Search

Objective In the actual metro construction, it is often necessary to lay turnouts on large-slope sections due to planning and construction constraints, land conservation or topographical limitations. However, it is found through practical application that the large-slope turnout structure leads to poor train stability and ride comfort during operation, thus an investigation on the factors influencing vehicle passing performance through large-slope metro turnouts is required. Method Based on multi-body dynamics theory, using simulation analysis software and taking the No.9 turnout installed on a 30‰ slope as research object, a coupled vehicle-turnout multi-body dynamics model is established. The dynamics performance indicators (including wheel-rail interaction, safety indicators, and stability indicators) of single vehicle passing through large-slope turnout at different operating speeds and friction coefficients are compared，aiming to analyze the impact of various factors on the vehicle passing performance through large-slope metro turnouts. Result & Conclusion It is revealed through simulation research that the impact of operating speed on wheel-rail interaction, stability indicators, and safety indicators is independent of the slope direction during vehicle passing turnouts. When a vehicle passes through turnouts on uphill and downhill slopes, the influence trends of operating speed on the dynamics indicators are consistent, with a more significant impact when going downhill; the friction coefficient greatly affects the wheel-rail dynamic interaction and the vehicle lateral acceleration. As the friction coefficient increases, the wheel-rail interaction force decreases, the carbody vertical acceleration shows no significant change, and the lateral acceleration increases significantly, with a more pronounced effect when going downhill. Therefore, certain strengthening and protective measures should be taken when vehicle going downhill.

Cold stress affects the seed germination and early growth of winter rapeseed, leading to yield losses. We employed transmission electron microscopy, physiological analyses, metabolome profiling, and transcriptome sequencing to understand the effect of cold stress (0 °C, LW) on the cotyledons of cold-tolerant (GX74) and -sensitive (XY15) rapeseeds. The mesophyll cells in cold-treated XY15 were severely damaged compared to slightly damaged cells in GX74. The fructose, glucose, malondialdehyde, and proline contents increased after cold stress in both genotypes; however, GX74 had significantly higher content than XY15. The pyruvic acid content increased after cold stress in GX74, but decreased in XY15. Metabolome analysis detected 590 compounds, of which 32 and 74 were differentially accumulated in GX74 (CK vs. cold stress) and XY15 (CK vs. cold stressed). Arachidonic acid and magnoflorine were the most up-accumulated metabolites in GX74 subjected to cold stress compared to CK. There were 461 and 1481 differentially expressed genes (DEGs) specific to XY15 and GX74 rapeseeds, respectively. Generally, the commonly expressed genes had higher expressions in GX74 compared to XY15 in CK and cold stress conditions. The expression changes in DEGs related to photosynthesis-antenna proteins, chlorophyll biosynthesis, and sugar biosynthesis-related pathways were consistent with the fructose and glucose levels in cotyledons. Compared to XY15, GX74 showed upregulation of a higher number of genes/transcripts related to arachidonic acid, pyruvic acid, arginine and proline biosynthesis, cell wall changes, reactive oxygen species scavenging, cold-responsive pathways, and phytohormone-related pathways. Taken together, our results provide a detailed overview of the cold stress responses in rapeseed cotyledons. [ABSTRACT FROM AUTHOR]

The application of phosphorus-solubilizing bacteria is an effective method for increasing the available phosphorus content and inhibiting wheat uptake of heavy metals. However, further research is needed on the mechanism by which phosphorus-solubilizing bacteria inhibit cadmium (Cd) uptake in wheat roots and its impact on the expression of root-related genes. Here, the effects of strain Klebsiella aerogenes M2 on Cd absorption in wheat and the expression of root-related Cd detoxification and immobilization genes were determined. Compared with the control, strain M2 reduced (64.1–64.6%) Cd uptake by wheat roots. Cd fluorescence staining revealed that strain M2 blocked the entry of exogenous Cd into the root interior and enhanced the immobilization of Cd by cell walls. Forty-seven genes related to Cd detoxification, including genes encoding peroxidase, chalcone synthase, and naringenin 3-dioxygenase, were upregulated in the Cd+M2 treatment. Strain M2 enhanced the Cd resistance and detoxification activity of wheat roots through the regulation of flavonoid biosynthesis and antioxidant enzyme activity. Moreover, strain M2 regulated the expression of genes related to phenylalanine metabolism and the MAPK signaling pathway to enhance Cd immobilization in roots. These results provide a theoretical basis for the use of phosphorus-solubilizing bacteria to remediate Cd-contaminated fields and reduce Cd uptake in wheat. [ABSTRACT FROM AUTHOR]

Hsp40s or DnaJ/J-proteins are evolutionarily conserved in all organisms as co-chaperones of molecular chaperone HSP70s that mainly participate in maintaining cellular protein homeostasis, such as protein folding, assembly, stabilization, and translocation under normal conditions as well as refolding and degradation under environmental stresses. It has been reported that Arabidopsis J-proteins are classified into four classes (types A-D) according to domain organization, but their phylogenetic relationships are unknown. Here, we identified 129 J-proteins in the world-wide popular vegetable Brassica oleracea, a close relative of the model plant Arabidopsis, and also revised the information of Arabidopsis J-proteins based on the latest online bioresources. According to phylogenetic analysis with domain organization and gene structure as references, the J-proteins from Arabidopsis and B. oleracea were classified into 15 main clades (I-XV) separated by a number of undefined small branches with remote relationship. Based on the number of members, they respectively belong to multigene clades, oligo-gene clades, and mono-gene clades. The J-protein genes from different clades may function together or separately to constitute a complicated regulatory network. This study provides a constructive viewpoint for J-protein classification and an informative platform for further functional dissection and resistant genes discovery related to genetic improvement of crop plants. Key words: J-proteins, Arabidopsis, Brassica oleracea, phylogenetic analysis, domain organization, gene structure. Resume : Les proteines HSP40s ou DNAJ/J ont ete conservees au cours de l'evolution chez tous les organismes a titre de co-chaperone des chaperones moleculaires HSP70s qui participent principalement au maintien de l'homeostasie proteique cellulaire, tel que le repliement, l'assemblage, la stabilisation et la translocation des proteines sous des conditions normales de meme que dans le repliement et la degradation en conditions de stress environnementaux. Il a ete rapporte que les proteines J chez l'Arabidopsis formaient quatre classes (types A-D) selon l'organisation des domaines, mais leurs relations phylogenetiques demeurent inconnues. Dans ce travail, les auteurs ont identifie 129 proteines J au sein du Brassica oleracea, une espece potagere mondialement apprecieeetunproche parent de l'espece modele Arabidopsis. Les auteurs ont egalement revise l'information sur les proteines J de l'Arabidopsis a l'aide des plus recentes ressources disponibles en ligne. Sur la base de l'analyse phylogenetique fondee sur l'organisation des domaines et la structure genique, les proteines J chez ces deux especes ont ete classifiees au sein de 15 clades principaux (I-XV), lesquels etaient separes par quelques petites branches mal definies aux relations eloignees. En fonction du nombre de membres, ces genes appartiennent a des clades multi-, oligo- ou monogeniques. Les proteines J des differents clades fonctionnent possiblement ensemble ou separement pour constituer un reseau de regulation complexe. Cette etude a fourni une assise constructive pour la classification et une plateforme informative pour de plus amples etudes fonctionnelles sur les proteines J ainsi que pour l'identification de genes de resistance lies a l'amelioration genetique des plantes cultivees. [Traduit par la Redaction] Mots-cles : proteines J, Arabidopsis, Brassica oleracea, analyse phylogenetique, organisation des domaines, structure genique., Introduction Prokaryotic and eukaryotic organisms respond and adapt to abiotic stress via the accumulation of heat shock proteins (HSPs) asa defense mechanism. HSPs are divided into seven groups based on [...]