RhizospherePub Date : 2025-06-25DOI: 10.1016/j.rhisph.2025.101128
Amrit Kumar Mishra , Syed Hilal Farooq
{"title":"Short-term nitrogen enrichment induces sulfide intrusion in tropical oligotrophic seagrass meadows","authors":"Amrit Kumar Mishra , Syed Hilal Farooq","doi":"10.1016/j.rhisph.2025.101128","DOIUrl":"10.1016/j.rhisph.2025.101128","url":null,"abstract":"<div><div>Sediment sulfide stress on seagrasses is related to anthropogenic nutrient enrichment and substrate type (e.g., sandy or muddy). This study investigated if anthropogenic nitrogen (N) enrichment resulted in sulfide stress in tropical seagrass <em>Thalassia hemprichii</em> inhabiting sandy habitats. Anthropogenic input resulted in 3.4-fold increase in sediment δ<sup>15</sup>N, and increase in the sediment organic matter and fine fraction content. N enrichment increased sediment sulfur (S) content and caused higher δ<sup>34</sup>S depletion in sediment. Higher N availability contributed towards significant increase of <em>T. hemprichii</em> shoot density and leaf biomass. Conversely, it reduced the root biomass, and root branching index coinciding with depleted root δ<sup>34</sup>S values. Additionally, in the sandy sediments the sediment Fe levels were lower than pristine conditions, suggesting Fe limitation and subsequent increased sediment sulfide intrusion into <em>T. hemprichii</em> roots. This highlights <em>T. hemprichii</em> growing in sandy sediments with low Fe levels are more prone to sulfide intrusion under N enrichment.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101128"},"PeriodicalIF":3.4,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490303","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}
RhizospherePub Date : 2025-06-24DOI: 10.1016/j.rhisph.2025.101129
Ajay Madhusudan Sorty , Athanasios Zervas , Vaidotas Kisielius , Chandana Pandey , Rosanna C. Hennessy , Tue K. Nielsen , Pedro N. Carvalho , Thomas G. Roitsch , Peter Stougaard
{"title":"Physiological and metabolic effects of a transposon-mediated mutation in the glutamate synthase gene, gltB, of plant-beneficial, cytokinin-producing Pseudomonas hormoni G20-18T","authors":"Ajay Madhusudan Sorty , Athanasios Zervas , Vaidotas Kisielius , Chandana Pandey , Rosanna C. Hennessy , Tue K. Nielsen , Pedro N. Carvalho , Thomas G. Roitsch , Peter Stougaard","doi":"10.1016/j.rhisph.2025.101129","DOIUrl":"10.1016/j.rhisph.2025.101129","url":null,"abstract":"<div><div><em>Pseudomonas</em> species are well-studied Gram-negative bacteria involved in plant-microbe interactions, particularly in the rhizosphere and phyllosphere, where they enhance plant growth and resilience under stress. A key trait of these bacteria is the production of plant hormones, which help plants resist biotic and abiotic stresses. <em>Pseudomonas hormoni</em> G20-18<sup>T</sup> (previously denoted <em>P. fluorescens</em> G20-18) is a beneficial bacterium that produces cytokinins (CKs), improving plant resistance to pathogens and drought. A mutant strain, CNT1, shows reduced CK levels, but the mechanisms behind this reduction and its effects on plant interactions are not fully understood. Genome sequencing of the mutant revealed insertion of a transposon in the glutamate synthase, large subunit gene (<em>glt</em>B). This mutation led to reduced growth, survival, and biofilm formation at 25 °C and pH 5.0. The carbon substrate utilization pattern also differed from the wild type, and applying exogenous CKs failed to restore the wild type effects, suggesting a broader impact on metabolism. Untargeted metabolomics confirmed the global influence of the <em>glt</em>B mutation, also affecting CK and auxin expression. These findings highlight the significant role of the <em>glt</em>B gene in regulating bacterial physiology and plant-beneficial interactions.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101129"},"PeriodicalIF":3.4,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490543","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}
RhizospherePub Date : 2025-06-23DOI: 10.1016/j.rhisph.2025.101125
Siyu Wen, Xinying Hao, Junyang Song
{"title":"The characteristics of rhizosphere and endophytic fungi in two wild Cymbidium orchid species from the Qinling Mountains","authors":"Siyu Wen, Xinying Hao, Junyang Song","doi":"10.1016/j.rhisph.2025.101125","DOIUrl":"10.1016/j.rhisph.2025.101125","url":null,"abstract":"<div><div>Wild orchids hold significant ornamental value, yet current research focuses on germplasm resources, lacks systematic studies on the native habitats and root endophytic fungi of species like <em>Cymbidium goeringii</em> and <em>Cymbidium faberi</em>. This study used fungal sequencing to explore the fungal community in the native habitats of these orchids in the Qinling Mountains. We compared rhizosphere and non-rhizosphere soil fungi and assessed the ecological functions of dominant fungal-groups. The impact of soil chemical indicators on fungal-communities was also analyzed. Endophytic fungi were isolated from orchid roots to evaluate their growth-promoting potential. Results showed that Ascomycota and Basidiomycota were dominant in the rhizosphere of both species. Symbiotic nutrient and pathology-saprophytic-symbiotic mixed fungal types were predominant, accounting for 56.76 % and 79.17 % of the fungal-community, respectively. Soil factors like total-nitrogen and ammonium-nitrogen correlated strongly with these communities. 17 fungal strains were isolated, with strains HL01, HL02, HL06, and HL17 exhibiting indole-3-acetic acid (IAA) production, nitrogen fixation, and phosphorus solubilization. Strain HL08 showed IAA production, nitrogen fixation, and potassium solubilization. These strains contribute to enriching growth-promoting fungal resources for both species. This research provides a theoretical and scientific basis for the conservation, artificial cultivation, and breeding of <em>Cymbidium goeringii</em> and <em>Cymbidium faberi</em>.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101125"},"PeriodicalIF":3.4,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480704","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}
RhizospherePub Date : 2025-06-20DOI: 10.1016/j.rhisph.2025.101120
Ceyda Kural-Rendon , Natalie E. Ford , Kara Hooser , Maggie R. Wagner
{"title":"Intraspecific plant-soil feedbacks alter root traits in a perennial grass","authors":"Ceyda Kural-Rendon , Natalie E. Ford , Kara Hooser , Maggie R. Wagner","doi":"10.1016/j.rhisph.2025.101120","DOIUrl":"10.1016/j.rhisph.2025.101120","url":null,"abstract":"<div><div>Drought is a common stressor faced by plants and their associated microbiomes. Projected climate data point toward an increase in the severity and frequency of extreme precipitation events, such as droughts. Previous research has shown that long-term exposure to drought can shape plants' genomes, resulting in genetic variation for drought tolerance. We hypothesized that these genetic changes also affect patterns of microbial colonization in the rhizosphere, potentially feeding back to influence plant drought responses. Here, we tested 33 soils conditioned by 33 genotypes of <em>Tripsacum dactyloides</em> (eastern gamagrass) that originated from native populations across a precipitation gradient in the southern plains of the United States. We used these 33 soils as inocula for a fully factorial experiment to test the responses of conspecific plants to the differentially conditioned soils under drought or well-watered conditions. Variation in aboveground traits such as shoot length, weight, and root-to-shoot ratios was primarily explained by watering treatment. However, many belowground traits, such as root anatomical and architectural traits, were more likely to be affected by the genotype of the conditioning plant. Of the traits we measured, only aerenchyma area was affected by the interaction between current watering treatment and genotype of the conditioning plant. Ultimately, both the current watering treatment and conditioning plant genotype altered plant physiological traits and the associated microbiome. The differential intraspecies plant-soil feedback dynamics driven by plant local adaptation will be key to understanding future plants’ responses to rapidly shifting climates, in both restoration projects and agricultural systems.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101120"},"PeriodicalIF":3.4,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480716","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}
RhizospherePub Date : 2025-06-20DOI: 10.1016/j.rhisph.2025.101126
Ram L. Ray , Kusalika M. Kularathna , Richard W. Griffin , Nimal Abeysingha , Selamawit Woldesenbet , Almoutaz Elhassan , Ripendra Awal , Ali Fares
{"title":"Enhancing plant and soil health through organic amendments in a humid environment","authors":"Ram L. Ray , Kusalika M. Kularathna , Richard W. Griffin , Nimal Abeysingha , Selamawit Woldesenbet , Almoutaz Elhassan , Ripendra Awal , Ali Fares","doi":"10.1016/j.rhisph.2025.101126","DOIUrl":"10.1016/j.rhisph.2025.101126","url":null,"abstract":"<div><div>Root distribution and soil characteristics significantly influence plant growth. Understanding the distribution of roots is essential for optimizing crop growth, soil health, and irrigation management. This research aimed to study the effects of type and rate of organic amendments (OA) on selected soil properties, root density, and distribution of roots in collard greens (<em>Brassica oleracea</em> var. <em>viridis</em>). A field experiment was conducted at Prairie View A&M University research farm in two seasons (October 2017 to April 2019). Three OA types, chicken manure (CM), dairy manure (DM), & milorganite (MG), were applied as treatments, including a control, to nine randomly selected plots (Total 9∗3 = 27 + 9 controls = 36 plots). One week before planting, these treatments were applied at three different rates as 168, 336, and 672 N-Kg/ha. Soil samples were collected from two depths (0–15 and 16–30 cm) to analyze the soil characteristics and quantify the root density and distribution of roots at the end of the growing season. Results showed that DM significantly increased total soil organic carbon (TOC) across all application rates and seasons. Bulk density in the surface layer decreased with OA application after 1.5 years. MG had the lowest root density and distribution of roots, possibly due to its slower nutrient release dynamics. The study determined that CM exhibited superior performance among the tested OA, resulting in enhanced root density and improved root distribution patterns, even at lower application rates (5.6 Mg/ha). These findings support the sustainable soil management practices by selecting appropriate soil amendments and application rates.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101126"},"PeriodicalIF":3.4,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471224","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}
RhizospherePub Date : 2025-06-19DOI: 10.1016/j.rhisph.2025.101123
Xu-Guang Gao , Ji-Peng Wang , Xian-Wei Li , Shangqi Ge , Huan-Xiang Qiu , Mo-Han Bai
{"title":"Combined effects of tree canopy and root systems on soil hydraulic properties: A field monitoring of a Populus alba","authors":"Xu-Guang Gao , Ji-Peng Wang , Xian-Wei Li , Shangqi Ge , Huan-Xiang Qiu , Mo-Han Bai","doi":"10.1016/j.rhisph.2025.101123","DOIUrl":"10.1016/j.rhisph.2025.101123","url":null,"abstract":"<div><div>Canopy and roots play crucial roles in regulating soil hydraulic processes, yet their combined effects on soil hydraulic properties remain poorly understood. In this study, the combined effects of canopy interception, transpiration, and root activity on soil hydraulic properties were investigated through field monitoring of a <em>Populus alba</em>. The results showed that the contact angle on the adaxial and abaxial leaf surfaces decreased from 104.3° to 75.1° and from 125.8° to 83.7° during the growth period, respectively, resulting in a significant increase in the canopy interception ratio. During rainfall, canopy interception and root water uptake limited increases in soil water content and decreases in matric suction beneath the canopy, but this effect diminished with increasing rainfall. Following rainfall, transpiration-induced root water uptake accelerated the dissipation of soil water content and the recovery of soil matric suction, exhibiting exponential and logarithmic relationships with leaf area index (LAI), respectively. The influence of canopy and roots on soil water and suction is predominantly observed during the high LAI period from June to October and was primarily within 150 cm soil depth. Although root activity increased soil saturated hydraulic conductivity by improving porosity, canopy interception reduced unsaturated hydraulic conductivity under high soil suction conditions (>60 kPa) during early rainfall. This study highlights the critical role of the combined effects of canopy and roots in regulating soil water content, suction, and permeability, which have important implications for understanding ecosystem hydrological processes and guiding ecological restoration practices.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101123"},"PeriodicalIF":3.4,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338771","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}
RhizospherePub Date : 2025-06-16DOI: 10.1016/j.rhisph.2025.101121
A.K. Lavanya , Koli Bhavya , Aditi Kundu , K.V. Vikram , G.K. Krishna , Viswanathan Chinnusamy , J.C. Padaria , N.M. Alam , Sangeeta Paul
{"title":"Bacillus sp. MRD-17 volatiles promote mustard (Brassica juncea L.) seedling growth under osmotic and nutrient stress","authors":"A.K. Lavanya , Koli Bhavya , Aditi Kundu , K.V. Vikram , G.K. Krishna , Viswanathan Chinnusamy , J.C. Padaria , N.M. Alam , Sangeeta Paul","doi":"10.1016/j.rhisph.2025.101121","DOIUrl":"10.1016/j.rhisph.2025.101121","url":null,"abstract":"<div><div>The influence of bacterial volatile organic compounds (VOCs) on plant growth has been investigated, but their effects on seedling growth under osmotic and nutrient stress are not well understood. Inoculation with <em>Bacillus</em> sp. MRD-17 has been shown to effectively alleviate drought and heat stress. This study aimed to investigate the effects of <em>Bacillus</em> sp. MRD-17 VOCs on biometric and physiological attributes of mustard seedlings under osmotic and nutrient stress, along with the profiling of rhizobacterial VOCs. In a hydroponic experiment, seedlings were given optimal and low dosages (macro-nutrients NPK stress) of Hoagland nutrient solution, while osmotic stress was induced using 20 % PEG-6000 (−0.491 Mpa). Rhizobacterium was then added to the setup without direct contact with the seedlings. Seedlings exposed to rhizobacterial VOCs under osmotic and dual stress, exhibited improved plumule length (50 % and 17 %, respectively), biomass, radicle architecture, carotenoids, osmolytes and antioxidant enzymes, phosphorus (27 % and 36 %, respectively) and potassium (49 % and 53 %, respectively) contents as well as reduced lipid peroxidation (47 % and 52 %, respectively). Under nutrient stress, rhizobacterial VOCs improved fresh and dry weight (36 % and 56 %, respectively), carotenoids, glycine betaine and antioxidant enzymes. Additionally, acid phosphatase (EC 3.1.3.2) activity (30 %) was increased under osmotic stress, while nitrogen content, nitrate reductase, and glutamine synthetase levels remained unaffected. n-decane (C10), a predominant volatile compound, was identified in the rhizobacterial culture broth as a possible factor promoting seedling growth. Thus, our findings highlighted the potential of bacterial VOCs to enhance plant osmotic and nutrient stress tolerance and promote seedling growth.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101121"},"PeriodicalIF":3.4,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144306409","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":"Root traits and root-rhizosphere interactions are overlooked players in the plant acclimation to heat stress","authors":"Jérémy Delamare , Sophie Brunel-Muguet , Mélanie Bressan , Stéphane Firmin , Claire Prigent-Combaret , Emmanuelle Personeni","doi":"10.1016/j.rhisph.2025.101124","DOIUrl":"10.1016/j.rhisph.2025.101124","url":null,"abstract":"<div><div>On-going climate change has become a major concern for maintaining plant based-ecosystem services, thus accelerating our need to get a broader knowledge of the plant responses, including the root system and its interactions with the rhizosphere. Indeed, a better understanding of the plant-rhizomicrobiome interactions is crucial to further prospect impacting solutions for food security worldwide. The impacts of heat stress, resulting from increased air temperatures, are mainly studied at the level of the aerial plant parts. However, roots are sensitive organs which can also be impacted by heat. Indeed, the effects on the photosynthetic plant parts cause alterations on plant C allocation, thus contributing to modifications of root C accumulation in root and C exudation. These shifts in the root system functions change the composition of exudates and generate modifications of the soil microbial communities’ compositions and activities. So far, very few studies were dedicated to the analysis of heat stress on the root system and even less on root exudation. In the same way, the links between the functions of the root system and the soil microbial communities in heat stress conditions have been overlooked. However, plants are able to develop strategies to cope with heat stress through the root system functions and its interactions with the soil microbial communities. It has been demonstrated that the root system does not just endure heat stress but it can be a keystone for enabling the plant to cope with heat stress, via the modulation of the root morphology and the selection of useful microorganisms for the stress tolerance. Finally, root responses to heat stress, together with changes in aerial plant parts and the rhizomicrobiome interactions must be considered to improve our understanding of the plant responses and drive novel directions to face climate change.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"35 ","pages":"Article 101124"},"PeriodicalIF":3.4,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480717","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}
RhizospherePub Date : 2025-06-01DOI: 10.1016/j.rhisph.2025.101112
Xiaoxing Li , Yupeng Liu , Ying Yang , Ruyi Zhang , Ying Zhou , Jiachun Zhang , Hao Zhang
{"title":"Study on ecological factors influencing growth and quality of newly developed Bletilla striata fibrous roots","authors":"Xiaoxing Li , Yupeng Liu , Ying Yang , Ruyi Zhang , Ying Zhou , Jiachun Zhang , Hao Zhang","doi":"10.1016/j.rhisph.2025.101112","DOIUrl":"10.1016/j.rhisph.2025.101112","url":null,"abstract":"<div><div>The fibrous roots of <em>Bletilla striata</em> are typically non-essential parts of the plant, yet studies have shown that they contain the same active components as the tubers, exhibiting even stronger antioxidant properties, making them promising for medicinal applications. As the foundational material for traditional Chinese medicine in both treatment and disease prevention, the yield and quality of medicinal products are directly linked to their clinical efficacy. The growth and quality of such medicinal plants are shaped by various environmental factors. This study focuses on newly grown fibrous roots of <em>B. striata</em> from three distinct regions. We analyzed their growth traits, physical characteristics, bioactive components, antioxidant properties, overall quality, growth environment, soil fertility, and microbial characteristics to determine how these factors collectively influence the growth and quality of <em>B. striata</em> fibrous roots across these regions. The growth traits, physical quality, total phenolic content, and antioxidant activity of <em>B. striata</em> fibrous roots differed significantly among regions. Yunyan District exhibited the highest polysaccharide content (4.42 %), while Shibing County showed the highest militarine concentration (4.57 %). The highest total phenol content (8.39 mg/g) was recorded in Bozhou District. Principal component analysis indicated that fibrous roots from the Yunyan area exhibited a notably higher comprehensive quality than those from Bozhou. Mantel's analysis further revealed that climatic factors primarily affected root growth characteristics, while soil fertility indicators influenced quality accumulation in the roots. Among soil microorganisms, only bacteria significantly promoted the accumulation of polysaccharides and total phenolics in the fibrous roots.</div></div><div><h3>Conclusion</h3><div>This study provides a reference for the resource potential of <em>B. striata</em> fibrous roots, offering insights into the intricate relationships between ecological factors and the medicinal properties of artificially cultivated medicinal plants.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"34 ","pages":"Article 101112"},"PeriodicalIF":3.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204194","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}
RhizospherePub Date : 2025-06-01DOI: 10.1016/j.rhisph.2025.101115
Felipe E. Sepúlveda Olea , Ian T. Burke , Robert D. Hancock , Simon D.A. Pont , Douglas I. Stewart
{"title":"Upregulating of organic acids in contrasting plant species results in moderation of high pH stress","authors":"Felipe E. Sepúlveda Olea , Ian T. Burke , Robert D. Hancock , Simon D.A. Pont , Douglas I. Stewart","doi":"10.1016/j.rhisph.2025.101115","DOIUrl":"10.1016/j.rhisph.2025.101115","url":null,"abstract":"<div><div>Development of vegetative cover on the surface of polluted waste deposits provides a physical protective layer and an input of organic compounds via root exudation. The monocot yorkshire fog (<em>Holcus lanatus</em>) and eudicot red clover (<em>Trifolium pratense</em>) are plant species that have been observed to grow successfully in alkaline waste, managed with phytostabilization. In this work the effects of pH-stress conditions (pH ∼10) on root exudation of both these species is studied in a hydroponic set up. Both species, when exposed to stress conditions, were able to neutralize the pH in the collection solution, with a reduction of ∼2 pH units. For both yorkshire fog and red clover, the net exudation had no statistical difference between non-stressed and pH-stressed conditions (263 vs 220 μg DOC (g-root)<sup>−1</sup>(hrs)<sup>−1</sup> for yorkshire fog and 158 vs 118 μg DOC (g-root)<sup>−1</sup>(hrs)<sup>−1</sup> for red clover). GC-MS analysis of the exudate solutions, however, shows a shift from a sugars and sugar alcohols-dominated exudate solution in non-stressed conditions, to an exudate solution with upregulated organic acids in pH stressed yorkshire fog and organic acids plus amino acids in red clover. These results show a similar stress response for these two species, contrary to the general assumption that grass species are less efficient than eudicots in producing organic acids in response to stress. The prevalence of organic acids in exudates under stress conditions, could favour metal and nutrient mobilization in growth substrates, though the lack of an increase in overall exudation limits the extent of their potential impact.</div></div>","PeriodicalId":48589,"journal":{"name":"Rhizosphere","volume":"34 ","pages":"Article 101115"},"PeriodicalIF":3.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221257","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}