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United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
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Full-Text Articles in Life Sciences
First Draft Genome Of Thecaphora Frezii, Causal Agent Of Peanut Smut Disease, Renee S. Arias, Cinthia Conforto, Valerie A. Orner, Edgardo J. Carloni, Juan H. Soave, Alicia N. Massa, Marshall C. Lamb, Nelson Bernardi-Lima, Alejandro M. Rago
First Draft Genome Of Thecaphora Frezii, Causal Agent Of Peanut Smut Disease, Renee S. Arias, Cinthia Conforto, Valerie A. Orner, Edgardo J. Carloni, Juan H. Soave, Alicia N. Massa, Marshall C. Lamb, Nelson Bernardi-Lima, Alejandro M. Rago
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Objectives: The fungal pathogen Thecaphora frezii Carranza & Lindquist causes peanut smut, a severe disease currently endemic in Argentina. To study the ecology of T. frezii and to understand the mechanisms of smut resistance in peanut plants, it is crucial to know the genetics of this pathogen. The objective of this work was to isolate the pathogen and generate the first draft genome of T. frezii that will be the basis for analyzing its potential genetic diversity and its interaction with peanut cultivars. Our research group is working to identify peanut germplasm with smut resistance and to understand the genetics …
Transformation Of Major Peanut (Arachis Hypogaea) Stilbenoid Phytoalexins Caused By Selected Microorganisms, Victor S. Sobolev, Travis E. Walk, Renee S. Arias, Alicia N. Massa, Valerie A. Orner, Marshall C. Lamb
Transformation Of Major Peanut (Arachis Hypogaea) Stilbenoid Phytoalexins Caused By Selected Microorganisms, Victor S. Sobolev, Travis E. Walk, Renee S. Arias, Alicia N. Massa, Valerie A. Orner, Marshall C. Lamb
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The peanut plant accumulates defensive stilbenoid phytoalexins in response to the presence of soil fungi, which in turn produce phytoalexin-detoxifying enzymes for successfully invading the plant host. Aspergillus spp. are opportunistic pathogens that invade peanut seeds; most common fungal species often produce highly carcinogenic aflatoxins. The purpose of the present research was to evaluate the in vitro dynamics of peanut phytoalexin transformation/detoxification by important fungal species. This work revealed that in feeding experiments, Aspergillus spp. from section Flavi were capable of degrading the major peanut phytoalexin, arachidin-3, into its hydroxylated homolog, arachidin-1, and a benzenoid, SB-1. However, Aspergillus niger from …
Genetic Mapping And Qtl Analysis For Peanut Smut Resistance, Francisco J. De Blas, Cecilia I. Bruno, Renee Arias, Carolina Ballén-Taborda, Eva Mamani, Claudio Oddino, Melina Rosso, Beatriz P. Costero, Marina Bressano, Juan H. Soave, Sara J. Soave, Mario I. Buteler, J. Guillermo Seijo, Alicia Massa
Genetic Mapping And Qtl Analysis For Peanut Smut Resistance, Francisco J. De Blas, Cecilia I. Bruno, Renee Arias, Carolina Ballén-Taborda, Eva Mamani, Claudio Oddino, Melina Rosso, Beatriz P. Costero, Marina Bressano, Juan H. Soave, Sara J. Soave, Mario I. Buteler, J. Guillermo Seijo, Alicia Massa
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Background: Peanut smut is a disease caused by the fungus Thecaphora frezii Carranza & Lindquist to which most commercial cultivars in South America are highly susceptible. It is responsible for severely decreased yield and no effective chemical treatment is available to date. However, smut resistance has been identified in wild Arachis species and further transferred to peanut elite cultivars. To identify the genome regions conferring smut resistance within a tetraploid genetic background, this study evaluated a RIL population {susceptible Arachis hypogaea subsp. hypogaea (JS17304-7-B) × resistant synthetic amphidiploid (JS1806) [A. correntina (K 11905) × A. cardenasii (KSSc 36015)] × A. …
Evaluation Of Leaf Spot Resistance In Wild Arachis Species Of Section Arachis, Alicia Massa, Renee Arias, Ronald B. Sorensen, Victor S. Sobolev, S. P. Tallury, H. T. Stalker, Marshall Lamb
Evaluation Of Leaf Spot Resistance In Wild Arachis Species Of Section Arachis, Alicia Massa, Renee Arias, Ronald B. Sorensen, Victor S. Sobolev, S. P. Tallury, H. T. Stalker, Marshall Lamb
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton), respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. A collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to leaf spots. Screening was conducted under field (natural inoculum) conditions in Dawson, Georgia, during 2017 and 2018. Accessions differed …
Suppression Of Aflatoxin Production In Aspergillus Species By Selected Peanut (Arachis Hypogaea) Stilbenoids, Victor S. Sobolev, R. S. Arias, Kerestin Goodman, Travis Walk, Valerie Orner, Paola C. Faustinelli, Alicia Massa
Suppression Of Aflatoxin Production In Aspergillus Species By Selected Peanut (Arachis Hypogaea) Stilbenoids, Victor S. Sobolev, R. S. Arias, Kerestin Goodman, Travis Walk, Valerie Orner, Paola C. Faustinelli, Alicia Massa
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Aspergillus flavus is a soil fungus that commonly invades peanut seeds and often produces carcinogenic aflatoxins. Under favorable conditions, the fungus-challenged peanut plant produces and accumulates resveratrol and its prenylated derivatives in response to such an invasion. These prenylated stilbenoids are considered peanut antifungal phytoalexins. However, the mechanism of peanut−fungus interaction has not been sufficiently studied. We used pure peanut stilbenoids arachidin-1, arachidin-3, and chiricanine A to study their effects on the viability of and metabolite production by several important toxigenic Aspergillus species. Significant reduction or virtually complete suppression of aflatoxin production was revealed in feeding experiments in A. flavus, …
Characterization Of Small Rna Populations In Non-Transgenic Andaflatoxin-Reducing-Transformed Peanut, Imana L. Power, Phat M. Dang, Victor S. Sobolev, Valerie Orner, Joseph L. Powell, Marshall C. Lamb, Renée S. Arias
Characterization Of Small Rna Populations In Non-Transgenic Andaflatoxin-Reducing-Transformed Peanut, Imana L. Power, Phat M. Dang, Victor S. Sobolev, Valerie Orner, Joseph L. Powell, Marshall C. Lamb, Renée S. Arias
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumula-tion of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNApopulations in a control line and in two transformed peanut lines that expressed an inverted repeattargeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was …
Aspergillus And Aflatoxin In Groundnut (Arachis Hypogaea L.) And Groundnut Cake In Eastern Ethiopia, Abdi Mohammed, Alemayehu Chala, Mashilla Dejene, Chemeda Fininsa, David A. Hoisington, Victor S. Sobolev, R. S. Arias
Aspergillus And Aflatoxin In Groundnut (Arachis Hypogaea L.) And Groundnut Cake In Eastern Ethiopia, Abdi Mohammed, Alemayehu Chala, Mashilla Dejene, Chemeda Fininsa, David A. Hoisington, Victor S. Sobolev, R. S. Arias
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers’ management practices. A total of 160 groundnut seed samples from farmers’ stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g−1 from 2013/2014 and 2014/2015 …
Rnai-Mediated Control Of Aflatoxins In Peanut: Method To Analyze Mycotoxin Production And Transgene Expression In The Peanut/Aspergillus Pathosystem, Renee S. Arias, Phat M. Dang, Victor S. Sobolev
Rnai-Mediated Control Of Aflatoxins In Peanut: Method To Analyze Mycotoxin Production And Transgene Expression In The Peanut/Aspergillus Pathosystem, Renee S. Arias, Phat M. Dang, Victor S. Sobolev
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, …