IRS-2 Deficiency Impairs NMDA Receptor-Dependent Long-term Potentiation

The beneficial effects of insulin and insulin-like growth factor I on cognition have been documented in humans and animal models. Conversely, obesity, hyperinsulinemia, and diabetes increase the risk for neurodegenerative disorders including Alzheimer's disease (AD). However, the mechanisms by which insulin regulates synaptic plasticity are not well understood. Here, we report that complete disruption of insulin receptor substrate 2 (Irs2) in mice impairs long-term potentiation (LTP) of synaptic transmission in the hippocampus. Basal synaptic transmission and paired-pulse facilitation were similar between the 2 groups of mice. Induction of LTP by high-frequency conditioning tetanus did not activate postsynaptic N-methyl-D-aspartate (NMDA) receptors in hippocampus slices from Irs2−/− mice, although the expression of NR2A, NR2B, and PSD95 was equivalent to wild-type controls. Activation of Fyn, AKT, and MAPK in response to tetanus stimulation was defective in Irs2−/− mice. Interestingly, IRS2 was phosphorylated during induction of LTP in control mice, revealing a potential new component of the signaling machinery which modulates synaptic plasticity. Given that IRS2 expression is diminished in Type 2 diabetics as well as in AD patients, these data may reveal an explanation for the prevalence of cognitive decline in humans with metabolic disorders by providing a mechanistic link between insulin resistance and impaired synaptic transmission

Present status of the development of mycoherbicides against water hyacinth: successes and challenges. A review

Recent trends in the implementation of bioherbicide use in the control of water hyacinth (Eichhornia crassipes [Martius] Solms Laubach) have depended primarily on several strategies. The use of bioherbicides has been stimulated as part of the search for alternatives to chemical control, as the use of these more environmentally-friendly formulations minimizes hazards resulting from herbicide residue to both human and animal health, and to the ecology. In addition, one of the major strategies in the concept of biological control is the attempt to incorporate biological weed control methods as a component of integrated weed management, in order to achieve satisfactory results while reducing herbicide application to a minimum. Several fungal pathogens with mycoherbicide potential (Sclerotinia sclerotiorum in Hyakillä and Cercospora rodmanii, named ABG-5003) have been discovered on diseased water hyacinth plants, but none has become commercially available in the market. Biological, technological, and commercial constraints have hindered progress in this area. Many of these constraints are being addressed, but there is a critical need to better understand the biochemical and physiological data regarding the pathogenesis of these new bioherbicides. Oil emulsions are recognized as a way to increase both efficiency of application and efficacy of biocontrol agents

Synthèse bibliographique : problématique de la jacinthe d'eau, Eichhornia crassipes, dans les régions tropicales et subtropicales du monde, notamment son éradication par la lutte biologique au moyen des phytopathogènes

eview: problems of the water hyacinth, Eichhornia crassipes, in the tropical and subtropical areas of the world, in particular its eradication using biological control method by means of plant pathogens. Water hyacinth, probably originating from South America, grows between 35th North and South parallels of the planet. It was introduced into several regions of the world as ornamental plant, where it became later one of the most dangerous world water weed. Its infestation can be controlled by physical and chemical treatments. However, these methods are expensive and dangerous for human health and environment. Moreover, following Western legislations example, those of developing countries are highly restrictive against authorised chemical molecules. Consequently, a growing interest was given to alternative solutions, such as biological control. That control using insects, fishes and mammiferes against water hyacinth could be strengthened with the application of mycoherbicides. These mycoherbicides are more respectful for environment and public health and seem to constitute an additional realistic alternative for water hyacinth durable management

Implementing plant biostimulants and biocontrol strategies in the agroecological management of cultivated ecosystems. A review

Introduction. In the context of sustainable agricultural production, agroecology aims at optimizing the economic and environmental performances of beneficial ecosystem services in order to (i) increase the productivity and resilience of cultivated ecosystems and (ii) preserve their natural resources. The maintenance of such performances is supported by research via the development of new tools that enhance plant tolerance to numerous biotic and abiotic stresses. Literature. Biostimulants can be used as a tool to complement the use of chemical inputs, by involving non-living-based products, or living-based products containing beneficial rhizosphere microbiome, such as plant growth-promoting rhizobacteria (PGPR). Pest management research has also made major advances in the development of efficient biocontrol methods. Elicitors and semiochemicals are considered to be some of the most promising tools for inducing plant resistance to various diseases and enhancing natural predation, respectively. Several products are already on the market. This review discusses current methods for exploiting and applying biostimulant and biocontrol products in contemporary agricultural systems. Future applications of these tools for sustainable management of cultivated ecosystems are also discussed. Conclusions. These tools are still difficult to use because of their lack of reliability in the field and their uneasy integration in the cropping systems. Further studies are needed to better understand the parameters influencing the efficiency of PGPR, elicitors and semiochemicals. Special attention needs to be given to the formulation and the interactions of these products with plant physiology and the environment

yeast species for biocontrol of apple postharvest disease: an encouranging case of study for pratical use

peer reviewe