A proteomic approach to analyzing responses of Arabidopsis thaliana root cells to different gravitational conditions using an agravitropic mutant, pin2 and its wild type

<p>Abstract</p> <p>Background</p> <p>Root gravitropsim has been proposed to require the coordinated, redistribution of the plant signaling molecule auxin within the root meristem, but the underlying molecular mechanisms are still unknown. PIN proteins are membrane transporters that mediate the efflux of auxin from cells. The PIN2 is important for the basipetal transport of auxin in roots and plays a critical role in the transmission of gravity signals perceived in the root cap to the root elongation zone. The loss of function <it>pin2 </it>mutant exhibits a gravity-insensitive root growth phenotype. By comparing the proteomes of wild type and the <it>pin2 </it>mutant root tips under different gravitational conditions, we hope to identify proteins involved in the gravity-related signal transduction.</p> <p>Results</p> <p>To identify novel proteins involved in the gravity signal transduction pathway we have carried out a comparative proteomic analysis of Arabidopsis <it>pin2 </it>mutant and wild type (WT) roots subjected to different gravitational conditions. These conditions included horizontal (H) and vertical (V) clinorotation, hypergravity (G) and the stationary control (S). Analysis of silver-stained two-dimensional SDS-PAGE gels revealed 28 protein spots that showed significant expression changes in altered gravity (H or G) compared to control roots (V and S). Whereas the majority of these proteins exhibited similar expression patterns in WT and <it>pin2 </it>roots, a significant number displayed different patterns of response between WT and <it>pin2 </it>roots. The latter group included 11 protein spots in the H samples and two protein spots in the G samples that exhibited an altered expression exclusively in WT but not in <it>pin2 </it>roots. One of these proteins was identified as annexin2, which was induced in the root cap columella cells under altered gravitational conditions.</p> <p>Conclusions</p> <p>The most interesting observation in this study is that distinctly different patterns of protein expression were found in WT and <it>pin</it>2 mutant roots subjected to altered gravity conditions. The data also demonstrate that PIN2 mutation not only affects the basipetal transport of auxin to the elongation zone, but also results in an altered expression of proteins in the root columella.</p

Effects of Different Exhaust Gas Recirculation (EGR) Rates on Combustion and Emission Characteristics of Biodiesel&ndash;Diesel Blended Fuel Based on an Improved Chemical Mechanism

This paper studies the effects of different exhaust gas recirculation (EGR) rates (0%, 5%, 10%, and 15%) on the combustion, performance, and emission characteristics of a biodiesel&ndash;diesel (20% biodiesel + 80% diesel) blended fuel engine. This paper mainly analyzes the effects on engine cylinder temperature, cylinder pressure, brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), NOx emissions, carbon monoxide (CO) emissions, hydrocarbon (HC) emissions, and soot emissions. Firstly, a 3D-CFD model was established by using CONVERGE software, combined with an improved chemical kinetic mechanism including 98 species and 314 reactions, and the accuracy of the simulation model was verified by experimental results. Secondly, the effects of different EGR rates on the combustion, performance, and emission characteristics of biodiesel&ndash;diesel blended fuel were studied. The results showed that with the increase in the EGR rate, the cylinder pressure and cylinder temperature in the cylinder decreased. When the EGR rate was 15%, the maximum cylinder temperature decreased by 4.33%. In addition, BSFC increased and BTE decreased. Moreover, with the increase in the EGR rate, NOx decreased significantly, and the higher the EGR rate, the more obvious the reduction in NOx emissions. When the EGR rate was 15%, NOx was reduced by 78.89%. However, with the increase in the EGR rate, the emissions of soot, HC, and CO increased. The optimal EGR rate for the engine is 10%

Geological Feature Modeling and Reserve Estimation of Uranium Deposits Based on Multiple Interpolation Methods

Uranium resource distribution and accurate reserve evaluation are important references for mineral investment and production. Eight kinds of interpolation methods in the Groundwater Modeling System (GMS), including ordinary kriging (OK), are used in this study to predict the spatial distribution of reserve-related parameters, such as uranium grade, ore thickness and uranium content per square meter. The present study draws the following conclusions: (1) Cross-validation found that the uranium grade value using the spherical method is the closest to the actual value. The spherical method has the best interpolation effect. (2) The relative error, which is +3.62%, between the uranium reserves that is calculated by the spherical interpolation method and that by the traditional calculation value is the smallest. (3) The setting of the number of interpolation grids is related to the actual number of boreholes. The ratio between the two will affect the accuracy of reserve estimation, and different interpolation methods have different degrees of influence on reserve estimation. This method is applicable to all in-situ leaching sandstone uranium mines. Further study needs to be carried out toward heterogeneity of three-dimensional space, which will make the estimation more accurate

Cryo-EM reveals a previously unrecognized structural protein of a dsRNA virus implicated in its extracellular transmission.

Mosquito viruses cause unpredictable outbreaks of disease. Recently, several unassigned viruses isolated from mosquitoes, including the Omono River virus (OmRV), were identified as totivirus-like viruses, with features similar to those of the Totiviridae family. Most reported members of this family infect fungi or protozoans and lack an extracellular life cycle stage. Here, we identified a new strain of OmRV and determined high-resolution structures for this virus using single-particle cryo-electron microscopy. The structures feature an unexpected protrusion at the five-fold vertex of the capsid. Disassociation of the protrusion could result in several conformational changes in the major capsid. All these structures, together with some biological results, suggest the protrusions' associations with the extracellular transmission of OmRV

In Situ Fabrication of Defective CoN_<i>x</i> Single Clusters on Reduced Graphene Oxide Sheets with Excellent Electrocatalytic Activity for Oxygen Reduction

A facile one-step strategy for anchoring defective CoN_<i>x</i> single clusters on partly reduced graphene oxide (RGO) is constructed to significantly improve the catalytic performance of non-noble metal complexes toward oxygen reduction reaction (ORR). Sequent loading with trace amounts of metal-free porphyrin and Co²⁺ in RGO can dramatically enhance both the half-wave potential and the peak current density. Intriguingly, the RGO/​P/​2Co single cluster exhibits the best ORR catalytic performance with the half-wave potential of 0.834 V, extremely approaching that of commercial Pt/C (0.836 V). This half-wave potential surpasses most of the reported half-wave potentials of RGO supported non-noble metal ORR catalysts through low-temperature synthesis. Furthermore, the as-prepared RGO/​P/​2Co delivers a peak current density of 1.3 times higher than that of Pt/C at the same loading, together with a high mass activity of 2.76 A mg_Co^–1. During the durability test, a cathodic current loss less than 10% is recorded after 8000 continuous potential cycles. Insights into this successful example will be conducive to the development of elegant routes for constructing metal nitrogen (MN)-based ORR catalysts with high efficiency, outstanding stability, and excellent selectivity