scholarly journals Interrelationship between stilbene producing ability and Aspergillus colonization on selected peanut (Arachis hypogaea L.) genotypes

2019 ◽  
Vol 46 (2) ◽  
pp. 118-126 ◽  
Author(s):  
Jwalit J Nayak ◽  
Pranavkumar D Gajjar ◽  
Sheikh M Basha ◽  
KSS Naik
Keyword(s):  
Comparative Evaluation ◽  
Breeding Population ◽  
Aflatoxin Contamination ◽  
Fungal Colonization ◽  
Biotic And Abiotic Stresses ◽  
Control Seed ◽  
Arachis Hypogaea L ◽  
Water Cutting ◽  
The Relationship

ABSTRACT Stilbenes are phytoalexins expressed by plants to avoid/resist certain biotic and abiotic stresses. This study was envisioned to determine the interrelationship between stilbenes producing ability of peanut genotypes and Aspergillus colonization level. Stilbenes were induced in peanut cotyledon in vitro by soaking in water, cutting them into thin slices, and subsequently challenging them with Aspergillus flavus. Fungal colonization was then measured in the cotyledon slices. The results showed major differences in fungal colonization levels between the control (seed without stilbene induction) and stilbenes-induced seeds. This finding was further validated using twenty peanut genotypes to ensure the relationship between stilbenes producing ability of the seed and fungal colonization level. The result showed that of the 20 genotypes tested, seeds of genotypes K1504, K1620 and K1632 showed minimal fungal colonization compared to control seed (without stilbenes induction), while genotypes DRT40, Kadiri-7, Narayani, DRT43 and Tirupati-3 showed no fungal colonization. The differences in stilbenes content and composition of cotyledon slices was determined by HPLC to assess genetic differences in their stilbenes producing ability. Comparative evaluation of these data showed that the genotypes that showed no fungal colonization expressed significantly higher amounts of stilbenes compared to genotypes which expressed relatively lower amounts of stilbenes. Overall, these data suggest that the genotypes expressing high amounts of stilbenes were able to mitigate fungal colonization while the genotypes expressing relatively lower amounts of stilbenes sustained fungal colonization, which indicates that this technique may be useful for screening breeding population to identify genotypes capable of avoiding Aspergillus colonization and aflatoxin contamination.

scholarly journals Antifungal Activity in Transgenic Peanut (Arachis hypogaea L.) Conferred by a Nonheme Chloroperoxidase Gene

2009 ◽  
Vol 36 (2) ◽  
pp. 126-132 ◽  
Author(s):  
C. Niu ◽  
Y. Akasaka-Kennedy ◽  
P. Faustinelli ◽  
M. Joshi ◽  
K. Rajasekaran ◽  
...  
Keyword(s):  
Crude Protein ◽  
Growth Inhibitor ◽  
Hyphal Growth ◽  
Aflatoxin Contamination ◽  
35S Promoter ◽  
Camv 35S ◽  
P Gene ◽  
Arachis Hypogaea L ◽  
Selection For

Abstract A nonheme chloroperoxidase gene (cpo-p) from Pseudomonas pyrrocinia, a growth inhibitor of mycotoxin-producing fungi, was introduced into peanut via particle bombardment. The expression of the cpo-p gene is predicted to increase pathogen defense in peanut. Embryogenic peanut tissues were bombarded with gold particles coated with plasmid pRT66 carrying the cpo-p and hygromycin phosphotransferase (hph) genes, under the control of a double CaMV 35S and a single CaMV 35S promoter, respectively. Selection for hygromycin-resistant somatic embryos was performed on a liquid medium containing 10–20 mg/L hygromycin 3–4 days after bombardment. The integration and expression of the cpo-p gene was confirmed by Southern, Northern and Western blot analyses. In vitro bioassay using crude protein extracts from transgenic T0, T1, and T4 plants showed inhibition of Aspergillus flavus hyphal growth, which could translate to a reduction in aflatoxin contamination of peanut seed.

Evaluation of Post-harvest Aflatoxin Production in Peanut Germplasm with Resistance to Seed Colonization and Pre-harvest Aflatoxin Contamination

2004 ◽  
Vol 31 (2) ◽  
pp. 124-134 ◽  
Author(s):  
H. Q. Xue ◽  
T. G. Isleib ◽  
G. A. Payne ◽  
G. OBrian
Keyword(s):  
Genotypic Variation ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Block Designs ◽  
Plastic Bags ◽  
Arachis Hypogaea L ◽  
Seed Colonization ◽  
Highly Correlated

Abstract Contamination of peanut (Arachis hypogaea L.) with aflatoxin produced by species of Aspergillus remains a problem for the U.S. peanut industry. Several peanut genotypes were reported to be resistant to in vitro seed colonization by Aspergillus flavus Link ex Fries (IVSCAF), to field seed colonization by A. flavus (FSCAF), or to preharvest aflatoxin contamination (PAC), but few to production of aflatoxin per se. Cotyledons of 39 peanut genotypes reportedly resistant to IVSCAF, FSCAF, or PAC, and eight susceptible to PAC were evaluated in four tests for their ability to support aflatoxin production after inoculation with A. flavus. Cultivars Perry and Gregory were used as checks in each test. Seed cotyledons were separated, manually blanched, inoculated with conidia of A. flavus, placed on moistened filter paper in petri dishes, and incubated for 8 d at 28 C. Dishes were arranged on plastic trays enclosed in plastic bags and stacked with PVC spacers between trays. Incomplete block designs were used for all tests. In each test, none of the genotypes examined was completely resistant to aflatoxin production, but significant genotypic variation was observed in the amount of total aflatoxin accumulated in seeds. Genotypes previously reported to be resistant to IVSCAF, FSCAF, or PAC exhibited differential abilities to support aflatoxin production. PI 590325, PI 590299, PI 290626, and PI 337409 supported reduced levels of aflatoxin, and their degree of resistance was consistent across tests. Fungal growth was highly correlated with aflatoxin production in three tests. The results from this study suggested that there were no absolute relationships of aflatoxin production resistance with IVSCAF, FSCAF, or PAC resistance, but that it should be possible to identify a genotype with high IVSCAF, FSCAF, or PAC resistance and reduced capacity for aflatoxin production by A. flavus.

scholarly journals Pseudomonas fluorescens Pf7: A Potential Biocontrol Agent against Aspergillus flavus Induced Aflatoxin Contamination in Groundnut

2019 ◽  
pp. 1-7 ◽  
Author(s):  
M. Ravi Teja ◽  
K. Vijay Krishna Kumar ◽  
H. Sudini
Keyword(s):  
Plant Growth ◽  
Aspergillus Flavus ◽  
Plant Growth Promoting Rhizobacteria ◽  
Aflatoxin Contamination ◽  
Dual Culture ◽  
Arachis Hypogaea L ◽  
Potential Biocontrol Agent ◽  
Plant Growth Promoting ◽  
Growth Promoting

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.

scholarly journals Peanut Seed Coat Acts as a Physical and Biochemical Barrier against Aspergillus flavus Infection

2021 ◽  
Vol 7 (12) ◽  
pp. 1000
Author(s):  
Leslie Commey ◽  
Theophilus K. Tengey ◽  
Christopher J. Cobos ◽  
Lavanya Dampanaboina ◽  
Kamalpreet K. Dhillon ◽  
...  
Keyword(s):  
Seed Coat ◽  
Aflatoxin Contamination ◽  
Peanut Seed ◽  
Biotic And Abiotic Stresses ◽  
The Media ◽  
Seed Colonization ◽  
Seed Coats ◽  
Potential Use

Aflatoxin contamination is a global menace that adversely affects food crops and human health. Peanut seed coat is the outer layer protecting the cotyledon both at pre- and post-harvest stages from biotic and abiotic stresses. The aim of the present study is to investigate the role of seed coat against A. flavus infection. In-vitro seed colonization (IVSC) with and without seed coat showed that the seed coat acts as a physical barrier, and the developmental series of peanut seed coat showed the formation of a robust multilayered protective seed coat. Radial growth bioassay revealed that both insoluble and soluble seed coat extracts from 55-437 line (resistant) showed higher A. flavus inhibition compared to TMV-2 line (susceptible). Further analysis of seed coat biochemicals showed that hydroxycinnamic and hydroxybenzoic acid derivatives are the predominant phenolic compounds, and addition of these compounds to the media inhibited A. flavus growth. Gene expression analysis showed that genes involved in lignin monomer, proanthocyanidin, and flavonoid biosynthesis are highly abundant in 55-437 compared to TMV-2 seed coats. Overall, the present study showed that the seed coat acts as a physical and biochemical barrier against A. flavus infection and its potential use in mitigating the aflatoxin contamination.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

Plasminogen Depletion during Streptokinase Treatment or Two-Chain Urokinase Incubation Correlates with Decreased Clot Lysability Ex Vivo and In Vitro

1993 ◽  
Vol 70 (06) ◽  
pp. 0998-1004 ◽  
Author(s):  
Páll T Önundarson ◽  
H Magnús Haraldsson ◽  
Lena Bergmann ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Myocardial Infarction ◽  
Ex Vivo ◽  
Time Dependent ◽  
State Variables ◽  
Thrombolytic Treatment ◽  
Direct Proportion ◽  
Plasmin Activity ◽  
Plasma Exposure ◽  
The Relationship

SummaryThe relationship between lytic state variables and ex vivo clot lysability was investigated in blood drawn from patients during streptokinase administration for acute myocardial infarction. A lytic state was already evident after 5 min of treatment and after 20 min the plasminogen concentration had decreased to 24%, antiplasmin to 7% and fibrinogen 0.2 g/1. Lysis of radiolabeled retracted clots in the patient plasmas decreased from 37 ± 8% after 5 min to 21 ± 8% at 10 min and was significantly lower (8 ± 9%, p <0.005) in samples drawn at 20, 40 and 80 min. Clot lysability correlated positively with the plasminogen concentration (r = 0.78, p = 0.003), but not with plasmin activity. Suspension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml two-chain urokinase for varying time to induce an in vitro lytic state was also associated with decreasing clot lysability in direct proportion with the duration of prior plasma exposure to urokinase. The decreased lysability correlated with the time-dependent reduction in plasminogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decreases in conjunction with the development of the lytic state and the associated plasminogen depletion. The lytic state may therefore limit reperfusion during thrombolytic treatment.

Monitoring Anticoagulant Therapy by Activated Partial Thromboplastin Time: Hirudin Assessment

1994 ◽  
Vol 72 (05) ◽  
pp. 685-692 ◽  
Author(s):  
Michael T Nurmohamed ◽  
René J Berckmans ◽  
Willy M Morriën-Salomons ◽  
Fenny Berends ◽  
Daan W Hommes ◽  
...  
Keyword(s):  
Whole Blood ◽  
Partial Thromboplastin Time ◽  
Ex Vivo ◽  
Fold Increase ◽  
Heparin Therapy ◽  
Activated Partial Thromboplastin Time ◽  
Recombinant Hirudin ◽  
Interindividual Differences ◽  
The Relationship

SummaryBackground. Recombinant hirudin (RH) is a new anticoagulant for prophylaxis and treatment of venous and arterial thrombosis. To which extent the activated partial thromboplastin time (APTT) is suitable for monitoring of RH has not been properly evaluated. Recently, a capillary whole blood device was developed for bed-side monitoring of the APTT and it was demonstrated that this device was suitable to monitor heparin therapy. However, monitoring of RH was not evaluated.Study Objectives. To evaluate in vitro and ex vivo the responsiveness and reproducibility for hirudin monitoring of the whole blood monitor and of plasma APTT assays, which were performed with several reagents and two conventional coagulometers.Results. Large interindividual differences in hirudin responsiveness were noted in both the in vitro and the ex vivo experiments. The relationship between the APTT, expressed as clotting time or ratio of initial and prolonged APTT, and the hirudin concentration was nonlinear. A 1.5-fold increase of the clotting times was obtained at 150-200 ng/ml plasma. However, only a 2-fold increase was obtained at hirudin levels varying from 300 ng to more than 750 ng RH/ml plasma regardless of the assays. The relationship linearized upon logarithmic conversion of the ratio and the hirudin concentration. Disregarding the interindividual differences, and presuming full linearity of the relationship, all combinations were equally responsive to hirudin.Conclusions. All assays were equally responsive to hirudin. Levels up to 300 ng/ml plasma can be reliably estimated with each assay. The manual device may be preferable in situations where rapid availability of test results is necessary.

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