Rhizosphere最新文献

{"title":"Growth regulators on shooting and adventitious rooting of Mimosa caesalpiniifolia adult stem cuttings","authors":"Deyvid Luis da Silva Sousa,&nbsp;Paulo César da Silva Santos,&nbsp;Moema Barbosa de Sousa,&nbsp;Erika Rayra Lima Nonato,&nbsp;Eliane Cristina Sampaio de Freitas,&nbsp;Ricardo Gallo","doi":"10.1016/j.rhisph.2024.100901","DOIUrl":"10.1016/j.rhisph.2024.100901","url":null,"abstract":"<div><p><em>Mimosa caesalpiniifolia</em>, crucial for fencing and firewood in Brazil's Caatinga dry forest, presents a promising avenue for commercial propagation. The challenges faced in seed propagation, such as the scarcity of inputs and the difficulties in overcoming dormancy, highlight the advantages of vegetative methods. These methods emerge as a viable alternative, enabling uniform and large-scale production of clonal plantlets. This technique ensures consistent plant quality, which is crucial given the wide variety of uses for this species. Additionally, the use of plant growth regulators is critical to enhance the success of vegetative propagation, promoting the formation of robust roots and overall development of plants from cuttings of adult trees. Recognizing the significance of creating clonal forests of <em>M. caesalpiniifolia</em> and the necessity for understanding methods to expedite this endeavor, this study was designed to assess the shooting and adventitious rooting of stem cuttings sourced from adult <em>M. caesalpiniifolia</em> trees, examining the effects of auxinic agents. <em>M. caesalpiniifolia</em> cuttings were harvested through vegetative rescue from six randomly selected adult trees, treated with indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) at concentrations of 0, 1,000, 2,000, and 4000 mg L⁻¹, using a completely randomized design in a 2 × 4 factorial arrangement. The evaluations included assessing root presence, number of shoots, vigor of clonal plantlets and plant survival under greenhouse conditions, shade house conditions, and full sun exposure. The study did not reveal any significant interaction between growth regulators and their concentrations under these conditions. IBA at intermediate concentrations enhanced root growth, while cuttings without growth regulators exhibited superior aerial development. A decrease in survival percentages with increasing concentrations of regulators was observed, while cuttings without regulators demonstrated better morphological development. The study suggests for large-scale nurseries, natural rooting and shoot formation in <em>M. caesalpiniifolia</em> cuttings may suffice for successful propagation without IBA or IAA.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141132780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PGPg_finder: A comprehensive and user-friendly pipeline for identifying plant growth-promoting genes in genomic and metagenomic data","authors":"Thierry Alexandre Pellegrinetti ,&nbsp;Gabriel Gustavo Tavares Nunes Monteiro ,&nbsp;Leandro Nascimento Lemos ,&nbsp;Renato Augusto Corrêa dos Santos ,&nbsp;Artur Gomes Barros ,&nbsp;Lucas William Mendes","doi":"10.1016/j.rhisph.2024.100905","DOIUrl":"https://doi.org/10.1016/j.rhisph.2024.100905","url":null,"abstract":"<div><p>Identifying and comparing plant growth-promoting traits (PGPT) within whole-genome and metagenomic sequencing data can significantly advance agricultural research and promote sustainable crop production. This study introduces <em>PGPg_finder</em>, a comprehensive pipeline designed to annotate and compare PGPT from both whole-genome and metagenome sequencing datasets. This pipeline utilizes direct sequence annotation alongside de novo assembly methods to accurately detect PGPT. By cross-referencing sequences from the PLaBAse database, it identifies and quantifies the presence of these genes within the original datasets, facilitating an intuitive comparison of the abundance and distribution of PGPT across various samples. We evaluated the performance of <em>PGPg_finder</em> by analyzing genomes from five rhizobacterial strains: <em>Paenibacillus vini</em>, <em>Paenibacillus polymyxa</em>, <em>Fictibacillus</em> sp., <em>Brevibacillus agri</em><em>,</em> and <em>Bacillus cereus</em>, and also metagenomic samples from bulk soils subjected to forest-to-pasture conversion in the Amazon rainforest. The genomic workflow revealed several genes associated with substrate utilization, abiotic stress neutralization, phosphate solubilization, and iron acquisition. It also identified genes unique to specific lineages, including those associated with colonization and plant-derived substrate usage in <em>P. polymyxa</em>, quorum sensing response and biofilm formation in <em>P. vini</em>, heavy metal detoxification and nitrogen acquisition in <em>B. agri</em>, and spore production and neutralizing biotic stress in <em>B. cereus</em>. The strain <em>Fictibacillus</em> sp. presented several unique genes related to surface attachment, stress response, xenobiotic degradation, phosphate solubilization, and phytohormone production. The use of <em>PGPg_finder</em> highlights its potential to uncover novel inoculants and strains. The metagenomic workflow distinguished plant-growth promotion gene profiles between soils from the Amazon rainforest and pasture, with the latter showing a profile more aligned with simple carbohydrate consumption, abiotic stress tolerance, motility and chemotaxis, and phosphorus mineralization. Native forests exhibited a profile associated with the degradation of complex organic matter, oxidative stress tolerance, xenobiotic degradation, bactericidal activity, iron acquisition, and volatile pathways. These findings underscore the effectiveness and sensitivity of <em>PGPg_finder</em> in accurately identifying and comparing PGPT genes, highlighting both commonalities and variations across samples. The application of this pipeline has the potential to significantly facilitate the identification of plant growth-promoting microbes.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141090961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Close linkage between available and microbial biomass phosphorus in the rhizosphere of alpine coniferous forests along an altitudinal gradient","authors":"Min Li ,&nbsp;Xi He ,&nbsp;Peipei Zhang ,&nbsp;Ruihong Wang ,&nbsp;Jipeng Wang ,&nbsp;Xinjun Zhang ,&nbsp;Huajun Yin","doi":"10.1016/j.rhisph.2024.100904","DOIUrl":"https://doi.org/10.1016/j.rhisph.2024.100904","url":null,"abstract":"<div><p>The rhizosphere is a hotspot of soil phosphorus (P) transformation, which profoundly influences the P status of plants. Although P is projected to limit the ability of forests to serve as a carbon sink, it remains unclear how rhizosphere P availability responds to changing environments in alpine forests. Here, we investigated changes in rhizosphere available P across a series of altitudinal bands (2850 m, 2950 m, 3060 m and 3200 m) in alpine forests and examined the potential regulators of rhizosphere P availability, including temperature and soil biotic and abiotic properties. The results showed that rhizosphere P availability decreased up to the 3060 m site but then increased at the 3200 m site. A structural equation model showed that temperature and soil properties (pH and organic carbon content) indirectly affected rhizosphere available P through amorphous iron/aluminum oxides and microbial biomass P, which had negative and positive effects on rhizosphere available P, respectively. Thus, sorption by soil minerals and turnover of microbial biomass P may be key processes regulating P availability. In contrast, soil organic acids and acid phosphatase, which may promote the release of P by ligand exchange and mineralization, respectively, did not show a positive relationship with rhizosphere available P. Overall, our findings highlight the potential role of microbial biomass as a labile P pool that provides readily available P by turnover and protects P from sorption by soil minerals, which could help in elucidating the mechanisms by which plants maintain their P nutrient supply in alpine ecosystems under environmental changes.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141091004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate–resilient strategy for shortening the crop cycle in rice and the host influenced rhizosphere microbiome","authors":"P. Umadevi ,&nbsp;S. Gopala Krishnan ,&nbsp;M. Nagarajan ,&nbsp;S. Manivannan ,&nbsp;K.K. Vinod ,&nbsp;A.K. Singh","doi":"10.1016/j.rhisph.2024.100903","DOIUrl":"10.1016/j.rhisph.2024.100903","url":null,"abstract":"<div><p>We present the field rapid generation advancement procedure for shortening the crop cycle in rice. The practical protocol developed by us using different maturity groups of rice showed promising early flower induction. We observed a shortening of crop cycle to about 35–40 days depending on the variety. The spacing between the plants was the major influencer for flower induction compared to other interventions tested viz., clipping, potassium di-hydrogen phosphate and paclobutrazol spray. Our raised bed direct seeding strategy completely avoided the transplantation. The work flow for flower induction can be a reference to increase generations of rice breeding. The rhizosphere bacterial dynamics using 16srRNA gene amplicon sequencing showed the <em>Acinetobacter</em> population abundance as a key mediator and marker for flowering time. The alpha diversity at flowered and unflowered stage showed the species richness as Control &lt; Pusa Sugandh 5 &lt; BPT-5204. The rice rhizosphere of this ecosystem had an abundance of <em>Methylotrophs</em> that utilize methane as a carbon source suggesting that the developed method is a green technique suitable for generation advancement that can be replaced for flooded condition assisted breeding in rice. Selective enrichment of functional abundance between varieties suggested the host - influenced microbiome for early flowering in rice. This protocol is expected to greatly accelerate the process of new variety breeding and the construction of mapping populations.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141133486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serratia marcescens AB1: A rhizosphere bacterium mitigating the acetochlor stress on the soil environment","authors":"Meiqi Dong ,&nbsp;Yufeng Xiao ,&nbsp;Bingbing Yang ,&nbsp;Siya Wang ,&nbsp;Liangpeng Sun ,&nbsp;Zhe Han ,&nbsp;Hao Zhang ,&nbsp;Xian Wu","doi":"10.1016/j.rhisph.2024.100898","DOIUrl":"10.1016/j.rhisph.2024.100898","url":null,"abstract":"<div><p>Microbial remediation, a significant research focus in bioremediation, shows promise in addressing pollution. In this study, the optimal medium for acetochlor-degrading bacteria AB1 was determined by the response surface method as 29.94 g L⁻¹ sucrose, 10.06 g L⁻¹ yeast extract, and 20.32 g L⁻¹ NaCl. The single-factor method identified optimum degradation conditions, including a temperature of 30 °C, pH of 7.0, inoculation with 3% AB1, and an initial acetochlor concentration of 10 mg L⁻¹. The strain reached a maximum degradation rate of 79.87% within 5 days. AB1 performed nitrogen fixation, phosphorus dissolution, potassium hydrolysis, siderophore production, and biofilm formation. In the presence of acetochlor, it also induced the upregulation of genes, <em>wza</em> and <em>luxS.</em> Utilizing a green fluorescent protein and rifampicin-resistant strain LAB1-gfp, it demonstrated stable colonization in maize rhizospheres and soils, enhancing growth and degradation. This reduced the acetochlor half-life to 12.77 days and increased soil enzyme activity, providing a theoretical foundation for acetochlor bioremediation.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141051464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel rapid screening assay to incorporate complexity and increase throughput in early-stage plant biological testing","authors":"Sabrina M. Pittroff,&nbsp;Alexander R. Brems,&nbsp;Rune J. Brunshøj,&nbsp;Johan V. Christiansen,&nbsp;Emma Melgaard,&nbsp;Morten Lindqvist Hansen,&nbsp;David Llorente Corcoles,&nbsp;Jonathan Funk,&nbsp;Vilhelm K. Møller,&nbsp;Søren D. Petersen,&nbsp;Rasmus J.N. Frandsen,&nbsp;Niels B. Jensen,&nbsp;Lars Jelsbak","doi":"10.1016/j.rhisph.2024.100897","DOIUrl":"https://doi.org/10.1016/j.rhisph.2024.100897","url":null,"abstract":"<div><p>The search for new biological products with a positive impact on crop performance is typically initiated by laboratory based <em>in vitro</em> assays. However, live plants and their associated microbes are often removed from <em>in vitro</em> testing assays as a way to reduce biological complexity (variation) and facilitate molecular techniques in the pursuit of uncovering mode-of-action (MoA) mechanisms. Nevertheless, when studying biological candidates intended for use in agriculture, it is essential to incorporate this complexity and validate mechanisms under conditions as close to <em>in situ</em> as possible in order to understand the capacities and MoA of the biologicals in the intended application environments. To address this paradox, we have developed a high-capacity early-stage plant assay that incorporates a live non-sterile plant while also enabling molecular MoA investigations, and that can be conducted in laboratories without greenhouse facilities. The high-capacity design features plants grown in 8-chamber transparent boxes to allow for multiplex imaging and increased biological replicates for greater statistical power. The transparent box design allows the visualization of shoots, roots, tagged-microbes, or visible substrates, and further non-destructive access to shoots or roots for sampling. The boxes are held in racks that hold eight plant boxes during growth in a 19 by 17 cm space, further increasing the throughput to &gt;670 plants per m² and easing the logistical challenges of plant assays. Furthermore, the box can support various levels of microbial complexity with the option to select the plant growth medium that meets experimental objectives, as well as using sterile or non-sterile seeds. A script-based post-imaging quantification was developed to automate image processing and allow for individual plant readings, further enabling increased statistical confidence. As proof of concept, we use the high-capacity plant system to evaluate the biocontrol potential of <em>Pseudomonas protegens</em> and the biostimulation potential of <em>Pseudomonas koreensis</em>, and are in both cases able to show statistically significant differing plant biomass between treatments under these closer-to-nature conditions. We further demonstrate that the high-capacity plant system is suitable for paired molecular investigations by performing metabolomics and qPCR DNA quantification directly from the plant box to explore <em>in situ</em> chemical MoA, as well as confirm the survival of the <em>P. protegens</em> strains to validate their role in the improved plant phenotype. In conclusion, the study presents a modular high-capacity plant assay system that enables increased throughput functional testing of microbial biocontrol and biostimulant candidates <em>in planta</em>. This novel assaying system saves time, reduces human error, provides quantitative and non-destructive <em>in planta</em> data, and can be used in laboratories","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2452219824000521/pdfft?md5=742338ed2d6af930004eea3cdaa02484&pid=1-s2.0-S2452219824000521-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141067935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simple, cost-effective and optimized protocol for collecting root exudates from soil grown plants","authors":"Stefanie Döll ,&nbsp;Hannah Koller ,&nbsp;Nicole M. van Dam","doi":"10.1016/j.rhisph.2024.100899","DOIUrl":"10.1016/j.rhisph.2024.100899","url":null,"abstract":"<div><p>Root exudates play a pivotal role in belowground interactions in both ecological and agricultural contexts. The metabolic composition of exudates profoundly influences the dynamics of these interactions, thereby shaping the intricate relationships between plants, microbes, and soil environments. Recent advances in mass-spectrometry have facilitated the analysis of root exudate metabolic composition to a greater depth. Previously used methods primarily analyze root exudates in hydroponic systems, or employ hybrid methodologies, which cultivate plants in soil and transitioning them briefly to hydroponic systems for exudate collection. Modern day ecological studies demand that exudates are collected in their natural habitats, because this will provide a more ecologically meaningful exudate metabolic profile. However, collecting exudates from soil grown plants poses several challenges with regard to the collection procedures, amongst others, the need for recovery after excavation of the roots, the collection period, and the solution in which to collect. Here, we present an optimized, cost-effective protocol for root exudate collection from potted plants, which is readily adaptable to field-grown specimens. Using tomato plants grown in pots, we examined and optimized various parameters: the collection medium (water versus nutrient solution), the use of wetted glass beads versus roots submerged in water, the recovery phase post-substrate removal, and the duration of exudation. Employing liquid chromatography-mass spectrometry (LC-MS), we assessed total amount of exudate, the number of features and background noise. Subsequent to data processing and statistical analyses, we assessed the chemical classes within exudates and variations in key metabolites among the different methods. Our results showed that each of the tested parameters can influence the outcome in different ways. Omitting the recovery phase increased the numbers of features and exudate amounts, likely due to adding metabolites from damaged roots, whereas the exudation medium and the duration of exudation had fewer effects. Based on our results, we propose to collect exudates in beakers containing ultrapure water, and to collect exudates for 4 h after a 24 h recovery phase. This is a straightforward and economical approach for collecting root exudates from soil-grown plants which is suitable for LC-MS analysis.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2452219824000545/pdfft?md5=7c3c9e608c54ee0801b8f367151773e2&pid=1-s2.0-S2452219824000545-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141044804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lettuce seedlings rapidly assemble their microbiome from the environment through deterministic processes","authors":"Nesma Zakaria Mohamed ,&nbsp;Leonardo Schena ,&nbsp;Antonino Malacrinò","doi":"10.1016/j.rhisph.2024.100896","DOIUrl":"https://doi.org/10.1016/j.rhisph.2024.100896","url":null,"abstract":"<div><p>Plant-associated microorganisms have significant impacts on plant biology, ecology, and evolution. Although several studies have examined the factors driving variations in plant microbiomes, the mechanisms underlying the assembly of the plant microbiome are still poorly understood. In this study, we used gnotobiotic plants to test (i) whether seedlings create a selective environment and drive the assembly of root and leaf microbiomes through deterministic or stochastic processes, and (ii) whether seedlings structure the microbiome that is transferred through seeds using deterministic processes and whether this pattern changes when seedlings are exposed to the environmental microbiome. Our results show that the microbiome of gnotobiotic plants (i.e., inherited through seeds) is not under the selective influence of the host plant but changes quickly when plants are exposed to soil microbiomes. Within one week, plants were able to select microorganisms from the inocula, assemble the root microbiome, and assemble the shoot microbiome. This study supports the hypothesis that plants at early developmental stages might exert strong selective activity on their microbiomes and contribute to clarifying the mechanisms of plant microbiome assembly.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S245221982400051X/pdfft?md5=3b1eba0976c7adf1c7aab57eea53442a&pid=1-s2.0-S245221982400051X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140918781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonality and vegetation shape the taxonomic and functional diversity of microorganisms in islands of fertility of a semi-arid region in the Colombian tropics","authors":"Leslie Leal ,&nbsp;Diego C. Franco ,&nbsp;Javier Vanegas","doi":"10.1016/j.rhisph.2024.100894","DOIUrl":"10.1016/j.rhisph.2024.100894","url":null,"abstract":"<div><p>The islands of fertility or resource islands play a crucial role in combating desertification, as they harbor diverse microbial communities essential for their establishment. The objective of this study was to determine the taxonomic and functional diversity of soil microorganisms in a semi-arid region of the Colombian tropics using a metagenomic approach. To achieve this, we sampled three species of nurse trees as well as bare soil during both the dry and wet seasons. Total DNA was extracted and sequenced extensively. Taxonomic diversity was established by comparing against the SILVA database, while functional diversity was determined using the DIAMOND program and the KEGG database. The analysis unveiled seasonal microbial dynamics influenced by vegetation cover. Islands of fertility exhibited higher diversity and nutritional value compared to bare soil. Wet season conditions boosted microbial diversity, narrowing the gap between vegetated and unvegetated soils. Under drought conditions, Proteobacteria predominated in the resource islands, while Actinobacteria prevailed in the bare soil. Both islands of fertility and the rainy season are significant drivers of microbial communities in these semi-arid environments. The presence of unique genera indicated specialized adaptations, revealing an under-explored microbial diversity. Although complete methanogenesis was absent, methane oxidation pathways were detected. Bacteria demonstrated notable adaptations for nitrate reduction, even under organic substrate limitation. Organic matter and anaerobic microenvironments could play a crucial role in nitrate reduction and denitrification. Sulfate reduction prevailed during the dry season, whereas thiosulfate oxidation was more prominent during the wet season. These findings underscore the remarkable adaptability of microbial communities in challenging environments and provide key insights for addressing desertification in semi-arid zones.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2452219824000478/pdfft?md5=be91596143d072f1bdaf43c984f45236&pid=1-s2.0-S2452219824000478-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141027641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arbuscular mycorrhiza and rhizosphere soil enzymatic activities as modulated by grazing intensity and plant species identity in a semi-arid grassland","authors":"Mohammad Matinizadeh ,&nbsp;Elham Nouri ,&nbsp;Mohammad Bayranvand ,&nbsp;Zuzana Kolarikova ,&nbsp;Martina Janoušková","doi":"10.1016/j.rhisph.2024.100893","DOIUrl":"https://doi.org/10.1016/j.rhisph.2024.100893","url":null,"abstract":"<div><p>Understanding the symbiosis of arbuscular mycorrhizal fungi (AMF) with plants in relation to soil nutrients and enzyme activities under different grazing intensities can be an important guide for the management and protection of semi-arid grasslands. The aim of the present study was to evaluate how the interaction of grazing intensity and plants shapes the composition of AMF communities and enzyme activities in a semi-arid grassland ecosystem in Iran. Sampling focused three dominant plant species (i.e., <em>Salsola laricina</em>, <em>Artemisia siberia</em>, and <em>Stipa hohenackeriana</em>) at sites with different grazing intensities. Soil chemical properties, enzyme activities, root colonization by AMF and AMF communities in the roots were evaluated. Potassium and nitrogen, as well as alkaline phosphatase and urease enzymatic activities were significantly increased at the heavily grazed site, whereas root colonization by AMF was reduced by the high grazing intensity. In addition, AM fungal root colonization is dependent on the host plant species and easier to measure as a sensitive indicator of sustainable grazing. Neither plant species nor grazing intensity affected AM fungal diversity in roots, which could be due to the overall low phylogenetic diversity of AMF in the grassland and the lack of significant differences in soil humidity, pH and organic carbon between the sites. However, plant species and soil properties were the two factors explaining variation in AMF community composition, while grazing had no significant effect. Therefore, AMF communities in root of the semi-arid grassland plants responded largely to plant type rather than to grazing intensity.</p></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140918782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}