scholarly journals Disease-Specific Expression of Host Genes During Downy Mildew Infection of Arabidopsis

2009 ◽  
Vol 22 (9) ◽  
pp. 1104-1115 ◽  
Author(s):  
Robin P. Huibers ◽  
Mark de Jong ◽  
René W. Dekter ◽  
Guido Van den Ackerveken
Keyword(s):  
Downy Mildew ◽  
In Silico Analysis ◽  
Effector Proteins ◽  
Ethylene Response Factor ◽  
Promoter Regions ◽  
Specific Expression ◽  
Transcription Factor Genes ◽  
Responsive Element ◽  
Hyaloperonospora Arabidopsidis ◽  
Incompatible Interactions

Here, we report on the identification of Arabidopsis genes that are induced during compatible but not during incompatible interactions with the downy mildew pathogen Hyaloperonospora arabidopsidis. This set of so-called compatible specific (CS) genes contrasts with the large group of defense-associated genes that is differentially expressed during both compatible and incompatible interactions. From the 17 identified CS genes, 6 belong to the ethylene response factor (ERF) family of transcription factor genes, suggesting that these ERF have a role during compatibility. The majority of CS genes are differentially regulated in response to various forms of abiotic stress. In silico analysis of the CS genes revealed an over-representation of dehydration-responsive element/C-repeat binding factor (DREB1A/CBF3) binding sites and EveningElement motifs in their promoter regions. The CS-ERF are closely related to the CBF transcription factors and could potentially bind the DREB1A/CBF3 promoter elements in the CS genes. Transcript levels of CS genes peak at 2 to 3 days postinoculation, when pathogen growth is highest, and decline at later stages of infection. The induction of several CS genes was found to be isolate specific. This suggests that the identified CS genes could be the direct or indirect targets of downy mildew effector proteins that promote disease susceptibility.

scholarly journals Downy Mildew effector HaRxL21 interacts with the transcriptional repressor TOPLESS to promote pathogen susceptibility

2020 ◽  
Author(s):  
Sarah Harvey ◽  
Priyanka Kumari ◽  
Dmitry Lapin ◽  
Thomas Griebel ◽  
Richard Hickman ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Transcriptional Repression ◽  
Plant Immunity ◽  
Effector Proteins ◽  
Host Susceptibility ◽  
Close Relative ◽  
C Terminus ◽  
Rxlr Effector ◽  
Oomycete Pathogen ◽  
Hyaloperonospora Arabidopsidis

AbstractHyaloperonospora arabidopsidis (Hpa) is an oomycete pathogen causing Arabidopsis downy mildew. Effector proteins secreted from the pathogen into the plant play key roles in promoting infection by suppressing plant immunity and manipulating the host to the pathogen’s advantage. One class of oomycete effectors share a conserved ‘RxLR’ motif critical for their translocation into the host cell. Here we characterize the interaction between an RxLR effector, HaRxL21 (RxL21), and the Arabidopsis transcriptional co-repressor Topless (TPL). We establish that RxL21 and TPL interact via an EAR motif at the C-terminus of the effector, mimicking the host plant mechanism for recruiting TPL to sites of transcriptional repression. We show that this motif, and hence interaction with TPL, is necessary for the virulence function of the effector. Furthermore, we provide evidence that RxL21 uses the interaction with TPL, and its close relative TPL-related 1, to repress plant immunity and enhance host susceptibility to both biotrophic and necrotrophic pathogens.

The role of hypoxia-induced genes in ovarian angiogenesis

2013 ◽  
Vol 25 (2) ◽  
pp. 343 ◽  
Author(s):  
Rina Meidan ◽  
Eyal Klipper ◽  
Yulia Zalman ◽  
Ronit Yalu
Keyword(s):  
Growth Factor ◽  
Hypoxia Inducible Factor ◽  
Luteal Cell ◽  
Promoter Regions ◽  
Specific Expression ◽  
Α Subunit ◽  
Hypoxia Inducible Factor 1 ◽  
Responsive Element ◽  
And Function ◽  
Endothelial Growth Factor

The hypoxic microenvironment that occurs in fast-growing tissue such as the corpus luteum (CL) is a major contributor to its ability to survive via the induction of an intricate vascular network. Cellular responses to hypoxia are mediated by hypoxia-inducible factor-1 (HIF-1), an oxygen-regulated transcriptional activator. HIF-1, a heterodimer consisting of a constitutively-expressed β subunit and an oxygen-regulated α subunit, binds to the hypoxia responsive element (HRE) present in the promoter regions of responsive genes. This review summarises evidence for the involvement of hypoxia and HIF-1α in CL development and function. Special emphasis is given to hypoxia-induced, luteal cell-specific expression of multiple genes (vascular endothelial growth factor A (VEGFA), fibroblast growth factor 2 (FGF-2), prokineticin receptor 2 (PK-R2), stanniocalcin 1 (STC-1) and endothelin 2 (EDN-2) that participate in the angiogenic process during CL formation.

scholarly journals Genomic Structure of the Porcine CYP19 Locus and Expression of the CYP19A3 Paralog

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 533
Author(s):  
Jens Vanselow ◽  
Alan J. Conley ◽  
Cynthia J. Corbin ◽  
Trish Berger
Keyword(s):  
Genomic Structure ◽  
In Silico Analysis ◽  
Chromosome 1 ◽  
Promoter Regions ◽  
Specific Expression ◽  
Tissue Specific ◽  
Additional Layer ◽  
Estrogen Synthesis ◽  
Key Enzyme ◽  
Specific Regulation

Proper, tissue-specific regulation of CYP19, the gene encoding aromatase, the key enzyme of estrogen synthesis, is essential for reproductive processes. Here, we analyzed transcriptional regulation of the porcine CYP19 in female and male gonads and brain by 5’RACE and RT-PCR and comprehensively mapped the pig CYP19 locus by in silico analysis. Our data revealed that the complete locus, including three paralogous copies, CYP19A1, CYP19A2 and CYP19A3, spans approximately 330 kb of the porcine chromosome 1. The locus also harbors the first exon of the Gliomedin gene (GLDN) in reverse orientation. Only transcripts of the CYP19A3 paralog were substantially expressed in gonads and hypothalamus. We identified CYP19A3-associated untranslated exons approximately 160 kb and 50 kb distal from the first codon. The 5´ untranslated regions of transcripts were derived from either a proximal or from one of these distal untranslated exons. Transcripts including only untranslated exons could be amplified from testis, thus suggesting long non-coding transcripts. The data revealed an additional layer of complexity in the regulation of the porcine CYP19 locus. Tissue-specific expression is not only achieved by tissue- and stage-specific expression of the three different CYP19 paralogs, but also by directing the expression of CYP19A3 from different, proximal and distal promoter regions.

scholarly journals Fungal effector Jsi1 hijacks plant JA/ET signaling through Topless

2019 ◽  
Author(s):  
Martin Darino ◽  
Joana Marques ◽  
Khong-Sam Chia ◽  
David Aleksza ◽  
Luz Mayela Soto ◽  
...  
Keyword(s):  
Fungal Species ◽  
Effector Proteins ◽  
Ethylene Response Factor ◽  
Sporisorium Scitamineum ◽  
Binding Factor ◽  
Colonization Process ◽  
Ear Motif ◽  
Wd40 Domain ◽  
Novel Strategy ◽  
Responsive Element

AbstractUstilago maydis (U. maydis) is the causal agent of maize smut disease. During the colonization process, the fungus secretes effector proteins which suppress immune responses and redirect the host-metabolism in favor of the pathogen. Here we describe a novel strategy by which U. maydis induces plant jasmonate/ethylene (JA/ET) hormone signaling and thereby biotrophic susceptibility. The U. maydis effector Jasmonate/Ethylene signaling inducer 1 (Jsi1) possesses an ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motif, DLNxxP, which interacts with the second WD40 domain of the conserved plant co-repressor family Topless/Topless related (TPL/TPR). Jsi1 interaction with TPL/TPRs leads to derepression of the ethylene response factor (ERF) branch of the JA/ET signaling pathway, supporting biotrophic susceptibility. Jsi1 likely activates the ERF branch by interfering with the binding of endogenous DLNxxP motif-containing ERF transcription factors to TPL/TPR proteins. The identification of effector proteins possessing a DLNxxP motif in different fungal species with biotrophic and hemibiotrophic lifestyles together with the validation of the interaction between such effectors from Magnaporthe oryzae (M. oryzae), Sporisorium scitamineum (S. scitamineum), and S. reilianum with TPL proteins indicates the convergent evolution of effectors for modulating the TPL/TPR co-repressor hub.

scholarly journals Sequence-specific activation of transcription by adenovirus EIa products is observed in HeLa cells but not in 293 cells.

1986 ◽  
Vol 6 (1) ◽  
pp. 201-208 ◽  
Author(s):  
T Leff ◽  
P Chambon
Keyword(s):  
Hela Cells ◽  
Upstream Region ◽  
Gene Products ◽  
Promoter Regions ◽  
Chimeric Promoter ◽  
293 Cells ◽  
Activation Of Transcription ◽  
Upstream Promoter ◽  
Sequence Elements ◽  
Responsive Element

The adenovirus EIa gene products activate transcription from the viral EIII and EIIaE promoters. We studied the mechanism of this stimulation by constructing a series of chimeric promoter recombinants containing the upstream regions of the EIII and EIIaE promoters linked to the TATA box-start-site regions of the viral major late and EIIa late promoters. By introducing these recombinants into HeLa cells together with recombinants producing the EIa gene products, we demonstrated that the induction of EIII and EIIaE transcription by EIa 13S and 12S mRNA products is dependent on sequences located in the upstream region (approximately -40 to -250) of these promoters. In addition, we showed that the major late and EIIa late upstream promoter regions do not contain such EIa-responsive sequence elements. In contrast, after transfection of these chimeric promoter recombinants into 293 cells (which constitutively express the EIa proteins), we found that their relative levels of transcription are similar and markedly different from those observed when they are cotransfected into HeLa cells with EIa protein-producing recombinants. We conclude that the efficiency of transcription from a given promoter in 293 cells is not necessarily related to the presence of a specific EIa-responsive element.

scholarly journals Intestinal Apolipoprotein A-IV Gene Transcription Is Controlled by Two Hormone-Responsive Elements: A Role for Hepatic Nuclear Factor-4 Isoforms

2005 ◽  
Vol 19 (9) ◽  
pp. 2320-2334 ◽  
Author(s):  
Amena Archer ◽  
Dominique Sauvaget ◽  
Valérie Chauffeton ◽  
Pierre-Etienne Bouchet ◽  
Jean Chambaz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Distal Region ◽  
Proximal Region ◽  
Dominant Negative ◽  
Specific Expression ◽  
Nuclear Factors ◽  
Dominant Negative Form ◽  
Responsive Element ◽  
Hormone Responsive Element

Abstract In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.

scholarly journals The Role of EjSVPs in Flower Initiation in Eriobotrya japonica

2019 ◽  
Vol 20 (23) ◽  
pp. 5933 ◽  
Author(s):  
Yuanyuan Jiang ◽  
Jiangrong Peng ◽  
Zhike Zhang ◽  
Shoukai Lin ◽  
Shunquan Lin ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Expression Patterns ◽  
Active Role ◽  
Eriobotrya Japonica ◽  
Flower Initiation ◽  
Mads Box ◽  
Promoter Regions ◽  
Expression Levels ◽  
Flowering Regulation ◽  
Responsive Element

Flowering plants have evolved different flowering habits to sustain long-term reproduction. Most woody trees experience dormancy and then bloom in the warm spring, but loquat blooms in the cold autumn and winter. To explore its mechanism of flowering regulation, we cloned two SHORT VEGETATIVE PHASE (SVP) homologous genes from ‘Jiefanzhong’ loquat (Eriobotrya japonica Lindl.), namely, EjSVP1 and EjSVP2. Sequence analysis revealed that the EjSVPs were typical MADS-box transcription factors and exhibited a close genetic relationship with other plant SVP/DORMANCY-ASSOCIATED MADS-BOX (DAM) proteins. The temporal and spatial expression patterns showed that EjSVP1 and EjSVP2 were mainly expressed in the shoot apical meristem (SAM) after the initiation of flowering; after reaching their highest level, they gradually decreased with the development of the flower until they could not be detected. EjSVP1 expression levels were relatively high in young tissues, and EjSVP2 expression levels were relatively high in young to mature transformed tissues. Interestingly, EjSVP2 showed relatively high expression levels in various flower tissues. We analyzed the EjSVP promoter regions and found that they did not contain the C-repeat/dehydration-responsive element. Finally, we overexpressed the EjSVPs in wild-type Arabidopsis thaliana Col-0 and found no significant changes in the number of rosette leaves of Arabidopsis thaliana; however, overexpression of EjSVP2 affected the formation of Arabidopsis thaliana flower organs. In conclusion, EjSVPs were found to play an active role in the development of loquat flowering. These findings may provide a reference for exploring the regulation mechanisms of loquat flowering and the dormancy mechanisms of other plants.

scholarly journals Nontoxic Nep1-Like Proteins of the Downy Mildew Pathogen Hyaloperonospora arabidopsidis: Repression of Necrosis-Inducing Activity by a Surface-Exposed Region

2012 ◽  
Vol 25 (5) ◽  
pp. 697-708 ◽  
Author(s):  
Adriana Cabral ◽  
Stan Oome ◽  
Nick Sander ◽  
Isabell Küfner ◽  
Thorsten Nürnberger ◽  
...  
Keyword(s):  
Amino Acids ◽  
Downy Mildew ◽  
Plant Pathogens ◽  
Exposed Region ◽  
Alternative Function ◽  
Early Expression ◽  
Specific Expansion ◽  
Species Specific ◽  
Hyaloperonospora Arabidopsidis ◽  
Specific Cluster

The genome of the downy mildew pathogen Hyaloperonospora arabidopsidis encodes necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLP). Although NLP are widely distributed in eukaryotic and prokaryotic plant pathogens, it was surprising to find these proteins in the obligate biotrophic oomycete H. arabidopsidis. Therefore, we analyzed the H. arabidopsidis NLP (HaNLP) family and identified 12 HaNLP genes and 15 pseudogenes. Most of the 27 genes form an H. arabidopsidis–specific cluster when compared with other oomycete NLP genes, suggesting this class of effectors has recently expanded in H. arabidopsidis. HaNLP transcripts were mainly detected during early infection stages. Agrobacterium tumefaciens–mediated transient expression and infiltration of recombinant NLP into tobacco and Arabidopsis leaves revealed that all HaNLP tested are noncytotoxic proteins. Even HaNLP3, which is most similar to necrosis-inducing NLP proteins of other oomycetes and which contains all amino acids that are critical for necrosis-inducing activity, did not induce necrosis. Chimeras constructed between HaNLP3 and the necrosis-inducing PsojNIP protein demonstrated that most of the HaNLP3 protein is functionally equivalent to PsojNIP, except for an exposed domain that prevents necrosis induction. The early expression and species-specific expansion of the HaNLP genes is suggestive of an alternative function of noncytolytic NLP proteins during biotrophic infection of plants.

scholarly journals Silicon flow from root to shoot in pepper: a comprehensive in silico analysis reveals a potential linkage between gene expression and hormone signaling that stimulates plant growth and metabolism

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10053
Author(s):  
Fernando Carlos Gómez-Merino ◽  
Libia Iris Trejo-Téllez ◽  
Atonaltzin García-Jiménez ◽  
Hugo Fernando Escobar-Sepúlveda ◽  
Sara Monzerrat Ramírez-Olvera
Keyword(s):  
Plant Growth ◽  
Plant Species ◽  
In Silico ◽  
In Silico Analysis ◽  
Regulatory Elements ◽  
Plant Tissues ◽  
Promoter Regions ◽  
Root Cells ◽  
Physiological Processes ◽  
Silico Analysis

Background Silicon (Si) is categorized as a quasi-essential element for plants thanks to the benefits on growth, development and metabolism in a hormetic manner. Si uptake is cooperatively mediated by Lsi1 and Lsi2. Nevertheless, Lsi channels have not yet been identified and characterized in pepper (Capsicum annuum), while genes involved in major physiological processes in pepper are Si-regulated. Furthermore, Si and phytohormones may act together in regulating plant growth, metabolism and tolerance against stress. Our aim was to identify potential synergies between Si and phytohormones stimulating growth and metabolism in pepper, based on in silico data. Methods We established a hydroponic system to test the effect of Si (0, 60, 125 and 250 mg L−1 Si) on the concentrations of this element in different pepper plant tissues. We also performed an in silico analysis of putative Lsi genes from pepper and other species, including tomato (Solanum lycopersicum), potato (Solanum tuberosum) and Arabidopsis thaliana, to look for cis-acting elements responsive to phytohormones in their promoter regions. With the Lsi1 and Lsi2 protein sequences from various plant species, we performed a phylogenetic analysis. Taking into consideration the Lsi genes retrieved from tomato, potato and Arabidopsis, an expression profiling analysis in different plant tissues was carried out. Expression of Si-regulated genes was also analyzed in response to phytohormones and different plant tissues and developmental stages in Arabidopsis. Results Si concentrations in plant tissues exhibited the following gradient: roots > stems > leaves. We were able to identify 16 Lsi1 and three Lsi2 genes in silico in the pepper genome, while putative Lsi homologs were also found in other plant species. They were mainly expressed in root tissues in the genomes analyzed. Both Lsi and Si-regulated genes displayed cis-acting elements responsive to diverse phytohormones. In Arabidopsis, Si-regulated genes were transcriptionally active in most tissues analyzed, though at different expressed levels. From the set of Si-responsive genes, the NOCS2 gene was highly expressed in germinated seeds, whereas RABH1B, and RBCS-1A, were moderately expressed in developed flowers. All genes analyzed showed responsiveness to phytohormones and phytohormone precursors. Conclusion Pepper root cells are capable of absorbing Si, but small amounts of this element are transported to the upper parts of the plant. We could identify putative Si influx (Lsi1) and efflux (Lsi2) channels that potentially participate in the absorption and transport of Si, since they are mainly expressed in roots. Both Lsi and Si-regulated genes exhibit cis-regulatory elements in their promoter regions, which are involved in phytohormone responses, pointing to a potential connection among Si, phytohormones, plant growth, and other vital physiological processes triggered by Si in pepper.

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