scholarly journals A Culture Filtrate of Phytophthora infestans Primes Defense Reaction in Potato Cell Suspensions

2008 ◽  
Vol 98 (6) ◽  
pp. 653-658 ◽  
Author(s):  
F. Val ◽  
S. Desender ◽  
K. Bernard ◽  
P. Potin ◽  
G. Hamelin ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Priming Effect ◽  
Cell Suspensions ◽  
Disease Suppression ◽  
Pectobacterium Atrosepticum ◽  
Defense Reactions ◽  
Potato Cell ◽  
High Concentrations ◽  
In Cells

Priming of defense reactions by an elicitor results in an enhanced ability of the plant to respond to subsequent pathogen challenges. We previously showed that application of lipopolysaccharides (LPS) to potato cell suspensions causes apoplastic acidification, but does not stimulate lipoxygenase (LOX) activity. Here, we tested the ability of various elicitors to prime and elicit defense reactions in potato cell suspensions. Adding 20 μg ml–1 LPS, laminarin, harpin N, or a concentrated culture filtrate (CCF) of Phytophthora infestans to cell cultures 18 h before a second elicitation with LPS did not alter the intensity of apoplastic acidification compared with a single LPS application. Conversely, high concentrations (200 or 400 μg ml–1) of LPS, laminarin, and harpin N activated LOX in cells pretreated with 1 μg ml–1 CCF, but not in cells pretreated with LPS, laminarin, or harpin N. LOX response was maximal in pretreated cells of potato cv. Bintje when the second elicitation occurred 18 to 24 h after CCF application. These results showed that LOX activation is primed in potato cells by CCF, but not by LPS, harpin N, or laminarin. Finally, bioassays showed a slightly greater reduction of rot weight in half tubers treated with CCF followed by LPS before inoculation with Pectobacterium atrosepticum than in half tubers treated with either preparation alone, indicating a priming effect of CCF on both LOX induction and disease suppression.

Differential Responses of Potato Cell Suspensions to a Culture Filtrate of Phytophthora infestans

1997 ◽  
Vol 52 (5-6) ◽  
pp. 333-338 ◽  
Author(s):  
M. F. M. Awan ◽  
U. Maciejewska ◽  
K. Kleczkowski ◽  
B. Wielgat
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Phenylalanine Ammonia Lyase ◽  
Solanum Tuberosum L ◽  
Defense Responses ◽  
Cell Suspensions ◽  
Plant Defense Responses ◽  
Polygenic Resistance ◽  
Pal Activity ◽  
Potato Cell

Abstract General (polygenic) resistance of plant hosts to an attack by a range of pathogens is an important feature of plant defense responses against the infection. In search of biochemical markers defining this resistance, cell suspensions derived from leaves of potato (Solanum tuberosum L .) cvs. Tarpan and Bzura that are polygenically susceptible and resistant to Phytophthora infestans, respectively, were inoculated with culture filtrate (CF) of the fungus. Cell suspension of Tarpan responded to CF treatment by a higher extracellular alkalinization and more significant reduction in their viability and growth than those of the Bzura cultivar. The stimulation of phenylalanine ammonia-lyase (PAL ) activity but not of β-1,3-glucanase, was significantly higher in CF treated Bzura cells than in Tarpan ones. The obtained results suggest that sensitivity to the fungal toxins and variation of PAL activity may represent useful markers for the evaluation of polygenic resistance in potato.

scholarly journals Identification of Three Elicitins and a Galactan-Based Complex Polysaccharide from a Concentrated Culture Filtrate of Phytophthora infestans Efficient against Pectobacterium atrosepticum

Molecules ◽  
2014 ◽  
Vol 19 (10) ◽  
pp. 15374-15390 ◽  
Author(s):  
Guillaume Saubeau ◽  
Fanny Gaillard ◽  
Laurent Legentil ◽  
Caroline Nugier-Chauvin ◽  
Vincent Ferrières ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Pectobacterium Atrosepticum

The Oxidative Processes Induced in Cell Suspensions of Solanum Species by Culture Filtrate of Phytophthora infestans

2001 ◽  
Vol 56 (3-4) ◽  
pp. 235-244 ◽  
Author(s):  
Lidia Polkowska-Kowalczyk ◽  
Urszula Maciejewska
Keyword(s):  
Lipid Peroxidation ◽  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Peroxidase Activity ◽  
Solanum Species ◽  
Cell Suspensions ◽  
Ros Production ◽  
Polygenic Resistance ◽  
Membrane Bound ◽  
Oxidative Processes

Abstract Solanum genotypes that differ in the level of polygenic resistance to the oomycete plant pathogen Phytophthora infestans were studied for their oxidative response to culture filtrate (CF) of the pathogen. Reactive oxygen species (ROS) production, peroxidase activity and lipid peroxidation have been studied in the CF-treated cell suspensions derived from leaves of the resistant S. nigrum (nonhost) and 5. tuberosum cv. Bzura as well as from the susceptible S. tuberosum cv. Tarpan and clone H-8105. In both the resistant and susceptible cells the CF induced similar processes, but these varied with respect to the kinetics and intensity. In all cells probably the membrane-bound NADPH oxidase, was responsible for the ROS production. This process was more intensive and prolonged in the susceptible cells than in the resistant ones. The CF treatment slightly affected peroxidase activity in all cells studied. Lipid peroxidation that occurred as a consequence of the ROS accumulation was pronounced mainly in the susceptible cells. We suggest that lack of stringent control of the oxidative processes and sensitivity to the pathogen toxins may be decisive for limited polygenic resistance in potato.

scholarly journals Nrf2 Signaling Pathway in Chemoprotection and Doxorubicin Resistance: Potential Application in Drug Discovery

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 349
Author(s):  
Sepideh Mirzaei ◽  
Ali Zarrabi ◽  
Farid Hashemi ◽  
Amirhossein Zabolian ◽  
Hossein Saleki ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Adverse Effects ◽  
Cancer Progression ◽  
Related Factor ◽  
Pharmacological Agents ◽  
Nrf2 Signaling Pathway ◽  
High Concentrations ◽  
Genetic Interventions ◽  
Underlying Mechanisms ◽  
In Cells

Doxorubicin (DOX) is extensively applied in cancer therapy due to its efficacy in suppressing cancer progression and inducing apoptosis. After its discovery, this chemotherapeutic agent has been frequently used for cancer therapy, leading to chemoresistance. Due to dose-dependent toxicity, high concentrations of DOX cannot be administered to cancer patients. Therefore, experiments have been directed towards revealing underlying mechanisms responsible for DOX resistance and ameliorating its adverse effects. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is activated to increase levels of reactive oxygen species (ROS) in cells to protect them against oxidative stress. It has been reported that Nrf2 activation is associated with drug resistance. In cells exposed to DOX, stimulation of Nrf2 signaling protects cells against cell death. Various upstream mediators regulate Nrf2 in DOX resistance. Strategies, both pharmacological and genetic interventions, have been applied for reversing DOX resistance. However, Nrf2 induction is of importance for alleviating side effects of DOX. Pharmacological agents with naturally occurring compounds as the most common have been used for inducing Nrf2 signaling in DOX amelioration. Furthermore, signaling networks in which Nrf2 is a key player for protection against DOX adverse effects have been revealed and are discussed in the current review.

In Vitro Reaction of Potato Micronodes to Culture Filtrate of Phytophthora Infestans

1989 ◽  
pp. 441-442 ◽  
Author(s):  
P. Crinò ◽  
R. Penuela ◽  
L. Martino ◽  
A. Sonnino ◽  
G. Ancora
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate

scholarly journals Geranic Acid Formation, an Initial Reaction of Anaerobic Monoterpene Metabolism in DenitrifyingAlcaligenes defragrans

2000 ◽  
Vol 66 (7) ◽  
pp. 3004-3009 ◽  
Author(s):  
Udo Heyen ◽  
Jens Harder
Keyword(s):  
Culture Medium ◽  
Degradation Pathway ◽  
Unsaturated Hydrocarbon ◽  
Cell Suspensions ◽  
Carbon Limitation ◽  
Initial Reaction ◽  
Activation Reaction ◽  
Geranic Acid ◽  
Monoterpene Metabolism ◽  
In Cells

ABSTRACT Monoterpenes with an unsaturated hydrocarbon structure are mineralized anaerobically by the denitrifying β-proteobacteriumAlcaligenes defragrans. Organic acids occurring in cells ofA. defragrans and culture medium were characterized to identify potential products of the monoterpene activation reaction. Geranic acid (E,E-3,7-dimethyl-2,6-octadienoic acid) accumulated to 0.5 mM in cells grown on α-phellandrene under nitrate limitation. Cell suspensions of A. defragrans65Phen synthesized geranic acid in the presence of β-myrcene, α-phellandrene, limonene, or α-pinene. Myrcene yielded the highest transformation rates. The alicyclic acid was consumed by cell suspensions during carbon limitation. Heat-labile substances present in cytosolic extracts catalyzed the formation of geranic acid from myrcene. These results indicated that a novel monoterpene degradation pathway must be present in A. defragrans.

scholarly journals A Mating-Induced Protein of Phytophthora infestans Is a Member of a Family of Elicitors with Divergent Structures and Stage-Specific Patterns of Expression

2003 ◽  
Vol 16 (10) ◽  
pp. 926-935 ◽  
Author(s):  
Anna-Liisa Fabritius ◽  
Howard S. Judelson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gene Family ◽  
Phytophthora Infestans ◽  
Amino Acid Identity ◽  
Acid Identity ◽  
Terminal Domain ◽  
Defense Reactions ◽  
The Family ◽  
Microbe Interactions

Five members of an elicitor-like gene family from Phytophthora infestans were examined. The family was identified through the analysis of M81, a mating-induced gene. The predicted M81 product resembled a 42-kDa P. sojae glycoprotein known to elicit defense reactions in plants, including a host of P. infestans, potato. M81 was the most structurally and functionally divergent of the P. infestans genes compared with the P. sojae sequence. M81 lacked elicitor activity, had the lowest protein identity (47%), displayed mating-specific transcription, and had a novel C-terminal domain. The latter contained a 30-residue proline- and threonine-rich motif, which, remarkably, was tandemly repeated 24 to 36 times in different alleles. M81C, M81D, and M81E better resembled the P. sojae protein based on amino acid identity (63 to 75%) and conserved elicitor activity. M81C and M81D mRNA accumulated only during zoosporogenesis, while M81E expression was restricted to hyphae. M81B, an apparent pseudogene, was physically linked to M81. The protein products of each gene were predicted to be extracellular transglutaminases ranging in size from 436 to 1,607 amino acids. Genes with an elicitor, proline- and threonine-rich repeat, and both elicitor and repeat domains were widely distributed throughout Phytophthora infestans. These findings help explain the natural functions of elicitors in pathogen biology and plant-microbe interactions.

scholarly journals Electroporation can cause artefacts due to solubilization of cations from the electrode plates. Aluminum ions enhance conversion of inositol 1,3,4,5-tetrakisphosphate into inositol 1,4,5-trisphosphate in electroporated L1210 cells

1991 ◽  
Vol 277 (3) ◽  
pp. 883-885 ◽  
Author(s):  
J W Loomis-Husselbee ◽  
P J Cullen ◽  
R F Irvine ◽  
A P Dawson
Keyword(s):  
Experimental System ◽  
Experimental Medium ◽  
Assay Medium ◽  
L1210 Cells ◽  
Aluminum Ions ◽  
Inositol 1,4,5 Trisphosphate ◽  
The Difference ◽  
High Concentrations ◽  
As If ◽  
In Cells

1. In electroporated L1210 cells, Ins(1,3,4,5)P4 causes Ca2+ release, owing to its conversion into Ins(1,4,5)P3, but this does not happen in cells permeabilized by digitonin treatment [Cullen, Irvine, Drøbak & Dawson (1989) Biochem. J. 259, 931-933]. 2. If the assay medium is subjected to electroporation by using a commercially available electroporation apparatus and then the cells are added and permeabilized with digitonin, the cells behave as if they had been electroporated. 3. Electroporation causes the release of high concentrations of Al3+ into the experimental medium, and addition of these concentrations of Al3+ into the experimental medium mimics the effect of electroporation on the conversion of Ins(1,3,4,5)P4 into Ins(1,4,5)P3. 4. It is concluded that the difference between electroporated and digitonin-permeabilized L1210 cells in this experimental system can be attributed to dissolution of Al3+ from the electroporation cuvette. Al3+ contamination may thus be a serious problem when using this apparatus.

scholarly journals Assembly of the mammalian muscle acetylcholine receptor in transfected COS cells.

1991 ◽  
Vol 114 (4) ◽  
pp. 799-807 ◽  
Author(s):  
Y Gu ◽  
J R Forsayeth ◽  
S Verrall ◽  
X M Yu ◽  
Z W Hall
Keyword(s):  
Acetylcholine Receptor ◽  
Surface Binding ◽  
Mouse Muscle ◽  
Cos Cells ◽  
Gamma Subunits ◽  
Alpha Beta ◽  
High Concentrations ◽  
Alpha Bungarotoxin ◽  
Transfection Mixture ◽  
In Cells

We have investigated the mechanisms of assembly and transport to the cell surface of the mouse muscle nicotinic acetylcholine receptor (AChR) in transiently transfected COS cells. In cells transfected with all four subunit cDNAs, AChR was expressed on the surface with properties resembling those seen in mouse muscle cells (Gu, Y., A. F. Franco, Jr., P.D. Gardner, J. B. Lansman, J. R. Forsayeth, and Z. W. Hall. 1990. Neuron. 5:147-157). When incomplete combinations of AChR subunits were expressed, surface binding of 125I-alpha-bungarotoxin was not detected except in the case of alpha beta gamma which expressed less than 15% of that seen with all four subunits. Immunoprecipitation and sucrose gradient sedimentation experiments showed that in cells expressing pairs of subunits, alpha delta and alpha gamma heterodimers were formed, but alpha beta was not. When three subunits were expressed, alpha delta beta and alpha gamma beta complexes were formed. Variation of the ratios of the four subunit cDNAs used in the transfection mixture showed that surface AChR expression was decreased by high concentrations of delta or gamma cDNAs in a mutually competitive manner. High expression of delta or gamma subunits also each inhibited formation of a heterodimer with alpha and the other subunit. These results are consistent with a defined pathway for AChR assembly in which alpha delta and alpha gamma heterodimers are formed first, followed by association with the beta subunit and with each other to form the complete AChR.

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