scholarly journals Inhibition of Blumeria graminis f. sp. tritici Germination and Partial Enhancement of Wheat Defenses by Milsana

2006 ◽  
Vol 96 (11) ◽  
pp. 1278-1286 ◽  
Author(s):  
Béatrice Randoux ◽  
Delphine Renard ◽  
Emmanuel Nowak ◽  
Jean Sanssené ◽  
Josiane Courtois ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Powdery Mildew ◽  
Active Oxygen Species ◽  
In Planta ◽  
Infection Level ◽  
Conidia Germination ◽  
Fungistatic Activity ◽  
Microscopic Studies ◽  
Partial Activity

The prophylactic efficiency of Milsana against powdery mildew was evaluated on wheat (Triticum aestivum). A single short spraying on 10-day-old plantlets reduced the infection level by 85% and two long sprayings led to the total restriction of the disease. Although microscopic studies showed that Milsana treatments enhance hydrogen peroxide accumulation at the fungal penetration site, biochemical analysis did not allow us to correlate this accumulation with the activation of several enzyme activities involved in active oxygen species (AOS) metabolism. Only lipoxygenase activity, which is involved in both AOS metabolism and lipid peroxidation, showed a 26 to 32% increase 48-h posttreatment in leaves infiltrated with Milsana. This weak effect of Milsana on wheat lipid metabolism was confirmed at the lipid peroxidation level, which surprisingly, was shown to decrease in treated plants. In order to explain the high efficacy of Milsana, the fungistatic effect on conidia germination was also examined. In planta, we showed that a Milsana treatment resulted in a higher proportion of abnormally long appressorial germ tubes, whereas in vitro, it dramatically inhibited fungal conidia germination. The partial activity of Milsana in terms of defense response induction in the wheat/powdery mildew pathosystem and its newly described direct fungistatic activity are discussed.

Factors affecting the infection of sweet cherry (Prunus avium) fruit by Podosphaera cerasi

Plant Disease ◽  
2021 ◽  
Author(s):  
Claudia Probst ◽  
Binod Pandey ◽  
Prashant Swamy ◽  
Gary Glenn Grove
Keyword(s):  
Powdery Mildew ◽  
Prunus Avium ◽  
Developmental Stages ◽  
Disease Incidence ◽  
The United States ◽  
In Planta ◽  
Full Bloom ◽  
Symptomatic Disease ◽  
Conidial Concentration

Powdery mildew caused by Podosphaera cerasi is the most important fungal disease of sweet cherries in the Pacific Northwest of the United States. In this study, several factors related to disease epidemiology were evaluated. The experiments were conducted to investigate flower susceptibility to P. cerasi infection by in planta and in vitro inoculation. The susceptibility of fruit at various developmental stages was investigated using defined concentrations of P. cerasi conidia. Furthermore, the threshold of conidial concentration required for fruit infection was determined. The pathogen activity during full bloom was limited and not related to fruit disease incidence and severity at harvest. Foliar infections always preceded fruit infections by an average of 42 days during the three years of the study. The onset of fruit infection followed, on average, 66 days after full bloom and appeared simultaneously on all susceptible cherry cultivars in the research orchard. Disease symptoms were only observed on fruit in Biologische Bundesanstalt, Bundessortenamt, and Chemical industry (BBCH) scale 8 (maturity) in all cultivars examined. During this stage, a concentration of 500 conidia/ ml was sufficient to cause fruit infection at harvest. Interaction between the inoculation dates and inoculum conidial concentration revealed a dependency of disease development on the host stage at the time of conidial inoculation; the younger the fruit, the more conidia are needed to cause disease at harvest. Molecular studies showed a rapid increase in conidia viability at the transition from asymptomatic to the symptomatic disease of fruit. No evidence of ontogenic resistance of fruit to powdery mildew infection was observed.

scholarly journals Biological Control of Celery Powdery Mildew Disease Caused by Erysiphe heraclei DC In Vitro and In Vivo Conditions

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2342
Author(s):  
Hamada F. A. Ahmed ◽  
Mahmoud F. Seleiman ◽  
Adel M. Al-Saif ◽  
Maha A. Alshiekheid ◽  
Martin L. Battaglia ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Germ Tube ◽  
The Other ◽  
Biocontrol Agents ◽  
Tube Length ◽  
Conidia Germination ◽  
Germ Tube Length

The present study aimed to investigate the potentiality of certain biocontrol agents, namely Bacillus subtilis, B. pumilus, B. megaterium, Pseudomonas fluorescens, Serratia marcescens, Trichoderma album, T. harzianum and T. viride, as well as the synthetic fungicide difenoconazole to control celery powdery mildew caused by Erysiphe heraclei DC, in vitro (against conidia germination and germ tube length of E. heraclei) and in vivo (against disease severity and AUDPC). In vitro, it was found that the antifungal activity of the tested biocontrol agents significantly reduced the germination percentage of the conidia and germ tube length of the pathogen. The reduction in conidia germination ranged between 88.2% and 59.6% as a result of the treatment with B. subtilis and T. album, respectively compared with 97.1% by the synthetic fungicide difenoconazole. Moreover, the fungicide achieved the highest reduction in germ tube length (92.5%) followed by B. megaterium (82.0%), while T. album was the least effective (62.8%). Spraying celery plants with the tested biocontrol agents in the greenhouse significantly reduced powdery mildew severity, as well as the area under the disease progress curve (AUDPC), after 7, 14, 21 and 28 days of application. In this regard, B. subtilis was the most efficient followed by B. pumilus, S. marcescens and B. megaterium, with 80.1, 74.4, 73.2 and 70.5% reductions in disease severity, respectively. In AUDPC, reductions of those microorganisms were 285.3, 380.9, 396.7 and 431.8, respectively, compared to 1539.1 in the control treatment. On the other hand, the fungicide difenoconazole achieved maximum efficacy in reducing disease severity (84.7%) and lowest AUDPC (219.3) compared to the other treatments. In the field, all the applied biocontrol agents showed high efficiency in suppressing powdery mildew on celery plants, with a significant improvement in growth and yield characteristics. In addition, they caused an increase in the concentration of leaf pigments, and the activities of defense-related enzymes such as peroxidase (PO) and polyphenol oxidase (PPO) and total phenol content (TPC). In conclusion, the results showed the possibility of using tested biocontrol agents as eco-friendly alternatives to protect celery plants against powdery mildew.

scholarly journals Ultra high diluted arsenic reduces spore germination of Alternaria brassicicola and dark leaf spot in cauliflower

2016 ◽  
Vol 34 (3) ◽  
pp. 318-325
Author(s):  
Grazia Trebbi ◽  
Paola Nipoti ◽  
Valeria Bregola ◽  
Maurizio Brizzi ◽  
Giovanni Dinelli ◽  
...  
Keyword(s):  
Spore Germination ◽  
Leaf Spot ◽  
Field Trial ◽  
Alternaria Brassicicola ◽  
In Planta ◽  
Infection Level ◽  
Copper Salts ◽  
High Dilutions ◽  
Germination Experiments

ABSTRACT A major problem in cauliflower crop is the fungus Alternaria brassicicola, which causes dark leaf spot on Brassicaceae family. The current use of copper salts in agriculture is questioned. In fact, these products present some disadvantages, connected mainly with their deposits in the soil and toxicity on plants. This work investigated the effects of arsenic treatments, in ultra high diluted form (UHD), prepared by a process of repeated dilution and succussion (shaking), through: 1) in vitro germination experiments, where spores of A. brassicicola were suspended in the treatments; 2) in planta experiments and 3) a field trial, where cauliflower plants infected by the fungus were sprayed with treatments. The results showed that ultra high dilutions of arsenic (where no more molecules of this substance are present) were effective in all the experiments, inhibiting spore germination by 60.0%, controlling fungal disease in in planta experiments (relative efficacy of 42.1%), and, in field trial, decreasing the mean infection level in cauliflower heads by 45.7% and 41.6% in artificially inoculated and naturally infected plants, respectively. This is the first study to demonstrate that ultra high dilutions effectively reduce in vitro spore germination and infection of A. brassicicola in cauliflower plants, both under controlled conditions and in the field. Our research is still very experimental, however, in light of the significant results obtained with ultra-diluted arsenic, and given that its extreme high dilution level precludes any toxicity or accumulation in the environment, the use of UHDs could be considered a potential and reliable approach for sustainable agriculture.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Biopharmaceutical and Preclinical Studies of Zaleplon as Semisolid Dispersions with Self-emulsifying Lipid Surfactants for Oral Delivery

1970 ◽  
Vol 9 (1) ◽  
pp. 3102-3111
Author(s):  
Narendar Dudhipala ◽  
Arjun Narala ◽  
Dinesh Suram ◽  
Karthik Yadav Janga
Keyword(s):  
Oral Delivery ◽  
Molecular State ◽  
In Vivo Studies ◽  
In Vitro Dissolution ◽  
Content Uniformity ◽  
Phase Solubility ◽  
Microscopic Studies ◽  
Pure Drug

The objective of this present study is to develop a semisolid dispersion (SSD) of zaleplon with the aid of self-emulsifying lipid based amphiphilic carriers (TPGS E or Gelucire 44/14) addressing the poor solubility of this drug. A linear relationship between the solubility of drug with respect to increase in the concentration of lipid surfactant in aqueous medium resulting in AL type phase diagram was observed from phase solubility studies. Fusion method was employed to obtain semisolid dispersions (SSD) of zaleplon which showed high content uniformity of drug. The absence of chemical interactions between the pure drug, excipients and formulations were conferred by Fourier transmission infrared spectroscopic examinations. The photographic images from polarized optical microscopic studies revealed the change in crystalline form of drug to amorphous or molecular state. The superior dissolution parameters of zaleplon from SSD over pure crystalline drug interpreted from in vitro dissolution studies envisage the ability of these lipid surfactants as solubility enhancers. Further, the caliber of TPGS E or Gelucire 44/14 in encouraging the GI absorption of drug was evident with the higher human effective permeability coefficient and fraction oral dose of drug absorbed from SSD in situ intestinal permeation study. In conclusion, in vivo studies in Wister rats demonstrated an improvement in the oral bioavailability of zaleplon from SSD over control pure drug suspension suggesting the competence of Gelucire 44/14 and TPGS E as conscientious carriers to augment the dissolution rate limited bioavailability of this active

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.

Chemosensitizing Activity of Histone Deacetylases Inhibitory Cyclic Hydroxamic Acids for Combination Chemotherapy of Lymphatic Leukemia

2018 ◽  
Vol 18 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Denis V. Mishchenko ◽  
Margarita E. Neganova ◽  
Elena N. Klimanova ◽  
Tatyana E. Sashenkova ◽  
Sergey G. Klochkov ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Acute Toxicity ◽  
Histone Deacetylases ◽  
Hydroxamic Acids ◽  
Water Soluble ◽  
Male Rat ◽  
Hybrid Male ◽  
Cyclic Hydroxamic Acids

Background: Anti-tumor effect of hydroxamic acid derivatives is largely connected with its properties as efficient inhibitors of histone deacetylases, and other metalloenzymes involved in carcinogenesis. Objective: The work was aimed to (i) determine the anti-tumor and chemosensitizing activity of the novel racemic spirocyclic hydroxamic acids using experimental drug sensitive leukemia P388 of mice, and (ii) determine the structure-activity relationships as metal chelating and HDAC inhibitory agents. Method: Outbreed male rat of 200-220 g weights were used in biochemical experiments. In vivo experiments were performed using the BDF1 hybrid male mice of 22-24 g weight. Lipid peroxidation, Fe (II) -chelating activity, HDAC fluorescent activity, anti-tumor and anti-metastatic activity, acute toxicity techniques were used in this study. Results: Chemosensitizing properties of water soluble cyclic hydroxamic acids (CHA) are evaluated using in vitro activities and in vivo methods and found significant results. These compounds possess iron (II) chelating properties, and slightly inhibit lipid peroxidation. CHA prepared from triacetonamine (1a-e) are more effective Fe (II) ions cheaters, as compared to CHA prepared from 1- methylpiperidone (2a-e). The histone deacetylase (HDAC) inhibitory activity, lipophilicity and acute toxicity were influenced by the length amino acids (size) (Glycine < Alanine < Valine < Leucine < Phenylalanine). All compounds bearing spiro-N-methylpiperidine ring (2a-e) are non-toxic up to 1250 mg/kg dose, while compounds bearing spiro-tetramethylpiperidine ring (1a-e) exhibit moderate toxicity which increases with increasing lipophility, but not excite at 400 mg/kg. Conclusion: It was shown that the use of combination of non-toxic doses of cisplatin (cPt) or cyclophosphamide with CHA in most cases result in the appearance of a considerable anti-tumor effect of cytostatics. The highest chemosensitizing activity with respect to leukemia Р388 is demonstrated by the CHA derivatives of Valine 1c or 2c.

scholarly journals Amelioration of lipid peroxidation in vivo and in vitro by Satureja khozestanica essential oil in alloxan-induced diabetic rats

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Hassan Ahmadvand ◽  
Majid Tavafi ◽  
Ali Khosrowbeygi ◽  
Gholamreza Shahsavari ◽  
Maryam Hormozi ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Essential Oil ◽  
Diabetic Rats

scholarly journals Alternative Control of Phragmidium rubi-idaei Infecting Two Rubus Species

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1452
Author(s):  
Raluca-Maria Pârlici ◽  
Aurel Maxim ◽  
Stefania Mirela Mang ◽  
Ippolito Camele ◽  
Lucia Mihalescu ◽  
...  
Keyword(s):  
Organic Farming ◽  
Plant Pathogens ◽  
Field Experiments ◽  
Control Sample ◽  
Field Tests ◽  
In Vitro Tests ◽  
Rust Disease ◽  
Conidia Germination ◽  
The Impact

Organic berry plantations have been gaining popularity among farmers during recent years. Even so, farmers experience serious challenges in disease control management, which is a concern in organic farming. Phragmidiumrubi-idaei (DC) P. Karst is the pathogen responsible for blackberry and raspberry rust disease, one of the most present and active diseases in plantations. The antifungal certified products found on the organic farming market offer the opportunity for an efficient control strategy over plant pathogens in fruit shrub plantations. In this study, 5 natural based products—namely Altosan, Mimox, Canelys, Zitron, and Zeolite—were tested for their fungistatic effect over P. rubi-idaei. The experiments were carried out under laboratory conditions, performing observations over the impact of organic products, used at different concentration levels, on rust conidia germination. Moreover, field experiments were conducted in order to evaluate the efficiency of different treatments for rust control on raspberry (‘Polka’, ‘Veten’ and ‘Heritage’) and blackberry (‘Thorn Free’, ‘Chester’ and ‘Loch Ness’) varieties. Data analysis based on ANOVA tests showed significant differences between the tested variants and the control sample at p < 0.001. Furthermore, LSD test confirmed differences between all substances tested (p < 0.005). The natural products Canelys (formulated with cinnamon) and Zytron (based on citrus extract) have proven the highest inhibitory capacity for conidia germination during in vitro tests registering values of 80.42% and 78.34%, respectively. The same high inhibitory rates against rust pathogen were kept also in the field tests using the same two natural-based products mentioned earlier. In addition, outcomes from this study demonstrated that Zeolite is not recommended for raspberry or blackberry rust control.

scholarly journals A peroxisomal β-oxidative pathway contributes to the formation of C6–C1 aromatic volatiles in poplar

2021 ◽  
Author(s):  
Nathalie D Lackus ◽  
Axel Schmidt ◽  
Jonathan Gershenzon ◽  
Tobias G Köllner
Keyword(s):  
Cinnamic Acid ◽  
Aromatic Compounds ◽  
Populus Trichocarpa ◽  
Alternative Pathway ◽  
Gene Families ◽  
Defense Responses ◽  
In Planta ◽  
Black Cottonwood ◽  
Oxidative Pathway

AbstractBenzenoids (C6–C1 aromatic compounds) play important roles in plant defense and are often produced upon herbivory. Black cottonwood (Populus trichocarpa) produces a variety of volatile and nonvolatile benzenoids involved in various defense responses. However, their biosynthesis in poplar is mainly unresolved. We showed feeding of the poplar leaf beetle (Chrysomela populi) on P. trichocarpa leaves led to increased emission of the benzenoid volatiles benzaldehyde, benzylalcohol, and benzyl benzoate. The accumulation of salicinoids, a group of nonvolatile phenolic defense glycosides composed in part of benzenoid units, was hardly affected by beetle herbivory. In planta labeling experiments revealed that volatile and nonvolatile poplar benzenoids are produced from cinnamic acid (C6–C3). The biosynthesis of C6–C1 aromatic compounds from cinnamic acid has been described in petunia (Petunia hybrida) flowers where the pathway includes a peroxisomal-localized chain shortening sequence, involving cinnamate-CoA ligase (CNL), cinnamoyl-CoA hydratase/dehydrogenase (CHD), and 3-ketoacyl-CoA thiolase (KAT). Sequence and phylogenetic analysis enabled the identification of small CNL, CHD, and KAT gene families in P. trichocarpa. Heterologous expression of the candidate genes in Escherichia coli and characterization of purified proteins in vitro revealed enzymatic activities similar to those described in petunia flowers. RNA interference-mediated knockdown of the CNL subfamily in gray poplar (Populus x canescens) resulted in decreased emission of C6–C1 aromatic volatiles upon herbivory, while constitutively accumulating salicinoids were not affected. This indicates the peroxisomal β-oxidative pathway participates in the formation of volatile benzenoids. The chain shortening steps for salicinoids, however, likely employ an alternative pathway.

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