Search results for "ABIOTIC"
showing 10 items of 201 documents
Prévalence de pathogènes humains dans les sols français, effet des facteurs pédoclimatiques, biologiques et du mode d'utilisation des sols
2013
Soil contamination by bacterial pathogens can occur through manure, sewage sludge spreading or irrigation using waste water treatment plants effluents. Agricultural soils may act as reservoirs for these pathogens, play a significant role in their dissemination, leading to the potential contamination of food and water resources. Health risk associated with the occurrence of pathogens in environmental matrices has to be thoroughly evaluated. In this context, the objectives of this work were: i) to determine the prevalence of two pathogenic bacterial species (Listeria monocytogenes and Enterococcus faecalis) in a large collection of French soils originated from a systematic soil survey of the …
Concepts and methods to assess phytosanitary quality of soils
2005
Chapitre 9.4 : Plant-microbe interactions and soil quality; International audience
Correlating stress and somatic embryogenesis for NBT: myth or reality?
2018
Global warming and growing demography have increased demand for agronomic resources, leading to increasing lack of land suitable for agriculture and provoking several abiotic stresses which, added to biotic ones, result in physiological and metabolic disorders that impact on crop yield when most needed. Reducing this impact is a major scientific and agronomic challenge and biotechnology would be an efficient alternative. However, to reduce risks of somaclonal variation among regenerants it is better to produce them by somatic embryogenesis directly from explants or gametes, or indirectly from callus or cell suspensions. Thus, globular embryos regenerate and develop through to the heart, tor…
Developing fall-sown pea cultivars as an answer to the challenges of climatic changes
2012
Chapitre 4; International audience; Pea is considered rather well adapted to wide temperature ranges, with seedlings able to survive even -20 °C. From a physiological viewpoint, pea becomes tolerant to frost if first exposed to low non-freezing temperatures, causing the so-called cold acclimation. Delayed floral initiation helps some forage pea genotypes to escape the main winter freezing periods, as susceptibility to frost increases during the transition to the reproductive state. The oldest winter pea cultivars carry the dominant allele, Hr, although some bear hr. They are generally characterized by prominent winter hardiness and a long growing season, from sowing in early October until e…
Transcriptional response of Medicago truncatula sulphate transporters to arbuscular mycorrhizal symbiosis with and without sulphur stress
2013
Sulphur is an essential macronutrient for plant growth, development and response to various abiotic and biotic stresses due to its key role in the biosynthesis of many S-containing compounds. Sulphate represents a very small portion of soil S pull and it is the only form that plant roots can uptake and mobilize through H(+)-dependent co-transport processes implying sulphate transporters. Unlike the other organically bound forms of S, sulphate is normally leached from soils due to its solubility in water, thus reducing its availability to plants. Although our knowledge of plant sulphate transporters has been growing significantly in the past decades, little is still known about the effect of…
Challenges and opportunities for innovative research on legume nutrition and stress adaptation: an ecophysiologist’s and phenotyping point of view
2019
International audience; Agroecology needs to reconcile agronomy and ecology, preserving and valorizing plant and microbe biodiversity. Legumes have merits for agroecology considering their ecological services. They constitute a protein source and their production relocation give merits for feed and food. However, they are still under represented due to both biotic and abiotic constraints. Research need to increase their profitability through higher and more stable yield and protein content, and new uses in a fluctuating environment [2]. Mechanisms which control nutrient use efficiency have to be highlighted i) considering nutrient acquisition, storage, remobilization [3] ii) under various c…
Microbial diversity and structure are drivers of the biological barrier effect against Listeria monocytogenes in soil
2013
International audience; Understanding the ecology of pathogenic organisms is important in order to monitor their transmission in the environment and the related health hazards. We investigated the relationship between soil microbial diversity and the barrier effect against Listeria monocytogenes invasion. By using a dilution-to-extinction approach, we analysed the consequence of eroding microbial diversity on L. monocytogenes population dynamics under standardised conditions of abiotic parameters and microbial abundance in soil microcosms. We demonstrated that highly diverse soil microbial communities act as a biological barrier against L. monocytogenes invasion and that phylogenetic compos…
Root growth and development under heat and water stresses: a comparative study determining independent and combined effects in four grain legume spec…
2018
International audience; hanks to their ability to fix atmospheric dinitrogen in symbiosis with soil bacteria, grain legumes provide a sustainable way to ensure food and nutritional security. Unfortunately, these crops are highly susceptible to environmental constraints such as heat or water stresses which leads to fluctuating yields as compared to cereals. In the context of climate change, more frequent episodes of heat stress, concomitant (or not) with water stress are expected. This emphasizes the need to identify key plant traits towards a better yield stability under stressful conditions.
Phenotyping: Case study of legumes plants
2012
International audience; The activities of the GEAPSI group, belonging to the large research unit Agroecology, is devoted to the genetic improvement of legumes important for European agriculture, and focuses on the cultivated species pea (Pisum sativum) and the field bean (Vicia faba). These studies are supported by basic research on a model legume, Medicago truncatula, used for taking advantage of the extensive genomics information available. Some examples will first illustrate how the combination of analytical, non-destructive phenotypical measurements and modelling can improve our understanding of plant functioning, taking as case studies legumes plants. The presentation will then describ…
Impact of stresses associated to climate changes on natural and induced grapevine resistance to pathogens
2013
France is a worldwide leader in grape production and has to face global changes including climate evolution and transitions towards sustainable systems of production. One major problem in viticulture is indeed the high susceptibility of most of the grown cultivars to cryptogamic diseases, such as downy mildew (Plasmopara viticola). Maintaining a satisfactory health status of grapevine currently requires numerous fungicide treatments. However, in an objective of sustainable viticulture, there is increasing societal request, winegrower awareness, and political incitation to reduce this use of pesticides. For these reasons, alternative strategies of protection are currently investigated at the…