Genetic Transformation, Regeneration and Analysis of Transgenic Peanut

Crop Production/Industries,

Purification, characterization and serological detection of virus-like particles associated with banana bunchy top disease in Australia

Isometric virus-like particles, 18 nm in diameter, have been isolated from banana (Musa spp.) affected by bunchy top disease in Australia. Banana bunchy top disease-associated virus-like particles (BBTV) banded as a single component with buoyant density of 1.28 to 1.29 g/ml in Cs2SO4 and sedimented at about 46S in isokinetic sucrose density gradients. The A 260/A 280 of purified preparations was about 1.33. A single coat protein of M r 20500 identified with antibodies to BBTV particles from Australia. Single-stranded DNA of about 1 kb as well as ssRNA smaller than 0.45 kb was also associated with the particles. A polyclonal antiserum to BBTV, suitable for use in ELISA, was prepared. Stability and antigenicity of purified BBTV was impaired by storage at pH ≥ 8.5 and freezing at -20 °C without protectants. BBTV was detected by double antibody sandwich-ELISA with monoclonal and polyclonal antibodies, in field-infected banana plants, single aphids from an infective colony, and in experimentally aphid-inoculated banana plants. After transmission of BBTV particles by aphids from a banana bunchy top disease-affected to an uninfected banana plant, the disease was induced and BBTV was detected by ELISA in symptomatic leaves only. BBTV isolates from Australia, Taiwan, People’s Republic of China, Tonga, Western Samoa and Hawaii were found to be serologically related, which suggests a common aetiology for the disease

Cucumber mosaic virus infection transiently breaks dsRNA-induced transgenic immunity to Potato virus Y in tobacco

Post-transcriptional gene silencing (PTGS), an intrinsic plant defense mechanism, can be efficiently triggered by double stranded (ds)RNA-producing transgenes and can provide high level virus resistance by specific targeting of cognate viral RNA. The discovery of virus-encoded suppressors of PTGS led to concerns about the stability of such resistance. Here, we show that Cucumber mosaic virus (CMV) is able to suppress dsRNA-induced PTGS and the associated Potato virus Y (PVY) immunity in tobacco. CMV suppression supported only a transient PVY accumulation and did not prevent recovery of the transgenic plants from PVY infection. CMV inoculation resulted in strongly increased transgene mRNA levels due to suppression of PTGS, but accumulation of PVY-specific small interfering (si)RNA was unaffected. However, PVY accumulation in previously immune plants resulted in increased PVY siRNA levels and transgene mRNA was no longer detected, despite the presence of CMV. Transgene mRNA returned to high levels once PVY was no longer detected in CMVinfected plants. Recovered and chronically CMV-infected tissues were immune to further PVY infection

Genetic transformation, regeneration and analysis of transgenic peanut

Conventional breeding has led to the improvement of some peanut traits such as seed yield and drought tolerance. However, many important agronomic traits have yet to be improved. The recent development of transformation and regeneration systems has allowed the introduction of useful genes into peanut germplasm. The understanding of disease resistance mechanisms is becoming increasingly advanced so that it should be possible to apply technologies that have been proven in other species to peanut.In this technical report we describe protocols for the routine regeration of transformed peanut plants of spanish and virginia market types based on microprojectile bombardment of embryogenic callus as well as Agrobacterium-mediated transformation of somatic embryos

The Plant Negative-Sense RNA Virosphere: Virus Discovery Through New Eyes

The use of high-throughput sequencing (HTS) for virus diagnostics, as well as the importance of this technology as a valuable tool for discovery of novel viruses has been extensively investigated. In this review, we consider the application of HTS approaches to uncover novel plant viruses with a focus on the negative-sense, single-stranded RNA virosphere. Plant viruses with negative-sense and ambisense RNA (NSR) genomes belong to several taxonomic families, including Rhabdoviridae, Aspiviridae, Fimoviridae, Tospoviridae, and Phenuiviridae. They include both emergent pathogens that infect a wide range of plant species, and potential endophytes which appear not to induce any visible symptoms. As a consequence of biased sampling based on a narrow focus on crops with disease symptoms, the number of NSR plant viruses identified so far represents only a fraction of this type of viruses present in the virosphere. Detection and molecular characterization of NSR viruses has often been challenging, but the widespread implementation of HTS has facilitated not only the identification but also the characterization of the genomic sequences of at least 70 NSR plant viruses in the last 7 years. Moreover, continuing advances in HTS technologies and bioinformatic pipelines, concomitant with a significant cost reduction has led to its use as a routine method of choice, supporting the foundations of a diverse array of novel applications such as quarantine analysis of traded plant materials and genetic resources, virus detection in insect vectors, analysis of virus communities in individual plants, and assessment of virus evolution through ecogenomics, among others. The insights from these advancements are shedding new light on the extensive diversity of NSR plant viruses and their complex evolution, and provide an essential framework for improved taxonomic classification of plant NSR viruses as part of the realm Riboviria. Thus, HTS-based methods for virus discovery, our ‘new eyes,’ are unraveling in real time the richness and magnitude of the plant RNA virosphere.Fil: Bejerman, Nicolas. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Debat, Humberto Julio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Dietzgen, Ralf G.. University of Queensland; Australi

„Praktinis protas“, arba moralė

Publikuojamas J. Dietzgeno veikalo „Praktinis protas“, arba moralė“ vertimas. Jame aptariamos pagrindinės metafizikos problemos. Filosofas teigia, kad protas negali absoliučiai, savarankiškai atskleisti spekuliatyvinio tyrimo objektų, moralinio pasaulio objektų. Jis vis dėlto gali, remdamasis jutimiškai duotais santykiais, skirti sąlygines bendrybes ir atskirybes, būtį ir reiškinį, būtinas reikmes ir kaprizingus įgeidžius. Daug dėmesio skiriama krikščioniškosios bei pagoniškosios moralės skirtumams įvardyti ir analizuoti. Moralė apibrėžiama kaip suvestinė sąvoka, apimanti skirtingiausius, vienas kitam prieštaraujančius dorovės įstatymus, kurių bendras tikslas yra taip tvarkyti poelgius jų pačių ir kitų atžvilgiu, kad dabartyje būtų atsižvelgiama ir į ateitį, greta vieno dalyko – ir į kitą, greta individo – ir į rūšį. Etikos pagrindas yra tikrasis jutiminis teisėtumas. Moralė turi būti tiriama induktyviai, moksliškai. Tikėjimas dorovine pasaulio tvarka yra žmogiškosios laisvės įsisąmoninimas. Aptariamos gėrio, šventumo, žmonijos sąvokos

Illuminating the Plant Rhabdovirus Landscape through Metatranscriptomics Data

Rhabdoviruses infect a large number of plant species and cause significant crop diseases. They have a negative-sense, single-stranded unsegmented or bisegmented RNA genome. The number of plant-associated rhabdovirid sequences has grown in the last few years in concert with the extensive use of high-throughput sequencing platforms. Here, we report the discovery of 27 novel rhabdovirus genomes associated with 25 different host plant species and one insect, which were hidden in public databases. These viral sequences were identified through homology searches in more than 3000 plant and insect transcriptomes from the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA) using known plant rhabdovirus sequences as the query. The identification, assembly and curation of raw SRA reads resulted in sixteen viral genome sequences with full-length coding regions and ten partial genomes. Highlights of the obtained sequences include viruses with unique and novel genome organizations among known plant rhabdoviruses. Phylogenetic analysis showed that thirteen of the novel viruses were related to cytorhabdoviruses, one to alphanucleorhabdoviruses, five to betanucleorhabdoviruses, one to dichorhaviruses and seven to varicosaviruses. These findings resulted in the most complete phylogeny of plant rhabdoviruses to date and shed new light on the phylogenetic relationships and evolutionary landscape of this group of plant viruses. Furthermore, this study provided additional evidence for the complexity and diversity of plant rhabdovirus genomes and demonstrated that analyzing SRA public data provides an invaluable tool to accelerate virus discovery, gain evolutionary insights and refine virus taxonomyInstituto de Patología VegetalFil: Bejerman, Nicolas Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Bejerman, Nicolas Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Dietzgen, Ralf G. University of Queensland. Queensland Alliance for Agriculture and Food Innovation; AustraliaFil: Debat, Humberto Julio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Debat, Humberto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentin