scholarly journals In planta and in vitro interactions between Phomopsis (Diaporthe) isolates and sunflower

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 461-465 ◽  
Author(s):  
A.M. Pennisi ◽  
M.R. Abenavoli ◽  
B. Maimone ◽  
L. Di Dio
Keyword(s):  
Time Course ◽  
Recognition System ◽  
Callus Cultures ◽  
In Planta ◽  
Culture Filtrates ◽  
Pathogenicity Tests ◽  
Hyphal Wall ◽  
Leaf Disks ◽  
In Vitro Interactions

In this study, we determined the amount of H<sub>2</sub>O<sub>2</sub> released by sunflower callus cultures challenged by both crude hyphal wall extracts and culture filtrates of 26 Phomopsis isolates from sunflower of worldwide origin (Argentina, France, Italy, Yugoslavia, Rumania). The amount of H<sub>2</sub>O<sub>2</sub> released by callus cultures and the production time-course response, however, did not correlate with both the amount of electrolytes released by sunflower leaf disks treated with crude culture filtrates and the results of pathogenicity tests on sunflower seedlings. Only few isolates induced a time-course response indicative of an oxidative burst. This would suggest that elicitors extracted from hyphal walls are not involved in this host-pathogen recognition system and toxic metabolites produced by Phomopsis in liquid cultures are not pathogenicity factors.

scholarly journals Analysis of differentially expressed Sclerotinia sclerotiorum genes during the interaction with moderately resistant and highly susceptible chickpea lines

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Virginia W. Mwape ◽  
Fredrick M. Mobegi ◽  
Roshan Regmi ◽  
Toby E. Newman ◽  
Lars G. Kamphuis ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Time Course ◽  
Reduction Process ◽  
Metabolic Process ◽  
Differentially Expressed ◽  
Transcriptional Analysis ◽  
Sclerotinia Stem Rot ◽  
In Planta ◽  
Moderately Resistant

Abstract Background Sclerotinia sclerotiorum, the cause of Sclerotinia stem rot (SSR), is a host generalist necrotrophic fungus that can cause major yield losses in chickpea (Cicer arietinum) production. This study used RNA sequencing to conduct a time course transcriptional analysis of S. sclerotiorum gene expression during chickpea infection. It explores pathogenicity and developmental factors employed by S. sclerotiorum during interaction with chickpea. Results During infection of moderately resistant (PBA HatTrick) and highly susceptible chickpea (Kyabra) lines, 9491 and 10,487 S. sclerotiorum genes, respectively, were significantly differentially expressed relative to in vitro. Analysis of the upregulated genes revealed enrichment of Gene Ontology biological processes, such as oxidation-reduction process, metabolic process, carbohydrate metabolic process, response to stimulus, and signal transduction. Several gene functional categories were upregulated in planta, including carbohydrate-active enzymes, secondary metabolite biosynthesis clusters, transcription factors and candidate secreted effectors. Differences in expression of four S. sclerotiorum genes on varieties with different levels of susceptibility were also observed. Conclusion These findings provide a framework for a better understanding of S. sclerotiorum interactions with hosts of varying susceptibility levels. Here, we report for the first time on the S. sclerotiorum transcriptome during chickpea infection, which could be important for further studies on this pathogen’s molecular biology.

scholarly journals Extracellular vesicles from the apoplastic fungal wheat pathogen Zymoseptoria tritici

2020 ◽  
Author(s):  
Erin H Hill ◽  
Peter Solomon
Keyword(s):  
Extracellular Vesicles ◽  
Fungal Pathogen ◽  
Plant Pathogens ◽  
Sequence Similarity ◽  
Protein Composition ◽  
Broth Culture ◽  
In Planta ◽  
Zymoseptoria Tritici ◽  
Culture Filtrates

Abstract Background: The fungal pathogen Zymoseptoria tritici is a significant constraint to wheat production in temperate cropping regions around the world. Despite its agronomic impacts, the mechanisms allowing the pathogen to asymptomatically invade and grow in the apoplast of wheat leaves before causing extensive host cell death remain elusive. Given recent evidence of extracellular vesicles (EVs) – secreted, membrane-bound nanoparticles containing molecular cargo – being implicated in extracellular communication between plants and fungal pathogen, we have initiated an in vitro investigation of EVs from this apoplastic fungal wheat pathogen. We aimed to isolate EVs from Z. tritici broth cultures and examine their protein composition in relation to the soluble protein in the culture filtrate and to existing fungal EV proteomes.Results: Zymoseptoria tritici EVs were isolated from broth culture filtrates using differential ultracentrifugation (DUC) and examined with transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Z. tritici EVs were observed as a heterogeneous population of particles, with most between 50 – 250 nm. These particles were found in abundance in the culture filtrates of viable Z. tritici cultures, but not heat-killed cultures incubated for an equivalent time and of comparable biomass. Bottom-up proteomic analysis using LC-MS/MS, followed by stringent filtering revealed 240 Z. tritici EV proteins. These proteins were distinct from soluble proteins identified in Z. tritici culture filtrates, but were similar to proteins identified in EVs from other fungi, based on sequence similarity analyses. Notably, a putative marker protein recently identified in Candida albicans EVs was also consistently detected in Z. tritici EVs.Conclusion: We have shown EVs can be isolated from the devastating fungal wheat pathogen Z. tritici and are similar to protein composition to previously characterised fungal EVs. EVs from human pathogenic fungi are implicated in virulence, but the role of EVs in the interaction of phytopathogenic fungi and their hosts is unknown. These in vitro analyses provide a basis for expanding investigations of Z. tritici EVs in planta, to examine their involvement in the infection process of this apoplastic wheat pathogen and more broadly, advance understanding of noncanonical secretion in filamentous plant pathogens.

scholarly journals The Dent Stage of Maize Kernels Is the Most Conducive for Fumonisin Biosynthesis under Field Conditions

2011 ◽  
Vol 77 (23) ◽  
pp. 8382-8390 ◽  
Author(s):  
Adeline Picot ◽  
Christian Barreau ◽  
Laëtitia Pinson-Gadais ◽  
François Piraux ◽  
Daniel Caron ◽  
...  
Keyword(s):  
Time Course ◽  
Fusarium Verticillioides ◽  
Animal Health ◽  
Maximum Level ◽  
Field Conditions ◽  
In Planta ◽  
Content Type ◽  
Short Period ◽  
Maize Kernels

ABSTRACTThe fungal pathogenFusarium verticillioidesinfects maize ears and produces fumonisins, known for their adverse effects on human and animal health. Basic questions remain unanswered regarding the kernel stage(s) associated with fumonisin biosynthesis and the kernel components involved in fumonisin regulation duringF. verticillioides-maize interaction under field conditions. In this 2-year field study, the time course ofF. verticillioidesgrowth and fumonisin accumulation in developing maize kernels, along with the variations in kernel pH and amylopectin content, were monitored using relevant and accurate analytical tools. In all experiments, the most significant increase in fumonisin accumulation or in fumonisin productivity (i.e., fumonisin production per unit of fungus) was shown to occur within a very short period of time, between 22/32 and 42 days after inoculation and corresponding to the dent stage. This stage was also characterized by acidification in the kernel pH and a maximum level of amylopectin content. Our data clearly support published results based onin vitroexperiments suggesting that the physiological stages of the maize kernel play a major role in regulating fumonisin production. Here we have validated this result forin plantaand field conditions, and we demonstrate that under such conditions the dent stage is the most conducive for fumonisin accumulation.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

The Effect of Heparin vs. Citrate on the Interaction of Platelets with Vascular Graft Materials

1985 ◽  
Vol 54 (04) ◽  
pp. 842-848 ◽  
Author(s):  
Kandice Kottke-Marchant ◽  
James M Anderson ◽  
Albert Rabinovitch ◽  
Richard A Huskey ◽  
Roger Herzig
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Vascular Graft ◽  
Time Course ◽  
Platelet Reactivity ◽  
Polymer Surfaces ◽  
In Vitro Perfusion ◽  
Citrate Anticoagulation ◽  
Platelet Release

SummaryHeparin is known to affect platelet function in vitro, but little is known about the effect of heparin on the interaction of platelets with polymer surfaces in general, and vascular graft materials in particular. For this reason, the effect of heparin vs. citrate anticoagulation on the interaction of platelets with the vascular graft materials expanded polytetrafluoroethylene (ePTFE), Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC) was studied in a recirculating, in vitro perfusion system. Platelet activation, as shown by a decrease in platelet count, an increase in platelet release and a decrease in platelet aggregation, was observed for all vascular graft materials tested using heparin and was greater for Dacron and preclotted Dacron than for ePTFE. Significant differences between heparin and citrate anticoagulation were seen for platelet release, platelet aggregation and the relative ranking of material platelet-reactivity. However, the trends and time course of platelet activation were similar with both heparin and citrate for the materials tested.

In Vitro Establishment of Powdery Mildew (Microsphaera pulchra) on Microshoots of Flowering Dogwood

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 506a-506
Author(s):  
L.A. Klein ◽  
M.T. Windham ◽  
R.N. Trigiano
Keyword(s):  
Powdery Mildew ◽  
Woody Plant ◽  
Infected Individual ◽  
Callus Cultures ◽  
Fungal Culture ◽  
Culture Collections ◽  
Flowering Dogwood ◽  
Plant Parasite ◽  
In Vitro Establishment

Microshoot and callus cultures of Cornus florida (flowering dogwood), which were grown on woody plant medium amended with BA, were inoculated with Microsphaera pulchra (an obligate plant parasite) by gently shaking infected leaves bearing numerous conidia over the tissue. Culture dishes were sealed with parafilm and incubated at 24 °C with 25 mol·m–2·s–1 provided by cool fluorescent bulbs for 15 h. Cultures were examined with a dissecting scope every 24 h and cultures transferred when contaminating fungi were present. Specimens were prepared light microscopy and SEM. The fungus infected individual callus cells, but did not sporulate. In contrast, powdery mildew was well-established (both primary and secondary hyphae) in 70% of the microshoot cultures after 6 days and sporulated on 20% by 7 to 8 days. The cellular relationship between host and pathogen in vitro was similar to that found in greenhouse-grown plants. This technique has possible applications in maintaining fungal culture collections and studying host–pathogen relationships under more stringently controlled conditions.

Studies on the mechanism of acute inhibition of thyroglobulin hydrolysis by iodine

1985 ◽  
Vol 108 (4) ◽  
pp. 511-517 ◽  
Author(s):  
Nandalal Bagchi ◽  
Birdie Shivers ◽  
Thomas R. Brown
Keyword(s):  
Time Course ◽  
Period 2 ◽  
Iodotyrosine Deiodinase ◽  
Rate Of Hydrolysis ◽  
Underlying Mechanisms ◽  
Excess Iodide ◽  
Sites Of Action ◽  
Hydrolysis Of

Abstract. Iodine in excess is known to acutely inhibit thyroidal secretion. In the present study we have characterized the time course of the iodine effect in vitro and investigated the underlying mechanisms. Labelled thyroid glands were cultured in vitro in medium containing mononitrotyrosine, an inhibitor of iodotyrosine deiodinase. The rate of hydrolysis of labelled thyroglobulin was measured as the proportion of labelled iodotyrosines and iodothyronines recovered at the end of culture and was used as an index of thyroidal secretion. Thyrotrophin (TSH) administered in vivo acutely stimulated the rate of thyroglobulin hydrolysis. Addition of Nal to the culture medium acutely inhibited both basal and TSH-stimulated thyroglobulin hydrolysis. The effect of iodide was demonstrable after 2 h, maximal after 6 h and was not reversible upon removal of iodide. Iodide abolished the dibutyryl cAMP induced stimulation of thyroglobulin hydrolysis. Iodide required organic binding of iodine for its effect but new protein or RNA synthesis was not necessary. The inhibitory effects of iodide and lysosomotrophic agents such as NH4C1 and chloroquin on thyroglobulin hydrolysis were additive suggesting different sites of action. Iodide added in vitro altered the distribution of label in prelabelled thyroglobulin in a way that suggested increased coupling in the thyroglobulin molecule. These data indicate that 1) the iodide effect occurs progressively over a 6 h period, 2) continued presence of iodide is not necessary once the inhibition is established, 3) iodide exerts its action primarily at a post cAMP, prelysosomal site and 4) the effect requires organic binding of iodine, but not new RNA or protein synthesis. Our data are consistent with the hypothesis that excess iodide acutely inhibits thyroglobulin hydrolysis by increasing the resistance of thyroglobulin to proteolytic degradation through increased iodination and coupling.

Comparative Investigation on Formation and Accumulation of Rare Phenylpropanoids in Plants and in vitro Cultures of Pimpinella major

1990 ◽  
Vol 45 (6) ◽  
pp. 602-606 ◽  
Author(s):  
B. Merkel ◽  
J. Reichling
Keyword(s):  
Callus Culture ◽  
Nutrient Medium ◽  
Callus Cultures ◽  
Comparative Investigation ◽  
In Vitro Cultures ◽  
Liquid Nutrient Medium ◽  
Whole Plants ◽  
Plant Seedlings

Abstract Unorganized callus and leaf/root-differentiating callus cultures of Pimpinella major have been established in liquid nutrient medium. Their capacity to accumulate rare phenylpropanoids such as epoxy-pseudoisoeugenol tiglate, epoxy-anol tiglate and anol tiglate was compared with that of seedlings and whole plants. The unorganized callus cultures were not able to accumulate any phenylpropanoids. In comparison, the leaf/root-differentiating callus culture promoted the accumulation of epoxy-pseudoisoeugenol tiglate (up to 90 mg/100 g fr.wt.) but not that of anol-derivatives. The accumulated amount of EPT in PMD-SH was comparable with that in plant seedlings.

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