Pub Date : 2025-12-01Epub Date: 2025-10-15DOI: 10.1016/j.rhisph.2025.101210
Julia Sacharow , David Rosado-Porto , Santiago Quiroga , Stefan Ratering , Rita Geißler-Plaum , Bellinda Schneider , Sylvia Schnell
The application of plant growth-promoting rhizobacteria (PGPR) for inoculation of seeds, soils, and plants is becoming increasingly important due to the environmental impact of extensive use of chemical treatments in plant production. In this study, we investigated the effects of seed inoculation with Hartmannibacter diazotrophicus E19 on the bacterial, fungal and protist (Cercozoa) microbiome of winter wheat. The results showed that the inoculation of H. diazotrophicus E19 had no significant effect on the microbiome of roots, rhizosphere and in the bulk soil of winter wheat. Instead, the composition of the winter wheat microbiome appears to be more influenced by plant developmental stage and sampling material. Inoculation resulted only in minor effects, reflected by a limited number of ASVs showing positive or negative differential abundance compared to the controls like Chryseolinea, Symbiobacterium, Malbranchea, Hormiactis and Sandonidae. These findings confirm that the microbiome composition of winter wheat undergoes only minimal changes upon inoculation with H. diazotrophicus E19.
{"title":"Plant developmental stage, rather than inoculation with Hartmannibacter diazotrophicus, determines the composition of the bacterial, fungal, and protist microbiome in winter wheat","authors":"Julia Sacharow , David Rosado-Porto , Santiago Quiroga , Stefan Ratering , Rita Geißler-Plaum , Bellinda Schneider , Sylvia Schnell","doi":"10.1016/j.rhisph.2025.101210","DOIUrl":"10.1016/j.rhisph.2025.101210","url":null,"abstract":"<div><div>The application of plant growth-promoting rhizobacteria (PGPR) for inoculation of seeds, soils, and plants is becoming increasingly important due to the environmental impact of extensive use of chemical treatments in plant production. In this study, we investigated the effects of seed inoculation with <em>Hartmannibacter diazotrophicus</em> E19 on the bacterial, fungal and protist (Cercozoa) microbiome of winter wheat. The results showed that the inoculation of <em>H. diazotrophicus</em> E19 had no significant effect on the microbiome of roots, rhizosphere and in the bulk soil of winter wheat. Instead, the composition of the winter wheat microbiome appears to be more influenced by plant developmental stage and sampling material. Inoculation resulted only in minor effects, reflected by a limited number of ASVs showing positive or negative differential abundance compared to the controls like <em>Chryseolinea</em>, <em>Symbiobacterium</em>, <em>Malbranchea</em>, <em>Hormiactis</em> and Sandonidae. These findings confirm that the microbiome composition of winter wheat undergoes only minimal changes upon inoculation with <em>H. diazotrophicus</em> E19.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101210"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363391","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}
Pub Date : 2025-12-01Epub Date: 2025-10-21DOI: 10.1016/j.rhisph.2025.101215
Yang Chen , Weitao Wang , Zhanfeng Liu , Xianhui Zhu , Shuyin Li , Xiaoju Yang , Ziyue Jing , Wenqi Luo , Youshi Wang , Buhang Li , Yuanzhi Li , Chengjin Chu
Plant-mycorrhizal symbiosis is influenced both by the types of mycorrhizae (qualitatively) and by mycorrhizal colonization rates (quantitatively). However, research on the variation of arbuscular mycorrhiza colonization rates (AMCR) remains limited, particularly at the individual level, which could provide deeper insights into the impact of mycorrhizae on plant performance. We sampled the roots of 1223 individuals from 103 tree species within a 50-ha subtropical forest plot in southern China and measured their individual-level AMCR. Using multivariate beta-regression analyses and piecewise structural equation models, we investigated how various biotic and abiotic factors jointly influence AMCR and quantified the relative importance of these factors. Our investigation revealed substantial individual-level variation in AMCR within the study plot. Among the factors examined, biotic factors, particularly neighboring effects (e.g., conspecific density, phylogenetic diversity), exerting a stronger influence than abiotic factors. Soil nutrient-based resource diversity (RD) had no direct effect on AMCR. It influenced AMCR only indirectly by altering plant community composition. These findings suggest the complexity of AMCR variation within natural forests, highlighting the potential role of interactions between biotic and abiotic factors in mediating individual-level AMCR. Our study provides a solid foundation for further investigation into the relationship between AMCR, key aspects of plant demographic performance, and other ecological processes.
{"title":"Biotic interactions outweigh abiotic factors in driving individual-level variation in arbuscular mycorrhizal colonization in a subtropical forest","authors":"Yang Chen , Weitao Wang , Zhanfeng Liu , Xianhui Zhu , Shuyin Li , Xiaoju Yang , Ziyue Jing , Wenqi Luo , Youshi Wang , Buhang Li , Yuanzhi Li , Chengjin Chu","doi":"10.1016/j.rhisph.2025.101215","DOIUrl":"10.1016/j.rhisph.2025.101215","url":null,"abstract":"<div><div>Plant-mycorrhizal symbiosis is influenced both by the types of mycorrhizae (qualitatively) and by mycorrhizal colonization rates (quantitatively). However, research on the variation of arbuscular mycorrhiza colonization rates (AMCR) remains limited, particularly at the individual level, which could provide deeper insights into the impact of mycorrhizae on plant performance. We sampled the roots of 1223 individuals from 103 tree species within a 50-ha subtropical forest plot in southern China and measured their individual-level AMCR. Using multivariate beta-regression analyses and piecewise structural equation models, we investigated how various biotic and abiotic factors jointly influence AMCR and quantified the relative importance of these factors. Our investigation revealed substantial individual-level variation in AMCR within the study plot. Among the factors examined, biotic factors, particularly neighboring effects (e.g., conspecific density, phylogenetic diversity), exerting a stronger influence than abiotic factors. Soil nutrient-based resource diversity (RD) had no direct effect on AMCR. It influenced AMCR only indirectly by altering plant community composition. These findings suggest the complexity of AMCR variation within natural forests, highlighting the potential role of interactions between biotic and abiotic factors in mediating individual-level AMCR. Our study provides a solid foundation for further investigation into the relationship between AMCR, key aspects of plant demographic performance, and other ecological processes.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101215"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416536","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}
Pub Date : 2025-12-01Epub Date: 2025-10-24DOI: 10.1016/j.rhisph.2025.101209
Amir Hossein Khoshgoftarmanesh , Ali Akbar Zare , Azam Hosseinian Moghaddam
Phytosiderophore secretion and zinc (Zn) uptake by roots of wheat in response to uniform and non-uniform distribution of salt in root environment was investigated. Two Zn-efficient (Triticum aestivum L. cvs. Rushan and Pishtaz) and a Zn-inefficient (Kavir) wheat genotypes were exposed to uniform and static and dynamic non-uniform NaCl salinity either in the presence or absence of Zn (Exp. 1) or at a constant Zn2+ activity (pZn2+ = 4.7) in nutrient solution (Exp. 2). Root zone consisted two equal sections filled with nutrient solution. In non-uniform salinity, one side was non-saline and the other side contained 80 mM NaCl. In static non-uniform salinity, the one side received saline solution to the end of experiment while in dynamic treatment, saline solutions was exchanged between two sides after 4 d. In uniform salinity, both sides were saline (40 mM NaCl). The growth response of wheat to salinity treatments was genotype-dependent, in ‘Kavir’, the shoot dry mass was unaffected by non-uniform dynamic salinity while in ‘Rushan’ and ‘Pishtaz’, all salinity treatments caused a significant decline in the shoot biomass in comparison with the control. Regardless of genotype, the greatest damage of salinity on dry mass of shoot was found at the uniform salinity. A greater reduction in the dry mass of all wheat genotypes observed at uniform salinity compared to non-uniform salinities was associated with a further decrease in Zn and more increase in Na concentration. The highest increase in the root-to-shoot transport of Zn and Na was observed at the uniform salinity. In all wheat genotypes, salinity resulted in higher PS secretion from roots of the Zn-supplied plants. The highest increase in PS secretion from the right side (A) root of ‘Rushan’, ‘Kavir’ and ‘Pishtaz’ (2.24, 1.96 and 1.75 times over the control, respectively) was found at the uniform salinity. At the constant activity of Zn2+, the increasing effect of salinity on the root exudation of PS was considerably reduced. In the Zn-free conditions, salinity was ineffective or slightly increased the PS secretion from roots. In Zn-containing solution, the magnitude of changes in Zn2+ activity determines how the uniform and non-uniform salinity affect the root PS exudation. In contrast, at the absence of Zn, the effect of salinity on the root PS secretion seems to be more associated with plant growth status.
The lower phytosiderophore secretion under saline conditions leads to lower ability to Zn uptake which should be compensated by improved zinc nutrition.
研究了小麦根系对盐均匀分布和不均匀分布对植物铁素分泌和锌吸收的响应。两种高效锌小麦。将乳山(Rushan)和Pishtaz (Pishtaz)和一个锌低效小麦(Kavir)基因型分别暴露于均匀、静态和动态非均匀NaCl盐度(有或无Zn (Exp. 1))和恒定Zn2+活性(pZn2+ = 4.7)的营养液中(Exp. 2)。根区由两等份的营养液填充而成。在非均匀盐度条件下,一侧为无盐,另一侧为80 mM NaCl。在静态不均匀盐度条件下,一侧接受生理盐水溶液直至实验结束;在动态条件下,4 d后两侧交换生理盐水溶液。等盐条件下,两侧均为盐水(40 mM NaCl)。小麦对盐胁迫的生长响应呈基因型依赖性,‘卡维尔’的茎部干质量不受非均匀动态盐胁迫的影响,而‘如山’和‘皮什塔兹’的茎部生物量均显著低于对照。无论基因型如何,盐度对茎干质量的损害均以均匀盐度下最大。与非均匀盐度相比,均匀盐度条件下所有小麦基因型的干质量下降幅度更大,这与锌进一步下降和钠浓度增加有关。均匀盐分处理下,锌和钠的根到梢转运增加幅度最大。在所有小麦基因型中,盐度导致锌供应植株根系分泌更高的PS。‘Rushan’、‘Kavir’和‘Pishtaz’的右侧(A)根PS分泌量在均匀盐度下增加最多(分别是对照的2.24倍、1.96倍和1.75倍)。在Zn2+活性不变的情况下,盐度对PS根系分泌物的增加作用明显减弱。在无锌条件下,盐度对根系PS分泌无效或略有增加。在含锌溶液中,Zn2+活性的变化幅度决定了均匀和非均匀盐度对根系PS渗出的影响。相反,在没有Zn的情况下,盐度对根系PS分泌的影响似乎更多地与植物的生长状态有关。生理盐水条件下植物铁素分泌减少导致锌吸收能力下降,这需要通过改善锌营养来弥补。
{"title":"Root exudation of phytosiderophores from wheat in response to dynamic and static non-uniform distribution of salt in the root medium","authors":"Amir Hossein Khoshgoftarmanesh , Ali Akbar Zare , Azam Hosseinian Moghaddam","doi":"10.1016/j.rhisph.2025.101209","DOIUrl":"10.1016/j.rhisph.2025.101209","url":null,"abstract":"<div><div>Phytosiderophore secretion and zinc (Zn) uptake by roots of wheat in response to uniform and non-uniform distribution of salt in root environment was investigated. Two Zn-efficient (<em>Triticum aestivum</em> L. cvs. Rushan and Pishtaz) and a Zn-inefficient (Kavir) wheat genotypes were exposed to uniform and static and dynamic non-uniform NaCl salinity either in the presence or absence of Zn (Exp. 1) or at a constant Zn<sup>2+</sup> activity (pZn<sup>2+</sup> = 4.7) in nutrient solution (Exp. 2). Root zone consisted two equal sections filled with nutrient solution. In non-uniform salinity, one side was non-saline and the other side contained 80 mM NaCl. In static non-uniform salinity, the one side received saline solution to the end of experiment while in dynamic treatment, saline solutions was exchanged between two sides after 4 d. In uniform salinity, both sides were saline (40 mM NaCl). The growth response of wheat to salinity treatments was genotype-dependent, in ‘Kavir’, the shoot dry mass was unaffected by non-uniform dynamic salinity while in ‘Rushan’ and ‘Pishtaz’, all salinity treatments caused a significant decline in the shoot biomass in comparison with the control. Regardless of genotype, the greatest damage of salinity on dry mass of shoot was found at the uniform salinity. A greater reduction in the dry mass of all wheat genotypes observed at uniform salinity compared to non-uniform salinities was associated with a further decrease in Zn and more increase in Na concentration. The highest increase in the root-to-shoot transport of Zn and Na was observed at the uniform salinity. In all wheat genotypes, salinity resulted in higher PS secretion from roots of the Zn-supplied plants. The highest increase in PS secretion from the right side (A) root of ‘Rushan’, ‘Kavir’ and ‘Pishtaz’ (2.24, 1.96 and 1.75 times over the control, respectively) was found at the uniform salinity. At the constant activity of Zn<sup>2+</sup>, the increasing effect of salinity on the root exudation of PS was considerably reduced. In the Zn-free conditions, salinity was ineffective or slightly increased the PS secretion from roots. In Zn-containing solution, the magnitude of changes in Zn<sup>2+</sup> activity determines how the uniform and non-uniform salinity affect the root PS exudation. In contrast, at the absence of Zn, the effect of salinity on the root PS secretion seems to be more associated with plant growth status.</div><div>The lower phytosiderophore secretion under saline conditions leads to lower ability to Zn uptake which should be compensated by improved zinc nutrition.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101209"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145416540","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}
Microorganisms are crucial for supporting the growth of tea plants and influencing their leaf chemical composition and quality, but the community composition and functional characteristics of microorganisms in the soil of high-quality rock tea plants grown in unique environments remain poorly understood. Here, we analysed the community diversity and potential functions of soil microorganisms of authentic rock tea gardens in Wuyishan. Our results revealed that the diversity of the rare bacterial communities was significantly greater than that of the dominant bacterial communities, all unique taxa were rare. However, the diversity of the dominant fungal communities was significantly greater than that of the rare fungal communities. Compared with that of fungi, the niche breadth of dominant bacterial communities mainly by homogeneous selection assembly process was significantly higher than that of rare bacterial communities mainly by drift and dispersal limitation assembly process. Rare bacteria dominated the microbial interaction network, and rare keystone bacterial taxa were pivotal to the complexity and stability of the network. Compared with the dominant taxa, the rare bacterial taxa were more sensitive to environmental variables, and the influences of ammonia and pH on the bacterial community and functional characteristics were stronger than any other variables measured. Total carbon and available potassium were the main factors affecting fungal communities and their functional trophic guilds. Ecological function and soil biogeochemical cycling are regulated primarily by rare bacterial taxa. Our study revealed that rare bacteria play a decisive role in soil multifunctionality and tea metabolite generation in high-quality rock tea gardens.
{"title":"Rare taxa of bacteria drive soil microbial community and functional diversity in the characteristic rock tea gardens in southeast China","authors":"Weihong Huang , Qiufang Zhang , Yan Zhou , Ximei Xue , Zhisheng Zheng , Yingjiao Zhang , Jingjing Peng , Junqi Wang","doi":"10.1016/j.rhisph.2025.101177","DOIUrl":"10.1016/j.rhisph.2025.101177","url":null,"abstract":"<div><div>Microorganisms are crucial for supporting the growth of tea plants and influencing their leaf chemical composition and quality, but the community composition and functional characteristics of microorganisms in the soil of high-quality rock tea plants grown in unique environments remain poorly understood. Here, we analysed the community diversity and potential functions of soil microorganisms of authentic rock tea gardens in Wuyishan. Our results revealed that the diversity of the rare bacterial communities was significantly greater than that of the dominant bacterial communities, all unique taxa were rare. However, the diversity of the dominant fungal communities was significantly greater than that of the rare fungal communities. Compared with that of fungi, the niche breadth of dominant bacterial communities mainly by homogeneous selection assembly process was significantly higher than that of rare bacterial communities mainly by drift and dispersal limitation assembly process. Rare bacteria dominated the microbial interaction network, and rare keystone bacterial taxa were pivotal to the complexity and stability of the network. Compared with the dominant taxa, the rare bacterial taxa were more sensitive to environmental variables, and the influences of ammonia and pH on the bacterial community and functional characteristics were stronger than any other variables measured. Total carbon and available potassium were the main factors affecting fungal communities and their functional trophic guilds. Ecological function and soil biogeochemical cycling are regulated primarily by rare bacterial taxa. Our study revealed that rare bacteria play a decisive role in soil multifunctionality and tea metabolite generation in high-quality rock tea gardens.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101177"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107537","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}
Pub Date : 2025-12-01Epub Date: 2025-10-18DOI: 10.1016/j.rhisph.2025.101190
Tamara Valenzuela , Jacquelinne J. Acuña , Haroldo Salvo , Roland Bol , Angela Sessitsch , Milko A. Jorquera
Plant growth–promoting bacteria (PGPB) are widely investigated as tools to mitigate the effects of abiotic stresses in crops; however, their effectiveness under field conditions is still highly variable and sometimes controversial. Consequently, systematic reviews represent a valuable tool for addressing scientific and biotechnological questions. Here, we used the PRISMA guidelines and Scopus database to formulate and answer four relevant questions concerning methodologies and modes of action of PGPB on plants under abiotic stresses. Based on a set of 212 PGPB articles published between 2017 and 2023, our results revealed that PGPB are mostly applied single strain liquid inoculants on seeds (particularly cereals) and typically tested under controlled conditions (growth chamber and greenhouse). Our results also revealed that plant parameters (e.g., physiology and photosynthetic pigments) were typically measured as indicators of the effectiveness of PGPB. In contrast, few studies have investigated the application of PGPB in planta (e.g., germination or flowering stage) under field conditions. The most representative genera of PGPB studied are Bacillus, Pseudomonas and Enterobacter; however, a wide diversity of PGPB taxa (∼60) were also identified as potential PGPB. The main stress conditions to be alleviated by PGPB include drought, salinity and metal toxicity, using diverse action mechanisms, including 1–aminocyclopropane–1–carboxylic acid deaminase activity, tryptophane-induced auxin production, and phosphorus solubilization. In general, our review points to gaps in the adoption of standardized protocols for testing PGPB, universal indicators of efficiency, and the validation of application of a high diversity of PGPB taxa particularly at field level.
{"title":"Systematic review reveals gaps in standardized protocol to determine efficacy of PGPB use in plants grown under abiotic stress conditions at the field level","authors":"Tamara Valenzuela , Jacquelinne J. Acuña , Haroldo Salvo , Roland Bol , Angela Sessitsch , Milko A. Jorquera","doi":"10.1016/j.rhisph.2025.101190","DOIUrl":"10.1016/j.rhisph.2025.101190","url":null,"abstract":"<div><div>Plant growth–promoting bacteria (PGPB) are widely investigated as tools to mitigate the effects of abiotic stresses in crops; however, their effectiveness under field conditions is still highly variable and sometimes controversial. Consequently, systematic reviews represent a valuable tool for addressing scientific and biotechnological questions. Here, we used the PRISMA guidelines and Scopus database to formulate and answer four relevant questions concerning methodologies and modes of action of PGPB on plants under abiotic stresses. Based on a set of 212 PGPB articles published between 2017 and 2023, our results revealed that PGPB are mostly applied single strain liquid inoculants on seeds (particularly cereals) and typically tested under controlled conditions (growth chamber and greenhouse). Our results also revealed that plant parameters (<em>e.g.</em>, physiology and photosynthetic pigments) were typically measured as indicators of the effectiveness of PGPB. In contrast, few studies have investigated the application of PGPB <em>in planta</em> (<em>e.g.</em>, germination or flowering stage) under field conditions. The most representative genera of PGPB studied are <em>Bacillus</em>, <em>Pseudomonas</em> and <em>Enterobacter</em>; however, a wide diversity of PGPB taxa (∼60) were also identified as potential PGPB. The main stress conditions to be alleviated by PGPB include drought, salinity and metal toxicity, using diverse action mechanisms, including 1–aminocyclopropane–1–carboxylic acid deaminase activity, tryptophane-induced auxin production, and phosphorus solubilization. In general, our review points to gaps in the adoption of standardized protocols for testing PGPB, universal indicators of efficiency, and the validation of application of a high diversity of PGPB taxa particularly at field level.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101190"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363392","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}
Pub Date : 2025-12-01Epub Date: 2025-10-30DOI: 10.1016/j.rhisph.2025.101221
Ieva Marija Sokolovaitė , Rasmus Kjøller , Marta Gil-Martínez , Anders Michelsen
Arbuscular mycorrhizal fungi (AMF) engage with plants in one of the most important and ubiquitous mutualisms on Earth. Within plant communities, mineral resources and photosynthates are allegedly relocated from plant to plant through the common mycorrhizal network (CMN). Most studies which investigate resource relocation within CMN have taken a plant-centered approach, but our perspective focuses on the fungal side. We ask how the properties of CMN itself shape the functioning of mycorrhizal symbiosis in terms of inter-plant carbon (C) transfer. Specifically, we inquired whether different levels of mycelial network’s physical density affected the amount of C transported from donor plant into receiver plant. Manipulation of CMN density was achieved by varying fungal inoculum potential by diluting soil from 100 % to 30 % and 5 % of the growing medium. Growth systems were constructed in which two crimson clover plants were grown separated by meshes that only allowed mycelial interconnection but prevented direct root contact. Changes in hyphal density were measured as the intensity of root colonisation, soil hyphal proliferations and shared AMF sequence variants between neighbouring plants. Directional photosynthate distribution was manipulated by shading the receiver plant, and subsequent C fluxes were tracked using 13C labelling. Significantly higher amounts of C (6.7–57.9 %) were transferred from donor to receiver plants in 100 % soil, corresponding to a denser hyphal network, than in 30 % (1.9–11.3 %) or 5 % (1.9 %) soil, corresponding to less dense networks. This suggests that the physical properties of the mycorrhizal system may contribute to the quantitative aspect of nutrient redistribution.
{"title":"Plant-to-plant carbon transfer responds to the density of the arbuscular mycorrhizal mycelial network","authors":"Ieva Marija Sokolovaitė , Rasmus Kjøller , Marta Gil-Martínez , Anders Michelsen","doi":"10.1016/j.rhisph.2025.101221","DOIUrl":"10.1016/j.rhisph.2025.101221","url":null,"abstract":"<div><div>Arbuscular mycorrhizal fungi (AMF) engage with plants in one of the most important and ubiquitous mutualisms on Earth. Within plant communities, mineral resources and photosynthates are allegedly relocated from plant to plant through the common mycorrhizal network (CMN). Most studies which investigate resource relocation within CMN have taken a plant-centered approach, but our perspective focuses on the fungal side. We ask how the properties of CMN itself shape the functioning of mycorrhizal symbiosis in terms of inter-plant carbon (C) transfer. Specifically, we inquired whether different levels of mycelial network’s physical density affected the amount of C transported from donor plant into receiver plant. Manipulation of CMN density was achieved by varying fungal inoculum potential by diluting soil from 100 % to 30 % and 5 % of the growing medium. Growth systems were constructed in which two crimson clover plants were grown separated by meshes that only allowed mycelial interconnection but prevented direct root contact. Changes in hyphal density were measured as the intensity of root colonisation, soil hyphal proliferations and shared AMF sequence variants between neighbouring plants. Directional photosynthate distribution was manipulated by shading the receiver plant, and subsequent C fluxes were tracked using <sup>13</sup>C labelling. Significantly higher amounts of C (6.7–57.9 %) were transferred from donor to receiver plants in 100 % soil, corresponding to a denser hyphal network, than in 30 % (1.9–11.3 %) or 5 % (1.9 %) soil, corresponding to less dense networks. This suggests that the physical properties of the mycorrhizal system may contribute to the quantitative aspect of nutrient redistribution.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101221"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465859","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}
Pub Date : 2025-12-01Epub Date: 2025-11-04DOI: 10.1016/j.rhisph.2025.101224
Jiechen Zhou , Xiang Duan , Jiao Peng , Tiancai Zhu , Yuanhao He , Guoying Zhou , Junang Liu
The temporal dynamics of fertilization effects on Camellia oleifera root-associated bacterial communities remain poorly understood. This study combined 16S rRNA sequencing and PICRUSt2-based functional prediction to assess fertilization impacts across seasons. Two treatments were applied: fertilized plots received microbial organic fertilizer while unfertilized served as controls. Fertilization effects across seasons significantly reshaped species richness, diversity, and evenness, rhizosphere diversity peaked in April then declined, while root communities recovered post-initial suppression. Rhizosphere and root endosphere communities diverged markedly: fertilization enriched Chloroflexi (rhizosphere) and Proteobacteria/Actinobacteriota (roots). At the genus level, fertilization drives spatiotemporally specific shifts in rhizosphere and root endosphere communities, with distinct dominant taxa adapting to seasonal nutrient changes (e.g., Actinospica enrichment in fertilized rhizospheres across seasons) and host-mediated selection, Particularly evident in stronger impacts on endophytic communities in July (peak growth). Seasonal shifts drive structural and functional reorganization of C. oleifera microbial networks. In the rhizosphere, Conexibacter (spring) and Ramlibacter (autumn) emerged as keystone taxa, while summer enriched Massilia and Pajaroellobacter. Root endosphere communities stability relied on Bauldia (year-round connectivity) and Pleomorphomonadaceae (summer), with Sphingomonas-Bdellovibrio modules (autumn). Fertilization drives niche partitioning of rhizosphere-endosphere bacteria in C. oleifera by amplifying community seasonal turnover, keystone taxa mediate this process, providing a theoretical basis for optimizing microbiome functionality through precision nutrient management.
{"title":"Fertilization drives seasonal differentiation and niche partitioning of root-associated bacterial communities in Camellia oleifera","authors":"Jiechen Zhou , Xiang Duan , Jiao Peng , Tiancai Zhu , Yuanhao He , Guoying Zhou , Junang Liu","doi":"10.1016/j.rhisph.2025.101224","DOIUrl":"10.1016/j.rhisph.2025.101224","url":null,"abstract":"<div><div>The temporal dynamics of fertilization effects on <em>Camellia oleifera</em> root-associated bacterial communities remain poorly understood. This study combined 16S rRNA sequencing and PICRUSt2-based functional prediction to assess fertilization impacts across seasons. Two treatments were applied: fertilized plots received microbial organic fertilizer while unfertilized served as controls. Fertilization effects across seasons significantly reshaped species richness, diversity, and evenness, rhizosphere diversity peaked in April then declined, while root communities recovered post-initial suppression. Rhizosphere and root endosphere communities diverged markedly: fertilization enriched <em>Chloroflexi</em> (rhizosphere) and <em>Proteobacteria</em>/<em>Actinobacteriota</em> (roots). At the genus level, fertilization drives spatiotemporally specific shifts in rhizosphere and root endosphere communities, with distinct dominant taxa adapting to seasonal nutrient changes (e.g., <em>Actinospica</em> enrichment in fertilized rhizospheres across seasons) and host-mediated selection, Particularly evident in stronger impacts on endophytic communities in July (peak growth). Seasonal shifts drive structural and functional reorganization of <em>C. oleifera</em> microbial networks. In the rhizosphere, <em>Conexibacter</em> (spring) and <em>Ramlibacter</em> (autumn) emerged as keystone taxa, while summer enriched Massilia and <em>Pajaroellobacter</em>. Root endosphere communities stability relied on <em>Bauldia</em> (year-round connectivity) and <em>Pleomorphomonadaceae</em> (summer), with <em>Sphingomonas-Bdellovibrio</em> modules (autumn). Fertilization drives niche partitioning of rhizosphere-endosphere bacteria in <em>C. oleifera</em> by amplifying community seasonal turnover, keystone taxa mediate this process, providing a theoretical basis for optimizing microbiome functionality through precision nutrient management.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101224"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465857","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}
Pub Date : 2025-12-01Epub Date: 2025-10-28DOI: 10.1016/j.rhisph.2025.101218
Jian Chen , Qingfeng Sun , Ruirui Chen , Zhihao Zhang , Zhen Liu , Gongyou Chen
Bacterial communities play significant roles in desert ecosystems through diverse interactions, including participation in rhizolith formation and establishment of root symbioses, yet related evidence remain limited. Using 16S rRNA amplicon sequencing, diversity metrics and co-occurrence network analyses, this study explored bacterial communities of rhizolith- and root-associated soils in the Tengeri Desert, China, with a focus on their potential role in carbonate precipitation. We identified significant differences in bacterial communities across root/soil types. The co-occurrence network was simpler in root-associated soils compared to bulk soils. Rhizolith-associated soils harbored unique taxa with low alpha diversity but with enriched specialists Propionibacterium, Corynebacterium and Acinetobacter linked to carbonate genesis. Our study provides new insights into plant–microbe–mineral interactions in desert ecosystems.
{"title":"Bacterial communities of rhizolith- and root-associated in the Tengeri Desert, China","authors":"Jian Chen , Qingfeng Sun , Ruirui Chen , Zhihao Zhang , Zhen Liu , Gongyou Chen","doi":"10.1016/j.rhisph.2025.101218","DOIUrl":"10.1016/j.rhisph.2025.101218","url":null,"abstract":"<div><div>Bacterial communities play significant roles in desert ecosystems through diverse interactions, including participation in rhizolith formation and establishment of root symbioses, yet related evidence remain limited. Using 16S rRNA amplicon sequencing, diversity metrics and co-occurrence network analyses, this study explored bacterial communities of rhizolith- and root-associated soils in the Tengeri Desert, China, with a focus on their potential role in carbonate precipitation. We identified significant differences in bacterial communities across root/soil types. The co-occurrence network was simpler in root-associated soils compared to bulk soils. Rhizolith-associated soils harbored unique taxa with low alpha diversity but with enriched specialists <em>Propionibacterium</em>, <em>Corynebacterium</em> and <em>Acinetobacter</em> linked to carbonate genesis. Our study provides new insights into plant–microbe–mineral interactions in desert ecosystems.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101218"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465856","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}
Pub Date : 2025-12-01Epub Date: 2025-10-01DOI: 10.1016/j.rhisph.2025.101201
Argha Sinha, Mohita Nigam, Shilpi Sharma
The necessity to effectively manage drought stress in agriculture is becoming more fundamental as climate change continues to compromise global food security. In plants, drought vitiates their osmotic balance, nutrient acquisition, and photosynthetic performance. Recent advances show that microbiome-mediated rhizosphere engineering can buffer these effects by activating defined physiological pathways in the host. Beneficial soil-dwelling microbes living in close association with roots can enhance drought tolerance via ABA-arbitrated stomatal regulation, osmolyte accumulation, antioxidant enzyme induction, aquaporin-mediated water transport modulation, and root system architecture restructuring. Rhizosphere engineering possesses excellent potential to bypass the limitations associated with conventional bioformulations such as limited persistence and competitive interactions with native microbes. Two complementary strategies dominate this field: designing synthetic microbial communities (SMCs), which stacks functional traits for stabilizing water-use efficiency, and host-mediated microbiome engineering (HMME), which selects adaptive communities through iterative host-driven filtering. While controlled investigations corroborate these processes, translation to field conditions is stalled by ecological variability and lack of systematic trial designs. Moving forward, progress will require systematic mapping of microbial functions to plant drought-response pathways using multi-omics. Besides, there is a need for development of hybrid pipelines that combine top-down and bottom-up microbiome engineering, standardized bioinoculant formulation, delivery, and persistence tracking, and long-term, multi-site validation under realistic agronomic scenarios. In this review, we synthesize mechanistic insights, benchmark current approaches, and outline practical roadmaps for scaling microbiome-based drought mitigation techniques towards producing resilient, climate-smart crops. Utilizing acclimatizable plant-microbiome interactions is of utmost importance for ushering in agricultural sustainability in water-scarce environments.
{"title":"Microbiome-mediated rhizosphere engineering for the alleviation of drought stress: A promising strategy for agricultural sustainability","authors":"Argha Sinha, Mohita Nigam, Shilpi Sharma","doi":"10.1016/j.rhisph.2025.101201","DOIUrl":"10.1016/j.rhisph.2025.101201","url":null,"abstract":"<div><div>The necessity to effectively manage drought stress in agriculture is becoming more fundamental as climate change continues to compromise global food security. In plants, drought vitiates their osmotic balance, nutrient acquisition, and photosynthetic performance. Recent advances show that microbiome-mediated rhizosphere engineering can buffer these effects by activating defined physiological pathways in the host. Beneficial soil-dwelling microbes living in close association with roots can enhance drought tolerance via ABA-arbitrated stomatal regulation, osmolyte accumulation, antioxidant enzyme induction, aquaporin-mediated water transport modulation, and root system architecture restructuring. Rhizosphere engineering possesses excellent potential to bypass the limitations associated with conventional bioformulations such as limited persistence and competitive interactions with native microbes. Two complementary strategies dominate this field: designing synthetic microbial communities (SMCs), which stacks functional traits for stabilizing water-use efficiency, and host-mediated microbiome engineering (HMME), which selects adaptive communities through iterative host-driven filtering. While controlled investigations corroborate these processes, translation to field conditions is stalled by ecological variability and lack of systematic trial designs. Moving forward, progress will require systematic mapping of microbial functions to plant drought-response pathways using multi-omics. Besides, there is a need for development of hybrid pipelines that combine top-down and bottom-up microbiome engineering, standardized bioinoculant formulation, delivery, and persistence tracking, and long-term, multi-site validation under realistic agronomic scenarios. In this review, we synthesize mechanistic insights, benchmark current approaches, and outline practical roadmaps for scaling microbiome-based drought mitigation techniques towards producing resilient, climate-smart crops. Utilizing acclimatizable plant-microbiome interactions is of utmost importance for ushering in agricultural sustainability in water-scarce environments.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101201"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268074","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}
Rhizosphere-associated fungi are recognized as a highly promising and sustainable approach for cultivating high-yielding disease-resistant crops. However, identifying beneficial rhizosphere fungi is a critical step toward achieving optimal protection. In this study, we evaluated 75 rhizosphere-associated fungi isolated from the rhizosphere soil of healthy native muskmelon (Cucumis melo) plants for their in vitro antagonistic activity against Stagonosporopsis cucurbitacearum, the pathogen causing gummy stem blight in muskmelon. Among the 75 isolates, three isolates, Asp-MRF54, Tri-MRF47, and Pen-MRF18, exhibited the highest inhibition rates of 81.9 %, 69.2 %, and 67.6 % respectively, against S. cucurbitacearum mycelial growth. Based on the ITS sequence, the three isolates were identified as Aspergillus niger (Asp-MRF54), Trichoderma virens (Tri-MRF47), and Penicillium italicum (Pen-MRF18). Furthermore, muskmelon seeds primed with Pen-MRF18 and Tri-MRF47 exhibited significantly higher germination rate of 86 % and 81 % and seedling vigor of 1987 and 1955, respectively. Pen-MRF18-primed plants exhibited significant growth improvements, with a 23.8 % increase in chlorophyll content and enhanced nutrient uptake, including nitrogen (33.8 %), phosphorus (42.2 %), and potassium (56.9 %), compared to Tri-MRF47-primed and untreated control plants. Additionally, Pen-MRF18-primed plants demonstrated the highest disease protection of 71.09 % against S. cucurbitacearum, followed by Tri-MRF47-treated plants with 77.5 % protection, compared to non-primed pathogen-inoculated plants. Furthermore, both Pen-MRF18 and Tri-MRF47 treatments induced a significant increase in the accumulation of callose, lignin, phenols, and hydrogen peroxide under both control and pathogen inoculation conditions, indicating an activated cellular defense response. In Pen-MRF18-treated plants challenged with a pathogen, enzymatic activities followed a consistent pattern, with phenylalanine ammonia-lyase and lipoxygenase peaking at 48 h, polyphenol oxidase at 24 h, and peroxidase at 12 h, compared with Tri-MRF47-treated plants. This study demonstrates that Pen-MRF18-primed muskmelon plants exhibit the highest resistance to S. cucurbitacearum infection, followed by those primed with Tri-MRF47, through the activation of integrated cellular, biochemical, and antioxidant defense pathways.
{"title":"Rhizosphere fungi mediated priming reinforces cellular and biochemical defenses against gummy stem blight in muskmelon","authors":"Sindhu Geemarahalli Mahadevaswamy , Savitha De Britto , Praveen Satapute , Mostafa Abdelrahman , Lam-Son Phan Tran , Kazunori Sasaki , Kestur Nagaraj Amruthesh , Sudisha Jogaiah","doi":"10.1016/j.rhisph.2025.101236","DOIUrl":"10.1016/j.rhisph.2025.101236","url":null,"abstract":"<div><div>Rhizosphere-associated fungi are recognized as a highly promising and sustainable approach for cultivating high-yielding disease-resistant crops. However, identifying beneficial rhizosphere fungi is a critical step toward achieving optimal protection. In this study, we evaluated 75 rhizosphere-associated fungi isolated from the rhizosphere soil of healthy native muskmelon (<em>Cucumis melo</em>) plants for their <em>in vitro</em> antagonistic activity against <em>Stagonosporopsis cucurbitacearum</em>, the pathogen causing gummy stem blight in muskmelon. Among the 75 isolates, three isolates, Asp-MRF54, Tri-MRF47, and Pen-MRF18, exhibited the highest inhibition rates of 81.9 %, 69.2 %, and 67.6 % respectively, against <em>S. cucurbitacearum</em> mycelial growth. Based on the ITS sequence, the three isolates were identified as <em>Aspergillus niger</em> (Asp-MRF54), <em>Trichoderma virens</em> (Tri-MRF47), and <em>Penicillium italicum</em> (Pen-MRF18). Furthermore, muskmelon seeds primed with Pen-MRF18 and Tri-MRF47 exhibited significantly higher germination rate of 86 % and 81 % and seedling vigor of 1987 and 1955, respectively. Pen-MRF18-primed plants exhibited significant growth improvements, with a 23.8 % increase in chlorophyll content and enhanced nutrient uptake, including nitrogen (33.8 %), phosphorus (42.2 %), and potassium (56.9 %), compared to Tri-MRF47-primed and untreated control plants. Additionally, Pen-MRF18-primed plants demonstrated the highest disease protection of 71.09 % against <em>S. cucurbitacearum</em>, followed by Tri-MRF47-treated plants with 77.5 % protection, compared to non-primed pathogen-inoculated plants. Furthermore, both Pen-MRF18 and Tri-MRF47 treatments induced a significant increase in the accumulation of callose, lignin, phenols, and hydrogen peroxide under both control and pathogen inoculation conditions, indicating an activated cellular defense response. In Pen-MRF18-treated plants challenged with a pathogen, enzymatic activities followed a consistent pattern, with phenylalanine ammonia-lyase and lipoxygenase peaking at 48 h, polyphenol oxidase at 24 h, and peroxidase at 12 h, compared with Tri-MRF47-treated plants. This study demonstrates that Pen-MRF18-primed muskmelon plants exhibit the highest resistance to <em>S. cucurbitacearum</em> infection, followed by those primed with Tri-MRF47, through the activation of integrated cellular, biochemical, and antioxidant defense pathways.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"36 ","pages":"Article 101236"},"PeriodicalIF":3.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693517","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}