scholarly journals Differential Expression of Genes Encoding Arabidopsis Phospholipases After Challenge with Virulent or Avirulent Pseudomonas Isolates

2002 ◽  
Vol 15 (8) ◽  
pp. 808-816 ◽  
Author(s):  
Marta de Torres Zabela ◽  
Isabelle Fernandez-Delmond ◽  
Totte Niittyla ◽  
Pedro Sanchez ◽  
Murray Grant
Keyword(s):  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Gene Interactions ◽  
Gene Encoding ◽  
Cellular Processes ◽  
Expression Of Genes ◽  
Pathogen Challenge ◽  
Genes Encoding ◽  
Plant Pathogen Interactions ◽  
Gene For Gene

Phospholipase D (PLD; EC 3.1.4.4) has been linked to a number of cellular processes, including Tran membrane signaling and membrane degradation. Four PLD genes (α, β, γ1, and γ2) have been cloned from Arabidopsis thalami. They encode isoforms with distinct regulatory and catalytic properties but little is known about their physiological roles. Using cDNA amplified fragment length polymorphism display and RNA blot analysis, we identified Arabidopsis PLDγ1 and a gene encoding a lysophospholipase (EC 3.1.1.5), lysoPL1, to be differentially expressed during host response to virulent and avirulent pathogen challenge. Examination of the expression pattern of phospholipase genes induced in response to pathogen challenge was undertaken using the lysoPL1 and gene-specific probes corresponding to the PLD isoforms α, β, and γ1. Each mRNA class exhibited different temporal patterns of expression after infiltration of leaves with Pseudomonas syringae pv. tomato with or without avrRpm1. PLDα was rapidly induced and remained constitutively elevated regardless of treatment. PLDβ was transiently induced upon pathogen challenge. However, mRNA for the lysoPL1 and PLDγ1 genes showed enhanced and sustained elevation during an incompatible interaction, in both ndr1 and overexpressing NahG genetic backgrounds. Further evidence for differential engagement of these PLD mRNA during defense responses, other than gene-for-gene interactions, was demonstrated by their response to salicylic acid treatment or wounding. Our results indicate that genes encoding lysoPL1, PLDγ1, and PLDβ are induced during early responses to pathogen challenge and, additionally, PLDγ1 and lysoPL1 are specifically upregulated during gene-for-gene interactions, leading to the hypersensitive response. We discuss the possible role of these genes in plant-pathogen interactions.

scholarly journals The Phytotoxin Coronatine Contributes to Pathogen Fitness and Is Required for Suppression of Salicylic Acid Accumulation in Tomato Inoculated with Pseudomonas syringae pv. tomato DC3000

2007 ◽  
Vol 20 (8) ◽  
pp. 955-965 ◽  
Author(s):  
Srinivasa Rao Uppalapati ◽  
Yasuhiro Ishiga ◽  
Tamding Wangdi ◽  
Barbara N. Kunkel ◽  
Ajith Anand ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Tomato Dc3000 ◽  
Defense Proteins ◽  
Tomato Plants ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Salicylic Acid Accumulation ◽  
Pathogen Fitness

The roles of the phytotoxin coronatine (COR) and salicylic acid (SA)-mediated defenses in the interaction of Pseudomonas syringae pv. tomato DC3000 and tomato (Solanum lycopersicum) were investigated. Unlike findings reported for Arabidopsis thaliana, DC3000 mutants impaired for production of COR or one of its components, coronafacic acid (CFA) or coronamic acid (CMA), induced distinctly different disease lesion phenotypes in tomato. Tomato plants inoculated with the CFA- CMA- mutant DB29 showed elevated transcript levels of SlICS, which encodes isochorismate synthase, an enzyme involved in SA biosynthesis in S. lycopersicum. Furthermore, expression of genes encoding SA-mediated defense proteins were elevated in DB29-inoculated plants compared with plants inoculated with DC3000, suggesting that COR suppresses SlICS-mediated SA responses. Sequence analysis of SlICS revealed that it encodes a protein that is 55 and 59.6% identical to the A. thaliana ICS-encoded proteins AtICS1 and AtICS2, respectively. Tomato plants silenced for SlICS were hypersusceptible to DC3000 and accumulated lower levels of SA after infection with DC3000 compared with inoculated wild-type tomato plants. Unlike what has been shown for A. thaliana, the COR- mutant DB29 was impaired for persistence in SlICS-silenced tomato plants; thus, COR has additional roles in virulence that are SA independent and important in the latter stages of disease development. In summary, the infection assays, metabolic profiling, and gene expression results described in this study indicate that the intact COR molecule is required for both suppression of SA-mediated defense responses and full disease symptom development in tomato.

scholarly journals Pseudomonas syringae pv. tomato OxyR Is Required for Virulence in Tomato and Arabidopsis

2016 ◽  
Vol 29 (2) ◽  
pp. 119-131 ◽  
Author(s):  
Yasuhiro Ishiga ◽  
Yuki Ichinose
Keyword(s):  
Oxidative Stress ◽  
Pseudomonas Syringae ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
High Sensitivity ◽  
Defense Responses ◽  
Bacterial Populations ◽  
Disease Symptoms ◽  
Expression Of Genes ◽  
Genes Encoding

Reactive oxygen species (ROS) have been shown to have a crucial role in plant defense responses and signaling pathways. In addition, ROS also have direct toxicity against pathogens. However, the molecular mechanisms of plant ROS in the direct effects against pathogens is still unclear. To investigate the function of plant ROS in the interactions of plant and bacterial pathogens, we focused on oxyR, encoding an oxidative stress-regulated transcription factor in Pseudomonas syringae pv. tomato DC3000 (DC3000), and generated an ΔoxyR mutant. The DC3000 ΔoxyR mutant showed high sensitivity to oxidative stress in comparison with wild type and the complemented line. The host plants of DC3000, including tomato and Arabidopsis inoculated with the ΔoxyR mutant, clearly showed reduced disease symptoms as well as reduced bacterial populations. Expression profiles of DC3000 genes revealed that OxyR could regulate the expression of genes encoding ROS-detoxifying enzymes, including catalases (KatB and KatG), in response to ROS. We also demonstrated that the expression of katB could be regulated by OxyR during the infection of DC3000 in Arabidopsis. These results suggest that OxyR has an important role in the virulence of DC3000 by regulating the expression of genes related to oxidative stress.

Transcriptome Analysis of Listeria monocytogenes Grown on a Ready-to-Eat Meat Matrix

2011 ◽  
Vol 74 (7) ◽  
pp. 1104-1111 ◽  
Author(s):  
DONGRYEOUL BAE ◽  
MICHAEL R. CROWLEY ◽  
CHINLING WANG
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Microarray Data ◽  
Meat Products ◽  
Phospholipid Metabolism ◽  
Transcriptional Level ◽  
Cellular Processes ◽  
Reverse Transcription Pcr ◽  
Expression Of Genes ◽  
Genes Encoding

The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. For a better understanding of the adaptation and survival ability of L. monocytogenes grown on turkey deli meat, the transcriptome of L. monocytogenes strain F2365 was determined with a microarray. Microarray data were validated with a quantitative real-time reverse transcription PCR assay. Based on the microarray data, 39 and 45 genes from L. monocytogenes were transcriptionally upregulated and down-regulated, respectively. The genes regulated at the transcriptional level were mainly involved in energy metabolism, fatty acid and phospholipid metabolism, biosynthesis of proteins, transport and binding proteins, DNA metabolism, cellular processes, and regulatory functions. No significant change was noted for the expression of genes encoding known virulence factors such as sigB, prfA, inlA, inlB, plcA, plcB, and hly. These results suggest that L. monocytogenes grown on RTE deli meat changes its transcription of proteins involved in its metabolic pathways to obtain an energy source or to adapt to environmental change without increasing the expression of virulence factors. The global transcriptome profiles provide a better understanding of the growth or adaptation of L. monocytogenes in RTE meat products.

scholarly journals Effects of Cordycepin in Cordyceps militaris during Its Infection to Silkworm Larvae

2021 ◽  
Vol 9 (4) ◽  
pp. 681
Author(s):  
Tatsuya Kato ◽  
Konomi Nishimura ◽  
Ahmad Suparmin ◽  
Kazuho Ikeo ◽  
Enoch Y. Park
Keyword(s):  
Cordyceps Militaris ◽  
Silkworm Larvae ◽  
Gene Encoding ◽  
Biosynthesis Gene Cluster ◽  
Expression Of Genes ◽  
Cuticular Proteins ◽  
Genes Encoding ◽  
Fat Bodies ◽  
In Vivo Growth

Cordyceps militaris produces cordycepin, a secondary metabolite that exhibits numerous bioactive properties. However, cordycepin pharmacology in vivo is not yet understood. In this study, the roles of cordycepin in C. militaris during its infection were investigated. After the injection of conidia, C. militaris NBRC100741 killed silkworm larvae more rapidly than NBRC103752. At 96 and 120 h, Cmcns genes (Cmcns1–4), which are part of the cordycepin biosynthesis gene cluster, were expressed in fat bodies and cuticles. Thus, cordycepin may be produced in the infection of silkworm larvae. Further, cordycepin enhanced pathogenicity toward silkworm larvae of Metarhizium anisopliae and Beauveria bassiana, that are also entomopathogenic fungi and do not produce cordycepin. In addition, by RNA-seq analysis, the increased expression of the gene encoding a lipoprotein 30K-8 (Bmlp20, KWMTBOMO11934) and decreased expression of genes encoding cuticular proteins (KWMTBOMO13140, KWMTBOMO13167) and a serine protease inhibitor (serpin29, KWMTBOMO08927) were observed when cordycepin was injected into silkworm larvae. This result suggests that cordycepin may aid the in vivo growth of C. militaris in silkworm larvae by the influence of the expression of some genes in silkworm larvae.

scholarly journals Virulence of the Phytopathogen Pseudomonas syringae pv. Maculicola Is rpoN Dependent

2000 ◽  
Vol 182 (12) ◽  
pp. 3498-3507 ◽  
Author(s):  
Erik L. Hendrickson ◽  
Pablo Guevera ◽  
Alejandro Peñaloza-Vàzquez ◽  
Jing Shao ◽  
Carol Bender ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Constitutive Expression ◽  
Nitrogen Sources ◽  
Dicarboxylic Acids ◽  
Avirulence Gene ◽  
Gene Encoding ◽  
Direct Role ◽  
Mrna Accumulation ◽  
Genes Encoding ◽  
Mutant Phenotypes

ABSTRACT We cloned the rpoN (ntrA andglnF) gene encoding ς54 from the phytopathogen Pseudomonas syringae pv. maculicola strain ES4326. The P. syringae ES4326 rpoN gene complemented Pseudomonas aeruginosa, Escherichia coli, and Klebsiella aerogenes rpoN mutants for a variety of rpoN mutant phenotypes, including the inability to utilize nitrate as sole nitrogen source. DNA sequence analysis of the P. syringae ES4326 rpoN gene revealed that the deduced amino acid sequence was most similar (86% identity; 95% similarity) to the ς54 protein encoded by thePseudomonas putida rpoN gene. A marker exchange protocol was used to construct an ES4326 rpoN insertional mutation,rpoN::Kmr. In contrast to wild-type ES4326, ES4326 rpoN::Kmr was nonmotile and could not utilize nitrate, urea, C4-dicarboxylic acids, several amino acids, or concentrations of ammonia below 2 mM as nitrogen sources.rpoN was essential for production of the phytotoxin coronatine and for expression of the structural genes encoding coronamic acid. In addition, ES4326rpoN::Kmr did not multiply or elicit disease symptoms when infiltrated into Arabidopsis thalianaleaves, did not elicit the accumulation of severalArabidopsis defense-related mRNAs, and did not elicit a hypersensitive response (HR) when infiltrated into tobacco (Nicotiana tabacum) leaves. Furthermore, whereas P. syringae ES4326 carrying the avirulence gene avrRpt2elicited an HR when infiltrated into Arabidopsis ecotype Columbia leaves, ES4326 rpoN::Kmrcarrying avrRpt2 elicited no response. Constitutive expression of ES4326 hrpL in ES4326rpoN::Kmr partially restored defense-related mRNA accumulation, showing a direct role for thehrp cluster in host defense gene induction in a compatible host-pathogen interaction. However, constitutive expression ofhrpL in ES4326 rpoN::Kmrdid not restore coronatine production, showing that coronatine biosynthesis requires factors other than hrpL.

scholarly journals PgRsp Is a Novel Redox-Sensing Transcription Regulator Essential for Porphyromonas gingivalis Virulence

2019 ◽  
Vol 7 (12) ◽  
pp. 623
Author(s):  
Michał Śmiga ◽  
Teresa Olczak
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Porphyromonas Gingivalis ◽  
Alternative Pathway ◽  
Redox Status ◽  
Oxidative Stress Response ◽  
Gene Encoding ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Redox Sensing

Porphyromonas gingivalis is one of the etiological agents of chronic periodontitis. Both heme and oxidative stress impact expression of genes responsible for its survival and virulence. Previously we showed that P. gingivalis ferric uptake regulator homolog affects expression of a gene encoding a putative Crp/Fnr superfamily member, termed P. gingivalis redox-sensing protein (PgRsp). Although PgRsp binds heme and shows the highest similarity to proteins assigned to the CooA family, it could be a member of a novel, separate family of proteins with unknown function. Expression of the pgrsp gene is autoregulated and iron/heme dependent. Genes encoding proteins engaged in the oxidative stress response were upregulated in the pgrsp mutant (TO11) strain compared with the wild-type strain. The TO11 strain showed higher biomass production, biofilm formation, and coaggregation ability with Tannerella forsythia and Prevotella intermedia. We suggest that PgRsp may regulate production of virulence factors, proteases, Hmu heme acquisition system, and FimA protein. Moreover, we observed growth retardation of the TO11 strain under oxidative conditions and decreased survival ability of the mutant cells inside macrophages. We conclude that PgRsp protein may play a role in the oxidative stress response using heme as a ligand for sensing changes in redox status, thus regulating the alternative pathway of the oxidative stress response alongside OxyR.

scholarly journals A Physical Map of the Syringomycin and Syringopeptin Gene Clusters Localized to an Approximately 145-kb DNA Region of Pseudomonas syringae pv. syringae Strain B301D

2001 ◽  
Vol 14 (12) ◽  
pp. 1426-1435 ◽  
Author(s):  
Brenda K. Scholz-Schroeder ◽  
Jonathan D. Soule ◽  
Shi-En Lu ◽  
Ingeborg Grgurina ◽  
Dennis C. Gross
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Physical Map ◽  
Regulatory Element ◽  
Gene Clusters ◽  
Gene Encoding ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Genes Encoding ◽  
Size Estimates

Genetic and phenotypic mapping of an approximately 145-kb DraI fragment of Pseudomonas syringae pv. syringae strain B301D determined that the syringomycin (syr) and syringopeptin (syp) gene clusters are localized to this fragment. The syr and syp gene clusters encompass approximately 55 kb and approximately 80 kb, respectively. Both phytotoxins are synthesized by a thiotemplate mechanism of biosynthesis, requiring large multienzymatic proteins called peptide synthetases. Genes encoding peptide synthetases were identified within the syr and syp gene clusters, accounting for 90% of the DraI fragment. In addition, genes encoding regulatory and secretion proteins were localized to the DraI fragment. In particular, the salA gene, encoding a regulatory element responsible for syringomycin production and lesion formation in P. syringae pv. syringae strain B728a, was localized to the syr gene cluster. A putative ATP-binding cassette (ABC) transporter homolog was determined to be physically located in the syp gene cluster, but phenotypically affects production of both phytotoxins. Preliminary size estimates of the syr and syp gene clusters indicate that they represent two of the largest nonribosomal peptide synthetase gene clusters. Together, the syr and syp gene clusters encompass approximately 135 kb of DNA and may represent a genomic island in P. syringae pv. syringae that contributes to virulence in plant hosts.

scholarly journals Identification, Cloning, and Characterization of l-Phenylserine Dehydrogenase from Pseudomonas syringae NK-15

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Sakuko Ueshima ◽  
Hisashi Muramatsu ◽  
Takanori Nakajima ◽  
Hiroaki Yamamoto ◽  
Shin-ichiro Kato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Syringae ◽  
Homology Search ◽  
Hydroxyl Group ◽  
Enzymatic Reactions ◽  
Reaction Products ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Single Operon

The gene encoding d-phenylserine dehydrogenase from Pseudomonas syringae NK-15 was identified, and a 9,246-bp nucleotide sequence containing the gene was sequenced. Six ORFs were confirmed in the sequenced region, four of which were predicted to form an operon. A homology search of each ORF predicted that orf3 encoded l-phenylserine dehydrogenase. Hence, orf3 was cloned and overexpressed in Escherichia coli cells and recombinant ORF3 was purified to homogeneity and characterized. The purified ORF3 enzyme showed l-phenylserine dehydrogenase activity. The enzymological properties and primary structure of l-phenylserine dehydrogenase (ORF3) were quite different from those of d-phenylserine dehydrogenase previously reported. l-Phenylserine dehydrogenase catalyzed the NAD+-dependent oxidation of the β-hydroxyl group of l-β-phenylserine. l-Phenylserine and l-threo-(2-thienyl)serine were good substrates for l-phenylserine dehydrogenase. The genes encoding l-phenylserine dehydrogenase and d-phenylserine dehydrogenase, which is induced by phenylserine, are located in a single operon. The reaction products of both enzymatic reactions were 2-aminoacetophenone and CO2.

scholarly journals Translational Paradigms in Cerebrovascular Gene Transfer

2003 ◽  
Vol 23 (11) ◽  
pp. 1251-1262 ◽  
Author(s):  
Vini G Khurana ◽  
Fredric B Meyer
Keyword(s):  
Gene Transfer ◽  
Blood Vessels ◽  
Ex Vivo ◽  
Present Report ◽  
Cerebral Arteries ◽  
Experimental Studies ◽  
Gene Encoding ◽  
Expression Of Genes ◽  
Genes Encoding

Gene transfer involves the use of an engineered biologic vehicle known as a vector to introduce a gene encoding a protein of interest into a particular tissue. In diseases with known defects at a genetic level, gene transfer offers a potential means of restoring a normal molecular environment via vector-mediated entry (transduction) and expression of genes encoding potentially therapeutic proteins selectively in diseased tissues. The technology of gene transfer therefore underlies the concept of gene therapy and falls under the umbrella of the current genomics revolution. Particularly since 1995, numerous attempts have been made to introduce genes into intracranial blood vessels to demonstrate and characterize viable transduction. More recently, in attempting to translate cerebrovascular gene transfer technology closer to the clinical arena, successful transductions of normal human cerebral arteries ex vivo and diseased animal cerebral arteries in vivo have been reported using vasomodulatory vectors. Considering the emerging importance of gene-based strategies for the treatment of the spectrum of human disease, the goals of the present report are to overview the fundamentals of gene transfer and review experimental studies germane to the clinical translation of a technology that can facilitate genetic modification of cerebral blood vessels.

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