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1.
Sci Total Environ ; 940: 173663, 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-38823714

RESUMO

In a mixed forest, certain plants can release allelochemicals that exert allelopathic effects on neighboring plants, thereby facilitating interspecific coexistence of two species. Previous studies have demonstrated that allelochemicals released from Ficus carica Linn. roots in mixed forest of F. carica and Taxus cuspidata Sieb. et Zucc. has phase characteristics over time, which can improve the soil physicochemical properties, enzyme activity and microbial diversity, thus promoting the growth of T. cuspidata. Based on the irrigation of exogenous allelochemicals, changes in soil fertility (soil physical and chemical properties, soil enzyme activity and soil microelement content) were observed in response to variations in allelochemicals during five phases of irrigation: initial disturbance phase (0-2 d), physiological compensation phase (2-8 d), screening phase (8-16 d), restore phase (16-32 d) and maturity phase (32-64 d), which was consistent with the response of soil microorganisms. The allelopathic response of growth physiological indexes of T. cuspidata, however, exhibited a slight lag behind the soil fertility, with distinct phase characteristics becoming evident on the 4th day following irrigation of allelochemicals. The findings demonstrated that the allelochemicals released by the root of F. carica induced a synergistic effect on soil fertility and microorganisms, thereby facilitating the growth of T. cuspidata. This study provides a comprehensive elucidation of the phased dynamic response-based allelopathic mechanism employed by F. carica to enhance the growth of T. cuspidata, thus establishing a theoretical basis for optimizing forest cultivation through allelopathic pathways.


Assuntos
Ficus , Feromônios , Raízes de Plantas , Taxus , Taxus/fisiologia , Alelopatia , Solo/química , Microbiologia do Solo , Exsudatos de Plantas
2.
Nat Commun ; 15(1): 5125, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879580

RESUMO

The plant health status is determined by the interplay of plant-pathogen-microbiota in the rhizosphere. Here, we investigate this tripartite system focusing on the pathogen Fusarium oxysporum f. sp. lycopersici (FOL) and tomato plants as a model system. First, we explore differences in tomato genotype resistance to FOL potentially associated with the differential recruitment of plant-protective rhizosphere taxa. Second, we show the production of fusaric acid by FOL to trigger systemic changes in the rhizosphere microbiota. Specifically, we show this molecule to have opposite effects on the recruitment of rhizosphere disease-suppressive taxa in the resistant and susceptible genotypes. Last, we elucidate that FOL and fusaric acid induce changes in the tomato root exudation with direct effects on the recruitment of specific disease-suppressive taxa. Our study unravels a mechanism mediating plant rhizosphere assembly and disease suppression by integrating plant physiological responses to microbial-mediated mechanisms in the rhizosphere.


Assuntos
Ácido Fusárico , Fusarium , Microbiota , Doenças das Plantas , Exsudatos de Plantas , Raízes de Plantas , Rizosfera , Solanum lycopersicum , Ácido Fusárico/metabolismo , Fusarium/patogenicidade , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Solanum lycopersicum/microbiologia , Solanum lycopersicum/metabolismo , Doenças das Plantas/microbiologia , Exsudatos de Plantas/metabolismo , Microbiologia do Solo , Resistência à Doença , Genótipo
3.
Ying Yong Sheng Tai Xue Bao ; 35(4): 1064-1072, 2024 Apr 18.
Artigo em Chinês | MEDLINE | ID: mdl-38884241

RESUMO

Transpiration is a significant part of water cycle in forest ecosystems, influenced by meteorological factors and potentially constrained by soil moisture. We used Granier-type thermal dissipation probes to monitor xylem sap flow dynamics of three tree species (Quercus liaotungensis, Platycladus orientalis, and Robinia pseudoacacia) in a semi-arid loess hilly region, and to continuously monitor the key meteorological factors and soil water content (SWC). We established the SWC thresholds delineating soil moisture-limited and -unlimited sap flow responses to transpiration drivers. The results showed that mean sap flux density (Js) of Q. liaotungensis and R. pseudoacacia was significantly higher during period with higher soil moisture compared to lower soil moisture, while the difference in Js for P. orientalis between the two periods was not significant. We used an exponential saturation function to fit the relationship between the Js of each tree species and the integrated transpiration variable (VT) which reflected solar radiation and vapor pressure deficit. The difference in the fitting curve parameters indicated that there were distinct response patterns between Js and VT under different soil moisture conditions. There was a threshold in soil moisture limitation on sap flow for each species, which was identified as 0.129 m3·m-3 for Q. liaotungensis, 0.116 m3·m-3 for P. orientalis, and 0.108 m3·m-3 for R. pseudoacacia. Below the thresholds, Js was limited by soil moisture. Above these points, the normalized sensitivity index (NSI) for Q. liaotungensis and P. orientalis reached saturation, while that of R. pseudoacacia did not reach saturation but exhibited a significant reduction in moisture limitation. Among the three species, P. orientalis was the most capable of overcoming soil moisture constraints.


Assuntos
Transpiração Vegetal , Solo , Árvores , Água , Solo/química , Água/metabolismo , Água/análise , Árvores/crescimento & desenvolvimento , Árvores/fisiologia , Árvores/metabolismo , China , Quercus/fisiologia , Quercus/crescimento & desenvolvimento , Quercus/metabolismo , Ecossistema , Robinia/fisiologia , Robinia/crescimento & desenvolvimento , Robinia/metabolismo , Florestas , Xilema/fisiologia , Xilema/metabolismo , Exsudatos de Plantas/metabolismo
4.
Sci Rep ; 14(1): 11274, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760388

RESUMO

Soil sickness a severe problem in tobacco production, leading to soil-borne diseases and reduce in tobacco yield. This occurs as a result of the interaction between root exudates and rhizosphere microorganisms, which is however, little studied until now. By combining the field investigation and pot experiment, we found the output yield consistently decreased during the first 10 years of continuous cropping in a tobacco field, but increased at the 15th year (15Y). The root exudate and rhizosphere bacterial community was further analyzed to reveal the underlying mechanism of the suppressive soil formation. Root exudate of 15Y tobacco enriched in amino acids and derivatives, while depleted in the typical autotoxins including phenolic acids and alkaloids. This was correlated to the low microbial diversity in 15Y, but also the changes in community composition and topological properties of the co-occurrence network. Especially, the reduced autotoxins were associated with low Actinobacteria abundance, low network complexity and high network modularity, which significantly correlated with the recovered output yield in 15Y. This study revealed the coevolution of rhizosphere microbiota and root exudate as the soil domesticated by continuous cropping of tobacco, and indicated a potential role of the autotoxins and theirs effect on the microbial community in the formation of suppressive soil.


Assuntos
Microbiota , Nicotiana , Raízes de Plantas , Rizosfera , Microbiologia do Solo , Nicotiana/microbiologia , Nicotiana/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Exsudatos de Plantas/metabolismo , Solo/química
5.
Zhongguo Zhong Yao Za Zhi ; 49(8): 2128-2137, 2024 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-38812228

RESUMO

The rhizosphere is an important place for material exchange between medicinal plants and soil. Root exudates are the medium of material and signal exchange between plants and soil and are the key factors in the regulation of rhizosphere microecology. Rhizosphere microorganisms are an important part of the rhizosphere microecology of medicinal plants, and the interaction between root exudates and rhizosphere microorganisms has an important influence on the growth and quality formation of medicinal plants. Rational utilization of the interaction between root exudates and rhizosphere microorganisms of medicinal plants is one of the important ways to ensure the healthy growth of medicinal plants and promote the development of ecological planting of Chinese medicinal materials. In the paper, the research status of root exudates and rhizosphere microorganisms of medicinal plants in recent years was summarized. The interaction mechanism between root exudates and rhizosphere microorganisms of medicinal plants, as well as the influence of rhizosphere microorganisms on the growth of medicinal plants, were analyzed. In addition, the advantages and promoting effects of intercropping ecological planting mode on rhizosphere microecology of medicinal plants and quality improvement of Chinese medicinal materials were explained, providing a good basis for the study of the interaction among medicinal plants, microorganisms, and soil. Furthermore, it could produce important theoretical and practical significance for the ecological planting and sustainable utilization of medicinal plants.


Assuntos
Raízes de Plantas , Plantas Medicinais , Rizosfera , Microbiologia do Solo , Plantas Medicinais/metabolismo , Plantas Medicinais/microbiologia , Plantas Medicinais/química , Plantas Medicinais/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Bactérias/metabolismo , Bactérias/classificação , Exsudatos de Plantas/metabolismo , Exsudatos de Plantas/química
6.
Appl Environ Microbiol ; 90(6): e0058924, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38814059

RESUMO

Dormant microsclerotia play a vital role in the survival and spread of Verticillium longisporum, as they can stay viable in the soil and maintain their infectivity for many years. In our previous work, we revealed that soil bacterial volatiles are a key inhibitory factor causing microsclerotia dormancy in the soil. In this study, we further demonstrate that root exudates collected from both host and non-host plants can effectively rescue microsclerotia from bacterial suppression and initiate germination. To identify the specific compounds in root exudates responsible for microsclerotia germination, we fractionated the collected root exudates into polar and non-polar compounds. Subsequently, we conducted comprehensive bioassays with each fraction on germination-suppressed microsclerotia. The result revealed a pivotal role of primary metabolites in root exudates, particularly glutamic acid, in triggering microsclerotia germination and overcoming bacterial inhibition. Moreover, our studies revealed a decrease in inhibitory bacterial volatile fatty acids when bacteria were cultured in the presence of root exudates or glutamic acid. This suggests a potential mechanism, by which root exudates set-off bacterial suppression on microsclerotia. Here, we reveal for the first time that plant root exudates, instead of directly inducing the germination of microsclerotia, enact a set-off effect by counteracting the suppressive impact of soil bacteria on the microsclerotia germination process. This nuanced interaction advances our understanding of the multifaceted dynamics governing microsclerotia dormancy and germination in the soil environment. IMPORTANCE: Our research provides first-time insights into the crucial interaction between plant root exudates and soil bacteria in regulating the germination of Verticillium longisporum microsclerotia, a significant structure in the survival and proliferation of this soil-borne pathogen. We describe so far unknown mechanisms, which are key to understand how root infections on oilseed rape can occur. By pinpointing primary metabolites in root exudates as key factors in overcoming bacteria-induced dormancy and promote microsclerotia germination, our study highlights the potential for exploiting plant - as well as soil microbe-derived - compounds to control V. longisporum. This work underscores the importance of elucidating the nuanced interactions within the soil ecosystem to devise innovative strategies for managing root infective plant diseases, thereby contributing to the resilience and health of cropping systems.


Assuntos
Exsudatos de Plantas , Raízes de Plantas , Microbiologia do Solo , Verticillium , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Verticillium/crescimento & desenvolvimento , Verticillium/fisiologia , Exsudatos de Plantas/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Bactérias/metabolismo , Bactérias/classificação
7.
Int J Biol Macromol ; 269(Pt 2): 132065, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38714280

RESUMO

Natural gums due to availability, multifunctionality, and nontoxicity are multifaceted in application. In corrosion inhibition applications, their performance, in unmodified form is unsatisfactory because of high hydration rate, solubility issues, algal and microbial contamination, as well as thermal instability. This work attempts to enhance the inhibitive performance of Berlinia grandiflora (BEG) and cashew (CEG) exudate gums through various modification approaches. The potential of biogenic BEG and CEG gums-silver (Ag) nanocomposites (NCPs) for corrosion inhibition of mild steel in 1 M HCl is studied. The nanocomposites were characterized using the FTIR, UV-vis, and TEM techniques. The corrosion studies through the gravimetric and electrochemical (PDP, EIS, LPR, and EFM) analyses reveal moderate inhibition performance by the nanocomposites. Furthermore, the PDP results reveal that both inhibitors are mixed-type with maximum corrosion inhibition efficiencies (IEs) of 61.2 % and 54.2 % for BEG-Ag NCP and CEG-Ag NCP, respectively at an optimum concentration of 1.0 %. Modification of these inhibitors with iodide ion (KI) significantly increased the IE values to 90.1 % and 88.5 % for BEG-Ag NCP and CEG-Ag NCP at the same concentration. Surface observation of the uninhibited and inhibited steel samples using SEM/EDAX, 3D Surface profilometer, and AFM affirm that the modified nanocomposites are highly effective.


Assuntos
Ácido Clorídrico , Nanocompostos , Gomas Vegetais , Prata , Aço , Prata/química , Aço/química , Nanocompostos/química , Corrosão , Ácido Clorídrico/química , Gomas Vegetais/química , Exsudatos de Plantas/química , Exsudatos de Plantas/farmacologia , Anacardium/química
8.
BMC Plant Biol ; 24(1): 340, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671402

RESUMO

Astragalus mongholicus is a medicinal plant that is known to decrease in quality in response to continuous cropping. However, the differences in the root-associated microbiome and root exudates in the rhizosphere soil that may lead to these decreases are barely under studies. We investigated the plant biomass production, root-associated microbiota, and root exudates of A. mongholicus grown in two different fields: virgin soil (Field I) and in a long-term continuous cropping field (Field II). Virgin soil is soil that has never been cultivated for A. mongholicus. Plant physiological measurements showed reduced fresh and dry weight of A. mongholicus under continuous cropping conditions (i.e. Field II). High-throughput sequencing of the fungal and bacterial communities revealed differences in fungal diversity between samples from the two fields, including enrichment of potentially pathogenic fungi in the roots of A. mongholicus grown in Field II. Metabolomic analysis yielded 20 compounds in A. mongholicus root exudates that differed in relative abundance between rhizosphere samples from the two fields. Four of these metabolites (2-aminophenol, quinic acid, tartaric acid, and maleamate) inhibited the growth of A. mongholicus, the soil-borne pathogen Fusarium oxysporum, or both. This comprehensive analysis enhances our understanding of the A. mongholicus microbiome, root exudates, and interactions between the two in response to continuous cropping. These results offer new information for future design of effective, economical approaches to achieving food security.


Assuntos
Microbiota , Raízes de Plantas , Rizosfera , Microbiologia do Solo , Raízes de Plantas/microbiologia , Astrágalo/microbiologia , Exsudatos de Plantas/metabolismo , Fungos/genética , Fungos/fisiologia , Produção Agrícola/métodos , Bactérias/genética , Bactérias/metabolismo
9.
Chemosphere ; 356: 141896, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38579949

RESUMO

Complex rhizoremediation is the main mechanism of phytoremediation in organic-contaminated soil. Low molecular weight organic acids (LMWOAs) in root exudates have been shown to increase the bioavailability of contaminants and are essential for promoting the dissipation of contaminants. The effects of root exudates on the dissipation of organophosphate esters (OPEs) in soil are unclear. Consequently, we studied the combined effects of root exudates, soil enzymes and microorganisms on OPEs (tri (1-chloro-2-propyl) phosphate (TCPP) and triphenyl phosphate (TPP)) dissipation through pot experiments. Oxalic acid (OA) was confirmed to be the main component of LMWOAs in root exudates of ryegrass. The existence of OA increased the dissipation rate of OPEs by 6.04%-25.50%. Catalase and dehydrogenase activities were firstly activated and then inhibited in soil. While, urease activity was activated and alkaline phosphatase activity was inhibited during the exposure period. More bacteria enrichment (e.g., Sphingomonas, Pseudomonas, Flavisolibacter, Pontibacter, Methylophilus and Massilia) improved the biodegradation of OPEs. In addition, the transformation paths of OPEs hydrolysis and methylation under the action of root exudates were observed. This study provided theoretical insights into reducing the pollution risk of OPEs in the soil.


Assuntos
Biodegradação Ambiental , Ésteres , Lolium , Ácido Oxálico , Raízes de Plantas , Microbiologia do Solo , Poluentes do Solo , Solo , Ácido Oxálico/metabolismo , Poluentes do Solo/metabolismo , Lolium/metabolismo , Raízes de Plantas/metabolismo , Solo/química , Ésteres/metabolismo , Organofosfatos/metabolismo , Oxirredutases/metabolismo , Catalase/metabolismo , Bactérias/metabolismo , Exsudatos de Plantas/metabolismo , Exsudatos de Plantas/química
10.
PLoS Biol ; 22(4): e3002232, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38662644

RESUMO

Plant-associated microbes play vital roles in promoting plant growth and health, with plants secreting root exudates into the rhizosphere to attract beneficial microbes. Exudate composition defines the nature of microbial recruitment, with different plant species attracting distinct microbiota to enable optimal adaptation to the soil environment. To more closely examine the relationship between plant genotype and microbial recruitment, we analysed the rhizosphere microbiomes of landrace (Chevallier) and modern (NFC Tipple) barley (Hordeum vulgare) cultivars. Distinct differences were observed between the plant-associated microbiomes of the 2 cultivars, with the plant-growth promoting rhizobacterial genus Pseudomonas substantially more abundant in the Tipple rhizosphere. Striking differences were also observed between the phenotypes of recruited Pseudomonas populations, alongside distinct genotypic clustering by cultivar. Cultivar-driven Pseudomonas selection was driven by root exudate composition, with the greater abundance of hexose sugars secreted from Tipple roots attracting microbes better adapted to growth on these metabolites and vice versa. Cultivar-driven selection also operates at the molecular level, with both gene expression and the abundance of ecologically relevant loci differing between Tipple and Chevallier Pseudomonas isolates. Finally, cultivar-driven selection is important for plant health, with both cultivars showing a distinct preference for microbes selected by their genetic siblings in rhizosphere transplantation assays.


Assuntos
Genótipo , Hordeum , Microbiota , Raízes de Plantas , Pseudomonas , Rizosfera , Hordeum/microbiologia , Hordeum/genética , Hordeum/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Microbiota/fisiologia , Microbiota/genética , Pseudomonas/genética , Pseudomonas/metabolismo , Pseudomonas/fisiologia , Microbiologia do Solo , Exsudatos de Plantas/metabolismo
11.
Nat Commun ; 15(1): 3436, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653767

RESUMO

Symbiosis with soil-dwelling bacteria that fix atmospheric nitrogen allows legume plants to grow in nitrogen-depleted soil. Symbiosis impacts the assembly of root microbiota, but it is unknown how the interaction between the legume host and rhizobia impacts the remaining microbiota and whether it depends on nitrogen nutrition. Here, we use plant and bacterial mutants to address the role of Nod factor signaling on Lotus japonicus root microbiota assembly. We find that Nod factors are produced by symbionts to activate Nod factor signaling in the host and that this modulates the root exudate profile and the assembly of a symbiotic root microbiota. Lotus plants with different symbiotic abilities, grown in unfertilized or nitrate-supplemented soils, display three nitrogen-dependent nutritional states: starved, symbiotic, or inorganic. We find that root and rhizosphere microbiomes associated with these states differ in composition and connectivity, demonstrating that symbiosis and inorganic nitrogen impact the legume root microbiota differently. Finally, we demonstrate that selected bacterial genera characterizing state-dependent microbiomes have a high level of accurate prediction.


Assuntos
Lotus , Microbiota , Nitrogênio , Raízes de Plantas , Transdução de Sinais , Simbiose , Lotus/microbiologia , Lotus/metabolismo , Nitrogênio/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/metabolismo , Microbiota/fisiologia , Rizosfera , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Microbiologia do Solo , Fixação de Nitrogênio , Exsudatos de Plantas/metabolismo
12.
Science ; 384(6693): 272-273, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38635697

RESUMO

Root exudation could be harnessed for ecological and applied research.


Assuntos
Exsudatos de Plantas , Raízes de Plantas , Plantas , Raízes de Plantas/fisiologia , Exsudatos de Plantas/fisiologia
13.
Plant Physiol Biochem ; 210: 108573, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38569423

RESUMO

Riboflavins are secreted under iron deficiency as a part of the iron acquisition Strategy I, mainly when the external pH is acidic. In plants growing under Fe-deficiency and alkaline conditions, riboflavins have been reported to accumulate inside the roots, with very low or negligible secretion. However, the fact that riboflavins may undergo hydrolysis under alkaline conditions has been so far disregarded. In this paper, we report the presence of riboflavin derivatives and products of their alkaline hydrolysis (lumichrome, lumiflavin and carboxymethylflavin) in nutrient solutions of Cucumis sativus plants grown under different iron regimes (soluble Fe-EDDHA in the nutrient solution, total absence of iron in the nutrient solution, or two different doses of FeSO4 supplied as a foliar spray), either cultivated in slightly acidic (pH 6) or alkaline (pH 8.8, 10 mM bicarbonate) nutrient solutions. The results show that root synthesis and exudation of riboflavins is controlled by shoot iron status, and that exuded riboflavins undergo hydrolysis, especially at alkaline pH, with lumichrome being the main product of hydrolysis.


Assuntos
Raízes de Plantas , Raízes de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Hidrólise , Cucumis sativus/metabolismo , Cucumis sativus/efeitos dos fármacos , Deficiências de Ferro , Riboflavina/metabolismo , Concentração de Íons de Hidrogênio , Estresse Fisiológico/efeitos dos fármacos , Ferro/metabolismo , Exsudatos de Plantas/metabolismo
14.
Can J Microbiol ; 70(5): 150-162, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427979

RESUMO

This study characterizes seedling exudates of peas, tomatoes, and cucumbers at the level of chemical composition and functionality. A plant experiment confirmed that Rhizobium leguminosarum bv. viciae 3841 enhanced growth of pea shoots, while Azospirillum brasilense Sp7 supported growth of pea, tomato, and cucumber roots. Chemical analysis of exudates after 1 day of seedling incubation in water yielded differences between the exudates of the three plants. Most remarkably, cucumber seedling exudate did not contain detectable sugars. All exudates contained amino acids, nucleobases/nucleosides, and organic acids, among other compounds. Cucumber seedling exudate contained reduced glutathione. Migration on semi solid agar plates containing individual exudate compounds as putative chemoattractants revealed that R. leguminosarum bv. viciae was more selective than A. brasilense, which migrated towards any of the compounds tested. Migration on semi solid agar plates containing 1:1 dilutions of seedling exudate was observed for each of the combinations of bacteria and exudates tested. Likewise, R. leguminosarum bv. viciae and A. brasilense grew on each of the three seedling exudates, though at varying growth rates. We conclude that the seedling exudates of peas, tomatoes, and cucumbers contain everything that is needed for their symbiotic bacteria to migrate and grow on.


Assuntos
Azospirillum brasilense , Cucumis sativus , Pisum sativum , Rhizobium leguminosarum , Plântula , Solanum lycopersicum , Solanum lycopersicum/microbiologia , Solanum lycopersicum/crescimento & desenvolvimento , Cucumis sativus/microbiologia , Cucumis sativus/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Rhizobium leguminosarum/crescimento & desenvolvimento , Rhizobium leguminosarum/metabolismo , Azospirillum brasilense/crescimento & desenvolvimento , Azospirillum brasilense/metabolismo , Pisum sativum/microbiologia , Pisum sativum/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Quimiotaxia , Exsudatos de Plantas/química , Exsudatos de Plantas/metabolismo
15.
Sci Rep ; 14(1): 2359, 2024 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-38286879

RESUMO

Biotransformation of organic pollutants is crucial for the dissipation of environmental pollutants. While the roles of microorganisms have been extensively studied, the significant contribution of various root exudates are still not very well understood. Through plant growth experiment, coupled with gas and liquid chromatography-mass spectrometry methods, this study examined the effect of the presence of M. sativa on microbial-associated biochemical transformation of petroleum hydrocarbons. The results of this study revealed that the concentration of exudates within the soil matrix is a function of proximity to root surfaces. Similarly, biodegradation was found to correlate with distance from roots, ranging from ≥ 90% within the rhizosphere to < 50% in bulk soil and unplanted control soil. Most importantly, for the first time in a study of an entire petroleum distillate, this study revealed a statistically significant negative correlation between root exudate concentration and residual total petroleum hydrocarbons. While not all the compounds that may influence biodegradation are derived from roots, the results of this study show that the presence of plant can significantly influence biodegradation of hydrocarbon pollutants through such root exudation as organic acids, amino acids, soluble sugars and terpenoids. Therefore, root exudates, including secondary metabolites, offer great prospects for biotechnological applications in the remediation of organic pollutants, including recalcitrant ones.


Assuntos
Poluentes Ambientais , Petróleo , Poluentes do Solo , Poluentes Ambientais/metabolismo , Poluentes do Solo/metabolismo , Rizosfera , Biodegradação Ambiental , Solo , Biotransformação , Exsudatos e Transudatos/metabolismo , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Raízes de Plantas/metabolismo , Microbiologia do Solo , Exsudatos de Plantas/metabolismo
16.
Sci Total Environ ; 912: 169048, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38061654

RESUMO

Biodegradable plastics (BPs) have gained increased attention as a promising solution to plastics pollution problem. However, BPs often exhibited limited in situ biodegradation in the soil environment, so they may also release microplastics (MPs) into soils just like conventional non-degradable plastics. Therefore, it is necessary to evaluate the impacts of biodegradable MPs (BMPs) on soil ecosystem. Here, we explored the effects of biodegradable poly(butylene adipate-co-terephthalate) (PBAT) MPs and conventional polyethylene (PE) MPs on soil-plant (pakchoi) system at three doses (0.02 %, 0.2 %, and 2 %, w/w). Results showed that PBAT MPs reduced plant growth in a dose-dependent pattern, while PE MPs exhibited no significant phytotoxicity. High-dose PBAT MPs negatively affected the rhizosphere soil nutrient availability, e.g., decreased available phosphorus and available potassium. Metagenomics analysis revealed that PBAT MPs caused more serious interference with the rhizosphere microbial community composition and function than PE MPs. In particular, compared with PE MPs, PBAT MPs induced greater changes in functional potential of carbon, nitrogen, phosphorus, and sulfur cycles, which may lead to alterations in soil biogeochemical processes and ecological functions. Moreover, untargeted metabolomics showed that PBAT MPs and PE MPs differentially affect plant root exudates. Mantel tests, correlation analysis, and partial least squares path model analysis showed that changes in plant growth and root exudates were significantly correlated with soil properties and rhizosphere microbiome driven by the MPs-rhizosphere interactions. This work improves our knowledge of how biodegradable and conventional non-degradable MPs affect plant growth and the rhizosphere ecology, highlighting that BMPs might pose greater threat to soil ecosystems than non-degradable MPs.


Assuntos
Plásticos Biodegradáveis , Brassica , Microplásticos , Rizosfera , Ecossistema , Plásticos , Exsudatos e Transudatos , Biodegradação Ambiental , Polietileno , Exsudatos de Plantas , Fósforo , Solo
17.
Microbiol Res ; 279: 127564, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38071833

RESUMO

A wide range of abiotic and biotic stresses adversely affect plant's growth and production. Under stress, one of the main responses of plants is the modulation of exudates excreted in the rhizosphere, which consequently leads to alterations in the resident microbiota. Thus, the exudates discharged into the rhizospheric environment play a preponderant role in the association and formation of plant-microbe interactions. In this review, we aimed to provide a synthesis of the latest and most pertinent literature on the diverse biochemical and structural compositions of plant root exudates. Also, this work investigates into their multifaceted role in microbial nutrition and intricate signaling processes within the rhizosphere, which includes quorum-sensing molecules. Specifically, it explores the contributions of low molecular weight compounds, such as carbohydrates, phenolics, organic acids, amino acids, and secondary metabolites, as well as the significance of high molecular weight compounds, including proteins and polysaccharides. It also discusses the state-of-the-art omics strategies that unveil the vital role of root exudates in plant-microbiome interactions, including defense against pathogens like nematodes and fungi. We propose multiple challenges and perspectives, including exploiting plant root exudates for host-mediated microbiome engineering. In this discourse, root exudates and their derived interactions with the rhizospheric microbiota should receive greater attention due to their positive influence on plant health and stress mitigation.


Assuntos
Microbiota , Raízes de Plantas , Raízes de Plantas/microbiologia , Microbiota/fisiologia , Exsudatos e Transudatos/metabolismo , Exsudatos de Plantas/metabolismo , Percepção de Quorum , Plantas/microbiologia , Rizosfera , Microbiologia do Solo
18.
Trends Plant Sci ; 29(4): 469-481, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37802692

RESUMO

Low-carbon approaches to agriculture constitute a pivotal measure to address the challenge of global climate change. In agroecosystems, rhizosphere exudates are significantly involved in regulating the nitrogen (N) cycle and facilitating belowground chemical communication between plants and soil microbes to reduce direct and indirect emissions of greenhouse gases (GHGs) and control N runoff from cultivated sites into natural water bodies. Here, we discuss specific rhizosphere exudates from plants and microorganisms and the mechanisms by which they reduce N loss and subsequent N pollution in terrestrial and aquatic environments, including biological nitrification inhibitors (BNIs), biological denitrification inhibitors (BDIs), and biological denitrification promoters (BDPs). We also highlight promising application scenarios and challenges in relation to rhizosphere exudates in terrestrial and aquatic environments.


Assuntos
Nitrificação , Rizosfera , Exsudatos de Plantas , Nitrogênio , Agricultura , Solo/química , Plantas , Exsudatos e Transudatos/química , Carbono
19.
Sci Total Environ ; 899: 165590, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37474067

RESUMO

Aquatic plant-derived dissolved organic matter (DOM) in water bodies is an important source of disinfection byproduct (DBP) precursors. It is therefore very important to investigate DBP formation, and the main DBP precursors that enter drinking water during treatment processes. In this study, Lythrum salicaria root extract (LSRE) and Acorus calamus root extract (ACRE) were analyzed. The LSRE and ACRE were chlorinated and disinfected to generate trihalomethanes, haloacetic acids, haloketones, and haloacetaldehydes. The DBP formation potential of LSRE, dominated by humus, was higher than that of Suwannee River natural organic matter (SRNOM), and trichloroacetic acid was the main DBP. It was calculated that 2.09 % of the increased DOC brought by the surface flow wetland planted with emergent aquatic plants, and the contribution rates of TCMFP, DCAAFP and TCAAFP in effluent were 3.34 %, 3.23 % and 3.05 %, respectively. A total of 706 chlorinated-formula were detected by FTICR-MS, among which mono- and di-chlorinated formulae were the most abundant. Macromolecular hydrophobic organics and tannins were the main precursors for LSRE. Unlike LSRE, the DOM composition of ACRE was dominated by protein or aliphatic compounds; therefore, the risk of DBP formation was not as high as that for LSRE. This study is the first to determine the risk of DBP formation associated with aquatic plant root extracts, and confirmed that tannins in plant-derived DOM are more important DBP precursors than lignins.


Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Desinfecção , Exsudatos de Plantas , Áreas Alagadas , Poluentes Químicos da Água/análise , Trialometanos/análise , Exsudatos e Transudatos/química , Raízes de Plantas/química , Desinfetantes/química
20.
Sci Rep ; 13(1): 10954, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37414773

RESUMO

Prunus armeniaca gum is used as food additive and ethno medicinal purpose. Two empirical models response surface methodology and artificial neural network were used to search for optimized extraction parameters for gum extraction. A four-factor design was implemented for optimization of extraction process for maximum yield which was obtained under the optimized extraction parameter (temperature, pH, extraction time, and gum/water ratio). Micro and macro-elemental composition of gum was determined by using laser induced breakdown spectroscopy. Gum was evaluated for toxicological effect and pharmacological properties. The maximum predicted yield obtained by response surface methodology and artificial neural network was 30.44 and 30.70% which was very close to maximum experimental yield 30.23%. Laser induced breakdown spectroscopic spectra confirmed the presence Calcium, Potassium, Magnesium, Sodium, Lithium, Carbon, Hydrogen, Nitrogen and Oxygen. Acute oral toxicity study showed that gum is non-toxic up to 2000 mg/Kg body weight in rabbits, accompanied by high cytotoxic effects of gum against HepG2 and MCF-7cells by MTT assay. Overall, Aqueous solution of gum showed various pharmacological activities with significant value of antioxidant, antibacterial, anti-nociceptive, anti-cancer, anti-inflammatory and thrombolytic activities. Thus, optimization of parameters using mathematical models cans offer better prediction and estimations with enhanced pharmacological properties of extracted components.


Assuntos
Antioxidantes , Exsudatos de Plantas , Animais , Coelhos , Antioxidantes/farmacologia , Antioxidantes/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Gomas Vegetais/química , Água , Exsudatos e Transudatos
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