Search results for "defense"
showing 10 items of 247 documents
Chemoecological study of the invasive alga Caulerpa taxifolia var. distichophylla from the Sicilian coast
2022
Marine invasive species and their bioactive metabolites have become critical ecological issues in the Mediterranean Sea. In particular, the highly invasive green algae Caulerpa taxifolia and Caulerpa cylindracea are known to contain the bioactive sesquiterpene caulerpenyne (1) and the bisindolic alkaloid caulerpin (2), potentially acting as chemical stressors for native species. The recent spread of a variety of C. taxifolia, Caulerpa taxifolia var. distichophylla, also raises urgent questions about its chemical composition. Indeed, the only chemical data available for this alga are limited to the seasonal variations of caulerpenyne (1) in samples collected in the Eastern Mediterranean. In …
Characterization of grapevine defense reactions and identification of elicitors : the endopolygalacturonase 1 from Botrytis cinerea, an avirulence fu…
2002
The fight against grapevine pathogens is mainly carried out by pesticides, the continued use of which is harmful to the environment and the health of users and consumers. The main organizations in charge of viticulture set as a priority the research and use of alternatives to chemical control. However, the genetic improvement of the vine is prohibited in AOC vineyards to preserve the varietal typicity, partly responsible for the quality of the wines. In addition, research undertaken some fifteen years ago reveals that plants have their own immune defenses, which they activate on contact with the microorganisms they recognize via molecules called elicitors. In this context, the objective of …
Regulation and role of nitric oxide production in Arabidopsis thaliana defense responses induced by oligogalacturonides
2014
SPEIPM; International audience
Use of social over personal information enhances nest defense against avian brood parasitism
2011
Interactions with conspecifics influence the behavioral repertoire of an organism, as they apply to foraging techniques, song acquisition, habitat selection, and mate choice. Few workers have studied the role of social interactions in molding defense responses, especially the defense of the nest. We tested the effect of social interaction on nest defense of the reed warbler (Acrocephalus scirpaceus), one of the main hosts of the brood-parasitic common cuckoo (Cuculus canorus) in Europe. This parasite reduces its host’s breeding success; therefore, any response that prevents successful parasitism should be selected. Because of their high nesting density and consistent cuckoo-specific respons…
Rôle de la dynamique de la membrane plasmique dans la mise en place des réactions de défense chez le tabac
2008
The binding of cryptogein, a plant defense elicitor secreted by an oomycete, to an unknown receptor triggers well-known biochemical events of early signal transduction at the plasma membrane of tobacco cells. One of these early events is the transient production of Reactive Oxygen Species (ROS) by an NADPH oxidase, NtrbohD. We were thus interested to analyze the dynamic of the plasma membrane during these early stages. We determined that internalization of the endocytotic marker FM4-64 is stimulated a few minutes after addition of cryptogein to tobacco BY-2 cells. This stimulation is specific to the signal transduction pathway elicited by cryptogein since a lipid transfer protein, which bin…
Defense Responses in Two Ecotypes of Lotus japonicus against Non-Pathogenic Pseudomonas syringae
2013
Lotus japonicus is a model legume broadly used to study many important processes as nitrogen fixing nodule formation and adaptation to salt stress. However, no studies on the defense responses occurring in this species against invading microorganisms have been carried out at the present. Understanding how this model plant protects itself against pathogens will certainly help to develop more tolerant cultivars in economically important Lotus species as well as in other legumes. In order to uncover the most important defense mechanisms activated upon bacterial attack, we explored in this work the main responses occurring in the phenotypically contrasting ecotypes MG-20 and Gifu B-129 of L. ja…
Interactions between Polyamines and Abiotic Stress Pathway Responses Unraveled by Transcriptome Analysis of Polyamine Overproducers
2011
Plant development and productivity are negatively regulated by adverse environmental conditions. The identification of stress-regulatory genes, networks, and signaling molecules should allow the development of novel strategies to obtain tolerant plants. Polyamines (PAs) are polycationic compounds with a recognized role in plant growth and development, as well as in abiotic and biotic stress responses. During the last years, knowledge on PA functions has been achieved using genetically modified plants with altered PA levels. In this review, we combine the information obtained from global transcriptome analyses in transgenic Arabidopsis plants with altered putrescine or spermine levels. Compa…
Comparison between tumors in plants and human beings: Mechanisms of tumor development and therapy with secondary plant metabolites
2019
Abstract Background Human tumors are still a major threat to human health and plant tumors negatively affect agricultural yields. Both areas of research are developing largely independent of each other. Treatment of both plant and human tumors remains unsatisfactory and novel therapy options are urgently needed. Hypothesis The concept of this paper is to compare cellular and molecular mechanisms of tumor development in plants and human beings and to explore possibilities to develop novel treatment strategies based on bioactive secondary plant metabolites. The interdisciplinary discourse may unravel commonalities and differences in the biology of plant and human tumors as basis for rational …
Capitolo VIII della Carta dell’ONU e modelli di azione militare regionale
2019
This contribution deals with relations between regional organizations and the UN Security Council under Chapter VIII of the UN Charter. In this respect, the most recent trends are a shift from subsidiarity to a more equal partnership between these two subjects. The two models of action by delegation or authorization of the Security Council are in fact autonomous. This is demonstrated by the preparatory works of the UN Charter and subsequent practice. The model of authorized regional action enriches the range of instruments that the United Nations Charter provides for the maintenance of peace and collective security.
Psychological defense styles, childhood adversities and psychopathology in adulthood.
2003
OBJECTIVE: The present study explores the link between reported sexual and/or physical abuse and psychological defense styles, as well as the association of both with psychological distress in adulthood. In two patient samples that differ in psychological distress and somatization, we examine whether the adversities reported and immature defense styles are associated with psychopathological symptoms. METHOD: We examined 266 consecutive inpatients in the psychosomatic department and 109 consecutive inpatients who had been treated for low-back pain in the orthopedic department of a German university hospital. Psychological defense styles were assessed by a two-factor solution of the German mo…