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1.
Braz. j. biol ; 83: e242676, 2023. tab, graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1278552

RESUMO

Abstract Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.


Resumo As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.


Assuntos
Poluentes do Solo , Micorrizas/química , Herbicidas , Solo , Microbiologia do Solo , Árvores , Brasil , Raízes de Plantas/química , Plântula , Rizosfera
2.
Environ Pollut ; 307: 119559, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35654253

RESUMO

Arbuscular mycorrhizal fungi (AMF) and plant rhizosphere microbes reportedly enhance plant tolerance to abiotic stresses and promote plant growth in contaminated soils. The co-contamination of soil by heavy metals (e.g., Cd) and rare earth elements (e.g., La) represents a severe environmental problem. Although the influence of AMF in the phytoremediation of contaminated soils is well documented, the underlying interactive mechanisms between AMF and rhizosphere microbes are still unclear. We conducted a greenhouse pot experiment to evaluate the effects of AMF (Claroideoglomus etunicatum) on maize growth, nutrient and metal uptake, rhizosphere microbial community, and functional genes in soils with separate and combined applications of Cd and La. The purpose of this experiment was to explore the mechanism of AMF affecting plant growth and metal uptake via interactions with rhizosphere microbes. We found that C. etunicatum (i) significantly enhanced plant nutritional level and biomass and decreased metal concentration in the co-contaminated soil; (ii) significantly altered the structure of maize rhizosphere bacterial and fungal communities; (iii) strongly enriched the abundance of carbohydrate metabolism genes, ammonia and nitrate production genes, IAA (indole-3-acetic acid) and ACC deaminase (1-aminocyclopropane-1-carboxylate) genes, and slightly altered the abundance of P-related functional genes; (iv) regulated the abundance of microbial quorum sensing system and metal membrane transporter genes, thereby improving the stability and adaptability of the rhizosphere microbial community. This study provides evidence of AMF improving plant growth and resistance to Cd and La stresses by regulating plant rhizosphere microbial communities and aids our understanding of the underlying mechanisms.


Assuntos
Metais Pesados , Microbiota , Micorrizas , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Fungos , Metais Pesados/análise , Micorrizas/metabolismo , Raízes de Plantas/metabolismo , Plantas/metabolismo , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Zea mays/metabolismo
3.
Mycorrhiza ; 32(3-4): 315-325, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35660964

RESUMO

The assembly of biological communities depends on deterministic and stochastic processes whose influence varies across spatial and temporal scales. Although ectomycorrhizal (ECM) fungi play a key role in forest ecosystems, our knowledge on ECM community assembly processes and their dependency on spatial scales is still scarce. We analysed the assembly processes operating on ECM fungal communities associated with Cistus albidus L. and Quercus spp. in Mediterranean mixed forests (Southern Spain), for which root tip ECM fungi were characterized by high-throughput sequencing. The relative contribution of deterministic and stochastic processes that govern the ECM fungal community assembly was inferred by using phylogenetic and compositional turnover descriptors across spatial scales. Our results revealed that stochastic processes had a significantly higher contribution than selection on root tip ECM fungal community assembly. The strength of selection decreased at the smallest scale and it was linked to the plant host identity and the environment. Dispersal limitation increased at finer scales, whilst drift showed the opposite pattern likely suggesting a main influence of priority effects on ECM fungal community assembly. This study highlights the potential of phylogeny to infer ECM fungal community responses and brings new insights into the ecological processes affecting the structure and dynamics of Mediterranean forests.


Assuntos
Micobioma , Micorrizas , Biodiversidade , Ecossistema , Florestas , Micorrizas/fisiologia , Filogenia , Microbiologia do Solo
4.
Curr Microbiol ; 79(7): 211, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672529

RESUMO

This research was conducted to compare the soil characteristics and arbuscular mycorrhizal fungi (AMF) spore density from different types of pastures. To this purpose, four different areas were selected including an artificial pasture (AP), a fertilized artificial pasture (FAP), a natural pasture (NP), and a fertilized natural pasture (FNP). From the spring period of 2008, urea has been used as a fertilizer at an annual rate of 5 kg/da. Different numbers of AMF spores were found in all soil samples taken from the artificial and natural pastures. The average numbers of AMF spores in 50 g of soil from the AP, the FAP, the NP, and the FNP were determined as 266.9, 125.3, 117.0, and 59.6, respectively. Both the number of AMF spores and the number of species were found to be lower in the fertilized pastures, and consequently, it was concluded that the urea fertilizer had reduced the number of AMF spores and species. Spores were identified according to their morphological characteristics. In all pastures, the study identified 25 different AMF species belonging to 11 genera from 7 families. Rhizoglomus aggregatum was classified as the dominant species in FNP soils. Acaulospora dilatata, A. laevis, Dentiscutata heterogama, Diversispora eburnea, Gigaspora albida, G. margarita, Claroideoglomus etunicatum, C. lamellosum, Funneliformis caledonium, Glomus hoi, Rhizoglomus clarum, R. irregulare, Sclerocystis sinuosa, and Ambispora gerdemannii were classified as rare species in all pastures. This study demonstrated a negative correlation between the AMF spore density and the soil organic carbon, total nitrogen, and available potassium.


Assuntos
Micorrizas , Mar Negro , Carbono , Fertilizantes , Fungos/genética , Humanos , Raízes de Plantas/microbiologia , Solo , Microbiologia do Solo , Esporos Fúngicos , Turquia , Ureia
5.
Proc Natl Acad Sci U S A ; 119(26): e2118852119, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35727987

RESUMO

Carbon storage and cycling in boreal forests-the largest terrestrial carbon store-is moderated by complex interactions between trees and soil microorganisms. However, existing methods limit our ability to predict how changes in environmental conditions will alter these associations and the essential ecosystem services they provide. To address this, we developed a metatranscriptomic approach to analyze the impact of nutrient enrichment on Norway spruce fine roots and the community structure, function, and tree-microbe coordination of over 350 root-associated fungal species. In response to altered nutrient status, host trees redefined their relationship with the fungal community by reducing sugar efflux carriers and enhancing defense processes. This resulted in a profound restructuring of the fungal community and a collapse in functional coordination between the tree and the dominant Basidiomycete species, and an increase in functional coordination with versatile Ascomycete species. As such, there was a functional shift in community dominance from Basidiomycetes species, with important roles in enzymatically cycling recalcitrant carbon, to Ascomycete species that have melanized cell walls that are highly resistant to degradation. These changes were accompanied by prominent shifts in transcriptional coordination between over 60 predicted fungal effectors, with more than 5,000 Norway spruce transcripts, providing mechanistic insight into the complex molecular dialogue coordinating host trees and their fungal partners. The host-microbe dynamics captured by this study functionally inform how these complex and sensitive biological relationships may mediate the carbon storage potential of boreal soils under changing nutrient conditions.


Assuntos
Basidiomycota , Micorrizas , Picea , Carbono/metabolismo , Ecossistema , Florestas , Micorrizas/fisiologia , Picea/metabolismo , Solo/química , Microbiologia do Solo , Taiga , Árvores/fisiologia
6.
Ying Yong Sheng Tai Xue Bao ; 33(6): 1709-1718, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35729151

RESUMO

Global changes have profound impacts on biodiversity and ecological functioning of terrestrial ecosystems. Arbuscular mycorrhizal (AM) fungi can form symbiotic associations with most terrestrial plant species and play an important role in nutrient acquisition of host plants, promotion of plant growth, and maintenance of plant diversity. In this review, we primarily focused on the responses and feedbacks of AM fungal community and functioning to elevated atmospheric CO2(eCO2) and warming in forest and grassland ecosystems. eCO2 influenced AM fungi mainly through indirectly impacting host plants and soil carbon inputs. A majority of previous studies reported that eCO2 could enhance the abundance and activity of AM fungi, and influence their diversity and community composition. Warming could have direct and indirect (via plant and/or soil pathways) impacts on AM fungi. Warming significantly altered the community compositions of AM fungi in forest soils. But the results from grassland were not consistent. We identified some outstanding problems in current studies and proposed future research topics which deserve more attentions. Our aim was to elucidate the AM fungal responses and adaptation to eCO2 and warming and to improve our understanding of AM fungal functioning in soil ecological processes. This review could provide insights into the implications of AM fungi to mitigate global change and improve the resilience of soil functions, as well as climate change adaptation of ecosystems.


Assuntos
Micorrizas , Dióxido de Carbono , Ecossistema , Fungos , Micorrizas/fisiologia , Plantas , Solo , Microbiologia do Solo
7.
Arch Microbiol ; 204(7): 375, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35674927

RESUMO

Arsenic (As) is a toxic metalloid that is present in natural surroundings in many forms with severe consequences to sustainable agriculture and human health. Plant growth-promoting Rhizobia have been found involved in the induction of plant tolerance under various biotic and abiotic stresses. An endofungal Rhizobium species associated with arbuscular mycorrhizal fungi (AMF) Serendipita indica deploy beneficial role in the promotion of plant growth and tolerance against various biotic and abiotic stresses. In the current study, we have determined the role of endofungal Rhizobium species in protection of host plant growth under As stress. We observed that endofungal Rhizobium species strain Si001 tolerate AsV up to 25 mM and its inoculation enhances tomato seed germination and seedling growth. A hyper-colonization of Rhizobium species Si001 in tomato roots was observed under As stress and results in modulation of GSH and proline content with reduced ROS. Rhizobium species Si001 colonization in host plant recovered pigment contents (chlorophyll-a and chlorophyll-b up to 189.5% and 192%, respectively), photosynthesis (157%), and water use efficiency (166%) compared to As-treated plants. Interestingly, bacterial colonization results in 40% increased As accumulation in the root, while a reduction in As translocation from root to shoot up to 89% was observed as compared to As treated plants. In conclusion, endofungal Rhizobium species Si001 association with the host plant may improve plant health and tolerance against As stress with reduced As accumulation in the crop produce.


Assuntos
Arsênio , Lycopersicon esculentum , Micorrizas , Rhizobium , Arsênio/toxicidade , Clorofila , Humanos , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia
8.
Int J Mol Sci ; 23(11)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35682640

RESUMO

Plant-microorganism interactions at the rhizosphere level have a major impact on plant growth and plant tolerance and/or resistance to biotic and abiotic stresses. Of particular importance for forestry and agricultural systems is the cooperative and mutualistic interaction between plant roots and arbuscular mycorrhizal (AM) fungi from the phylum Glomeromycotina, since about 80% of terrestrial plant species can form AM symbiosis. The interaction is tightly regulated by both partners at the cellular, molecular and genetic levels, and it is highly dependent on environmental and biological variables. Recent studies have shown how fungal signals and their corresponding host plant receptor-mediated signalling regulate AM symbiosis. Host-generated symbiotic responses have been characterized and the molecular mechanisms enabling the regulation of fungal colonization and symbiosis functionality have been investigated. This review summarizes these and other recent relevant findings focusing on the molecular players and the signalling that regulate AM symbiosis. Future progress and knowledge about the underlying mechanisms for AM symbiosis regulation will be useful to facilitate agro-biotechnological procedures to improve AM colonization and/or efficiency.


Assuntos
Glomeromycota , Micorrizas , Glomeromycota/fisiologia , Micorrizas/fisiologia , Desenvolvimento Vegetal , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Simbiose/genética
9.
J Vis Exp ; (183)2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35660719

RESUMO

Structural botany is an indispensable perspective to fully understand the ecology, physiology, development, and evolution of plants. When researching mycoheterotrophic plants (i.e., plants that obtain carbon from fungi), remarkable aspects of their structural adaptations, the patterns of tissue colonization by fungi, and the morphoanatomy of subterranean organs can enlighten their developmental strategies and their relationships with hyphae, the source of nutrients. Another important role of symbiotic fungi is related to the germination of orchid seeds; all Orchidaceae species are mycoheterotrophic during germination and seedling stage (initial mycoheterotrophy), even the ones that photosynthesize in adult stages. Due to the lack of nutritional reserves in orchid seeds, fungal symbionts are essential to provide substrates and enable germination. Analyzing germination stages by structural perspectives can also answer important questions regarding the fungi interaction with the seeds. Different imaging techniques can be applied to unveil fungi endophytes in plant tissues, as are proposed in this article. Freehand and thin sections of plant organs can be stained and then observed using light microscopy. A fluorochrome conjugated to wheat germ agglutinin can be applied to the fungi and co-incubated with Calcofluor White to highlight plant cell walls in confocal microscopy. In addition, the methodologies of scanning and transmission electron microscopy are detailed for mycoheterotrophic orchids, and the possibilities of applying such protocols in related plants is explored. Symbiotic germination of orchid seeds (i.e., in the presence of mycorrhizal fungi) is described in the protocol in detail, along with possibilities of preparing the structures obtained from different stages of germination for analyses with light, confocal, and electron microscopy.


Assuntos
Micorrizas , Orchidaceae , Germinação , Microscopia , Micorrizas/fisiologia , Orchidaceae/microbiologia , Orchidaceae/fisiologia , Plantas , Sementes , Simbiose
10.
Plant Sci ; 321: 111308, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35696908

RESUMO

The Heirloom Golden tangerine tomato fruit variety is highly nutritious due to accumulation of tetra-cis-lycopene, that has a higher bioavailability and recognised health benefits in treating anti-inflammatory diseases compared to all-trans-lycopene isomers found in red tomatoes. We investigated if photoisomerization of tetra-cis-lycopene occurs in roots of the MicroTom tangerine (tangmic) tomato and how this affects root to shoot biomass, mycorrhizal colonization, abscisic acid accumulation, and responses to drought. tangmic plants grown in soil under glasshouse conditions displayed a reduction in height, number of flowers, fruit yield, and root length compared to wild-type (WT). Soil inoculation with Rhizophagus irregularis revealed fewer arbuscules and other fungal structures in the endodermal cells of roots in tangmic relative to WT. The roots of tangmic hyperaccumulated acyclic cis-carotenes, while only trace levels of xanthophylls and abscisic acid were detected. In response to a water deficit, leaves from the tangmic plants displayed a rapid decline in maximum quantum yield of photosystem II compared to WT, indicating a defective root to shoot signalling response to drought. The lack of xanthophylls biosynthesis in tangmic roots reduced abscisic acid levels, thereby likely impairing endomycorrhizal colonisation and drought-induced root to shoot signalling.


Assuntos
Citrus , Lycopersicon esculentum , Micorrizas , Ácido Abscísico , Carotenoides , Citrus/química , Secas , Licopeno , Lycopersicon esculentum/química , Solo , Xantofilas
11.
Appl Microbiol Biotechnol ; 106(11): 4237-4250, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35657436

RESUMO

Arbuscular mycorrhizal fungi (AMF) and beneficial bacteria are found naturally associated with most terrestrial plant roots. While it is now well known that bacteria colonize AMF and can form aggregates and biofilms, little is known about how interactions between bacterial communities and AMF take place under both in situ and in vitro conditions. We investigated the impact of inoculation with AMF-associated bacteria (AABs) of AMF by in vitro recreation of the interaction on synthetic growth media in a two-compartment Petri plate system. The inoculated AABs were found to be associated with the mycorrhizal co-culture and were found to migrate along growing AMF hyphae and to be associated with the spore surface. AABs differentially influenced the growth of the AMF and their functional capability demonstrated by analysis of phosphate solubilization, nitrogen fixation, and biofilm formation. We have thus characterized these important interactions adding to a further understanding of the synergistic relationship between the two cross-kingdom microbial partners. KEY POINTS: • An in vitro assay was utilized to recreate functional biofilms with AMF-associated bacteria. • AMF-associated bacteria formed a biofilm and enhanced sporulation of Rhizophagus irregularis. • AMF-bacterial interactions through biofilm formation influence the functional capability of both partners.


Assuntos
Micorrizas , Bactérias , Biofilmes , Raízes de Plantas/microbiologia , Simbiose
12.
Environ Res ; 212(Pt E): 113594, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35679908

RESUMO

Arbuscular mycorrhizal fungi (AMF) are ubiquitous in farmland. But the knowledge on AMF impact on lead (Pb) migration in farmland is limited. A field experiment was conducted in the rainy season (May-October) for two years in a Pb-polluted farmland. Benomyl was used to specifically suppress the native AMF growth in the farmland. The effect of benomyl-induced AMF suppression on the Pb uptake in maize, and Pb loss via surface runoff and interflows (20 cm and 40 cm depth) from the farmland was investigated. The benomyl significantly inhibited the AMF growth, resulting in decreases in the colonization rate, spore number, and contents of total and easily extractable glomalin-related soil protein (GRSP); and promoted the Pb migration into maize shoots and mainly enriched in leaves. The particulate Pb accounted for 83.2%-90.6% of Pb loss via surface runoff, while the proportion of particulate Pb loss via interflow was decreased and the proportion of dissolved Pb loss increased with the increase of soil depth. The AMF suppression led to a decrease in dissolved Pb concentration and loss, but an increase in particulate Pb concentration and loss, and enhanced the total Pb loss via surface runoff and interflows. Moreover, significant or very significant negative correlations were observed between the AMF colonization rate in roots with the Pb uptake in leaves, and the content of easily extractable GRSP with the particulate Pb loss. These results indicated the native AMF contributed to immobilizing Pb in soil and inhibited its migration to crops and the surrounding environment.


Assuntos
Micorrizas , Poluentes do Solo , Benomilo/metabolismo , Benomilo/farmacologia , Fazendas , Chumbo/metabolismo , Micorrizas/química , Micorrizas/metabolismo , Folhas de Planta , Raízes de Plantas/metabolismo , Solo , Poluentes do Solo/análise , Zea mays/metabolismo
13.
J Hazard Mater ; 435: 128991, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35650720

RESUMO

Phytoremediation is a promising and sustainable technology to remediate the risk of heavy metals (HMs) contaminated soils, however, this way is limited to some factors contributing to slow plant growth and low remediation efficiency. As soil beneficial microbe, arbuscular mycorrhizal fungi (AMF) assisted phytoremediation is an environment-friendly and high-efficiency bioremediation technology. However, AMF-symbiotic formation and their functional expression responsible for HMs-polluted remediation are significantly influenced by edaphic fauna. Earthworms as common soil fauna, may have various effects on formation of AMF symbiosis, and exhibit synergy with AMF for the combined remediation of HMs-contaminated soils. For now, AMF-assisted phytoremediation incorporating earthworm coexistence is scarcely reported. Therefore, the main focus of this review is to discuss the AMF effects under earthworm coexistence. Effects of AMF-symbiotic formation influenced by earthworms are fully reviewed. Moreover, underlying mechanisms and synergy of the two in HMs remediation, soil improvement, and plant growth were comprehensively elucidated. Phenomenon of "functional synergism" between earthworms and AMF may be a significant mechanism for HMs phytoremediation. Finally, this review analyses shortcomings and prescriptions in the practical application of the technology and provides new insights into AMF- earthworms synergistic remediation of HMs-contaminated soils.


Assuntos
Metais Pesados , Micorrizas , Oligoquetos , Poluentes do Solo , Animais , Biodegradação Ambiental , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Micorrizas/metabolismo , Oligoquetos/metabolismo , Raízes de Plantas/metabolismo , Solo , Poluentes do Solo/metabolismo
14.
J Hazard Mater ; 435: 129077, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35650732

RESUMO

Cadmium (Cd) pollution in croplands is a global environmental problem. Measures to improve the tolerance of sensitive crops and reduce pollutant absorption and accumulation are needed in contaminated agricultural areas, and inoculation with rhizosphere microorganisms to regulate plant resistance and heavy metal transport can provide an effective solution. A pot experiment was conducted to analyse the impact of arbuscular mycorrhizal fungi (AMF) on alfalfa oxidase activity, heavy metal resistance genes and transport proteins, metabolism, and other biochemical regulation mechanisms that lead to complexation, compartmentalisation, efflux, enrichment, and antioxidant detoxification pathways. The AMF reduced shoot and protoplasm Cd inflow, and promoted organic compound production (e.g., by upregulating HM-Res4 for 1.2 times), to complex with Cd, reducing its biological toxicity. The AMF increased the ROS scavenging efficiency and osmotic regulatory substance content of the alfalfa plants, reduced oxidative stress (ROS dereased), and maintained homeostasis. It also alleviated Cd inhibition of photosynthetic electron transport, tricarboxylic acid circulation, and nitrogen assimilation. These AMF effects improved leaf and root biomass by 43.87% and 59.71% and facilitated recovery of a conservative root economic strategy. It is speculated that AMF induces the resistance signal switch by regulating the negative feedback regulation mode of indole acetic acid upward transport and methyl jasmonate downward transmission in plants.


Assuntos
Metais Pesados , Micorrizas , Poluentes do Solo , Cádmio/metabolismo , Medicago sativa/metabolismo , Metais Pesados/metabolismo , Micorrizas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Poluentes do Solo/metabolismo
15.
J Hazard Mater ; 436: 129113, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35580502

RESUMO

Nickel (Ni) contamination imposes deleterious effects on the stability of soil ecosystem. Soil fungal community as a crucial moderator of soil remediation and biochemical processes has attracted more and more research interests. In the present study, soil fungal community composition and diversity under long-term Ni contamination were investigated and fungal interaction networks were built to reveal fungal co-occurrence patterns. The results showed that moderate Ni contamination significantly increased fungal diversity and altered fungal community structure. Functional predictions based on FUNGuild suggested that the relative abundance of arbuscular mycorrhizal fungi (AMF) significantly increased at moderate Ni contamination level. Ni contamination strengthened fungal interactions. Keystone taxa at different Ni contamination levels, such as Penicillium at light contamination, were identified, which might have ecological significance in maintaining the stability of fungal community to Ni stress. The present study provided a deeper insight into the effect of long-term Ni contamination on fungal community composition and co-occurrence patterns, and was helpful to further explore ecological risk of Ni contamination in cultivated field.


Assuntos
Micobioma , Micorrizas , Ecossistema , Fungos , Níquel/toxicidade , Solo/química , Microbiologia do Solo
16.
Int J Mol Sci ; 23(9)2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35563675

RESUMO

Plants evolved an impressive arsenal of multifunctional specialized metabolites to cope with the novel environmental pressures imposed by the terrestrial habitat when moving from water. Here we examine the multifarious roles of flavonoids in plant terrestrialization. We reason on the environmental drivers, other than the increase in UV-B radiation, that were mostly responsible for the rise of flavonoid metabolism and how flavonoids helped plants in land conquest. We are reasonably based on a nutrient-deficiency hypothesis for the replacement of mycosporine-like amino acids, typical of streptophytic algae, with the flavonoid metabolism during the water-to-land transition. We suggest that flavonoids modulated auxin transport and signaling and promoted the symbiosis between plants and fungi (e.g., arbuscular mycorrhizal, AM), a central event for the conquest of land by plants. AM improved the ability of early plants to take up nutrients and water from highly impoverished soils. We offer evidence that flavonoids equipped early land plants with highly versatile "defense compounds", essential for the new set of abiotic and biotic stressors imposed by the terrestrial environment. We conclude that flavonoids have been multifunctional since the appearance of plants on land, not only acting as UV filters but especially improving both nutrient acquisition and biotic stress defense.


Assuntos
Flavonoides , Micorrizas , Flavonoides/metabolismo , Raízes de Plantas , Plantas/metabolismo , Simbiose , Água/metabolismo
17.
Mycorrhiza ; 32(3-4): 353-360, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35641704

RESUMO

The members of the genus Tuber are Ascomycota that form ectomycorrhizal associations with various coniferous and broadleaf tree species. In the teleomorphic stage, the species of the genus produce fruit bodies known as true truffles. Recent studies have discovered mitosporic structures, including spore mats, of several Tuber species on forest soils, indicating the presence of a cryptic anamorphic stage or an unknown reproductive strategy. Here, we report in vitro mitospore formation on the mycelium of T. japonicum, which belongs to the Japonicum clade, collected in several regions in Japan. Twenty of the 25 strains formed mitospores on modified Melin-Norkrans agar medium, indicating that mitospore formation is likely a common trait among strains of T. japonicum. The fungus forms repeatedly branched conidiophores on aerial hyphae on colonies and generates holoblastic mitospores sympodially on the terminal and near apical parts and/or occasionally on the middle and basal parts of the conidiogenous cells. Mitospores are hyaline and elliptical, obovate, oblong, or occasionally bacilliform, with a vacuole and often distinct hilar appendices. Formation of mitospores by T. japonicum in vitro is useful in understanding the functions of mitospores in the genus Tuber under controlled environmental conditions.


Assuntos
Ascomicetos , Micorrizas , Ascomicetos/genética , DNA Fúngico , Filogenia
18.
Sci Rep ; 12(1): 9044, 2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35641544

RESUMO

Soybean (Glycine max L.) is an economically important crop, and is cultivated worldwide, although increasingly long periods of drought have reduced the productivity of this plant. Research has shown that inoculation with arbuscular mycorrhizal fungi (AMF) provides a potential alternative strategy for the mitigation of drought stress. In the present study, we measured the physiological and morphological performance of two soybean cultivars in symbiosis with Rhizophagus clarus that were subjected to drought stress (DS). The soybean cultivars Anta82 and Desafio were grown in pots inoculated with R. clarus. Drought stress was imposed at the V3 development stage and maintained for 7 days. A control group, with well-irrigated plants and no AMF, was established simultaneously in the greenhouse. The mycorrhizal colonization rate, and the physiological, morphological, and nutritional traits of the plants were recorded at days 3 and 7 after drought stress conditions were implemented. The Anta82 cultivar presented the highest percentage of AMF colonization, and N and K in the leaves, whereas the DS group of the Desafio cultivar had the highest water potential and water use efficiency, and the DS + AMF group had thermal dissipation that permitted higher values of Fv/Fm, A, and plant height. The results of the principal components analysis demonstrated that both cultivars inoculated with AMF performed similarly under DS to the well-watered plants. These findings indicate that AMF permitted the plant to reduce the impairment of growth and physiological traits caused by drought conditions.


Assuntos
Micorrizas , Secas , Fungos , Micorrizas/fisiologia , Soja , Água
19.
Ying Yong Sheng Tai Xue Bao ; 33(4): 963-971, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35543048

RESUMO

A pot experiment was conducted to investigate the effects of drought stress and arbuscular mycorrhizal fungi (AMF) inoculation on C:N:P stoichiometry and non-structural carbohydrate (NSC) contents in two-year-old Heptacodium miconioides seedlings. There were four treatments, including control (CK), drought stress (D), AMF inoculation (AMF), and combined drought stress and AMF inoculation (D+AMF). The results showed that drought stress significantly reduced AMF colonization rate, whereas plant height and leaf number of inoculated treatment were significantly higher than the non-inoculated treatment. Inoculation with AMF significantly increased soluble sugar and NSC content in root and leaf, as well as starch content in stem and leaf. The inoculation significantly decreased the stem and leaf soluble sugar to starch ratio under drought stress. Drought stress caused a significant increase in C content in roots and leaves, and a significant decrease in P content in stems. Compared with no inoculation drought stress, P content in roots, stems, leaves, and C content in leaves of mycorrhizal seedlings were significantly increased by inoculation under drought stress, whereas root C and N content and stem C content were significantly reduced. Under drought stress, AMF inoculation significantly decreased C:N, C:P, and N:P ratios in roots and stems, and N:P ratios in leaves of H. miconioides. P content in roots and leaves were significantly positively correlated with soluble sugar and NSC content. Stem P content was significantly positively correlated with starch and NSC content. N:P ratios in each organ was significantly negatively correlated with NSC content. In all, inoculation with AMF can improve the drought tolerance of H. miconioides seedling by increasing soluble sugar content in roots and leaves and the soluble sugar/starch ratio in roots, improving starch content in above-ground organs, promoting the P absorption, and reducing N:P ratios in each organ. Therefore, AMF colonization could improve the survival rate of H. miconioides seedling in dry environments.


Assuntos
Micorrizas , Carboidratos , Secas , Raízes de Plantas/microbiologia , Plântula , Amido , Açúcares
20.
Ying Yong Sheng Tai Xue Bao ; 33(4): 1091-1098, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35543064

RESUMO

The special eco-physiological characteristics of moso bamboo (Phyllostachys edulis) facilitate their fast invasion in nature ecosystems. The widespread expansion of moso bamboo causes degradation of adjacent forest ecosystem and change of landscape, as well as soil properties and microbial community composition. However, how moso bamboo expansion affects soil microbial composition is far from fully understood. Herein, we selected four moso bamboo expansion transects with three forest types at the Anji Lingfeng temple forest farm, Zhejiang Province, including evergreen broadleaved forest (BLF), mixed P. edulis and broadleaved forest (MEF) and P. edulis forest (PEF). We examined the effects of moso bamboo expansion on soil properties and soil microbial phospholipid fatty acids (PLFAs). Our results showed that soil pH was higher in moso bamboo forest than in MEF and BLF by 0.37 and 0.32 unit. In contrast, soil organic carbon, ammonium, and nitrate contents significantly decreased. Biomass of soil microbial groups displayed a decreasing trend except arbuscular mycorrhizal fungi, and the microbial richness index (SR) and diversity index (H) decreased significantly. In summary, moso bamboo expansion affected soil nutrient and carbon inputs, which was an important factor affecting soil microbial community structure. Results of redundancy analysis showed that changes of soil organic carbon and ammonium content were the main factors driving soil microbial community.


Assuntos
Compostos de Amônio , Microbiota , Micorrizas , Carbono/química , Florestas , Poaceae , Solo/química
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