.

scholarly journals Dynamic expression of Ralstonia solanacearum virulence factors and metabolism-controlling genes during plant infection

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
R. de Pedro-Jové ◽  
M. Puigvert ◽  
P. Sebastià ◽  
A. P. Macho ◽  
J. S. Monteiro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Factors ◽  
Ralstonia Solanacearum ◽  
Virulence Genes ◽  
Metabolic Adaptation ◽  
Economic Losses ◽  
Sequencing Analysis ◽  
In Planta ◽  
Plant Infection ◽  
Dynamic Expression

Abstract Background Ralstonia solanacearum is the causal agent of bacterial wilt, a devastating plant disease responsible for serious economic losses especially on potato, tomato, and other solanaceous plant species in temperate countries. In R. solanacearum, gene expression analysis has been key to unravel many virulence determinants as well as their regulatory networks. However, most of these assays have been performed using either bacteria grown in minimal medium or in planta, after symptom onset, which occurs at late stages of colonization. Thus, little is known about the genetic program that coordinates virulence gene expression and metabolic adaptation along the different stages of plant infection by R. solanacearum. Results We performed an RNA-sequencing analysis of the transcriptome of bacteria recovered from potato apoplast and from the xylem of asymptomatic or wilted potato plants, which correspond to three different conditions (Apoplast, Early and Late xylem). Our results show dynamic expression of metabolism-controlling genes and virulence factors during parasitic growth inside the plant. Flagellar motility genes were especially up-regulated in the apoplast and twitching motility genes showed a more sustained expression in planta regardless of the condition. Xylem-induced genes included virulence genes, such as the type III secretion system (T3SS) and most of its related effectors and nitrogen utilisation genes. The upstream regulators of the T3SS were exclusively up-regulated in the apoplast, preceding the induction of their downstream targets. Finally, a large subset of genes involved in central metabolism was exclusively down-regulated in the xylem at late infection stages. Conclusions This is the first report describing R. solanacearum dynamic transcriptional changes within the plant during infection. Our data define four main genetic programmes that define gene pathogen physiology during plant colonisation. The described expression of virulence genes, which might reflect bacterial states in different infection stages, provides key information on the R. solanacearum potato infection process.

tiRNAs & tRFs Biogenesis and Regulation of Diseases: A Review

2019 ◽  
Vol 26 (31) ◽  
pp. 5849-5861 ◽  
Author(s):  
Pan Jiang ◽  
Feng Yan
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Metabolic Diseases ◽  
Viral Infections ◽  
Regulatory Mechanisms ◽  
Biological Functions ◽  
Reverse Transcriptases ◽  
Dna Damage Responses ◽  
Potential Applications ◽  
Viral Reverse Transcriptases

tiRNAs & tRFs are a class of small molecular noncoding tRNA derived from precise processing of mature or precursor tRNAs. Most tiRNAs & tRFs described originate from nucleus-encoded tRNAs, and only a few tiRNAs and tRFs have been reported. They have been suggested to play important roles in inhibiting protein synthesis, regulating gene expression, priming viral reverse transcriptases, and the modulation of DNA damage responses. However, the regulatory mechanisms and potential function of tiRNAs & tRFs remain poorly understood. This review aims to describe tiRNAs & tRFs, including their structure, biological functions and subcellular localization. The regulatory roles of tiRNAs & tRFs in translation, neurodegeneration, metabolic diseases, viral infections, and carcinogenesis are also discussed in detail. Finally, the potential applications of these noncoding tRNAs as biomarkers and gene regulators in different diseases is also highlighted.

scholarly journals VipariNama: RNA viral vectors to rapidly elucidate the relationship between gene expression and phenotype

2021 ◽  
Author(s):  
Arjun Khakhar ◽  
Cecily Wang ◽  
Ryan Swanson ◽  
Sydney Stokke ◽  
Furva Rizvi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Viral Vectors ◽  
Viral Vector ◽  
Tobacco Rattle Virus ◽  
Plant Size ◽  
Great Promise ◽  
Attractive Alternative ◽  
Gibberellin Biosynthesis ◽  
In Planta

Abstract Synthetic transcription factors have great promise as tools to help elucidate relationships between gene expression and phenotype by allowing tunable alterations of gene expression without genomic alterations of the loci being studied. However, the years-long timescales, high cost, and technical skill associated with plant transformation have limited their use. In this work we developed a technology called VipariNama (ViN) in which vectors based on the Tobacco Rattle Virus (TRV) are used to rapidly deploy Cas9-based synthetic transcription factors and reprogram gene expression in planta. We demonstrate that ViN vectors can implement activation or repression of multiple genes systemically and persistently over several weeks in Nicotiana benthamiana, Arabidopsis (Arabidopsis thaliana), and tomato (Solanum lycopersicum). By exploring strategies including RNA scaffolding, viral vector ensembles, and viral engineering, we describe how the flexibility and efficacy of regulation can be improved. We also show how this transcriptional reprogramming can create predictable changes to metabolic phenotypes, such as gibberellin biosynthesis in N. benthamiana and anthocyanin accumulation in Arabidopsis, as well as developmental phenotypes, such as plant size in N. benthamiana, Arabidopsis, and tomato. These results demonstrate how ViN vector-based reprogramming of different aspects of gibberellin signaling can be used to engineer plant size in a range of plant species in a matter of weeks. In summary, VipariNama accelerates the timeline for generating phenotypes from over a year to just a few weeks, providing an attractive alternative to transgenesis for synthetic transcription factor-enabled hypothesis testing and crop engineering.

scholarly journals Olfactory expression of trace amine-associated receptors requires cooperative cis-acting enhancers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ami Shah ◽  
Madison Ratkowski ◽  
Alessandro Rosa ◽  
Paul Feinstein ◽  
Thomas Bozza
Keyword(s):  
Gene Expression ◽  
Large Family ◽  
Sequence Motifs ◽  
Specific Expression ◽  
Cis Acting ◽  
Conserved Sequence ◽  
Trace Amine ◽  
Sequence Elements ◽  
Cell Type Specific Expression ◽  
Cell Type Specific

AbstractOlfactory sensory neurons express a large family of odorant receptors (ORs) and a small family of trace amine-associated receptors (TAARs). While both families are subject to so-called singular expression (expression of one allele of one gene), the mechanisms underlying TAAR gene choice remain obscure. Here, we report the identification of two conserved sequence elements in the mouse TAAR cluster (T-elements) that are required for TAAR gene expression. We observed that cell-type-specific expression of a TAAR-derived transgene required either T-element. Moreover, deleting either element reduced or abolished expression of a subset of TAAR genes, while deleting both elements abolished olfactory expression of all TAARs in cis with the mutation. The T-elements exhibit several features of known OR enhancers but also contain highly conserved, unique sequence motifs. Our data demonstrate that TAAR gene expression requires two cooperative cis-acting enhancers and suggest that ORs and TAARs share similar mechanisms of singular expression.

scholarly journals The Effect of Fusarium verticillioides Fumonisins on Fatty Acids, Sphingolipids, and Oxylipins in Maize Germlings

2021 ◽  
Vol 22 (5) ◽  
pp. 2435
Author(s):  
Marzia Beccaccioli ◽  
Manuel Salustri ◽  
Valeria Scala ◽  
Matteo Ludovici ◽  
Andrea Cacciotti ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fusarium Verticillioides ◽  
Fungal Growth ◽  
Defense Responses ◽  
Ceramide Synthase ◽  
Ear Rot ◽  
In Planta ◽  
Disease Symptoms ◽  
The Impact

Fusarium verticillioides causes multiple diseases of Zea mays (maize) including ear and seedling rots, contaminates seeds and seed products worldwide with toxic chemicals called fumonisins. The role of fumonisins in disease is unclear because, although they are not required for ear rot, they are required for seedling diseases. Disease symptoms may be due to the ability of fumonisins to inhibit ceramide synthase activity, the expected cause of lipids (fatty acids, oxylipins, and sphingolipids) alteration in infected plants. In this study, we explored the impact of fumonisins on fatty acid, oxylipin, and sphingolipid levels in planta and how these changes affect F. verticillioides growth in maize. The identity and levels of principal fatty acids, oxylipins, and over 50 sphingolipids were evaluated by chromatography followed by mass spectrometry in maize infected with an F. verticillioides fumonisin-producing wild-type strain and a fumonisin-deficient mutant, after different periods of growth. Plant hormones associated with defense responses, i.e., salicylic and jasmonic acid, were also evaluated. We suggest that fumonisins produced by F. verticillioides alter maize lipid metabolism, which help switch fungal growth from a relatively harmless endophyte to a destructive necrotroph.

scholarly journals The crucial roles of N6-methyladenosine (m6A) modification in the carcinogenesis and progression of colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhihao Fang ◽  
Yiqiu Hu ◽  
Jinhui Hu ◽  
Yanqin Huang ◽  
Shu Zheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Nuclear Export ◽  
Messenger Rna ◽  
Regulatory Proteins ◽  
Biological Processes ◽  
The Past ◽  
Common Cancer ◽  
Potential Applications ◽  
Regulated Gene Expression

AbstractAs the predominant modification in RNA, N6-methyladenosine (m6A) has attracted increasing attention in the past few years since it plays vital roles in many biological processes. This chemical modification is dynamic, reversible and regulated by several methyltransferases, demethylases and proteins that recognize m6A modification. M6A modification exists in messenger RNA and affects their splicing, nuclear export, stability, decay, and translation, thereby modulating gene expression. Besides, the existence of m6A in noncoding RNAs (ncRNAs) could also directly or indirectly regulated gene expression. Colorectal cancer (CRC) is a common cancer around the world and of high mortality. Increasing evidence have shown that the changes of m6A level and the dysregulation of m6A regulatory proteins have been implicated in CRC carcinogenesis and progression. However, the underlying regulation laws of m6A modification to CRC remain elusive and better understanding of these mechanisms will benefit the diagnosis and therapy. In the present review, the latest studies about the dysregulation of m6A and its regulators in CRC have been summarized. We will focus on the crucial roles of m6A modification in the carcinogenesis and development of CRC. Moreover, we will also discuss the potential applications of m6A modification in CRC diagnosis and therapeutics.

scholarly journals Heat-induced expression of albumin during early stages of rat embryo development.

1987 ◽  
Vol 7 (12) ◽  
pp. 4599-4602 ◽  
Author(s):  
U K Srinivas ◽  
C J Revathi ◽  
M R Das
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Embryonic Liver ◽  
Rat Embryo ◽  
Adult Liver ◽  
Stages Of Development ◽  
Induced Expression ◽  
Molecular Events ◽  
Internal Change ◽  
Shock Proteins

An examination of heat-induced expression of proteins in tissues from adult and embryonic liver in rats shows that albumin, which is constitutively expressed in adult liver and is not synthesized in embryos before 16 days of gestation, appears in liver cells at earlier stages of development upon heat shock. On the basis of available evidence for the expression of heat shock proteins at distinct stages of development and on the basis of our findings, it may be argued that there could be common molecular events taking place during development and as a result of heat shock. We suggest also that one of the consequences of heat shock could be an internal change of pH within the cell which, in turn, might trigger alterations in gene expression.

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