Variations in Soil Bacterial Community Diversity and Structures Among Different Revegetation Types in the Baishilazi Nature Reserve

We compared patterns of soil bacterial community diversity and structure in six secondary forests (JM, Juglans mandshurica; QM, Quercus mongolica; MB, mixed Broadleaf forest; BE, Betula ermanii; CB, conifer-broadleaf forest; PT, Pinus tabuliformis) and two plantation forests (LG, Larix gmelinii; PK, Pinus koraiensis) of the Baishilazi Nature Reserve, China, based on the 16S rRNA high-throughput Illumina sequencing data. The correlations between the bacterial community and soil environmental factors were also examined. The results showed that the broadleaf forests (JM, QM, MB) had higher levels of total C (TC), total N (TN), available N (AN), and available K (AK) compared to the coniferous forests (PT, LG, PK) and conifer-broadleaf forest (CB). Different revegetation pathways had different effects on the soil bacterial community diversity and structure. For the α-diversity, the highest Shannon index and Simpson index were found in JM. The Simpson index was significantly positively correlated with the available P (AP) (P < 0.05), and the Shannon index was significantly positively correlated with AK (P < 0.05). Compared with others, the increased ACE index and Chao1 index were observed in the CB and MB, and both of these α-diversity were significantly negative with AK (P < 0.05). The relative abundances of bacterial phyla and genera differed among different revegetation types. At the phylum level, the dominant phylum groups in all soils were Proteobacteria, Acidobacteria, Actinobacteria, Verrucomicrobia, Chloroflexi, Bacteroidetes, Gemmatimonadetes, and Planctomycetes. Significant differences in relative abundance of bacteria phyla were found for Acidobacteria, Actinobacteria, Chloroflexi, Gemmatimonadetes, and Proteobacteria. Correlation analysis showed that Soil pH, TC, TN, AP, and AK were the main abiotic factors structuring the bacterial communities. As revealed by the clear differentiation of bacterial communities and the clustering in the heatmap and in the PCA plots, broadleaf forests and coniferous forests harbored distinct bacterial communities, indicating a significant impact of the respective reforestation pathway on soil bacterial communities in the Baishilazi Nature Reserve

Differences in phyllosphere microbiomes among different Populus spp. in the same habitat

IntroductionThe above-ground parts of terrestrial plants are collectively known as the phyllosphere. The surface of the leaf blade is a unique and extensive habitat for microbial communities. Phyllosphere bacteria are the second most closely associated microbial group with plants after fungi and viruses, and are the most abundant, occupying a dominant position in the phyllosphere microbial community. Host species are a major factor influencing the community diversity and structure of phyllosphere microorganisms.MethodsIn this study, six Populus spp. were selected for study under the same site conditions and their phyllosphere bacterial community DNA fragments were paired-end sequenced using 16S ribosomal RNA (rRNA) gene amplicon sequencing. Based on the distribution of the amplicon sequence variants (ASVs), we assessed the alpha-diversity level of each sample and further measured the differences in species abundance composition among the samples, and predicted the metabolic function of the community based on the gene sequencing results.ResultsThe results revealed that different Populus spp. under the same stand conditions resulted in different phyllosphere bacterial communities. The bacterial community structure was mainly affected by the carbon and soluble sugar content of the leaves, and the leaf nitrogen, phosphorus and carbon/nitrogen were the main factors affecting the relative abundance of phyllosphere bacteria.DiscussionPrevious studies have shown that a large proportion of the variation in the composition of phyllosphere microbial communities was explained by the hosts themselves. In contrast, leaf-borne nutrients were an available resource for bacteria living on the leaf surface, thus influencing the community structure of phyllosphere bacteria. These were similar to the conclusions obtained in this study. This study provides theoretical support for the study of the composition and structure of phyllosphere bacterial communities in woody plants and the factors influencing them

Different revegetation types alter soil physical-chemical characteristics and fungal community in the Baishilazi Nature Reserve

The effects of different revegetation types on soil physical–chemical characteristics and fungal community diversity and composition of soils sampled from five different revegetation types (JM, Juglans mandshurica; QM, Quercus mongolica; conifer-broadleaf forest (CB); LG, Larix gmelinii; PK, Pinus koraiensis) in the Baishilazi Nature Reserve were determined. Soil fungal communities were assessed employing ITS rRNA Illunima Miseq high-throughput sequencing. Responses of the soil fungi community to soil environmental factors were assessed through canonical correspondence analysis (CCA) and Pearson correlation analysis. The coniferous forests (L. gmelinii, P. koraiensis) and CB had reduced soil total carbon (C), total nitrogen (N), and available nitrogen (AN) values compared with the broadleaf forest (J. mandshurica, Q. mongolica). The average fungus diversity according to the Shannon, ACE, Chao1, and Simpson index were increased in the J. mandshurica site. Basidiomycota, Ascomycota, Zygomycota, and Rozellomycota were the dominant fungal taxa in this region. The phylum Basidiomycota was dominant in the Q. mongolica, CB, L. gmelinii, and P. koraiensis sites, while Ascomycota was the dominant phylum in the J. mandshurica site. The clear differentiation of fungal communities and the clustering in the heatmap and in non-metric multidimensional scaling plot showed that broadleaf forests, CB, and coniferous forests harbored different fungal communities. The results of the CCA showed that soil environmental factors, such as soil pH, total C, total N, AN, and available phosphorus (P) greatly influenced the fungal community structure. Based on our results, the different responses of the soil fungal communities to the different revegetation types largely dependent on different forest types and soil physicochemical characteristic in Baishilazi Nature Reserve

Chitosan-salvianolic acid B coating on the surface of nickel-titanium alloy inhibits proliferation of smooth muscle cells and promote endothelialization

Introduction: Intracranial stents are of paramount importance in managing cerebrovascular disorders. Nevertheless, the currently employed drug-eluting stents, although effective in decreasing in-stent restenosis, might impede the re-endothelialization process within blood vessels, potentially leading to prolonged thrombosis development and restenosis over time.Methods: This study aims to construct a multifunctional bioactive coating to enhance the biocompatibility of the stents. Salvianolic acid B (SALB), a bioactive compound extracted from Salvia miltiorrhiza, exhibits potential for improving cardiovascular health. We utilized dopamine as the base and adhered chitosan-coated SALB microspheres onto nickel-titanium alloy flat plates, resulting in a multifunctional drug coating.Results: By encapsulating SALB within chitosan, the release period of SALB was effectively prolonged, as evidenced by the in vitro drug release curve showing sustained release over 28 days. The interaction between the drug coating and blood was examined through experiments on water contact angle, clotting time, and protein adsorption. Cellular experiments showed that the drug coating stimulates the proliferation, adhesion, and migration of human umbilical vein endothelial cells.Discussion: These findings indicate its potential to promote re-endothelialization. In addition, the bioactive coating effectively suppressed smooth muscle cells proliferation, adhesion, and migration, potentially reducing the occurrence of neointimal hyperplasia and restenosis. These findings emphasize the exceptional biocompatibility of the newly developed bioactive coating and demonstrate its potential clinical application as an innovative strategy to improve stent therapy efficacy. Thus, this coating holds great promise for the treatment of cerebrovascular disease

Could social robots facilitate children with autism spectrum disorders in learning distrust and deception?

Social robots have been increasingly involved in our daily lives and provide a new environment for children\u27s growth. The current study aimed to examine how children with and without Autism Spectrum Disorders (ASD)learned complex social rules from a social robot through distrust and deception games. Twenty children with ASD between the ages of 5–8 and 20 typically-developing (TD)peers whose age and IQ were matched participated in distrust and deception tasks along with an interview about their perception of the human-likeness of the robot. The results demonstrated that: 1)children with ASD were slower to learn to and less likely to distrust and deceive a social robot than TD children and 2)children with ASD who perceived the robot to appear more human-like had more difficulty in learning to distrust the robot. Besides, by comparing to a previous study the results showed that children with ASD appeared to have more difficulty in learning to distrust a human compared to a robot, particularly in the early phase of learning. Overall, our study verified that social robots could facilitate children with ASD\u27s learning of some social rules and showed that children\u27s perception of the robot plays an important role in their social learning, which provides insights on robot design and its clinical applications in ASD intervention

Intercropping changed the soil microbial community composition but no significant effect on alpha diversity

IntroductionEnhancing the planning of the forest-agricultural composite model and increasing the efficiency with which forest land is utilized could benefit from a thorough understanding of the impacts of intercropping between forests and agriculture on soil physicochemical properties and microbial communities.MethodsPopulus cathayana × candansis cv. Xinlin No.1 and Glycine max intercrop soils, along with their corresponding monocrops, were used in this study’s llumina high-throughput sequencing analysis to determine the composition and diversity of soil bacterial and fungal communities.ResultsThe findings indicated that intercropping considerably raised the soil’s total phosphorus content and significantly lowered the soil’s carbon nitrogen ratio when compared to poplar single cropping. Furthermore, the total carbon and nitrogen content of soil was increased and the soil pH was decreased. The sequencing results showed that intercropping had no significant effect on soil alpha diversity. Intercropping could increase the composition of fungal community and decrease the composition of bacterial community in poplar soil. At the phylum level, intercropping significantly increased the relative abundance of four dominant phyla, i.e., Patescibacteria, Proteobacteria, Patescibacteria and Deinococcus-Thermus. And the relative abundances of only two dominant phyla were significantly increased. It was found that soil total phosphorus and available phosphorus content had the strongest correlation with soil bacterial community diversity, and soil pH had the strongest correlation with soil fungal community diversity.DiscussionThe results of this study were similar to those of previous studies. This study can serve as a theoretical foundation for the development of a poplar and black bean-based forest-agricultural complex management system in the future

Rootstock Alleviates Salt Stress in Grafted Mulberry Seedlings: Physiological and PSII Function Responses

This study investigated the effect of NaCl stress on Na+ and K+ absorption and transport by roots, nitrogen and phosphorus content in leaves, PSII photochemical activity and reactive oxygen species (ROS) in leaves of mulberry own-root seedlings and grafted seedlings. To determine the response, own-root seedlings of a high yielding mulberry cultivar, Tieba mulberry (Morus alba L.), and the grafted seedlings, obtained by using Qinglong mulberry with high salt tolerance as rootstock and Tieba mulberry as scion, were used. The Na+ content in roots and leaves of grafted seedlings was significantly lower than that in own-root seedlings under salt stress; while K+ content in roots and leaves of grafted seedlings was significantly higher than that in own-root seedlings. The root activity in grafted seedlings was significantly higher than that in own-root seedlings, as well as the content of nitrogen, phosphorous and water. PSII photochemical activity in leaves of grafted seedlings was less significantly affected by salt stress compared to own-root seedlings. The electron transport at the acceptor side of PSII from QA to QB was less affected by salt stress, which resulted in a significantly lower ROS content in leaves of grafted seedlings than that of own-root seedlings. Therefore, grafting high-yielding and good-quality Tieba mulberry with salt tolerant Qinglong mulberry as rootstock showed a relatively high salt tolerance. This may be because (1) the root system of rootstock presented high Na+ resistance and has selective absorption capacity for Na+ and K+ (2) the root system of rootstock prevented excess Na+ from being transported to aerial parts in order to reduce adverse effects of Na+ (3) the root system of rootstock had enhanced root activity under salt stress, which accelerated water and nutrient absorption (4) the leaves of grafted seedlings had higher PSII photochemical activity and electron transport rate compared with those of own-root seedlings under salt stress, which effectively reduced ROS burst mediated by photosynthesis and reduced oxidative damage

Identifying and characterizing key nodes among communities based on electrical-circuit networks.

Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes

Soil Organic Carbon Chemical Functional Groups under Different Revegetation Types Are Coupled with Changes in the Microbial Community Composition and the Functional Genes

Different revegetatiom types can affect the chemical composition of soil organic carbon (SOC), soil microbial community and the functional genes related to carbon cycle. However, the relationships between SOC chemical functional groups and soil microbial communities and the functional genes remains poorly unclear under different revegetation types. Using the solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, we examined changes in the SOC chemical composition of five soils (0–10 cm depth) from Larix gmelinii Rupr. (LG), Pinus koraiensis Sieb. (PK), Quercus mongolica Fisch. (QM), Juglans mandshurica Maxim. (JM), and conifer-broadleaf forest (CB). And the soil microbial community genes related to metabolism of macro-molecular compounds were determined via whole genome shotgun based on Illumina HiSeq. Our results indicated that broadleaf forests (JM, QM) had increased the contents of soil total carbon (C), total nitrogen (N), dissolved organic carbon (DOC), and microbial biomass carbon (MBC), compared with coniferous forests (LG, PK) and the conifer-broadleaf forest (CB). While, the coniferous forests generated a lower O-alcoxyl C, a higher alkyl C, and the ratio of alkyl C/O-alkyl C than broadleaf forests. A total of four kingdoms were identified via whole metagenome shotgun sequencing, including eight archaea, 55 bacteria, 15 eukaryota, and two viruses, giving a total 80 phyla. The contents of alkyne C, phenolic C, methoxyl C, COO/NC=O, and alkyl C were strong related to the composition of soil microbial community and their contents illuminated a major part of the variation in soil microbial composition. We detected seven corresponding macro-molecular compounds of different organic carbon functional group, and 244 genes related to metabolism across all samples, and soil total C, total N, and DOC could be the main factors for microbial functional gene composition. Interestingly, the relative abundances of different SOC chemical functional groups, the phylogenetic distance for microbes, the genes of C cycling based on the KEGG database, and the relative abundance of genes related to metabolism of macro-molecular compounds of different SOC chemical functional groups under different revegetation types all could be divided into three groups, including PK plus LG, JM plus QM, and CB. Our results also illustrated that variations in SOC chemical functional groups were strongly associated with changes of soil microbial community taxa and functional genes, which might be affected by the changes of soil characteristics