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1.
Plant Dis ; 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39175272

RESUMEN

Bean leafroll virus (BLRV; Bean leafroll virus), a single-stranded RNA virus in the genus Luteovirus, is phloem-limited and primarily transmitted by aphids in a non-propagative, persistent manner (Rashed et al., 2018; Kidanemariam and Abraham, 2023). BLRV infects various legumes and has been reported from major pulse-growing regions worldwide (Agindotan et al., 2019) but not in the Canadian Prairies. Its impact on crop yield varies with plant and virus genotypes and the timing of infection. Some pea fields have experienced disease rates of up to 80% (Clement et al., 2020; Hampton, 1983). Throughout the 2022 growing season (June and July), pulse fields from across Saskatchewan were randomly selected and surveyed, and symptomatic plants demonstrating leaf yellowing and chlorosis were collected and stored at -80°C before processing. Observed symptoms included necrotic spots, chlorosis, leaf mottling, leaf rolling in peas, severe bright yellowing, and leaf marginal necrosis in chickpeas. BLRV detection was performed on 35 leaves of the collected samples using both Enzyme-Linked Immunosorbent Assay (ELISA) and Reverse transcription polymerase chain reaction (RT-PCR). ELISA testing followed the manufacturer's protocol using a commercial kit (Nano Diagnostics, San Jose, CA, USA). Total RNAs were extracted from the frozen samples using TRIzol (Invitrogen, Carlsbad, CA, USA). For the detection of the diverse BLRV isolates, sequences of various isolates were aligned and primers were specifically designed in-house, targeting the virus's highly conserved regions on the GP3 and 3' UTR (see Supplementary material). Additional primers were also designed targeting coat protein (CP) coding regions which were previously used for BLRV detection (Agindotan et al. 2019; Larsen & Webster 1999). PCR testing of 35 symptomatic samples including 12 pea plants and 23 chickpea plants, identified the presence of BLRV in two symptomatic samples, one each from a field pea (Pisum sativum L. var. CDC Inca) and a desi-type chickpea (Cicer arietinum L. var. CDC Leader). The infected pea and chickpea samples were found in Saskatoon, SK (Coordinates: 52°9'27''N,106°34'14"W), and the Leader area, southwest of Saskatchewan, SK (Coordinates: 50°52'14"N,109°23'11"W), respectively. PCR amplicons were purified and sent for Sanger sequencing. The reads were assembled to generate 1666 and 323 nucleotides from pea and chickpea, respectively, with a minimum of 2X coverage. Partial nucleotide sequences of the BLRV isolates obtained from pea (PsSK1) and chickpea (CaSK1) (GenBank accession numbers: PP240429, PP266588) showed (1521/1574 bp) 96.63% and (316/323 bp) 97.83% similarity with a BLRV reference isolate sequence (NC_003369) and to an isolate from Argentina (KR261610) which was reported on Medicago sativa L. with (1555/1574 bp) 98.79% and (319/323 bp) 98.76% similarity, correspondingly. Both infected samples were confirmed to be BLRV-infected through the ELISA and exhibited a high interaction ratio (PsSK1: 0.319 and CsSK1: 0.245) compared to a positive control (0.292) after 30 minutes as measured at 450 nm. This is the first report of BLRV in the pulse-growing region of the Canadian Prairies. In Saskatchewan, there is no history of BLRV despite the large amount of area growing susceptible crops. Therefore, the survey project that this study was part of was not intended to evaluate the severity of BLRV but rather to determine if there is any virus present that might have been overlooked. The samples were therefore taken randomly, with a focus on the number of fields and geographic coverage rather than focusing on multiple plants per field. Moreover, fields were not chosen based on symptoms but rather at random. Although, plants within fields were chosen because they displayed symptoms. Typically, a disease note includes estimates of severity and potential risk; however, that is not possible for this study. Rather, the fact that it was detected indicates a greater risk than previously perceived, since it was assumed that BLRV was not present. These findings highlight the need for further research on the virus's current status, its impact on crop production, and the resistance of pulse varieties grown in Saskatchewan.

2.
J Pers ; 91(4): 928-946, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36577709

RESUMEN

Personality researchers are increasingly interested in the dynamics of personality, that is, the proximal causal mechanisms underlying personality and behavior. Here, we review the Zurich Model of Social Motivation concerning its potential to explain central aspects of personality. It is a cybernetic model that provides a nomothetic structure of the causal relationships among needs for security, arousal, and power, and uses them to explain an individual's approach-avoidance or "proximity-distance" behavior. We review core features of the model and extend them by adding features based on recent behavioral and neuroscientific evidence. We close by discussing the model considering contemporary issues in personality science such as the dynamics of personality, five-factor personality traits and states, and personality growth.


Asunto(s)
Motivación , Personalidad , Humanos , Trastornos de la Personalidad , Inventario de Personalidad , Conducta Social
3.
Sustain Sci ; 17(2): 621-635, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35222728

RESUMEN

Over the past decade, widespread concern has emerged over how environmental governance can be transformed to avoid impending catastrophes such as climate change, biodiversity loss, and livelihood insecurity. A variety of approaches have emerged, focusing on either politics, technological breakthrough, social movements, or macro-economic processes as the main drivers of change. In contrast, this paper presents theoretical insights about how systemic change in environmental governance can be triggered by critical and intellectually grounded social actors in specific contexts of environment and development. Conceptualising such actors as critical action intellectuals (CAI), we analyze how CAI emerge in specific socio-environmental contexts and contribute to systemic change in governance. CAI trigger transformative change by shifting policy discourse, generating alternative evidence, and challenging dominant policy assumptions, whilst aiming to empower marginalized groups. While CAI do not work in a vacuum, nor are the sole force in transformation, we nevertheless show that the praxis of CAI within fields of environmental governance has the potential to trigger transformation. We illustrate this through three cases of natural resource governance in Nepal, Nicaragua and Guatemala, and Kenya, where the authors themselves have engaged as CAI. We contribute to theorising the 'how' of transformation by showing the ways CAI praxis reshape fields of governance and catalyze transformation, distinct from, and at times complementary to, other dominant drivers such as social movements, macroeconomic processes or technological breakthroughs.

4.
PLoS One ; 16(4): e0249928, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33836032

RESUMEN

Tomato ringspot virus (ToRSV, genus Nepovirus, family Secoviridae, order Picornavirales) is a bipartite positive-strand RNA virus, with each RNA encoding one large polyprotein. ToRSV RNAs are linked to a 5'-viral genome-linked protein (VPg) and have a 3' polyA tail, suggesting a non-canonical cap-independent translation initiation mechanism. The 3' untranslated regions (UTRs) of RNA1 and RNA2 are unusually long (~1.5 kb) and share several large stretches of sequence identities. Several putative in-frame start codons are present in the 5' regions of the viral RNAs, which are also highly conserved between the two RNAs. Using reporter transcripts containing the 5' region and 3' UTR of the RNA2 of ToRSV Rasp1 isolate (ToRSV-Rasp1) and in vitro wheat germ extract translation assays, we provide evidence that translation initiates exclusively at the first AUG, in spite of a poor codon context. We also show that both the 5' region and 3' UTR of RNA2 are required for efficient cap-independent translation of these transcripts. We identify translation-enhancing elements in the 5' proximal coding region of the RNA2 polyprotein and in the RNA2 3' UTR. Cap-dependent translation of control reporter transcripts was inhibited when RNAs consisting of the RNA2 3' UTR were supplied in trans. Taken together, our results suggest the presence of a CITE in the ToRSV-Rasp1 RNA2 3' UTR that recruits one or several translation factors and facilitates efficient cap-independent translation together with the 5' region of the RNA. Non-overlapping deletion mutagenesis delineated the putative CITE to a 200 nts segment (nts 773-972) of the 1547 nt long 3' UTR. We conclude that the general mechanism of ToRSV RNA2 translation initiation is similar to that previously reported for the RNAs of blackcurrant reversion virus, another nepovirus. However, the position, sequence and predicted structures of the translation-enhancing elements differed between the two viruses.


Asunto(s)
Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Nepovirus/genética , Caperuzas de ARN/fisiología , ARN Viral/biosíntesis , Secuencia de Bases , Codón Iniciador , Genes Reporteros , Solanum lycopersicum/virología , Mutagénesis , ARN Viral/genética , Alineación de Secuencia
5.
Front Plant Sci ; 9: 1575, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30450108

RESUMEN

Tolerance is defined as an interaction in which viruses accumulate to some degree without causing significant loss of vigor or fitness to their hosts. Tolerance can be described as a stable equilibrium between the virus and its host, an interaction in which each partner not only accommodate trade-offs for survival but also receive some benefits (e.g., protection of the plant against super-infection by virulent viruses; virus invasion of meristem tissues allowing vertical transmission). This equilibrium, which would be associated with little selective pressure for the emergence of severe viral strains, is common in wild ecosystems and has important implications for the management of viral diseases in the field. Plant viruses are obligatory intracellular parasites that divert the host cellular machinery to complete their infection cycle. Highjacking/modification of plant factors can affect plant vigor and fitness. In addition, the toxic effects of viral proteins and the deployment of plant defense responses contribute to the induction of symptoms ranging in severity from tissue discoloration to malformation or tissue necrosis. The impact of viral infection is also influenced by the virulence of the specific virus strain (or strains for mixed infections), the host genotype and environmental conditions. Although plant resistance mechanisms that restrict virus accumulation or movement have received much attention, molecular mechanisms associated with tolerance are less well-understood. We review the experimental evidence that supports the concept that tolerance can be achieved by reaching the proper balance between plant defense responses and virus counter-defenses. We also discuss plant translation repression mechanisms, plant protein degradation or modification pathways and viral self-attenuation strategies that regulate the accumulation or activity of viral proteins to mitigate their impact on the host. Finally, we discuss current progress and future opportunities toward the application of various tolerance mechanisms in the field.

6.
Virology ; 524: 127-139, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30195250

RESUMEN

ARGONAUTEs (notably AGO1 and AGO2) are effectors of plant antiviral RNA silencing. AGO1 was shown to be required for the temperature-dependent symptom recovery of Nicotiana benthamiana plants infected with tomato ringspot virus (isolate ToRSV-Rasp1) at 27 °C. In this study, we show that symptom recovery from isolate ToRSV-GYV shares similar hallmarks of antiviral RNA silencing but occurs at a wider range of temperatures (21-27 °C). At 21 °C, an early spike in AGO2 mRNAs accumulation was observed in plants infected with either ToRSV-Rasp1 or ToRSV-GYV but the AGO2 protein was only consistently detected in ToRSV-GYV infected plants. Symptom recovery from ToRSV-GYV at 21 °C was not prevented in an ago2 mutant or by silencing of AGO1 or AGO2. We conclude that other factors (possibly other AGOs) contribute to symptom recovery under these conditions. The results also highlight distinct expression patterns of AGO2 in response to ToRSV isolates and environmental conditions.


Asunto(s)
Antivirales/metabolismo , Proteínas Argonautas/metabolismo , Interacciones Huésped-Patógeno , Nepovirus/patogenicidad , Nicotiana/virología , Enfermedades de las Plantas/virología , Proteínas Argonautas/genética , Resistencia a la Enfermedad , Nepovirus/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferencia de ARN , Nicotiana/inmunología , Virulencia
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