Pedosphere最新文献

{"title":"Silicon reduces cadmium accumulation in Moso bamboo (Phyllostachys edulis) root cell sap by sequestering cadmium in hemicellulose 1","authors":"Yuzhen CHANG ,&nbsp;Fan YANG ,&nbsp;Chaofeng YANG ,&nbsp;Yiting ZHENG ,&nbsp;Xianyu PAN ,&nbsp;Shanshan MA ,&nbsp;Haibao JI ,&nbsp;Ji Feng SHAO","doi":"10.1016/j.pedsph.2023.07.015","DOIUrl":"10.1016/j.pedsph.2023.07.015","url":null,"abstract":"<div><div>Moso bamboo is one of the most important economic bamboo species in China, but cadmium (Cd) pollution has become a potential threat of its sustainable development. Silicon (Si) reduces Cd accumulation in many plant species. However, the exact mechanisms of this effect in Moso bamboo are still poorly understood. Here, we investigated the effect of Si on Cd accumulation in Moso bamboo in terms of Cd concentration in roots, Cd cellular and subcellular distribution, root cell morphology, and gene expression. Seedlings (ten days old) were exposed to different concentrations of Cd (0, 1, 5, and 50 μmol L^-1) in a 0.5 mmol L^-1 CaCl₂ solution treated with (+Si) and without (-Si) 1 mmol L^-1 Si (as silicic acid) for two days. The effect of Si on the alleviation of Cd-induced inhibition of root elongation was not obvious, but Si could significantly reduce Cd accumulation in roots at all tested Cd concentrations (1, 5, and 50 μmol L^-1). Cadmium was localized in all cells of roots, but Si application altered the Cd distribution from all cells to distal side of exodermis cells in roots. Semi-quantitative determination of Cd using energy-dispersive X-rays revealed higher Cd concentrations in exodermis, but lower concentrations in the stele when Si was applied. However, Si increased Cd accumulation in root cell wall, but decreased it in cell sap. Moreover, more than 70% of Cd and Si were found in hemicellulose 1 of the cell wall. These results suggested that Si reduced Cd accumulation by sequestering Cd in hemicellulose 1 in the root cell wall at the subcellular level and retaining most of the Cd in the root exodermis at the cellular level in Moso bamboo under short-term Si application.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"34 6","pages":"Pages 1002-1013"},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41572491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial genes for degrading plant-derived carbon are a key factor affecting soil respiration and temperature sensitivity in plateau peatlands","authors":"Wei JIANG ,&nbsp;Mingyao XIONG ,&nbsp;Shuzhen ZOU ,&nbsp;Di KANG","doi":"10.1016/j.pedsph.2024.07.003","DOIUrl":"10.1016/j.pedsph.2024.07.003","url":null,"abstract":"<div><div>Peatlands on the southwestern plateau of China are important carbon sinks for high-altitude terrestrial ecosystems in Asia. However, the specific microecological mechanism responsible for alterations in carbon processes in this region due to the simultaneous impacts of global warming and drought has not been fully elucidated. Investigating this mechanism will improve our understanding of carbon cycle feedback in peatland ecosystems, as it is affected by changes in hydrology and temperature, especially in vulnerable habitats. This study examined the influence of soil carbon decomposition functional microorganisms on soil respiration and temperature sensitivity (expressed as <em>Q</em>₁₀) in high-elevation peatlands using field investigations, simulated warming experiments, and metagenomic sequencing. We found that hydrothermal conditions had a significant effect on soil respiration, leading to an increase in cumulative soil respiration as soil moisture and temperature increased. Soil moisture affected soil respiration and soil organic carbon mainly through soil microorganisms, with a predominance of carbon-decomposing genes. We found that genes regulating the decomposition of plant-derived carbon such as cellulose and lignin were the critical factor influencing <em>Q</em>₁₀ in peatlands. Genes involved in cellulose and lignin decomposition showed a significant positive correlation with <em>Q</em>₁₀ (<em>P</em> &lt; 0.05), while genes involved in hemicellulose decomposition showed a significant negative correlation with <em>Q</em>₁₀ (<em>P</em> &lt; 0.05). Specifically, genes such as <em>ACO</em>, <em>xylF</em>, and <em>hpaE</em>, which are involved in lignin decomposition, and <em>glgB</em>, which is responsible for cellulose decomposition, showed significant positive correlations (<em>P</em> &lt; 0.05) with <em>Q</em>₁₀. Conversely, the gene <em>uxaC</em>, involved in the decomposition of hemicellulose, showed a significant negative correlation (<em>P</em> &lt; 0.05) with <em>Q</em>₁₀. Finally, we analyzed the relevant carbon metabolic pathways and found that although they were affected by water, they were not significantly related to <em>Q</em>₁₀. In short, this research highlights the importance of microorganisms with genes for decomposing plant-derived carbon in influencing carbon emissions in plateau peatlands during periods of warming.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"34 6","pages":"Pages 1026-1037"},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141708180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of nosZ I-carrying microorganisms in regulating nitrous oxide reduction during forest conversion: A comparison of plantations and a secondary forest in subtropical soils","authors":"Milin DENG ,&nbsp;Guiping YE ,&nbsp;Hang-Wei HU ,&nbsp;Chao XU ,&nbsp;Ping YANG ,&nbsp;Yong ZHENG ,&nbsp;Jupei SHEN ,&nbsp;Shengsheng JIN ,&nbsp;Ji-Zheng HE ,&nbsp;Yongxin LIN","doi":"10.1016/j.pedsph.2023.09.006","DOIUrl":"10.1016/j.pedsph.2023.09.006","url":null,"abstract":"<div><div>The conversion of natural forests in subtropical regions to plantations or secondary forests has resulted in alterations in soil variables, microbial communities, and microbially mediated processes, including nitrous oxide (N₂O) emissions. However, how forest conversion influences soil N₂O reduction and the abundance and community structure of N₂O-reducing microorganisms remains unclear. Here, we investigated the impact of converting natural forests to a secondary forest and <em>Cunninghamia lanceolata</em> and <em>Pinus massoniana</em> plantations on the abundance and community structure of N₂O-reducing microorganisms in both bulk soils and soil aggregates. Compared with the secondary forest, plantations had higher soil pH and available phosphorus and moisture contents, lower soil NH₄⁺ content, but similar aggregate sizes. Compared with the secondary forest, the conversion of natural forest to plantations resulted in significantly higher soil N₂O reduction rate and increased abundances of <em>nosZ</em> I and <em>nosZ</em> II genes in bulk soils and soil aggregates. The abundance of <em>nosZ</em> I was higher than that of <em>nosZ</em> II in all tested soils and had a stronger association with N₂O reduction rate, suggesting the greater role of <em>nosZ</em> I-carrying microorganisms in N₂O consumption. Forest conversion had a greater impact on the community composition of <em>nosZ</em> I than <em>nosZ</em> II, mainly by increasing the relative abundances of alpha- and beta-Proteobacteria, while decreasing gamma-Proteobacteria. However, <em>nosZ</em> II-carrying microorganisms were exclusively dominated by Gemmatimonadetes and less affected by forest conversion. Taken together, our findings significantly contribute to our understanding of the eco-physiological characteristics of N₂O-reducing microorganisms and highlight the importance of <em>nosZ</em> I-carrying microorganisms in N₂O consumption in subtropical forest soils.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"34 6","pages":"Pages 1066-1075"},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134994401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial-temporal simulation and prediction of root zone soil moisture based on Hydrus-1D and CNN-LSTM-attention models in Yutian Oasis, southern Xinjiang, China","authors":"Xiaobo LÜ ,&nbsp;Ilyas NURMEMET ,&nbsp;Sentian XIAO ,&nbsp;Jing ZHAO ,&nbsp;Xinru YU ,&nbsp;Yilizhati AILI ,&nbsp;Shiqin LI","doi":"10.1016/j.pedsph.2024.10.008","DOIUrl":"10.1016/j.pedsph.2024.10.008","url":null,"abstract":"<div><div>Root zone soil moisture (RZSM) plays a critical role in land-atmosphere hydrological cycles and serves as the primary water source for vegetation growth. However, the correlations between RZSM and its associated variables, including surface soil moisture (SSM), often exhibit nonlinearities that are challenging to identify and quantify using conventional statistical techniques. Therefore, this study presents a hybrid convolutional neural network (CNN)-long short-term memory neural network (LSTM)-attention (CLA) model for predicting RZSM. Owing to the scarcity of soil moisture (SM) observation data, the physical model Hydrus-1D was employed to simulate a comprehensive dataset of spatial-temporal SM. Meteorological data and moderate resolution imaging spectroradiometer vegetation characterization parameters were used as predictor variables for the training and validation of the CLA model. The results of the CLA model for SM prediction in the root zone were significantly enhanced compared with those of the traditional LSTM and CNN-LSTM models. This was particularly notable at the depth of 80–100 cm, where the fitness (<em>R</em>²) reached nearly 0.929 8. Moreover, the root mean square error of the CLA model was reduced by 49% and 57% compared with those of the LSTM and CNN-LSTM models, respectively. This study demonstrates that the integration of physical modeling and deep learning methods provides a more comprehensive and accurate understanding of spatial-temporal SM variations in the root zone.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 846-857"},"PeriodicalIF":7.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiency-enhancing methods for predicting nitrogen mineralization characteristics in paddy soils using soil properties and rapid soil extractions","authors":"Yujuan LIU ,&nbsp;Yuqi CHEN ,&nbsp;Xiuyun LIU ,&nbsp;Siyuan CAI ,&nbsp;Jiahui YUAN ,&nbsp;Lingying XU ,&nbsp;Yu WANG ,&nbsp;Xu ZHAO ,&nbsp;Xiaoyuan YAN","doi":"10.1016/j.pedsph.2024.10.001","DOIUrl":"10.1016/j.pedsph.2024.10.001","url":null,"abstract":"<div><div>Soil mineralized nitrogen (N) is a vital component of soil N supply capacity and an important N source for rice growth. Unveiling N mineralization (Nm) process characteristics and developing a simple and effective approach to evaluate soil Nm are imperative to guide N fertilizer application and enhance its efficiency in various paddy soils with different physicochemical properties. Soil properties are important driving factors contributing to soil Nm differences and must be considered to achieve effective N management. Nevertheless, discrepancies in Nm capacity and other key influencing factors remain uncertain. To address this knowledge gap, this study collected 52 paddy soil samples from Taihu Lake Basin, China, which possess vastly different physicochemical properties. The samples were subjected to a 112-d submerged anaerobic incubation experiment at a constant temperature to obtain the soil Nm characteristics. Reaction kinetics models, including one-pool exponential model, two-pool exponential model, and effective cumulative temperature model, were employed to compare characteristic differences between Nm potential (Nmp) and short-term accumulated mineralized N (Amn) processes in relation to soil physicochemical properties. Based on these relationships, simplified Nmp prediction methods for paddy soils were established. The results revealed that the Nmp values were 145.18, 88.64, and 21.03 mg kg^-1 in paddy soils with pH &lt; 6.50, 6.50 ≤ pH ≤ 7.50, and pH &gt; 7.50, respectively. Significantly, short-term Amn at day 14 showed a good correlation (<em>P</em> &lt; 0.01) with Nmp (<em>R</em>² = 0.94), indicating that the prevailing short-term incubation experiment is an acceptable marker for Nmp. Moreover, Nmp correlated well with the ultraviolet absorbance value at 260 nm based on NaHCO₃ extraction (Na260), further streamlining the Nmp estimation method. The incorporation of easily obtainable soil properties, including pH, total N (TN), and the ratio of total organic carbon to TN (C/N), alongside Na260 for Nmp evaluation allowed the multiple regression model, Nmp = 58.62 × TN - 23.18 × pH + 13.08 × C/N + 86.96 × Na260, to achieve a high prediction accuracy (<em>R</em>² = 0.95). The reliability of this prediction was further validated with published data of paddy soils in the same region and other rice regions, demonstrating the regional applicability and prospects of this model. This study underscored the roles of soil properties in Nm characteristics and mechanisms and established a site-specific prediction model based on rapid extractions and edaphic properties of paddy soils, paving the way for developing rapid and precise Nm prediction models.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 1054-1064"},"PeriodicalIF":7.3,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nano-sized humic acid improves phosphate fertiliser efficiency in chilli pepper","authors":"Qizhong XIONG ,&nbsp;Shaojie WANG ,&nbsp;Xuxiang CHEN ,&nbsp;Jianyuan JING ,&nbsp;Yonglin JIN ,&nbsp;Hongying LI ,&nbsp;Chaochun ZHANG ,&nbsp;Yuji JIANG ,&nbsp;Xinxin YE","doi":"10.1016/j.pedsph.2024.09.007","DOIUrl":"10.1016/j.pedsph.2024.09.007","url":null,"abstract":"<div><div>Humic acid (HA) prevents phosphorus (P) fixation and promotes P absorption by plants, thereby effectively increasing the efficiency of phosphate fertiliser utilisation. Although nano-sized HA (NHA) might exhibit superior effects compared to conventional-sized HA (CHA), evidence is limited. Therefore, we investigated the effects of CHA and NHA applied with conventional phosphate fertiliser (CHA+CP and NHA+CP, respectively) on chilli pepper biomass, P uptake, and root morphology, as well as soil available P content, and evaluated CHA, NHA, and their residues in the soil for differences in specific surface area, functional groups, molecular weight distribution, and surface elemental compositions in a 40-d pot cultivation experiment. Results showed that the CHA+CP and NHA+CP treatments significantly increased pepper biomass and P uptake by 15.2%–24.7% and 37.9%–49.0%, respectively, compared to the conventional phosphate fertiliser applied alone (CP) treatment (<em>P</em> &lt; 0.05), with NHA exhibiting a greater effect than CHA. This was primarily related to NHA's stronger ability to reduce P fixation than that of CHA. Soil available P content significantly increased by 5.8% and 3.8% in the NHA+CP treatment compared with CHA+CP on days 22 and 40 of cultivation, respectively (<em>P</em> &lt; 0.05). Nano-sized HA contained more small-molecule components and carboxyl groups than CHA, which can more stimulate root elongation and thus promote root P uptake. Furthermore, fertiliser-derived P gradually entered the structure of CHA or NHA during cultivation. The presence of more plant-available forms (<em>e.g</em>., H₂\u0000\t\t\t\t<span><math><mtext>P</mtext><msubsup><mi>O</mi><mrow><mn>4</mn></mrow><mrow><mo>−</mo></mrow></msubsup></math></span> and HPO₄^2-) in NHA compared to CHA also contributed to better regulation of phosphate fertiliser efficacy. In conclusion, NHA is superior to CHA in improving phosphate fertiliser efficiency, making it a potential alternative material for the development of high-efficiency phosphate fertilisers. This presents an excellent opportunity to minimise P resource waste.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 1065-1077"},"PeriodicalIF":7.3,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of thermo-water-vapor-carbon coupling in a permafrost region: A case study in the Beiluhe region of the Qingzang Plateau, China","authors":"Haotian WEI ,&nbsp;Enlong LIU ,&nbsp;Chuan HE ,&nbsp;Bingtang SONG ,&nbsp;Dan WANG ,&nbsp;Jian KANG ,&nbsp;Ling CHEN ,&nbsp;Qiong LI","doi":"10.1016/j.pedsph.2024.09.006","DOIUrl":"10.1016/j.pedsph.2024.09.006","url":null,"abstract":"<div><div>With global warming and the intensification of human activities, frozen soils continue to melt, leading to the formation of thermokarst collapses and thermokarst lakes. The thawing of permafrost results in the microbial decomposition of large amounts of frozen organic carbon (C), releasing greenhouse gases such as carbon dioxide (CO₂) and methane (CH₄). However, little research has been done on the thermo-water-vapor-carbon coupling process in permafrost, and the interactions among hydrothermal transport, organic matter decomposition, and CO₂ transport processes in permafrost remain unclear. We considered the decomposition and release of organic C and established a coupled thermo-water-vapor-carbon model for permafrost based on the study area located in the Beiluhe region of the Qingzang Plateau, China. The model established accurately reflected changes in permafrost temperature, moisture, and C fluxes. Dramatic changes in temperature and precipitation in the warm season led to significant soil water and heat transport, CO₂ transport, and organic matter decomposition. During the cold season, however, the soil froze, which weakened organic matter decomposition and CO₂ transport. The sensitivity of soil layers to changes in the external environment varied with depth. Fluctuations in energy, water, and CO₂ fluxes were greater in shallow soil layers than in deeper ones. The latent heat of water-vapor and water-ice phase changes played a crucial role in regulating the temperature of frozen soil. The low content of soil organic matter in the study area resulted in a smaller influence of the decomposition heat of soil organic matter on soil temperature, compared to the high organic matter content in other soil types (such as peatlands).</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 1039-1053"},"PeriodicalIF":7.3,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of microplastics, fluoride and mancozeb on tomato plant growth and rhizosphere microbial dynamics: A metagenomic analysis","authors":"Ajay KUMAR ,&nbsp;Rajni SHARMA ,&nbsp;Muskan BOKOLIA ,&nbsp;Riyapi DAS ,&nbsp;Sanjiv KUMAR ,&nbsp;Ravindresh CHABBRA ,&nbsp;Baljinder SINGH","doi":"10.1016/j.pedsph.2024.09.001","DOIUrl":"10.1016/j.pedsph.2024.09.001","url":null,"abstract":"<div><div>Microplastics (MPs), fluoride (FR), and fungicide mancozeb (MZ) are common contaminants in soil. However, there is no information about the combined impacts of MPs, FR, and MZ on tomato plant growth features in the literature. This study aimed to investigate the effects of combined application of MPs, FR, and MZ (both analytical grade and commercial) on the growth and development of tomato plants and metagenomics of rhizosphere soil. A pot experiment was set up in an artificial greenhouse with two sets of treatments. One set was the combined application of MPs, FR, and analytical grade MZ (B2) and a control without the application of MPs, FR, and MZ (W2), and the other set was the combined application of MPs, FR, and commercial MZ (B3) and a control without the application of MPs, FR, and MZ (W3). No detrimental effects of MPs, FR, and MZ were detected on the growth parameters of tomato plants, including the number of leaves and chlorophyll concentration. However, tomato roots showed knot and nodulation-type structures, and metabolomic profiling revealed that combined exposure to MPs, FR, and MZ profoundly reprogrammed the primary metabolism in tomato roots, with marked alterations in carbohydrate and amino acid pathways. Metagenome whole genome sequencing showed that the B2 and B3 treatments profoundly affected soil microbial community composition, diversity, gene abundances, and functional gene variations compared to W2 and W3. Proteobacteria became the dominating phylum in B2 and B3, causing a significant shift in the microbiome. Its abundance soared to 66.7% in B2 and 75.4% in B3, compared to only 35.9% in W2 and 28.9% in W3. On the other hand, Actinobacteria decreased significantly from 55.6% in W2 and 63.8% in W3 to 18.1% in B2 and 9.6% in B3. This study highlights the microbial shifts due to combined application of MPs, FR, and MZ, providing evidence for understanding their environmental risks.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 1078-1088"},"PeriodicalIF":7.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of rice cropping method and growth stage on rhizosphere bacterial diversity and soil biological attributes","authors":"Surathi ADITHYA,&nbsp;Sai Aparna Devi NUNNA,&nbsp;Chinnappan CHINNADURAI,&nbsp;Dananjeyan BALACHANDAR","doi":"10.1016/j.pedsph.2024.08.010","DOIUrl":"10.1016/j.pedsph.2024.08.010","url":null,"abstract":"<div><div>Rice cropping method is primarily decided by soil moisture regime. System of rice intensification (SRI) and direct-seeded aerobic rice are two primary modifications of traditional wetland rice. Understanding rice rhizosphere microbiome and functioning as influenced by these cropping methods is essential for sustaining rice productivity. The objective of this study was to assess the impact of three different rice cropping methods (wetland rice, SRI, and aerobic rice) on the biochemical properties and bacterial communities within the rice rhizosphere across three key rice growth stages: tillering, flowering, and maturity. Soil organic carbon (SOC), microbial biomass carbon (MBC), dehydrogenase activity, substrate-induced respiration (SIR), and metabolic quotient (MQ) were assessed along with high-throughput 16S rRNA sequencing of rice rhizosphere soils. The rice rhizosphere soil registered the highest SOC, MBC, and dehydrogenase activity in SRI followed by wetland rice and then aerobic rice. Cropping method had a minimal impact on SIR and MQ. Along with cropping method, growth stage also significantly altered these biological attributes of rice rhizosphere. The trends of the highest SOC content and dehydrogenase activity at the flowering stage and the highest MBC content and SIR at the tillering stage of rice were observed in all three rice cropping methods. The analysis of bacterial communities, based on 16S rRNA gene sequencing, revealed that both cropping method and growth stage significantly impacted the composition of rhizosphere microbiomes. However, the influence of cropping method was less pronounced compared to growth stage. Cropping method caused notable shifts in the abundances of Proteobacteria, Bacteroidetes, and Chloroflexi, while growth stage affected the abundances of Proteobacteria, Actinobacteria, Cyanobacteria, Firmicutes, Chloroflexi, and Bacteroidetes. Based on these results, the SRI method led to higher diversification to the rhizosphere bacteriobiota, as well as greater incorporation of carbon into the soil and increased dehydrogenase activity compared to wetland rice and aerobic rice. This study deepens our understanding of how different cropping methods influence plant-microbe interaction and the implications for overall rice productivity and soil health.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 983-994"},"PeriodicalIF":7.3,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complementing culture-dependent and -independent approaches is essential when assessing bacterial community potential functions in chronically polycyclic aromatic hydrocarbon-contaminated soils","authors":"Sabrina FESTA ,&nbsp;Esteban Emanuel NIETO ,&nbsp;Penélope RAPOSEIRAS ALDORINO ,&nbsp;Sara CUADROS-ORELLANA ,&nbsp;José Matías IRAZOQUI ,&nbsp;Claudio QUEVEDO ,&nbsp;Bibiana Marina COPPOTELLI ,&nbsp;Irma Susana MORELLI","doi":"10.1016/j.pedsph.2024.08.005","DOIUrl":"10.1016/j.pedsph.2024.08.005","url":null,"abstract":"<div><div>Bioremediation is an eco-friendly alternative for soil restoration. However, its outcomes are still variable. Different bioremediation strategies were used in a chronically polycyclic aromatic hydrocarbon (PAH)-contaminated soil, and no degradation was achieved. This work attempts to study whether the soil bacterial community has the genetic potential for aromatic compound degradation (ACD). While 16S rRNA metabarcoding of that soil showed a predominance of Proteobacteria, shotgun metagenomics indicated that 99.5% of the sequences were taxonomically assigned to Streptomycetales, and almost all genes related to ACD were assigned to the latter. As comprehension of the composition and metabolic potential of a soil community can be enhanced by exploring enrichment cultures of that soil, a culture approach followed by a shotgun metagenomic analysis was performed. These enrichment cultures were obtained by sequential transfers with pyrene conducted every 7 (r-EFP) and 28 (k-MSP2) d. Both r-EFP and k-MSP2 demonstrated the ability to degrade pyrene and the presence of genes related to ACD. While <em>Pseudomonas</em> and <em>Olivibacter</em> were the predominant genera in r-EFP, <em>Mycobacterium</em>, <em>Chitoniphaga</em>, <em>Bacillus</em>, and <em>Pseudoxanthomonas</em> were predominant in k-MSP2. This study demonstrated the soil bacterial community's potential to degrade PAHs of three and four rings. Therefore, exploration of bioremediation strategies aimed at activating this potential would be worthwhile. It was confirmed that shotgun metagenomics may not fully reveal potential bacterial functions when characterizing impacted soil microbiomes. Additionally, culture-based methods complemented and increased the knowledge obtained from culture-independent approaches, demonstrating their utility for bioprospecting PAH degraders and designing microbiome engineering strategies.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 6","pages":"Pages 931-944"},"PeriodicalIF":7.3,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}