Characterization and monitoring of selected rhizobial strains isolated from tree legumes in Thailand

Tree legume rhizobia were isolated from five tree legumes; Acacia auriculaformis Cunn., A. mangium Willd., Milletia leucantha Kurz., Pterocarpus indicus Willd., and Xylia xylocarpa Taub. grown in Thailand.Forty four highly effective rhizobial strains were selected on the basis of nitrogenase activity, number of nodules and plant biomass. The selected strains were characterized in both terms of physiology andgenetics. Most of the strains are slow grower and able to nodulate cowpea rather than soybean. In addition, IAA production could be detected only from few strains. When almost complete 16S rRNAsequences were analysed, the results indicated that most of the selected strains most likely belong to Bradyrhizobium elkanii and Bradyrhizobium sp. except strains AA67 and PT59 which most likely belong to B. japonicum. The nodule occupancy of selected strains in forest soil condition was investigated by using GUS reporter gene. The nodule occupancy is in the range of 63 - 100%. This suggests theappropriate strains should be produced as inoculum for further application in reforestation programmes in Thailand

Growth, symbiotic, and proteomics studies of soybean Bradyrhizobium in response to adaptive acid tolerance

Bradyrhizobial inoculated soybean often performs poorly on acid-soil because of the acid sensitivity of their associated root nodule bacteria. Acid tolerance in rhizobia has been considered as a key phenotypic characteristic in that it enables the bacteria to perform well under the restrictive conditions of excessive acidity. Since bacteria could develop acid tolerance to a more acid condition by using adaptive acid tolerance response (ATR), it is interesting to investigate whether bradyrhizobia could have this response and what proteins are involved in ATR. Bradyrhizobium sp. DASA01007 was selected for this study based on its ATR ability and symbiosis efficiency with soybean under acid condition. To establish an ATR in bradyrhizobia, late log phase culture of cell grown in mild acid condition was subsequently used as inoculum to more acid conditions. The 2D-gel and proteomic analyses were used to investigate the proteins response during ATR compared with non-adaptive conditions. The 29 identified proteins were grouped into 8 categories based on category orthologous group (COG) and one group of unknown categories. Hypothetical protein, transport and binding proteins, and translation protein were up-regulated at pH 4.5N (non-adaptive condition). While up-regulated proteins found during growth at pH 4.5A (adaptive condition) consisted of proteins in cellular processes, translation, energy metabolism, regulatory functions, interconversions and salvage of nucleosides and nucleotides, and conserved hypothetical proteins group. However, transport and binding proteins were absent in adaptive condition. At pH 5.5A, proteins involved in cellular processes were also detected. Several proteins overproduced in adaptive condition may be involved in ATR of bradyrhizobia. An importance of ATR in root nodule bacteria would support a better chance of survival in low pH soils than those conventionally grown in neutral pH. These results suggest that the use of ATR condition could provide an improvement in the production of inoculants.Keywords: Adaptive acid tolerance, Bradyrhizobium, Soybean, 2D-gel electrophoresi

Membrane pathology and microglial activation of mice expressing membrane anchored or membrane released forms of Aβ and mutated human APP

Rona Barron - ORCID: 0000-0003-4512-9177 https://orcid.org/0000-0003-4512-9177Item not available in this repositoryAlzheimer's disease and the transmissible spongiform encephalopathies or prion diseases accumulate misfolded and aggregated forms of neuronal cell membrane proteins. Distinctive membrane lesions caused by the accumulation of disease-associated prion protein (PrPd) are found in prion disease but morphological changes of membranes are not associated with Aβ in Alzheimer's disease. Membrane changes occur in all prion diseases where PrPd is attached to cell membranes by a glycosyl-phosphoinositol (GPI) anchor but are absent from transgenic mice expressing anchorless PrPd. Here we investigate whether GPI membrane attached Aβ may also cause prion-like membrane lesions.https://doi.org/10.1111/nan.1217341

Automatisation de l'irrigation au goutte a goutte de la tomate cultivee en sol et hors sol sous serre

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Automated Transmission-Mode Scanning Electron Microscopy (tSEM) for Large Volume Analysis at Nanoscale Resolution

Transmission-mode scanning electron microscopy (tSEM) on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm2 (65.54 µm per side) at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM) system, which were only 66.59 µm2 (8.160 µm per side) at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ~100 µm2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (~45 nm). Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems.This study was funded by United States National Institutes of Health (http://www.nih.gov; grant numbers NS021184, NS074644, and MH095980 to KMH) and Texas Emerging Technologies Fund (http://governor.state.tx.us/ecodev/etf/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Biological Sciences, School o