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 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 Distinct Biphasic mRNA Changes in Response to Asian Soybean Rust Infection

2007 ◽  
Vol 20 (8) ◽  
pp. 887-899 ◽  
Author(s):  
Martijn van de Mortel ◽  
Justin C. Recknor ◽  
Michelle A. Graham ◽  
Dan Nettleton ◽  
Jaime D. Dittman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Expression Profiles ◽  
Fungal Growth ◽  
Initial Response ◽  
Soybean Rust ◽  
Specific Response ◽  
Susceptible Genotype ◽  
Rust Infection ◽  
Asian Soybean Rust

Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, is now established in all major soybean-producing countries. Currently, there is little information about the molecular basis of ASR–soybean interactions, which will be needed to assist future efforts to develop effective resistance. Toward this end, abundance changes of soybean mRNAs were measured over a 7-day ASR infection time course in mock-inoculated and infected leaves of a soybean accession (PI230970) carrying the Rpp2 resistance gene and a susceptible genotype (Embrapa-48). The expression profiles of differentially expressed genes (ASR-infected compared with the mock-inoculated control) revealed a biphasic response to ASR in each genotype. Within the first 12 h after inoculation (hai), which corresponds to fungal germination and penetration of the epidermal cells, differential gene expression changes were evident in both genotypes. mRNA expression of these genes mostly returned to levels found in mock-inoculated plants by 24 hai. In the susceptible genotype, gene expression remained unaffected by rust infection until 96 hai, a time period when rapid fungal growth began. In contrast, gene expression in the resistant genotype diverged from the mock-inoculated control earlier, at 72 h, demonstrating that Rpp2-mediated defenses were initiated prior to this time. These data suggest that ASR initially induces a non-specific response that is transient or is suppressed when early steps in colonization are completed in both soybean genotypes. The race-specific resistance phenotype of Rpp2 is manifested in massive gene expression changes after the initial response prior to the onset of rapid fungal growth that occurs in the susceptible genotype.

scholarly journals Overexpression of a Redox-Regulated Cutinase Gene, MfCUT1, Increases Virulence of the Brown Rot Pathogen Monilinia fructicola on Prunus spp.

2010 ◽  
Vol 23 (2) ◽  
pp. 176-186 ◽  
Author(s):  
Miin-Huey Lee ◽  
Chiu-Min Chiu ◽  
Tatiana Roubtsova ◽  
Chien-Ming Chou ◽  
Richard M. Bostock
Keyword(s):  
Gene Expression ◽  
Redox Regulation ◽  
Brown Rot ◽  
Gus Expression ◽  
Apple Fruit ◽  
Gus Activity ◽  
Monilinia Fructicola ◽  
Gus Reporter ◽  
Flanking Regions ◽  
Prunus Spp

A 4.5-kb genomic DNA containing a Monilinia fructicola cutinase gene, MfCUT1, and its flanking regions were isolated and characterized. Sequence analysis revealed that the genomic MfCUT1 carries a 63-bp intron and a promoter region with several transcription factor binding sites that may confer redox regulation of MfCUT1 expression. Redox regulation is indicated by the effect of antioxidants, shown previously to inhibit MfCUT1 gene expression in cutin-induced cultures, and in the present study, where H2O2 enhanced MfCUT1 gene expression. A β-glucuronidase (GUS) reporter gene (gusA) was fused to MfCUT1 under the control of the MfCUT1 promoter, and this construct was then used to generate an MfCUT1-GUS strain by Agrobacterium spp.-mediated transformation. The appearance of GUS activity in response to cutin and suppression of GUS activity by glucose in cutinase-inducing medium verified that the MfCUT1-GUS fusion protein was expressed correctly under the control of the MfCUT1 promoter. MfCUT1-GUS expression was detected following inoculation of peach and apple fruit, peach flower petals, and onion epidermis, and during brown rot symptom development on nectarine fruit at a relatively late stage of infection (24 h postinoculation). However, semiquantitative reverse-transcriptase polymerase chain reaction provided sensitive detection of MfCUT1 expression within 5 h of inoculation in both almond and peach petals. MfCUT1-GUS transformants expressed MfCUT1 transcripts at twice the level as the wild type and caused more severe symptoms on Prunus flower petals, consistent with MfCUT1 contributing to the virulence of M. fructicola.

scholarly journals RETRACTED ARTICLE: The specific MYB binding sites bound by TaMYB in the GAPCp2/3 promoters are involved in the drought stress response in wheat

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lin Zhang ◽  
Zhiqiang Song ◽  
Fangfang Li ◽  
Xixi Li ◽  
Haikun Ji ◽  
...  
Keyword(s):  
Gene Expression ◽  
Abiotic Stress ◽  
Drought Stress ◽  
Reporter Gene ◽  
Binding Sites ◽  
Promoter Sequence ◽  
Regulatory Elements ◽  
Cis Elements ◽  
Gus Reporter ◽  
Almost All

Abstract Background Drought stress is one of the major abiotic stresses that affects plant growth and productivity. The GAPCp genes play important roles in drought stress tolerance in multiple species. The aim of this experiment was to identify the core cis-regulatory elements that may respond to drought stress in the GAPCp2 and GAPCp3 promoter sequences. Results In this study, the promoters of GAPCp2 and GAPCp3 were cloned. The promoter activities were significantly improved under abiotic stress via regulation of Rluc reporter gene expression, while promoter sequence analysis indicated that these fragments were not almost identical. In transgenic Arabidopsis with the expression of the GUS reporter gene under the control of one of these promoters, the activities of GUS were strong in almost all tissues except the seeds, and the activities were induced after abiotic stress. The yeast one-hybrid system and EMSA demonstrated that TaMYB bound TaGAPCp2P/3P. By analyzing different 5′ deletion mutants of these promoters, it was determined that TaGAPCp2P (− 1312~ − 528) and TaGAPCp3P (− 2049~ − 610), including the MYB binding site, contained enhancer elements that increased gene expression levels under drought stress. We used an effector and a reporter to co-transform tobacco and found that TaMYB interacted with the specific MYB binding sites of TaGAPCp2P (− 1197~ − 635) and TaGAPCp3P (− 1456~ − 1144 and − 718~ − 610) in plant cells. Then, the Y1H system and EMSA assay demonstrated that these MYB binding sites in TaGAPCp2P (− 1135 and − 985) and TaGAPCp3P (− 1414 and − 665) were the target cis-elements of TaMYB. The deletion of the specific MYB binding sites in the promoter fragments significantly restrained the drought response, and these results confirmed that these MYB binding sites (AACTAAA/C) play vital roles in improving the transcription levels under drought stress. The results of qRT-PCR in wheat protoplasts transiently overexpressing TaMYB indicated that the expression of TaGAPCp2/3 induced by abiotic stress was upregulated by TaMYB. Conclusion The MYB binding sites (AACTAAA/C) in TaGAPCp2P/3P were identified as the key cis-elements for responding to drought stress and were bound by the transcription factor TaMYB.

scholarly journals Pseudomonas syringae AlgU Downregulates Flagellin Gene Expression, Helping Evade Plant Immunity

2019 ◽  
Vol 202 (4) ◽  
Author(s):  
Zhongmeng Bao ◽  
Hai-Lei Wei ◽  
Xing Ma ◽  
Bryan Swingle
Keyword(s):  
Gene Expression ◽  
Pseudomonas Syringae ◽  
Plant Pathogens ◽  
Control Point ◽  
Plant Colonization ◽  
Compensatory Mechanisms ◽  
Flagellin Gene ◽  
Content Type ◽  
Immune Systems ◽  
Plant Infection

ABSTRACT Flagella power bacterial movement through liquids and over surfaces to access or avoid certain environmental conditions, ultimately increasing a cell’s probability of survival and reproduction. In some cases, flagella and chemotaxis are key virulence factors enabling pathogens to gain entry and attach to suitable host tissues. However, flagella are not always beneficial; both plant and animal immune systems have evolved receptors to sense the proteins that make up flagellar filaments as signatures of bacterial infection. Microbes poorly adapted to avoid or counteract these immune functions are unlikely to be successful in host environments, and this selective pressure has driven the evolution of diverse and often redundant pathogen compensatory mechanisms. We tested the role of AlgU, the Pseudomonas extracytoplasmic function sigma factor σE/σ22 ortholog, in regulating flagellar expression in the context of Pseudomonas syringae-plant interactions. We found that AlgU is necessary for downregulating bacterial flagellin expression in planta and that this results in a corresponding reduction in plant immune elicitation. This AlgU-dependent regulation of flagellin gene expression is beneficial to bacterial growth in the course of plant infection, and eliminating the plant’s ability to detect flagellin makes this AlgU-dependent function irrelevant for bacteria growing in the apoplast. Together, these results add support to an emerging model in which P. syringae AlgU functions at a key control point that serves to optimize the expression of bacterial functions during host interactions, including minimizing the expression of immune elicitors and concomitantly upregulating beneficial virulence functions. IMPORTANCE Foliar plant pathogens, like Pseudomonas syringae, adjust their physiology and behavior to facilitate host colonization and disease, but the full extent of these adaptations is not known. Plant immune systems are triggered by bacterial molecules, such as the proteins that make up flagellar filaments. In this study, we found that during plant infection, AlgU, a gene expression regulator that is responsive to external stimuli, downregulates expression of fliC, which encodes the flagellin protein, a strong elicitor of plant immune systems. This change in gene expression and resultant change in behavior correlate with reduced plant immune activation and improved P. syringae plant colonization. The results of this study demonstrate the proximate and ultimate causes of flagellar regulation in a plant-pathogen interaction.

scholarly journals Novel Genes of Fusarium graminearum That Negatively Regulate Deoxynivalenol Production and Virulence

2009 ◽  
Vol 22 (12) ◽  
pp. 1588-1600 ◽  
Author(s):  
Donald M. Gardiner ◽  
Kemal Kazan ◽  
John M. Manners
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Global Analysis ◽  
Gene Clusters ◽  
Head Blight ◽  
Knock Out ◽  
Serious Disease ◽  
Amine Compounds ◽  
Fungal Genes ◽  
Fungal Gene Expression

Fusarium head blight of wheat, caused by Fusarium graminearum, is a serious disease resulting in both reduced yields and contamination of grain with trichothecene toxins, with severe consequences for mammalian health. Recently, we have identified several related amine compounds such as agmatine and putrescine that promote the production of high levels of trichothecene toxins, such as deoxynivalenol (DON), in culture by F. graminearum and F. sporotrichioides. Here, a global analysis of fungal gene expression using the Affymetrix Fusarium GeneChip during culture under DON-inducing conditions compared with noninducing conditions is reported. Agmatine differentially regulated a large number of fungal genes, including both known and previously uncharacterized putative secondary metabolite biosynthetic gene clusters. In silico prediction of binding sites for the transcriptional regulator (TRI6) controlling TRI gene expression and gene expression analysis in a TRI6 mutant of F. graminearum showed that three of the differentially regulated genes were under the control of TRI6. Gene knock-out mutations of two of these genes resulted in mutants with massively increased production of DON and increased aggressiveness toward wheat. Our results not only identify a novel mechanism of negative regulation of DON production and virulence in F. graminearum but also point out the potential of this pathogen to evolve with an ability to produce massively increased amounts of toxins and increased virulence.

scholarly journals Differential accumulation of poly(A)+ RNA between virulent and double-stranded RNA-induced hypovirulent strains of Cryphonectria (Endothia) parasitica.

1987 ◽  
Vol 7 (10) ◽  
pp. 3688-3693 ◽  
Author(s):  
W A Powell ◽  
N K Van Alfen
Keyword(s):  
Gene Expression ◽  
Specific Effect ◽  
Rna Sequences ◽  
Double Stranded Rna ◽  
Total Rna ◽  
Rna Sequence ◽  
Differential Hybridization ◽  
Endothia Parasitica ◽  
Fungal Gene Expression ◽  
Fungal Gene

The double-stranded RNA responsible for transmissible hypovirulence in Cryphonectria (Endothia) parasitica was found to affect the accumulation of specific poly(A)+ RNA. Using differential hybridization techniques, two genes were isolated, Vir1 and Vir2, which were specifically expressed as poly(A)+ RNAs in the virulent cells. The highly expressed RNA sequences from these genes were not found in total RNA isolated from either American or European hypovirulent strains, although the genes were present in their genomes. Other virulence- and hypovirulence-specific RNA sequences were also detected. One isolated hypovirulence-specific RNA sequence was expressed in both virulent and hypovirulent cells, but in a two- to fourfold-higher concentration in the hypovirulent cells. The results show that hypovirulence is associated with concurrent changes in a few highly expressed poly(A)+ RNAs, which suggests a specific effect of the double-stranded RNA on fungal gene expression.

scholarly journals Deciphering the Infectious Process of Colletotrichum lupini in Lupin through Transcriptomic and Proteomic Analysis

2020 ◽  
Vol 8 (10) ◽  
pp. 1621
Author(s):  
Guillaume Dubrulle ◽  
Adeline Picot ◽  
Stéphanie Madec ◽  
Erwan Corre ◽  
Audrey Pawtowski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Protein Synthesis ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
White Lupin ◽  
Post Inoculation ◽  
Infectious Process ◽  
Plant Infection ◽  
Colletotrichum Lupini

The fungal phytopathogen Colletotrichum lupini is responsible for lupin anthracnose, resulting in significant yield losses worldwide. The molecular mechanisms underlying this infectious process are yet to be elucidated. This study proposes to evaluate C. lupini gene expression and protein synthesis during lupin infection, using, respectively, an RNAseq-based transcriptomic approach and a mass spectrometry-based proteomic approach. Patterns of differentially-expressed genes in planta were evaluated from 24 to 84 hours post-inoculation, and compared to in vitro cultures. A total of 897 differentially-expressed genes were identified from C. lupini during interaction with white lupin, of which 520 genes were predicted to have a putative function, including carbohydrate active enzyme, effector, protease or transporter-encoding genes, commonly described as pathogenicity factors for other Colletotrichum species during plant infection, and 377 hypothetical proteins. Simultaneously, a total of 304 proteins produced during the interaction were identified and quantified by mass spectrometry. Taken together, the results highlight that the dynamics of symptoms, gene expression and protein synthesis shared similarities to those of hemibiotrophic pathogens. In addition, a few genes with unknown or poorly-described functions were found to be specifically associated with the early or late stages of infection, suggesting that they may be of importance for pathogenicity. This study, conducted for the first time on a species belonging to the Colletotrichum acutatum species complex, presents an opportunity to deepen functional analyses of the genes involved in the pathogenicity of Colletotrichum spp. during the onset of plant infection.

FungiExp: A Comprehensive Platform For Exploring Fungal Gene Expression and Alternative Splicing Based On 35,821 RNA-Seq Experiments From 220 Fungi

2021 ◽  
Author(s):  
Jinding Liu ◽  
Fei Yin ◽  
Kun Lang ◽  
Wencai Jie ◽  
Suxu Tan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Sequence Similarity ◽  
Expression Regulation ◽  
Rna Seq ◽  
Specific Expression ◽  
Data Accessibility ◽  
Wide Range ◽  
Fungal Gene Expression ◽  
Fungal Gene

Abstract Background: RNA-seq has become a standard tool in biology and has produced large and diverse transcriptomic datasets for users to explore fungal expression regulation. Fungal alternative splicing, which is attracting increasing attention because of evolutionary adaptations to changing external conditions has not been thoroughly investigated in previous studies, unlike that of animals and plants. However, the analyses of RNA-seq datasets are made difficult by the heterogeneity of study design and complex bioinformatics approaches. Comprehensive analyses of these published datasets should contribute new insights into fungal expression regulation.Results: We have developed a web-based platform called FungiExp hosting fungal gene expression levels and alternative splicing profiles in 35,821 curated RNA-seq experiments from 220 species. It allows users to perform retrieval via diverse terms and sequence similarity. Moreover, users can customize experimental groups to perform differential and specific expression analyses. The wide range of data visualization is an additional important feature that should help users intuitively understand retrieval and analysis results.Conclusions: With its uniform data processing, easy data accessibility, convenient retrieval, and analysis functions, FungiExp is a valuable resource and tool that allows users to (re)use published RNA-seq datasets. It is accessible at http://bioinfo.njau.edu.cn/fungiExp.

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