25 research outputs found

    A tuber mustard AP2/ERF transcription factor gene, BjABR1, functioning in abscisic acid and abiotic stress responses, and evolutionary trajectory of the ABR1 homologous genes in Brassica species

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    The AP2/ERF superfamily of transcription factors is one of the largest transcription factor families in plants and plays an important role in plant development processes and stress responses. In this study, BjABR1, an AP2/ERF superfamily gene, from tuber mustard (Brassica juncea var. tumida Tsen et Lee), sharing high amino acid sequence similarity with the AtABR1 (Arabidopsis thaliana AP2-like abscisic acid repressor 1) gene, were performed functional research, and the ABR1 homologous genes in Brassica species were identified and performed phylogenetic analysis. The promoter sequence of BjABR1 contained many phytohormone- and stress-related cis-elements; ABA (abscisic acid) and abiotic stresses can induce BjABR1 expression in tuber mustard; overexpression of BjABR1 in Arabidopsis can alleviate plant sensitivity to ABA and salt and osmotic stresses, and the alleviation may be due to changes in stress/ABA-induced gene expression. These results indicated that BjABR1 functions in ABA and abiotic stress responses. By BLAST searches against the genome database of five Brassica species (three diploids, B. rapa, B. nigra, and B. oleracea, and two allotetraploid, B. juncea and B. napus) using the protein sequence of AtABR1, 3, 3, 3, 6, and 5 ABR1 homologous genes in B. nigra, B. rapa, B. oleracea, B. juncea, and B. napus were identified, respectively, and they shared high sequence similarity. By sequence analysis, annotation mistakes of the protein-coding regions of two ABR1 homologous genes, GSBRNA2T00134741001 and BjuB007684, were found and corrected. Then, the evolution analysis of these ABR1 homologous genes showed that the ancestor of the three diploid species had three ABR1 homologous genes and each diploid inherited all the three genes from their ancestor; then, allotetraploid B. juncea inherited all the six genes from B. rapa and B. nigra with no gene lost, while allotetraploid B. napus inherited all the three genes from B. oleracea and two genes from B. rapa with one gene lost, indicating that ABR1 homologous genes possessed greater hereditary conservation in Brassica species. The ABR1 homologous genes between B. rapa and B. oleracea shared much higher sequence similarity compared to that of B. nigra in diploid species, indicating that ABR1 homologous genes in B. nigra had experienced more rapid evolution, and B. rapa and B. oleracea may share closer relationship compared to B. nigra. Moreover, the spatial and temporal expression analysis of six ABR1 homologous genes of tuber mustard showed that they possessed different expression models. These results imply that ABR1 homologous genes are important to Brassica plants, and they may possess similar function in ABA and abiotic stress responses but play a role in different tissues and growing stages of plant. This study will provide the foundation to the functional research of ABR1 homologous genes in the Brassica species and help to reveal and understand the evolution mechanisms of Brassica species

    SOLO-SLAM: A Parallel Semantic SLAM Algorithm for Dynamic Scenes

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    Simultaneous localization and mapping (SLAM) is a core technology for mobile robots working in unknown environments. Most existing SLAM techniques can achieve good localization accuracy in static scenes, as they are designed based on the assumption that unknown scenes are rigid. However, real-world environments are dynamic, resulting in poor performance of SLAM algorithms. Thus, to optimize the performance of SLAM techniques, we propose a new parallel processing system, named SOLO-SLAM, based on the existing ORB-SLAM3 algorithm. By improving the semantic threads and designing a new dynamic point filtering strategy, SOLO-SLAM completes the tasks of semantic and SLAM threads in parallel, thereby effectively improving the real-time performance of SLAM systems. Additionally, we further enhance the filtering effect for dynamic points using a combination of regional dynamic degree and geometric constraints. The designed system adds a new semantic constraint based on semantic attributes of map points, which solves, to some extent, the problem of fewer optimization constraints caused by dynamic information filtering. Using the publicly available TUM dataset, SOLO-SLAM is compared with other state-of-the-art schemes. Our algorithm outperforms ORB-SLAM3 in accuracy (maximum improvement is 97.16%) and achieves better results than Dyna-SLAM with respect to time efficiency (maximum improvement is 90.07%)

    How Does Change in Rural Residential Land Affect Cultivated Land Use Efficiency? An Empirical Study Based on 42 Cities in the Middle Reaches of the Yangtze River

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    The growth of rural residential land (RRL) areas has led to the encroachment of cultivated land, which has seriously reduced cultivated land use efficiency (CLUE). This paper takes 42 cities in the middle reaches of the Yangtze River (MRYR) as an example, using the kernel density estimation method, the Super-SBM model, and mediating effect test methods to explore the impact of RRL change on CLUE during 2000–2020. Specifically, based on the analysis of the spatiotemporal distribution characteristics of RRL and CLUE, this paper attempts to further explore the influence path of RRL change on CLUE and test whether there is a mediating effect. The results show that (1) the overall RRL area increased by 30,386.34 hm2, except for the decrease in RRL area in a few regions of Hunan Province, and the RRL area in other regions increased. (2) The hot-spot and sub-hot-spot regions of CLUE in the MRYR were mainly concentrated in northwestern Hubei Province and eastern Hunan Province, and the hot-spot and sub-hot-spot regions in Hunan Province are the highest among the three provinces. (3) Under the control of socioeconomic variables, the change in RRL has a significant negative impact on CLUE. (4) The area of cultivated land occupied by rural residential land (CLRRL) has a mediating role during 2000–2020, while the per capita cultivated land area (PCLA) and the rural permanent population (RPP) only have a mediating role during 2000–2010. In the future, the government should strictly prohibit the occupation of cultivated land by RRL and to improve the CLUE

    Angiotensin II Induces C-Reactive Protein Expression via AT1-ROS-MAPK-NF-κB Signal Pathway in Hepatocytes

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    Background: C-reactive protein (CRP) participates in development of inflammatory diseases. Hepatocytes are a major contributor of circulating CRP. Although angiotensin II (Ang II) is known to evoke inflammatory response, it remains unknown whether Ang II induces CRP expression in hepatocytes. The present study observed effect of Ang II on CRP expression and the related signal pathway in hepatocytes. Methods: mRNA and protein expressions in human hepatocytes were determined with RT-PCR and Western blot respectively. Reactive oxygen species (ROS) was measured using a fluorescence probe. CRP in liver and serum of rats was determined by immunohistochemistry and ELISA respectively. Results: Ang II induced mRNA and protein expression of CRP in hepatocytes and increased CRP production in liver and CRP level in serum. Losartan reduced Ang II- induced CRP expression in hepatocytes. Losartan and thenoyltrifluoroacetone decreased Ang II-stimulated ROS production. N-acetylcysteine antagonized Ang II-induced CRP expression. Losartan and N-acetylcysteine inhibited Ang II-activated ERK1/2. Unlike ERK1/2, only losartan inhibited Ang II-activated JNK. Furthermore, pyrrolidine dithiocarbamate abolished Ang II-induced CRP expression. Conclusion: Ang II has ability to induce CRP expression in hepatocytes in vitro and in vivo through AT1 receptor followed by ROS, MAPK and NF-κB signal pathway

    Discovery of dibenzyl amide derivatives as novel CXCR4 modulators against inflammatory bowel disease

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    The CXCR4/CXCL12 chemokine axis demonstrates significant potential in the treatment of inflammatory bowel disease (IBD) due to its crucial roles in inflammatory and immune responses. Modulating the CXCR4/CXCL12 pathway can be an effective therapeutic approach to ameliorate the inflammatory state of IBD. In this study, a novel series of meta-dibenzyl amide derivatives were designed and synthesized based on the lead compound AMD3100 and its structurally modified derivatives. Both in vitro and in vivo assays conclusively established that these compounds exhibited potent CXCR4 antagonism and anti-inflammatory activity. Compound 5t demonstrated superior inhibitory rates of binding affinity and chemotaxis of CXCR4+ cells compared to AMD3100. Furthermore, compound 5t notably reduced swelling volume and tissue thickness in the carrageenan-induced mouse paw edema model. Most importantly, in the dextran sodium sulfate (DSS)-induced colitis model, compound 5t significantly mitigated colonic inflammation on both macroscopic and microscopic levels, while suppressing the expression of inflammatory factors and myeloperoxidase (MPO). These findings unequivocally establish the immense potential of compound 5t in the treatment of IBD
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