2020, Año internacional de la Sanidad Vegetal

Estamos en el Año Internacional de la Sanidad Vegetal. Tras una primera propuesta del Gobierno Finlandés en 2015 para establecer este año internacional ante la décima Comisión de Medidas Fitosanitarias de la Convención Internacional para la Protección Vegetal (IPPC), tratado internacional firmado por más de 180 países, y un arduo trabajo para establecer los objetivos y la búsqueda de los recursos necesarios para el avance de esta propuesta, finalmente la Asamblea General de Naciones Unidas adoptó en diciembre de 2018 la resolución para la declaración de 2020 como Año Internacional de la Sanidad Vegetal. Como reza textualmente la página web de la FAO dedicada a este año internacional (http://www.fao.org/plant-health-2020/home/es/), estamos ante …una oportunidad única e irrepetible para sensibilizar a escala internacional sobre cómo la protección de la salud vegetal puede ayudar a acabar con el hambre, reducir la pobreza, proteger el medio ambiente y estimular el desarrollo económico. A primera vista, la actual pandemia de COVID-19 puede haber restado protagonismo a este año internacional (en las actuales circunstancias, ¿quién recuerda ahora que estamos en el Año Internacional de la Sanidad Vegetal?), dificultando y aplazando muchos de los eventos programados para su celebración. Sin embargo, la pandemia también ha contribuido a poner de manifiesto la esencialidad del sector de la producción de alimentos, de la que la producción de plantas es el pilar fundamental, ya que de ella depende tanto la nutrición humana como la de los animales...

2020, Año internacional de la Sanidad Vegetal

Estamos en el Año Internacional de la Sanidad Vegetal. Tras una primera propuesta del Gobierno Finlandés en 2015 para establecer este año internacional ante la décima Comisión de Medidas Fitosanitarias de la Convención Internacional para la Protección Vegetal (IPPC), tratado internacional firmado por más de 180 países, y un arduo trabajo para establecer los objetivos y la búsqueda de los recursos necesarios para el avance de esta propuesta, finalmente la Asamblea General de Naciones Unidas adoptó en diciembre de 2018 la resolución para la declaración de 2020 como Año Internacional de la Sanidad Vegetal. Como reza textualmente la página web de la FAO dedicada a este año internacional (http://www.fao.org/plant-health-2020/home/es/), estamos ante …una oportunidad única e irrepetible para sensibilizar a escala internacional sobre cómo la protección de la salud vegetal puede ayudar a acabar con el hambre, reducir la pobreza, proteger el medio ambiente y estimular el desarrollo económico. A primera vista, la actual pandemia de COVID-19 puede haber restado protagonismo a este año internacional (en las actuales circunstancias, ¿quién recuerda ahora que estamos en el Año Internacional de la Sanidad Vegetal?), dificultando y aplazando muchos de los eventos programados para su celebración. Sin embargo, la pandemia también ha contribuido a poner de manifiesto la esencialidad del sector de la producción de alimentos, de la que la producción de plantas es el pilar fundamental, ya que de ella depende tanto la nutrición humana como la de los animales...

Estado fitosanitario del azafrán en Aragón (España): Insectos, ácaros, nematodos, virus, bacterias y malas hierbas

El azafrán cultivado en España está adquiriendo relevancia en las últimas décadas como producto de gran calidad, lo que requiere la selección de cormos, sus órganos reproductivos, sanos para la plantación con el objetivo de mantener un adecuado estado fitosanitario del cultivo. Este trabajo presenta un estudio del estado fitosanitario del azafrán en Teruel, donde el cultivo fue muy importante económica y socialmente. Además, este estudio pretende ser de utilidad para las zonas productoras con características agroclimáticas similares. Con dichos objetivos, se prospectaron 10 plantaciones comerciales de azafrán en 6 localidades del valle del Jiloca entre los años 2008 y 2011, estudiando la presencia de insectos, ácaros, nematodos, virus, bacterias y malas hierbas. El ácaro Rhizoglyphus robini, una de las plagas más importantes del azafrán, se detectó en los cormos y en el suelo en una parcela. También el nematodo Aphelenchoides blastophtorus, plaga en plantas ornamentales, se encontró abundantemente en cormos de dos parcelas. Se detectaron infecciones ocasionales de virus del género potyvirus en el cultivo y en la mala hierba Eruca vesicaria. Las malas hierbas Lolium rigidum y Descurainia sophia podrían causar serios problemas de competencia al cultivo y se considera necesario realizar operaciones de escarda en otoño y en invierno. No se detectaron insectos nocivos ni bacterias fitopatógenas. La multiplicación vegetativa del azafrán hace aconsejable realizar muestreos, especialmente en los cormos antes de ser replantados, para detectar la presencia de ácaros, nematodos y virus que podrían ocasionar pérdidas de producción y calidad. In the last decades, saffron produced in Spain is gaining relevance as a high-quality product, which requires the selection of healthy corms (the reproductive organ) for planting in order to maintain adequa-te phytosanitary status of the crop. In this work, the phytosanitary status of saffron was studied in Teruel (Aragón, Spain), where the crop has economic and social importance. Moreover, it aims to be useful for the production areas with similar agro-climatic characteristics. Ten commercial saffron plantations in six locations of the Jiloca valley have been surveyed between 2008 and 2011 and the presence of insects, mites, nematodes, virus, bacteria and weeds was studied. The mite Rhizoglyphus robini, one of the most important pests of saffron, was detected in both corms and soil in one plantation. The nematode Aphelenchoides blastophtorus, pest in ornamental plants, was also found in corms in two plantations. Potyvirus infections were occasionally detected in both the crop and in the weed Eruca vesicaria. The weeds Lolium rigidum and Descurainia sophia could cause diminutions of the yield by competition, therefore, weeding operations are necessary in autumn and winter. No harmful insects and phytopatogenic bacteria were detected. Because reproduction is only possible through corm propagation, it is advisable to analyse the plants, especially the corms, before being re-planted, in order to detect the presence of mites, nematodes and virus that could reduce yield and quality decreases

The Relationship of Within-Host Multiplication and Virulence in a Plant-Virus System

Background. Virulence does not represent any obvious advantage to parasites. Most models of virulence evolution assume that virulence is an unavoidable consequence of within-host multiplication of parasites, resulting in trade-offs between within-host multiplication and between-host transmission fitness components. Experimental support for the central assumption of this hypothesis, i.e., for a positive correlation between within-host multiplication rates and virulence, is limited for plant-parasite systems. Methodology/Principal Findings. We have addressed this issue in the system Arabidopsis thaliana-Cucumber mosaic virus (CMV). Virus multiplication and the effect of infection on plant growth and on viable seed production were quantified for 21 Arabidopsis wild genotypes infected by 3 CMV isolates. The effect of infection on plant growth and seed production depended of plant architecture and length of postembryonic life cycle, two genetically-determined traits, as well as on the time of infection in the plant's life cycle. A relationship between virus multiplication and virulence was not a general feature of this host-parasite system. This could be explained by tolerance mechanisms determined by the host genotype and operating differently on two components of plant fitness, biomass production and resource allocation to seeds. However, a positive relationship between virus multiplication and virulence was detected for some accessions with short life cycle and high seed weight to biomass ratio, which show lower levels of tolerance to infection. Conclusions/Significance. These results show that genotype-specific tolerance mechanisms may lead to the absence of a clear relationship between parasite multiplication and virulence. Furthermore, a positive correlation between parasite multiplication and virulence may occur only in some genotypes and/or environmental conditions for a given host-parasite system. Thus, our results challenge the general validity of the trade-off hypothesis for virulence evolution, and stress the need of considering the effect of both the host and parasite genotypes in analyses of host-parasite interactions. © 2007 Pagán et al.Ministerio de Educación y Ciencia, Spain.Peer Reviewe

The Relationship of Within-Host Multiplication and Virulence in a Plant-Virus System

Background. Virulence does not represent any obvious advantage to parasites. Most models of virulence evolution assume that virulence is an unavoidable consequence of within-host multiplication of parasites, resulting in trade-offs between within-host multiplication and between-host transmission fitness components. Experimental support for the central assumption of this hypothesis, i.e., for a positive correlation between within-host multiplication rates and virulence, is limited for plant-parasite systems. Methodology/Principal Findings. We have addressed this issue in the system Arabidopsis thaliana-Cucumber mosaic virus (CMV). Virus multiplication and the effect of infection on plant growth and on viable seed production were quantified for 21 Arabidopsis wild genotypes infected by 3 CMV isolates. The effect of infection on plant growth and seed production depended of plant architecture and length of postembryonic life cycle, two genetically-determined traits, as well as on the time of infection in the plant's life cycle. A relationship between virus multiplication and virulence was not a general feature of this host-parasite system. This could be explained by tolerance mechanisms determined by the host genotype and operating differently on two components of plant fitness, biomass production and resource allocation to seeds. However, a positive relationship between virus multiplication and virulence was detected for some accessions with short life cycle and high seed weight to biomass ratio, which show lower levels of tolerance to infection. Conclusions/Significance. These results show that genotype-specific tolerance mechanisms may lead to the absence of a clear relationship between parasite multiplication and virulence. Furthermore, a positive correlation between parasite multiplication and virulence may occur only in some genotypes and/or environmental conditions for a given host-parasite system. Thus, our results challenge the general validity of the trade-off hypothesis for virulence evolution, and stress the need of considering the effect of both the host and parasite genotypes in analyses of host-parasite interactions. © 2007 Pagán et al.Ministerio de Educación y Ciencia, Spain.Peer Reviewe

Differences in Accumulation and Virulence Determine the Outcome of Competition during Tobacco etch virus Coinfection

Understanding the evolution of virulence for RNA viruses is essential for developing appropriate control strategies. Although it has been usually assumed that virulence is a consequence of within-host replication of the parasite, viral strains may be highly virulent without experiencing large accumulation as a consequence of immunopathological host responses. Using two strains of Tobacco etch potyvirus (TEV) that show a negative relationship between virulence and accumulation rate, we first explored the evolution of virulence and fitness traits during simple and mixed infections. Short-term evolution experiments initiated with each strain independently confirmed the genetic and evolutionary stability of virulence and viral load, although infectivity significantly increased for both strains. Second, competition experiments between hypo- and hypervirulent TEV strains have shown that the outcome of competition is driven by differences in replication rate. A simple mathematical model has been developed to analyze the dynamics of these two strains during coinfection. The model qualitatively reproduced the experimental results using biologically meaningful parameters. Further analyses of the model also revealed a wide parametric region in which a low-fitness but hypovirulent virus can still outcompete a high-fitness but hypervirulent one. These results provide additional support to the observation that virulence and within-host replication may not necessarily be strongly tied in plant RNA viruses

Choline kinase alpha as an androgen receptor chaperone and prostate cancer therapeutic target

Background: The androgen receptor (AR) is a major drug target in prostate cancer (PCa). We profiled the AR-regulated kinome to identify clinically relevant and druggable effectors of AR signaling. Methods: Using genome-wide approaches, we interrogated all AR regulated kinases. Among these, choline kinase alpha (CHKA) expression was evaluated in benign (n = 195), prostatic intraepithelial neoplasia (PIN) (n = 153) and prostate cancer (PCa) lesions (n = 359). We interrogated how CHKA regulates AR signaling using biochemical assays and investigated androgen regulation of CHKA expression in men with PCa, both untreated (n = 20) and treated with an androgen biosynthesis inhibitor degarelix (n = 27). We studied the effect of CHKA inhibition on the PCa transcriptome using RNA sequencing and tested the effect of CHKA inhibition on cell growth, clonogenic survival and invasion. Tumor xenografts (n = 6 per group) were generated in mice using genetically engineered prostate cancer cells with inducible CHKA knockdown. Data were analyzed with χ 2 tests, Cox regression analysis, and Kaplan-Meier methods. All statistical tests were two-sided. Results: CHKA expression was shown to be androgen regulated in cell lines, xenografts, and human tissue (log fold change from 6.75 to 6.59, P = .002) and was positively associated with tumor stage. CHKA binds directly to the ligand-binding domain (LBD) of AR, enhancing its stability. As such, CHKA is the first kinase identified as an AR chaperone. Inhibition of CHKA repressed the AR transcriptional program including pathways enriched for regulation of protein folding, decreased AR protein levels, and inhibited the growth of PCa cell lines, human PCa explants, and tumor xenografts. Conclusions: CHKA can act as an AR chaperone, providing, to our knowledge, the first evidence for kinases as molecular chaperones, making CHKA both a marker of tumor progression and a potential therapeutic target for PCa.Mohammad Asim ... Luke A. Selth ... Wayne D. Tilley et al

A reciprocal feedback between the PDZ binding kinase and androgen receptor drives prostate cancer

Elucidation of mechanisms underlying the increased androgen receptor (AR) activity and subsequent development of aggressive prostate cancer (PrCa) is pivotal in developing new therapies. Using a systems biology approach, we interrogated the AR-regulated proteome and identified PDZ binding kinase (PBK) as a novel AR-regulated protein that regulates full-length AR and AR variants (ARVs) activity in PrCa. PBK overexpression in aggressive PrCa is associated with early biochemical relapse and poor clinical outcome. In addition to its carboxy terminus ligand-binding domain, PBK directly interacts with the amino terminus transactivation domain of the AR to stabilise it thereby leading to increased AR protein expression observed in PrCa. Transcriptome sequencing revealed that PBK is a mediator of global AR signalling with key roles in regulating tumour invasion and metastasis. PBK inhibition decreased growth of PrCa cell lines and clinical specimen cultured ex vivo. We uncovered a novel interplay between AR and PBK that results in increased AR and ARVs expression that executes AR-mediated growth and progression of PrCa, with implications for the development of PBK inhibitors for the treatment of aggressive PrCa.Anne Y. Warren, Charlie E. Massie, Kate Watt, Katarina Luko ... Luke A. Selth ... Wayne D. Tilley ... et al

Comparación de modelos de regresión logística y modelos de función de crecimiento para el análisis de la incidencia de infección por virus

A logistic regression model was compared to logistic, Gompertz and log-logistic growth functions for analyzing a set of data describing the incidence of Alfalfa mosaic virus infection in lucerne fields aged from one to five years, and located in three different ecological areas of the Ebro Valley, Northeast Spain. Models were fitted in the form of generalized linear models, and none of them explained well the high variability of the field data, although they were useful to analyze the interdependence among epidemiological factors associated with estimated parameters in the models. The logistic regression model proved more sensitive than classical growth function models to detect significant differences in parameters such as the rate of incidence increase with age of lucerne field or the initial amount of disease, and to detect differences associated to explanatory variables such as the ecological area. Results indicate that logistic regression may be a method well suited to statistical analyses in plant epidemiology.Se ha comparado un modelo de regresión logística con modelos de función de crecimiento logístico, de Gompertz y log-logístico para el análisis de un conjunto de datos que describen la incidencia de infección del virus del mosaico de la alfalfa en campos de alfalfa con edades comprendidas entre uno y cinco años, localizados en tres áreas ecológicas distintas del Valle del Ebro en España. Ninguno de los modelos, que se ajustaron como modelos lineales generalizados, explicaron suficientemente la alta variabilidad existente en los datos de campo, pero fueron útiles para analizar la interdependencia entre determinados factores epidemiológicos asociados con los parámetros estimados por los modelos. El modelo de regresión logística proporcionó mayor sensibilidad que los modelos clásicos de crecimiento para detectar diferencias significativas en los parámetros, como el índice de aumento de la incidencia con la edad del alfalfar o la cantidad inicial de infección, y diferencias asociadas con las variables explicativas del modelo, como el área ecológica. Los resultados indican que la regresión logística puede ser un método adecuado de análisis estadístico para estudios de epidemiología vegetal