Search results for "N fixation"

Optimizing [13N]N2 radiochemistry for nitrogen-fixation in root nodules of legumes

2010

Here we explored the conditions for synthesizing [ 13 N]N 2 in a state that is suitable for the administration to plant root nodules enabling studies of nitrogen fixation. [ 13 N]N 2 was prepared batchwise, starting with [ 13 N]NO ― 3 from the 16 O(p,α) 13 N nuclear reaction on a liquid water target. [ 13 N]NO ― 3 was first reduced to [ 13 N]NH 3 using Devarda's alloy, and then the [ 13 N]NH 3 was oxidized to [ 13 N]N 2 by hypobromite using carrier-added NH 4 CI. The amounts of carrier NH 4 CI and hypobromite were varied to determine the effects these parameters had on the radiochemical yield, and on the radiotracer specific activity. As expected, increasing the amount of carrier NH 4 CI im…

Novel Glutamate–Putrescine Ligase Activity in Haloferax mediterranei: A New Function for glnA-2 Gene

2021

This article belongs to the Section Cellular Biochemistry.

Effetti della modalità di utilizzazione sulla produttività e sull’azotofissazione simbiotica del Trifolium squarrosum allevato in purezza o in consoc…

2011

In Situ X-Ray Tomography Imaging of Soil Water and Cyanobacteria From Biological Soil Crusts Undergoing Desiccation

2018

Biological soil crusts (biocrusts) are millimeter-sized microbial communities developing on the topsoils of arid lands that cover some 12% of Earth’s continental area. Biocrusts consist of an assemblage of mineral soil particles consolidated into a crust by microbial organic polymeric substances that are mainly produced by the filamentous bundle-forming cyanobacteria, among which Microcoleus vaginatus is perhaps the most widespread. This cyanobacterium is the primary producer for, and main architect of biocrusts in many arid soils, sustaining the development of a diverse microbial community. Biocrusts are only active when wet, and spend most of their time in a state of desiccated quiescence…

Nodulating symbiotic bacteria and soil quality

2005

Chapitre 9 : Plant microbe interactions and soil quality Partie : 9-2; International audience

Genetic Diversity of Rhizobia Isolated from the Legume Genera Astragalus, Oxytropis and Onobrychis

1998

The legume genera Astragalus and Oxytropis belong to the tribe Galegae. These legumes are common in Arctic and Temperate climatic zones. Previous studies based on cross-inoculation experiments and numerical taxonomy (Prevost et al., 1987; Novikova et al., 1993; 1994) suggested that the rhizobia associated with these legumes were closely related. Also the legume species Onobrychis viciifolia (sainfoin, tribe Hedysareae) was effectively nodulated by rhizobia isolated from Astragalus and Oxytropis spp. (Prevost et al., 1987). Rhizobia isolated from A. sinicus were classified in a new species, Mesorhizobium huakuii, (Chen et al., 1991; Jarvis et al., 1997). Other rhizobia from Astragalus and Ox…

Comment le mode de nutrition azotée influence-t-il le prélèvement, le stockage et la remobilisation des nutriments en conditions hydriques fluctuante…

2019

National audience; Pea seeds have interesting nutritional properties through their protein, vitamin and mineral contents. However, environmental conditions such as soil water availability during plant growth influence both final yield and seed quality in pea. Soil water conditions not only modulates pea nitrogen acquisition whatever the mode of nitrogen nutrition: mineral nitrogen acquisition by roots and atmospheric di-nitrogen fixation by nodules in interaction with rhizobia, but also the overall plant mineral nutrition. The aim of this study is to get a better understanding of soil water deficit impact on nutrient acquisition, storage and distribution inside the plant according to the mo…

How does pea (Pisum sativum) recover from water deficit?

2020

International audience

Synchronie entre l'offre et la demande dans le cycle des nutriments: apprendre des écosystèmes naturels pour construire des agrosystèmes durables

2023

Redesigning agrosystems with more ecological regulations can help feed a growing population, preserve soils for future productivity and reduce environmental impacts. However, guidelines for redesigning agrosystems from natural systems are limited. Reviewing the last knowledge of ecosystem functioning, we outlined four ecological systems synchronizing the supply of soluble nutrients by soil biota to fluctuating plant nutrient demand. This synchrony limits deficiencies and excesses of soluble nutrient, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. We detail how ecological systems promoting synchrony can be ins…

Quantification des flux d’azote induits par les cultures de légumineuses et étude de leurs déterminants : comparaison de 10 espèces de légumineuses à…

2019

In the context of agroecological transition, the reintroduction of legume crops should play a key role in cropping system sustainability by allowing a reduction of nitrogen (N) inputs. But few references are available concerning the agronomical and ecological services provided by a wide range of legume crops, particularly within crops succession scale. Thus, the main objective of our study is to quantify the N fluxes during and after the legume crops taking into account 10 legume crops (peas, lupin, faba bean, soybean...). Our experiment consists in i) quantifying symbiotic N fixation depending on the amount of soil inorganic N, the mineralisation of N present in legume crop residues after …