scholarly journals Development and Significance of Dicarboximide Resistance in Sclerotinia minor Isolates from Commercial Lettuce Fields in California

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 148-153 ◽  
Author(s):  
J. C. Hubbard ◽  
K. V. Subbarao ◽  
S. T. Koike
Keyword(s):  
Fungicide Resistance ◽  
Disease Incidence ◽  
Vegetative Mycelium ◽  
Wild Type ◽  
In Vitro Production ◽  
Field Isolates ◽  
Resistant Strains ◽  
Measurable Growth ◽  
Vitro Production

Three growth stages of each of 20 Sclerotinia minor isolates were tested for resistance to iprodione. Sclerotia and both vegetative and mature mycelium of each isolate were plated on potato-dextrose agar (PDA) amended with 0, 1, 5, 10, 25, and 100 µg of the fungicide per ml, and radial growth was measured. All wild-type field isolates were initially sensitive and did not grow in the presence of iprodione. However, fungicide resistance arose readily in vitro. All 20 isolates produced measurable growth (≥2 mm) on iprodione at 5 µg/ml after 2 weeks when started from mature mycelium, and 18 of 20 isolates produced measurable growth after 4 weeks when started from vegetative mycelium. In general, fungicide-resistant growth arose more frequently and mean colony diameters were significantly greater (P ≤ 0.05) with mature mycelium than with vegetative mycelium at all times and concentrations. In sclerotial germination tests, at least 1% of sclerotia germinated in 18 of 20 isolates after 2 weeks on iprodione at 5 µg/ml, and in 19 of 20 isolates after 5 weeks on 100 µg/ml. Of growth produced on 79 plates containing iprodione, 73 remained viable on PDA after 5 months, and 71 retained resistance to 5 µg/ml. Seventy of these also exhibited cross-resistance to vinclozolin, another dicarboximide fungicide. Pathogenicity of five fungicide-resistant strains was tested in greenhouse, microplot, and field experiments, with and without iprodione. Two months after in vitro production, one of the five resistant strains was avirulent, but disease incidence for the other four ranged from 40 to 75%, compared with 40% for the wild-type isolates. However, the virulence of the fungicide-resistant strains declined over time. Ten months after their production, two of the isolates were avirulent and disease incidence for the others ranged from 3 to 17%, compared with 40 to 90% for the wild-type isolates. The strains that remained virulent 5 and 7 months after in vitro production were not significantly controlled by iprodione sprayed according to labeled rates, although disease was significantly controlled by the fungicide in treatments inoculated with wild-type field isolates (P > 0.05). In experiments in commercial fields to determine the efficacy of fungicide sprays on the wild-type S. minor population, there was no evidence that fungicide resistance was the cause of lack of lettuce drop control observed in many coastal California fields. Application of fungicides at a less than optimal time may account for some incidents of control failure.

scholarly journals Kinetic analysis of in vitro production of wild-type Spodoptera frugiperda nucleopolyhedrovirus

2010 ◽  
Vol 53 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Andréa Farias de Almeida ◽  
Gorete Ribeiro de Macedo ◽  
Leslie Chee Loong Chan ◽  
Márcia Regina da Silva Pedrini
Keyword(s):  
Cell Line ◽  
Spodoptera Frugiperda ◽  
Wild Type ◽  
In Vitro Production ◽  
Extracellular Virus ◽  
Cell Productivity ◽  
The Mean ◽  
Body Production ◽  
Vitro Production

In this study, the kinetic behavior of Sf9 and Sf21 cells used in the production of a baculovirus biopesticide to control the pest of corn Spodoptera frugiperda was analyzed. Kinetic variables such as maximum specific growth rate, cell productivity, mean rate of infection, as well as the mean rate of occlusion body production were determined during the infection of these cell-lines with the extracellular virus of the S. frugiperda nucleopolyhedrovirus (SfMNPV). The Sf9 cell-line resulted in better viral production results (5.0 x 10(8) OB/mL) than the Sf21 cell-line (2.5 x 10(8) OB/mL).

scholarly journals CO and CN− syntheses by [FeFe]-hydrogenase maturase HydG are catalytically differentiated events

2015 ◽  
Vol 113 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Adrien Pagnier ◽  
Lydie Martin ◽  
Laura Zeppieri ◽  
Yvain Nicolet ◽  
Juan C. Fontecilla-Camps
Keyword(s):  
Elimination Reaction ◽  
Wild Type ◽  
In Vitro Production ◽  
Iron Sulfur Cluster ◽  
Iron Sulfur ◽  
Catalytic Sites ◽  
Well Differentiated ◽  
Vitro Production ◽  
Formate Production

The synthesis and assembly of the active site [FeFe] unit of [FeFe]-hydrogenases require at least three maturases. The radical S-adenosyl-l-methionine HydG, the best characterized of these proteins, is responsible for the synthesis of the hydrogenase CO and CN− ligands from tyrosine-derived dehydroglycine (DHG). We speculated that CN− and the CO precursor −:CO2H may be generated through an elimination reaction. We tested this hypothesis with both wild type and HydG variants defective in second iron-sulfur cluster coordination by measuring the in vitro production of CO, CN−, and −:CO2H-derived formate. We indeed observed formate production under these conditions. We conclude that HydG is a multifunctional enzyme that produces DHG, CN−, and CO at three well-differentiated catalytic sites. We also speculate that homocysteine, cysteine, or a related ligand could be involved in Fe(CO)x(CN)y transfer to the HydF carrier/scaffold.

Antifungal susceptibilities, in vitro production of virulence factors and activities of ceragenins against Candida spp. isolated from vulvovaginal candidiasis

2018 ◽  
Vol 57 (3) ◽  
pp. 291-299 ◽  
Author(s):  
Mayram Hacioglu ◽  
Cagla Bozkurt Guzel ◽  
Paul B Savage ◽  
A Seher Birteksoz Tan
Keyword(s):  
Candida Albicans ◽  
Vulvovaginal Candidiasis ◽  
In Vitro Production ◽  
Candida Spp ◽  
Common Cause ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Vitro Production ◽  
Potential Use

Abstract Vulvovaginal candidiasis (VVC) is the second most common cause of vaginitis after bacterial vaginosis, affecting millions of women worldwide every year. Candida albicans is the most frequent agent of VVC followed by other species of Candida such as C. glabrata and C. parapsilosis. Out of a total of 100 clinical isolates of Candida spp. obtained from patients diagnosed with VVC, 84 were identified as C. albicans, while the remaining isolates were identified as non–-albicans Candida strains. Phospholipases and proteinases were produced by a majority of the C. albicans strains and esterases and hemolysins a minority of these strains. Among the non–C. albicans strains, only a few of the strains produced these proteins. Nearly all of the isolates formed biofilms. Our results showed that the butoconazole, clotrimazole, and fluconazole were active against C. albicans and less so against the non–albicans Candida strains. The MIC90 of amphotericin B and nystatins were 2 and 4 μg/ml, respectively, against either C. albicans or non–albicans Candida spp. Representative ceragenins (CSA-13, CSA-131, and CSA-138), developed as mimics of endogenous antimicrobial peptides, were active against fluconazole-resistant strains, both alone and in combination with fluconazole. These results suggest the potential use of ceragenins in treating VVC, including infections caused by fluconazole-resistant isolates.

In vitro production studies with a wild-type Helicoverpa baculovirus

1996 ◽  
Vol 22 (1-3) ◽  
pp. 217-224 ◽  
Author(s):  
Shukla Chakraborty ◽  
Paul Greenfield ◽  
Steven Reid
Keyword(s):  
Wild Type ◽  
In Vitro Production ◽  
Production Studies ◽  
Vitro Production

THE IN VITRO PRODUCTION OF ANDROGENS BY FOLLICULAR TISSUE OF RABBITS

1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz
Keyword(s):  
In Vitro Production ◽  
Vitro Production

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

scholarly journals Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

2021 ◽  
Vol 11 (4) ◽  
pp. 1694
Author(s):  
Amna Komal Khan ◽  
Sidra Kousar ◽  
Duangjai Tungmunnithum ◽  
Christophe Hano ◽  
Bilal Haider Abbasi ◽  
...  
Keyword(s):  
World Market ◽  
Culture Technique ◽  
In Vitro Cultures ◽  
Defense System ◽  
In Vitro Production ◽  
Metallic Oxide ◽  
Global Demand ◽  
Over Exploitation ◽  
Vitro Production

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

Sign in / Sign up

Export Citation Format

Share Document