Frontiers in Microbiology最新文献

{"title":"Electromicrobiological concentration cells are an overlooked potential energy conservation mechanism for subsurface microorganisms.","authors":"Ian P G Marshall","doi":"10.3389/fmicb.2024.1407868","DOIUrl":"10.3389/fmicb.2024.1407868","url":null,"abstract":"<p><p>Thermodynamics has predicted many different kinds of microbial metabolism by determining which pairs of electron acceptors and donors will react to produce an exergonic reaction (a negative net change in Gibbs free energy). In energy-limited environments, such as the deep subsurface, such an approach can reveal the potential for unexpected or counter-intuitive energy sources for microbial metabolism. Up until recently, these thermodynamic calculations have been carried out with the assumption that chemical species appearing on the reactant and product side of a reaction formula have a constant concentration, and thus do not count towards net concentration changes and the overall direction of the reaction. This assumption is reasonable considering microorganisms are too small (~1 μm) for any significant differences in concentration to overcome diffusion. However, recent discoveries have demonstrated that the reductive and oxidative halves of reactions can be separated by much larger distances, from millimetres to centimetres via conductive filamentous bacteria, mineral conductivity, and biofilm conductivity. This means that the concentrations of reactants and products can indeed be different, and that concentration differences can contribute to the net negative change in Gibbs free energy. It even means that the same redox reaction, simultaneously running in forward and reverse, can drive energy conservation, in an ElectroMicrobiological Concentration Cell (EMCC). This paper presents a model to investigate this phenomenon and predict under which circumstances such concentration-driven metabolism might take place. The specific cases of oxygen concentration cells, sulfide concentration cells, and hydrogen concentration cells are examined in more detail.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371792/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142135099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the potential mechanism of Xiaojin Pill therapy for benign prostatic hyperplasia through metabolomics and gut microbiota analysis.","authors":"Yuying Yang, Yunyun Quan, Yunteng Liu, Juhua Yang, Keyu Chen, Xiaozhou You, Hua Hua, Liangchun Yan, Junning Zhao, Jianbo Wang","doi":"10.3389/fmicb.2024.1431954","DOIUrl":"10.3389/fmicb.2024.1431954","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Xiaojin Pill (XJP) is a traditional Chinese medicine prescribed for treating benign prostatic hyperplasia (BPH). It has been proven to have multiple effects, such as regulating sex hormone levels, exhibiting anti-tumor, anti-inflammatory, analgesic, and anti-platelet aggregation properties, and improving immunity. However, the material basis of XJP's therapeutic effect on BPH and its metabolic process &lt;i&gt;in vivo&lt;/i&gt; remains to be clarified. At the same time, many microorganisms that exist in the urogenital tract, including those related to BPH, can also affect the health of the host.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), the chemical components of XJP were identified. A BPH model was created through bilateral testicular ablation and injections of testosterone propionate. A comprehensive evaluation of XJP efficacy was conducted using pathological ELISA, TUNEL, and immunohistochemical techniques. In addition, UPLC-MS metabolomics and 16S rRNA sequencing revealed the serum metabolic profile and intestinal microbiota composition. We performed a Spearman correlation coefficient analysis to highlight the interactions between \"intestinal microbiota-serum factors\" and \"intestinal microbiota-metabolites.\"&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;XJP contains 91 compounds that alleviate pathologies of BPH in rats, decreasing prostate weight, index, and serum levels of Dihydrotestosterone (DHT), Prostate-Specific Antigen (PSA), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) levels. It inhibits prostatic epithelial cell apoptosis and downregulates Bax, TGF-β1, and IGF-1 proteins in the caspase-3 pathway. Metabolomics studies have revealed 10 upregulated and 10 downregulated metabolites in treated rats, with 5-methylcytosine, uracil, and cytosine enriched in pyrimidine metabolism. L-arginine plays a pivotal role in metabolic pathways encompassing pyrimidine metabolism, arginine biosynthesis, and the mammalian target of rapamycin (mTOR) signaling pathway. 16S rRNA sequencing revealed that XJP optimized the diversity and balance of intestinal flora in BPH rats by decreasing the Bacteroidetes/Firmicutes (B/F) ratio, enhancing the beneficial bacteria, such as &lt;i&gt;Eggerthellaceae, Anaerovoracaceae&lt;/i&gt;, and &lt;i&gt;Romboutsia&lt;/i&gt;, and suppressing the dysfunctional bacteria, such as &lt;i&gt;Atopobiaceae, Prevotellaceae_NK3B31_group, Dorea&lt;/i&gt;, and &lt;i&gt;Frisingicoccus&lt;/i&gt;. According to the Spearman correlation coefficient analysis, &lt;i&gt;Lactobacillus&lt;/i&gt; was found to be most associated with serum factors, whereas &lt;i&gt;Romboutsia&lt;/i&gt; showed the highest correlation with metabolites. This finding suggests that XJP modulates pyrimidine metabolism disorders in BPH rats, a regulation that aligns closely with &lt;i&gt;Romboutsia, Prevotellaceae_NK3B31_group, Lactobacillus, Chujaibacter&lt;/i&gt;, and &lt;i&gt;Enterorhabdus&lt;/i&gt;, thereby prov","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation of highly copper-resistant bacteria from deep-sea hydrothermal fields and description of a novel species <i>Marinobacter metalliresistant</i> sp. nov.","authors":"Tong Yu, Meng Qin, Zongze Shao, Yuemei Zhao, Xiang Zeng","doi":"10.3389/fmicb.2024.1390451","DOIUrl":"10.3389/fmicb.2024.1390451","url":null,"abstract":"<p><strong>Introduction: </strong>Hydrothermal vents, rich in heavy metals, provided a unique niche for heavy metal resistant microbes. However, knowledge about copper resistant microbes in deep sea hydrothermal vents is still limited.</p><p><strong>Methods: </strong>The copper-resistant bacteria were isolated from deep-sea hydrothermal vent samples and conducted thorough physical, phylogenetic, and genomic analyses to elucidate their copper resistance capability and related genes.</p><p><strong>Results: </strong>Twelve highly copper-resistant bacteria (up to 6-10 mM) were isolated from deep sea hydrothermal fields They were affiliated with the <i>Pseudoalteromonas</i> (4), <i>Marinobacter</i> (3), <i>Halomonas</i> (2), <i>Psychrobacter</i> (1), and <i>Pseudomonas</i> (1) genus in the α-Proteobacteria, and the <i>Sphingomonas</i> (1) genus in the β-Proteobacteria. The presence of copper in the medium obviously induced the amount of polysaccharides and proteins in the crude extracellular polymeric substances (EPS) produced by <i>Halomonas</i> sp. CuT 3-1, <i>Pseudoalteromonas</i> sp. CuT 4-3 and <i>Marinobacter metalliresistant</i> CuT 6, which could absorb 40 to 50 mg•g^-1 copper. We further described a novel species, <i>Marinobacter metalliresistant</i> sp. nov. CuT 6^T, which exhibited a higher copper resistance and encoded more heavy metal resistance-related genes than other Marinobacter species.</p><p><strong>Discussion: </strong>It revealed that the copper resistance capability exhibited by these strains in hydrothermal fields is likely attributed to the production of exopolymeric substances, such as polysaccharides and proteins, as well as active transport or efflux mechanisms for heavy metals.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371751/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The diel disconnect between cell growth and division in <i>Aureococcus</i> is interrupted by giant virus infection.","authors":"Alexander R Truchon, Emily E Chase, Ashton R Stark, Steven W Wilhelm","doi":"10.3389/fmicb.2024.1426193","DOIUrl":"10.3389/fmicb.2024.1426193","url":null,"abstract":"<p><p>Viruses of eukaryotic algae have become an important research focus due to their role(s) in nutrient cycling and top-down control of algal blooms. Omics-based studies have identified a boon of genomic and transcriptional potential among the <i>Nucleocytoviricota</i>, a phylum of large dsDNA viruses which have been shown to infect algal and non-algal eukaryotes. However, little is still understood regarding the infection cycle of these viruses, particularly in how they take over a metabolically active host and convert it into a virocell state. Of particular interest are the roles light and the diel cycle in virocell development. Yet despite such a large proportion of <i>Nucleocytoviricota</i> infecting phototrophs, little work has been done to tie infection dynamics to the presence, and absence, of light. Here, we examine the role of the diel cycle on the physiological and transcriptional state of the pelagophyte <i>Aureococcus anophagefferens</i> while undergoing infection by <i>Kratosvirus quantuckense</i> strain AaV. Our observations demonstrate how infection by the virus interrupts the diel growth and division of this cell strain, and that infection further complicates the system by enhancing export of cell biomass.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371579/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole exome sequencing identifies genetic markers of enterovirus susceptibility in East Asians.","authors":"Chia-Cheng Sung, G W Gant Luxton, Kuo-Sheng Hung, Yung-Fu Wu, Chih-Chien Wang, Chih-Sin Hsu, Chih-Fen Hu","doi":"10.3389/fmicb.2024.1452595","DOIUrl":"10.3389/fmicb.2024.1452595","url":null,"abstract":"<p><strong>Introduction: </strong>Following acute enterovirus (EV) infection, outcomes vary based on factors like the immune response, viral cell entry receptor expression levels, tissue tropism, and genetic factors of both the host and virus. While most individuals exhibit mild, self-limited symptoms, others may suffer severe complications or prolonged infections that can lead to autoimmune disorders.</p><p><strong>Methods: </strong>To elucidate host responses to EV infection, we performed whole exome sequencing on blood samples from both infected and uninfected individuals. Our initial focus was on genes encoding EV entry receptors-PSGL-1, SCARB2, and ANAXA2 for EV-A71, and CD155 for poliovirus-and on host genes <i>ACBD3</i> and <i>PI4KΒ</i>, crucial for EV replication.</p><p><strong>Results: </strong>Although no specific genetic variants directly associated with EV infection were identified, we discovered 118 variants across 116 genes enriched in East Asian populations through multi-layered variant filtering. These variants were further analyzed for their potential impacts on organs, biological processes, and molecular pathways. Phenome-wide association studies were conducted to refine our understanding of their contributions to EV infection susceptibility.</p><p><strong>Discussion: </strong>Our findings aim to develop a predictive panel based on these 118 variants, which could help susceptible individuals during EV outbreaks, guiding targeted clinical interventions and preventative strategies.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11372244/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of bacterial community dynamics dominated by salinity in lakes of the Inner Mongolian Plateau, China.","authors":"Guo Xin, Shi Xiaohong, Shi Yujiao, Li Wenbao, Wang Yanjun, Cui Zhimou, Lauri Arvolab","doi":"10.3389/fmicb.2024.1448919","DOIUrl":"10.3389/fmicb.2024.1448919","url":null,"abstract":"<p><p>Microorganisms in lakes are sensitive to salinity fluctuations. Despite extensive prior research on bacterial communities, our understanding of their characteristics and assembly mechanisms in lakes, especially in desert lakes with different salinities. To address this issue, we collected three samples from freshwater lakes, six from brackish lakes, and five from salt lakes in the Badanjilin Desert. The 16S rRNA gene sequencing was applied to investigate the bacterial interactions with rising salinity, community coexistence patterns, and assembly mechanisms. Our findings suggested that the increased lake salinity significantly reduces the bacterial community diversity and enhanced the community differentiation. Significant variations were observed in the contribution of biomarkers from Cyanobacteria, Chloroflexi, and Halobacterota to the composition of the lake bacterial communities. The bacterial communities in the salt lakes exhibited a higher susceptibility to salinity limitations than those in the freshwater and brackish lakes. In addition, the null modeling analyses confirmed the quantitative biases in the stochastic assembly processes of bacterial communities across freshwater, brackish, and saline lakes. With the increasing lake salinity, the significance of undominated and diffusion limitation decreased slightly, and the influence of homogenizing dispersal on community assembly increased. However, the stochasticity remained the dominant process across all lakes in the Badanjilin Desert. The analysis of co-occurring networks revealed that the rising salinity reduced the complexity of bacterial network structures and altered the interspecific interactions, resulting in the increased interspecies collaboration with increasing salinity levels. Under the influence of salinity stress, the key taxon Cyanobacteria in freshwater lakes (<i>Schizothrix_LEGE_07164</i>) was replaced by Proteobacteria (<i>Thalassobaculum</i> and <i>Polycyclovorans</i>) in brackish lakes, and Thermotogota (<i>SC103</i>) in salt lakes. The results indicated the symbiotic patterns of bacterial communities across varying salinity gradients in lakes and offer insights into potential mechanisms of community aggregation, thereby enhancing our understanding of bacterial distribution in response to salinity changes.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371557/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the population interaction of Przewalski's gazelle (<i>Procapra przewalskii</i>) based on the variations in gut microbiota across diverse geographic populations.","authors":"Jingjie Zhang, Pengfei Song, Feng Jiang, Tongzuo Zhang","doi":"10.3389/fmicb.2024.1439554","DOIUrl":"10.3389/fmicb.2024.1439554","url":null,"abstract":"<p><p>The differences in gut microbiota among different populations, to a certain extent, reflect the degree of interaction between individuals within populations. To assess the interaction levels among several small populations of Przewalski's gazelle (<i>Procapra przewalskii</i>) (<i>n</i> = 105, from seven different regions) based on differences in gut microbiota, we used the closely related Tibetan gazelle (<i>P. picticaudata</i>) (<i>n</i> = 52, from seven different regions) as a control. We then compared the gut microbial communities between different populations of the two species using high-throughput sequencing of the 16S rRNA gene. The results showed that within a 100 km geographical distance, the intergroup differences in relative abundance of dominant bacteria, α-diversity, β-diversity, and functional metabolism abundance were higher or significantly higher in Przewalski's gazelle (narrowly distributed species) compared to the Tibetan gazelle (widely distributed species). Additionally, the proportion of shared OTUs between groups in Przewalski's gazelle was significantly lower than in Tibetan gazelle (<i>p</i> < 0.05). Additionally, neutral community model results also showed lower dispersal limitation in the Tibetan gazelle compared to Przewalski's gazelle. Therefore, based on the above results, we comprehensively speculate that the spatial interaction degree of Przewalski's gazelle in different habitat patches is relatively low. This study, starting from the perspective of gut microbiota, adopts a non-genetic perspective or method to assess whether there is, or to what extent there is, close interaction between species populations.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371741/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetically predicted the causal relationship between gut microbiota and the risk of polymyositis/dermatomyositis: a Mendelian randomization analysis.","authors":"Yanna Niu, Yaochen Zhang, Keyi Fan, Jialin Hou, Liu Liu, Heyi Zhang, Xinlei Geng, Xiyue Ma, Shilei Lin, Meilin Guo, Xiaofeng Li, Shengxiao Zhang","doi":"10.3389/fmicb.2024.1409497","DOIUrl":"10.3389/fmicb.2024.1409497","url":null,"abstract":"<p><strong>Introduction: </strong>Observational studies suggest associations between gut microbiota and polymyositis (PM) and dermatomyositis (DM), but causal relationships are unclear. We investigate the causal effects of gut microbiota on PM and DM, providing insights hoping to provide insights for future treatment and prevention.</p><p><strong>Methods: </strong>Summary statistics of gut microbiota were obtained from a multi-ethnic Genome Wide Association Studies (GWAS) meta-analysis, including 119 taxa from 18,340 Europeans. PM/DM statistics were extracted from GWAS analyses. Mendelian randomization (MR) with IVW, MR-Egger, and weighted median methods was performed. Sensitivity analyses addressed heterogeneity and pleiotropy. Of the 119 bacterial genera studied, six showed causal links.</p><p><strong>Results: </strong><i>Alloprevotella</i> (OR: 3.075, 95% CI: 1.127-8.386, <i>p</i> = 0.028), <i>Ruminococcaceae</i> UCG003 (OR: 4.219, 95% CI: 1.227-14.511, <i>p</i> = 0.022), <i>Dialister</i> (OR: 0.273, 95% CI: 0.077-0.974, <i>p</i> = 0.045) were associated with PM. <i>Anaerotruncus</i> (OR: 0.314, 95% CI: 0.112-0.882, <i>p</i> = 0.028), <i>Ruminococcaceae</i> UCG002 (OR: 2.439, 95% CI: 1.173-5.071, <i>p</i> = 0.017), <i>Sutterella</i> (OR: 3.392, 95% CI: 1.302-8.839, <i>p</i> = 0.012) were related to DM. Sensitivity analyses validated these associations.</p><p><strong>Discussion: </strong>We establish causal relationships between <i>Ruminococcaceae</i>, <i>Sutterella</i>, <i>Anaerotruncus</i> with DM, <i>Alloprevotella</i>, <i>Ruminococcaceae</i> UCG003, and <i>Dialister</i> with PM. Common microbiota, like <i>Ruminococcaceae</i>, have significant clinical implications. These findings open up greater possibilities for the gut microbiota to contribute to the development of PM/DM and for future monitoring of the gut microbiota in patients with PM/DM.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371719/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aromatic components and endophytic fungi during the formation of agarwood in <i>Aquilaria sinensis</i> were induced by exogenous substances.","authors":"Shengjiang Pang, Weiwei Zhao, Qingqing Zhang, Zuwei Tian, Dan Wu, Shuokun Deng, Pei Zhang, Zhongguo Li, Shiling Liu, Baoguo Yang, Guihua Huang, Zaizhi Zhou","doi":"10.3389/fmicb.2024.1446583","DOIUrl":"10.3389/fmicb.2024.1446583","url":null,"abstract":"<p><p>The process of formation of aromatic components for agarwood in <i>Aquilaria sinensis</i> is closely related to endophytic fungi and the result of complex multiple long-term joint interactions with them. However, the interactions between the aromatic components and endophytic fungi remain unclear during the formation of agarwood. In this study, precise mixed solution of hormones, inorganic salts, and fungi was used to induce its formation in <i>A. sinensis</i>, and sample blocks of wood were collected at different times after inoculation. This study showed that the aromatic compounds found in the three treatments of <i>A. sinensis</i> were primarily chromones (31.70-33.65%), terpenes (16.68-27.10%), alkanes (15.99-23.83%), and aromatics (3.13-5.07%). Chromones and terpenes were the primary components that characterized the aroma. The different sampling times had a more pronounced impact on the richness and diversity of endophytic fungal communities in the <i>A. sinensis</i> xylem than the induction treatments. The species annotation of the operational taxonomic units (OTUs) demonstrated that the endophytic fungi were primarily composed of 18 dominant families and 20 dominant genera. A linear regression analysis of the network topology properties with induction time showed that the interactions among the fungal species continued to strengthen, and the network structure tended to become more complex. The terpenes significantly negatively correlated with the Pielou evenness index (<i>p</i> < 0.05), while the chromones significantly positively correlated with the OTUs and Shannon indices.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371604/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant growth-promoting rhizobacterium <i>Bacillus megaterium</i> modulates the expression of antioxidant-related and drought-responsive genes to protect rice (<i>Oryza sativa</i> L.) from drought.","authors":"Sanghun Lee, Jung-Ae Kim, Jeongsup Song, Seonbong Choe, Geupil Jang, Yangseon Kim","doi":"10.3389/fmicb.2024.1430546","DOIUrl":"10.3389/fmicb.2024.1430546","url":null,"abstract":"<p><p>Global climate change poses a significant threat to plant growth and crop yield and is exacerbated by environmental factors, such as drought, salinity, greenhouse gasses, and extreme temperatures. Plant growth-promoting rhizobacteria (PGPR) help plants withstand drought. However, the mechanisms underlying PGPR-plant interactions remain unclear. Thus, this study aimed to isolate PGPR, <i>Bacillus megaterium</i> strains CACC109 and CACC119, from a ginseng field and investigate the mechanisms underlying PGPR-stimulated tolerance to drought stress by evaluating their plant growth-promoting activities and effects on rice growth and stress tolerance through <i>in vitro</i> assays, pot experiments, and physiological and molecular analyses. Compared with <i>B. megaterium</i> type strain ATCC14581, CACC109 and CACC119 exhibited higher survival rates under osmotic stress, indicating their potential to enhance drought tolerance. Additionally, CACC109 and CACC119 strains exhibited various plant growth-promoting activities, including phosphate solubilization, nitrogen fixation, indole-3-acetic acid production, siderophore secretion, 1-aminocyclopropane-1-carboxylate deaminase activity, and exopolysaccharide production. After inoculation, CACC109 and CACC119 significantly improved the seed germination of rice (<i>Oryza sativa</i> L.) under osmotic stress and promoted root growth under stressed and non-stressed conditions. They also facilitated plant growth in pot experiments, as evidenced by increased shoot and root lengths, weights, and leaf widths. Furthermore, CACC109 and CACC119 improved plant physiological characteristics, such as chlorophyll levels, and production of osmolytes, such as proline. In particular, CACC109- and CACC119-treated rice plants showed better drought tolerance, as evidenced by their higher survival rates, greater chlorophyll contents, and lower water loss rates, compared with mock-treated rice plants. Application of CACC109 and CACC119 upregulated the expression of antioxidant-related genes (e.g., <i>OsCAT</i>, <i>OsPOD</i>, <i>OsAPX</i>, and <i>OsSOD</i>) and drought-responsive genes (e.g., <i>OsWRKY47, OsZIP23, OsDREB2, OsNAC066, OsAREB1,</i> and <i>OsAREB2</i>). In conclusion, CACC109 and CACC119 are promising biostimulants for enhancing plant growth and conferring resistance to abiotic stresses in crop production. Future studies should conduct field trials to validate these findings under real agricultural conditions, optimize inoculation methods for practical use, and further investigate the biochemical and physiological responses underlying the observed benefits.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11371581/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}