A map of the diversity of RNA3 recombinants appearing in plants infected with cucumber mosaic virus and tomato aspermy virus

AbstractIn order to better understand the role of recombination in creating the diversity of viral genomes that is acted on by selection, we have studied in detail the population of recombinant RNA3 molecules occurring in tobacco plants coinfected with wild-type strains of cucumber mosaic virus (CMV) and tomato aspermy virus (TAV) under conditions of minimal selection pressure. Recombinant RNA3s were observed in 9.6% of the samples. Precise homologous recombination predominated since it was observed at 28 different sites, primarily in six hot spots. Imprecise homologous recombination was observed at two sites, particularly within a GU repeat in the 5′ noncoding region. Seven of the eight aberrant homologous recombination sites observed were clustered in the 3′ noncoding region. These results have implications on the role of recombination in host adaptation and virus evolution. They also provide essential baseline information for understanding the potential epidemiological impact of recombination in transgenic plants expressing viral sequences

La caméline, une plante modèle pour la recherche translationnelle

National audienceEn biologie végétale, la recherche translationnelle vise à accélérer la valorisation de découvertes scientifiques réalisées à partir de plantes modèles au bénéfice de plantes d’intérêt agronomique. Dans ce domaine, la caméline est un outil particulièrement efficace : génétiquement proche de l’espèce modèle Arabidopsis thaliana, elle permet d’évaluer simplement de nouveaux caractères associés aux plantes oléoprotéagineuses

Virus effects on plant quality and vector behavior are species specific and do not depend on host physiological phenotype

There is growing evidence that plant viruses manipulate host plants to increase transmission-conducive behaviors by vectors. Reports of this phenomenon frequently include only highly susceptible, domesticated annual plants as hosts, which constrains our ability to determine whether virus effects are a component of an adaptive strategy on the part of the pathogen or simply by-products of pathology. Here, we tested the hypothesis that transmission-conducive effects of a virus (Turnip yellows virus [TuYV]) on host palatability and vector behavior (Myzus persicae) are linked with host plant tolerance and physiological phenotype. Our study system consisted of a cultivated crop, false flax (Camelina sativa) (Brassicales: Brassicaceae), a wild congener (C. microcarpa), and a viable F1 hybrid of these two species. We found that the most tolerant host (C. microcarpa) exhibited the most transmission-conducive changes in phenotype relative to mock-inoculated healthy plants: Aphids preferred to settle and feed on TuYV-infected C. microcarpa and did not experience fitness changes due to infection—both of which will increase viruliferous aphid numbers. In contrast, TuYV induced transmission-limiting phenotypes in the least tolerant host (C. sativa) and to a greater degree in the F1 hybrid, which exhibited intermediate tolerance to infection. Our results provide no evidence that virus effects track with infection tolerance or physiological phenotype. Instead, vector preferences and performance are driven by host-specific changes in carbohydrates under TuYV infection. These results provide evidence that induction of transmission-enhancing phenotypes by plant viruses is not simply a by-product of general pathology, as has been proposed as an explanation for putative instances of parasite manipulation by viruses and many other taxa

Outcome of a workshop

International audience; In tackling agricultural challenges, policy-makers in sub-Saharan Africa (SSA) have increasingly considered genetically modified (GM) crops as a potential tool to increase productivity and to improve product quality. Yet, as elsewhere in the world, the adoption of GM crops in SSA has been marked by controversy, encompassing not only the potential risks to animal and human health, and to the environment, but also other concerns such as ethical issues, public participation in decision-making, socio-economic factors and intellectual property rights. With these non-scientific factors complicating an already controversial situation, disseminating credible information to the public as well as facilitating stakeholder input into decision-making is essential. In SSA, there are various and innovative risk communication approaches and strategies being developed, yet a comprehensive analysis of such data is missing. This gap is addressed by giving an overview of current strategies, identifying similarities and differences between various country and institutional approaches and promoting a way forward, building on a recent workshop with risk communicators working in SSA

Camelina, a swiss knife for plant lipid biotechnology

Camelina has emerged in the last decade as a multipurpose crop plant particularly suitable for engineering new lipids for diverse uses, including feed, biofuel and green chemistry. The rebirth of this ancient crop was based on several intrinsic favorable characteristics: robust agronomic qualities, attractive oil profile, genetic proximity with the model plant arabidopsis, ease of genetic transformation by floral dip. The need to increase both the production and diversity of plant oils, while improving the sustainability of agricultural systems, has been the driving forces behind the ever-increasing investment in camelina research. Worldwide interest in engineering camelina has led to the development of a remarkable pipeline that allows the rapid production and phenotyping of new lines; it includes specific tools, such as databases, collections of natural accessions, methods of genetic transformation and lipid analysis. Implementation of numerous metabolic pathways in camelina for the production of novel lipids has highlighted the potential as well as the versatility of this new "old" oilseed crop that is well on the way to becoming an ideal plant chassis for lipid synthetic biology

Potential ecological risks in transgenic plants expressing viral genes

International audienc

Que faut-il penser des risques écologiques liés à l'utilisation des plantes transgéniques exprimant des séquences virales?

National audienc