RESUMEN
Arbuscular mycorrhizal (AM) symbiosis is the oldest and most widespread mutualistic association on Earth and involves plants and soil fungi belonging to Glomeromycotina. A complex molecular, cellular, and genetic developmental program enables partner recognition, fungal accommodation in plant tissues, and activation of symbiotic functions such as transfer of phosphorus in exchange for carbohydrates and lipids. AM fungi, as ancient obligate biotrophs, have evolved strategies to circumvent plant defense responses to guarantee an intimate and long-lasting mutualism. They are among those root-associated microorganisms able to boost plants' ability to cope with biotic stresses leading to mycorrhiza-induced resistance (MIR), which can be effective across diverse hosts and against different attackers. Here, we examine the molecular mechanisms underlying the modulation of plant immunity during colonization by AM fungi and at the onset and display of MIR against belowground and aboveground pests and pathogens. Understanding the MIR efficiency spectrum and its regulation is of great importance to optimizing the biotechnological application of these beneficial microbes for sustainable crop protection.
Asunto(s)
Micorrizas , Inmunidad de la Planta , Simbiosis , Micorrizas/fisiología , Plantas/inmunología , Plantas/microbiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunologíaRESUMEN
Knowledge is scarce to what extent environmental drivers and native symbiotic fungi in soil induce abrupt (short-term), systemic (multiple traits), or specific (a subset of traits) shifts in C3 plants' ecophysiological/mycorrhizal responses. We cultivated an emblematic native C3 species (Capsicum annuum var. glabriusculum, "Chiltepín") to look at how the extreme heat of the Sonoran desert, sunlight regimes (low = 2, intermediate = 15, high = 46 mol m2 d-1) and density of native arbuscular mycorrhizal fungi in soil (low AMF = 1% v/v, high AMF = 100% v/v), drive shifts on mycorrhizal responses through multiple functional traits (106 traits). The warming thresholds were relentlessly harsh even under intensive shade (e.g. superheat maximum thresholds reached ranged between 47-63°C), and several pivotal traits were synergistically driven by AMF (e.g. photosynthetic capacity, biomass gain/allometry, and mycorrhizal colonization traits); whereas concurrently, sunlight regimes promoted most (76%) alterations in functional acclimation traits in the short-term and opposite directions (e.g. survival, phenology, photosynthetic, carbon/nitrogen economy). Multidimensional reduction analysis suggests that the AMF promotes a synergistic impact on plants' phenotypic integration and functional plasticity in response to sunlight regimes; however, complex relationships among traits suggest that phenotypic variation determines the robustness degree of ecophysiological/mycorrhizal phenotypes between/within environments. Photosynthetic canopy surface expansion, Rubisco activity, photosynthetic nitrogen allocation, carbon gain, and differential colonization traits could be central to plants' overall ecophysiological/mycorrhizal fitness strengthening. In conclusion, we found evidence that a strong combined effect among environmental factors in which AMF are key effectors could drive important trade-offs on plants' ecophysiological/mycorrhizal fitness in the short term.
Asunto(s)
Clima Desértico , Micorrizas , Fenotipo , Micorrizas/fisiología , Capsicum/microbiología , Capsicum/fisiología , Capsicum/efectos de la radiación , Fotosíntesis/fisiología , Simbiosis/fisiología , Luz Solar , BiomasaRESUMEN
Bacterial endosymbionts manipulate reproduction in arthropods to increase their prevalence in the host population. One such manipulation is cytoplasmic incompatibility (CI), wherein the bacteria sabotage sperm in infected males to reduce the hatch rate when mated with uninfected females, but zygotes are 'rescued' when that male mates with an infected female. In the spider Mermessus fradeorum (Linyphiidae), Rickettsiella symbionts cause variable levels of CI. We hypothesised that temperature affects the strength of CI and its rescue in M. fradeorum, potentially mediated by bacterial titre. We reared Rickettsiella-infected spiders in two temperature conditions (26°C vs. 20°C) and tested CI induction in males and rescue in females. In incompatible crosses between infected males and uninfected females, the hatch rate from warm males was doubled (mean ± standard error = 0.687 ± 0.052) relative to cool males (0.348 ± 0.046), indicating that CI induction is weaker in warm males. In rescue crosses between infected females and infected males, female rearing temperature had a marginal effect on CI rescue, but the hatch rate remained high for both warm (0.960 ± 0.023) and cool females (0.994 ± 0.004). Bacterial titre, as measured by quantitative polymerase chain reaction, was lower in warm than cool spiders, particularly in females, suggesting that bacterial titre may play a role in causing the temperature-mediated changes in CI.
Asunto(s)
Calor , Arañas , Simbiosis , Animales , Arañas/microbiología , Femenino , Masculino , Citoplasma/microbiología , Coxiellaceae/genética , Reproducción , TemperaturaRESUMEN
The genomes of obligately host-restricted bacteria suffer from accumulating mildly deleterious mutations, resulting in marked size reductions. Psyllids (Hemiptera) are phloem sap-sucking insects with a specialized organ called the bacteriome, which typically harbors two vertically transmitted bacterial symbionts: the primary symbiont "Candidatus Carsonella ruddii" (Gammaproteobacteria) and a secondary symbiont that is phylogenetically diverse among psyllid lineages. The genomes of several Carsonella lineages were revealed to be markedly reduced (158-174| |kb), AT-rich (14.0-17.9% GC), and structurally conserved with similar gene inventories devoted to synthesizing essential amino acids that are scarce in the phloem sap. However, limited genomic information is currently available on secondary symbionts. Therefore, the present study investigated the genomes of the bacteriome-associated dual symbionts, Secondary_AM (Gammaproteobacteria) and Carsonella_AM, in the mulberry psyllid Anomoneura mori (Psyllidae). The results obtained revealed that the Secondary_AM genome is as small and AT-rich (229,822 bp, 17.3% GC) as those of Carsonella lineages, including Carsonella_AM (169,120 bp, 16.2% GC), implying that Secondary_AM is an evolutionarily ancient obligate mutualist, as is Carsonella. Phylogenomic ana-lyses showed that Secondary_AM is sister to "Candidatus Psyllophila symbiotica" of Cacopsylla spp. (Psyllidae), the genomes of which were recently reported (221-237| |kb, 17.3-18.6% GC). The Secondary_AM and Psyllophila genomes showed highly conserved synteny, sharing all genes for complementing the incomplete tryptophan biosynthetic pathway of Carsonella and those for synthesizing B vitamins. However, sulfur assimilation and carotenoid-synthesizing genes were only retained in Secondary_AM and Psyllophila, respectively, indicating ongoing gene silencing. Average nucleotide identity, gene ortholog similarity, genome-wide synteny, and substitution rates suggest that the Secondary_AM/Psyllophila genomes are more labile than Carsonella genomes.
Asunto(s)
Gammaproteobacteria , Genoma Bacteriano , Hemípteros , Morus , Filogenia , Simbiosis , Animales , Hemípteros/microbiología , Genoma Bacteriano/genética , Morus/microbiología , Morus/genética , Gammaproteobacteria/genética , Gammaproteobacteria/clasificación , Gammaproteobacteria/aislamiento & purificaciónRESUMEN
Biological nitrogen fixation is the main source of nitrogen in ecosystems. The diversity of soil rhizobia and their effects on soybeans need further research. In this study, we collected soybean rhizosphere samples from eight sites in the black soil soybean planting area in Northeast China. A total of 94 strains of bacteria were isolated and identified using the 16S rRNA and symbiotic genes (nodC, nifH) analysis, of which 70 strains were identified as rhizobia belonging to the genus Bradyrhizobium. To further validate the application effects of rhizobia, we selec-ted seven representative indigenous rhizobia based on the results of phylogenetic analysis, and conducted laboratory experiments to determine their nodulation and the impacts on soybeans. The results showed that, compared to the control without rhizobial inoculation, all the seven indigenous rhizobia exhibited good promoting and nodulation abilities. Among them, strains H7-L22 and H34-L6 performed the best, with the former significantly increasing plant height by 25.7% and the latter increasing root nodule dry weight by 20.9% to 67.1% compared to other indi-genous rhizobia treatments. We tested these two efficient rhizobia strains as soybean rhizobial inoculants in field experiments. The promoting effect of mixed rhizobial inoculants was significantly better than single ones. Compared to the control without inoculation, soybean yield increased by 8.4% with the strain H7-L22 treatment and by 17.9% with the mixed inoculant treatment. Additionally, there was a significant increase in the number of four-seed pods in soybeans. In conclusion, the application of rhizobial inoculants can significantly increase soybean yield, thereby reducing dependence on nitrogen fertilizer during soybean production, improving soil health, and promoting green development in agriculture in the black soil region of Northeast China.
Asunto(s)
Bradyrhizobium , Glycine max , Microbiología del Suelo , Glycine max/microbiología , Glycine max/crecimiento & desarrollo , China , Bradyrhizobium/aislamiento & purificación , Bradyrhizobium/fisiología , Bradyrhizobium/genética , Bradyrhizobium/clasificación , Rhizobium/aislamiento & purificación , Rhizobium/fisiología , Rhizobium/genética , Rhizobium/clasificación , Simbiosis , Filogenia , Fijación del Nitrógeno , Biodiversidad , Rizosfera , ARN Ribosómico 16S/genéticaRESUMEN
BACKGROUND: Potassium (K) is an essential nutrient for plant growth and development. Maize (Zea mays) is a widely planted crops in the world and requires a huge amount of K fertilizer. Arbuscular mycorrhizal fungi (AMF) are closely related to the K uptake of maize. Genetic improvement of maize K utilization efficiency will require elucidating the molecular mechanisms of maize K uptake through the mycorrhizal pathway. Here, we employed transcriptome and gene family analysis to elucidate the mechanism influencing the K uptake and utilization efficiency of mycorrhizal maize. METHODS AND RESULTS: The transcriptomes of maize were studied with and without AMF inoculation and under different K conditions. AM symbiosis increased the K concentration and dry weight of maize plants. RNA sequencing revealed that genes associated with the activity of the apoplast and nutrient reservoir were significantly enriched in mycorrhizal roots under low-K conditions but not under high-K conditions. Weighted gene correlation network analysis revealed that three modules were strongly correlated with K content. Twenty-one hub genes enriched in pathways associated with glycerophospholipid metabolism, glycerolipid metabolism, starch and sucrose metabolism, and anthocyanin biosynthesis were further identified. In general, these hub genes were upregulated in AMF-colonized roots under low-K conditions. Additionally, the members of 14 gene families associated with K obtain were identified (ARF: 38, ILK: 4, RBOH: 12, RUPO: 20, MAPKK: 89, CBL: 14, CIPK: 44, CPK: 40, PIN: 10, MYB: 174, NPF: 79, KT: 19, HAK/HKT/KUP: 38, and CPA: 8) from maize. The transcript levels of these genes showed that 92 genes (ARF:6, CBL:5, CIPK:13, CPK:2, HAK/HKT/KUP:7, PIN:2, MYB:26, NPF:16, RBOH:1, MAPKK:12 and RUPO:2) were upregulated with AM symbiosis under low-K conditions. CONCLUSIONS: This study indicated that AMF increase the resistance of maize to low-K stress by regulating K uptake at the gene transcription level. Our findings provide a genome-level resource for the functional assignment of genes regulated by K treatment and AM symbiosis in K uptake-related gene families in maize. This may contribute to elucidate the molecular mechanisms of maize response to low K stress with AMF inoculation, and provided a theoretical basis for AMF application in the crop field.
Asunto(s)
Micorrizas , Potasio , Simbiosis , Transcriptoma , Zea mays , Micorrizas/fisiología , Zea mays/genética , Zea mays/microbiología , Zea mays/metabolismo , Potasio/metabolismo , Simbiosis/genética , Genes de Plantas , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Raíces de Plantas/microbiología , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Perfilación de la Expresión GénicaRESUMEN
This work uses response surface methodology (RSM) to study the co-cultivation of symbiotic indigenous wastewater microalgae and bacteria under different conditions (inoculum ratio of bacteria to microalgae, CO2, light intensity, and harvest time) for optimal bioenergy feedstock production. The findings of this study demonstrate that the symbiotic microalgae-bacteria culture not only increases total microalgal biomass and lipid productivity, but also enlarges microalgal cell size and stimulates lipid accumulation. Meanwhile, inoculum ratio of bacteria to microalgae, light intensity, CO2, and harvest time significantly affect biomass and lipid productivity. CO2 concentration and harvest time have significant interactive effect on lipid productivity. The response of microalgal biomass and lipid productivity varies significantly from 2.1 × 105 to 1.9 × 107 cells/mL and 2.8 × 102 to 3.7 × 1012 Total Fluorescent Units/mL respectively. Conditions for optimum biomass and oil accumulation are 100% of inoculation ratio (bacteria/microalgae), 3.6% of CO2 (v/v), 205.8 µmol/m2/s of light intensity, and 10.6 days of harvest time. This work provides a systematic methodology with RSM to explore the benefits of symbiotic microalgae-bacteria culture, and to optimize various cultivation parameters within complex wastewater environments for practical applications of integrated wastewater-microalgae systems for cost-efficient bioenergy production.
Asunto(s)
Bacterias , Biocombustibles , Biomasa , Dióxido de Carbono , Microalgas , Aguas Residuales , Aguas Residuales/microbiología , Microalgas/crecimiento & desarrollo , Microalgas/metabolismo , Biocombustibles/microbiología , Bacterias/metabolismo , Bacterias/crecimiento & desarrollo , Dióxido de Carbono/metabolismo , Técnicas de Cocultivo/métodos , Simbiosis , Lípidos/biosíntesis , Lípidos/análisisRESUMEN
Sponge microbiomes are often highly diverse making it difficult to determine which lineages are important for maintaining host health and homeostasis. Characterising genomic traits associated with symbiosis can improve our knowledge of which lineages have adapted to their host and what functions they might provide. Here we examined five microbial families associated with sponges that have previously shown evidence of cophylogeny, including Endozoicomonadaceae, Nitrosopumilaceae, Spirochaetaceae, Microtrichaceae and Thermoanaerobaculaceae, to better understand the mechanisms behind their symbiosis. We compared sponge-associated genomes to genomes found in other environments and found that sponge-specific clades were enriched in genes encoding many known mechanisms for symbiont survival, such as avoiding phagocytosis and defence against foreign genetic elements. We expand on previous knowledge to show that glycosyl hydrolases with sulfatases and sulfotransferases likely form multienzyme degradation pathways to break and remodel sulfated polysaccharides and reveal an enrichment in superoxide dismutase that may prevent damage from free oxygen radicals produced by the host. Finally, we identified novel traits in sponge-associated symbionts, such as urea metabolism in Spirochaetaceae which was previously shown to be rare in the phylum Spirochaetota. These results identify putative mechanisms by which symbionts have adapted to living in association with sponges.
Asunto(s)
Bacterias , Genómica , Poríferos , Simbiosis , Poríferos/microbiología , Animales , Bacterias/genética , Bacterias/clasificación , Bacterias/metabolismo , Microbiota , Filogenia , Genoma BacterianoRESUMEN
Leafcutter ants are dominant herbivores in the Neotropics and rely on a fungus (Leucoagaricus gongylophorus) to transform freshly gathered leaves into a source of nourishment rather than consuming the vegetation directly. Here we report two virus-like particles that were isolated from L. gongylophorus and observed using transmission electron microscopy. RNA sequencing identified two +ssRNA mycovirus strains, Leucoagaricus gongylophorus tymo-like virus 1 (LgTlV1) and Leucoagaricus gongylophorus magoulivirus 1 (LgMV1). Genome annotation of LgTlV1 (7401 nt) showed conserved domains for methyltransferase, endopeptidase, viral RNA helicase, and RNA-dependent RNA polymerase (RdRp). The smaller genome of LgMV1 (2636 nt) contains one open reading frame encoding an RdRp. While we hypothesize these mycoviruses function as symbionts in leafcutter farming systems, further study will be needed to test whether they are mutualists, commensals, or parasites.
Asunto(s)
Hormigas , Virus Fúngicos , Genoma Viral , ARN Viral , Virus Fúngicos/genética , Virus Fúngicos/clasificación , Virus Fúngicos/aislamiento & purificación , Virus Fúngicos/fisiología , Animales , Hormigas/microbiología , Hormigas/virología , ARN Viral/genética , Filogenia , Sistemas de Lectura Abierta , Simbiosis , ARN Polimerasa Dependiente del ARN/genética , Microscopía Electrónica de Transmisión , Virus ARN/genética , Virus ARN/clasificación , Virus ARN/aislamiento & purificación , Virus ARN/fisiología , Agaricales/virología , Agaricales/genéticaRESUMEN
Three bacterial strains, 1AS14IT, 1AS12I and 6AS6, isolated from root nodules of Acacia saligna, were characterized using a polyphasic approach. Phylogenetic analysis based on rrs sequences placed all three strains within the Rhizobium leguminosarum complex. Further phylogeny, based on 1â756 bp sequences of four concatenated housekeeping genes (recA, atpD, glnII and gyrB), revealed their distinction from known rhizobia species of the R. leguminosarum complex (Rlc), forming a distinct clade. The closest related species, identified as Rhizobium laguerreae, with a sequence identity of 96.4% based on concatenated recA-atpD-glnII-gyrB sequences. The type strain, 1AS14IT, showed average nucleotide identity (ANI) values of 94.9, 94.3 and 94.1% and DNA-DNA hybridization values of 56.1, 57.4 and 60.0% with the type strains of closest known species: R. laguerreae, Rhizobium acaciae and 'Rhizobium indicum', respectively. Phylogenomic analyses using 81 up-to-date bacteria core genes and the Type (Strain) Genome Server pipeline further supported the uniqueness of strains 1AS14IT, 1AS12I and 6AS6. The relatedness of the novel strains to NCBI unclassified Rhizobium sp. (396 genomes) and metagenome-derived genomes showed ANI values from 76.7 to 94.8% with a species-level cut-off of 96%, suggesting that strains 1AS14I, 1AS12I and 6AS6 are a distinct lineage. Additionally, differentiation of strains 1AS14IT, 1AS12I and 6AS6 from their closest phylogenetic neighbours was achieved using phenotypic, physiological and fatty acid content analyses. Based on the genomic, phenotypic and biochemical data, we propose the establishment of a novel rhizobial species, Rhizobium aouanii sp. nov., with strain 1AS14IT designated as the type strain (=DSM 113914T=LMG 33206T). This study contributes to the understanding of microbial diversity in nitrogen-fixing symbioses, specifically within Acacia saligna ecosystems in Tunisia.
Asunto(s)
Acacia , Técnicas de Tipificación Bacteriana , ADN Bacteriano , Ácidos Grasos , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Rhizobium , Nódulos de las Raíces de las Plantas , Análisis de Secuencia de ADN , Rhizobium/genética , Rhizobium/clasificación , Rhizobium/aislamiento & purificación , ADN Bacteriano/genética , Acacia/microbiología , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , Túnez , Nódulos de las Raíces de las Plantas/microbiología , Genes Esenciales/genética , Genes Bacterianos , Composición de Base , SimbiosisRESUMEN
Root exudates are known signaling agents that influence legume root nodulation, but the molecular mechanisms for nonflavonoid molecules remain largely unexplored. The number of soybean root nodules during the initial growth phase shows substantial discrepancies at distinct developmental junctures. Using a combination of metabolomics analyses on root exudates and nodulation experiments, we identify a pivotal role for certain root exudates during the rapid growth phase in promoting nodulation. Phenoxyacetic acid (POA) was found to activate the expression of GmGA2ox10 and thereby facilitate rhizobial infection and the formation of infection threads. Furthermore, POA exerts regulatory control on the miR172c-NNC1 module to foster nodule primordia development and consequently increase nodule numbers. These findings collectively highlight the important role of POA in enhancing nodulation during the accelerated growth phase of soybeans.
Asunto(s)
Glycine max , Nodulación de la Raíz de la Planta , Simbiosis , Glycine max/crecimiento & desarrollo , Glycine max/metabolismo , Glycine max/microbiología , Glycine max/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Raíces de Plantas/efectos de los fármacos , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , MicroARNs/metabolismo , MicroARNs/genética , Acetatos/metabolismo , Acetatos/farmacologíaRESUMEN
Global warming is a leading environmental stress that reduces plant productivity worldwide. Several beneficial microorganisms reduce stress; however, the mechanism by which plant-microbe interactions occur and reduce stress remains to be fully elucidated. The aim of the present study was to elucidate the mutualistic interaction between the plant growth-promoting rhizobacterial strain SH-19 and soybeans of the Pungsannamul variety. The results showed that SH-19 possessed several plant growth-promoting traits, such as the production of indole-3-acetic acid, siderophore, and exopolysaccharide, and had the capacity for phosphate solubilisation. The heat tolerance assay showed that SH-19 could withstand temperatures up to 45 °C. The strain SH-19 was identified as P. megaterium using the 16S ribosomal DNA gene sequence technique. Inoculation of soybeans with SH-19 improved seedling characteristics under high-temperature stress. This may be due to an increase in the endogenous salicylic acid level and a decrease in the abscisic acid level compared with the negative control group. The strain of SH-19 increased the activity of the endogenous antioxidant defense system, resulting in the upregulation of GSH (44.8%), SOD (23.1%), APX (11%), and CAT (52.6%). Furthermore, this study involved the transcription factors GmHSP, GmbZIP1, and GmNCED3. The findings showed upregulation of the two transcription factors GmbZIP1 (17%), GmNCED3 (15%) involved in ABA biosynthesis and induced stomatal regulation, similarly, a downregulation of the expression pattern of GmHSP by 25% was observed. Overall, the results of this study indicate that the strain SH-19 promotes plant growth, reduces high-temperature stress, and improves physiological parameters by regulating endogenous phytohormones, the antioxidant defense system, and genetic expression. The isolated strain (SH-19) could be commercialized as a biofertilizer.
Asunto(s)
Glycine max , Glycine max/microbiología , Glycine max/genética , Glycine max/metabolismo , Glycine max/fisiología , Respuesta al Choque Térmico , Transducción de Señal , Burkholderiales/genética , Burkholderiales/fisiología , Burkholderiales/metabolismo , Metabolismo Secundario , Reguladores del Crecimiento de las Plantas/metabolismo , Simbiosis , Ácido Salicílico/metabolismoRESUMEN
Mutations in voltage-gated sodium (Nav) channels, which are essential for generating and propagating action potentials, can lead to serious neurological disorders, such as epilepsy. However, disease-causing Nav channel mutations do not always result in severe symptoms, suggesting that the disease conditions are significantly affected by other genetic factors and various environmental exposures, collectively known as the "exposome". Notably, recent research emphasizes the pivotal role of commensal bacteria in neural development and function. Although these bacteria typically benefit the nervous system under normal conditions, their impact during pathological states remains largely unknown. Here, we investigated the influence of commensal microbes on seizure-like phenotypes exhibited by paraShu-a gain-of-function mutant of the Drosophila Nav channel gene, paralytic. Remarkably, the elimination of endogenous bacteria considerably ameliorated neurological impairments in paraShu. Consistently, reintroducing bacteria, specifically from the Lactobacillus or Acetobacter genera, heightened the phenotypic severity in the bacteria-deprived mutants. These findings posit that particular native bacteria contribute to the severity of seizure-like phenotypes in paraShu. We further uncovered that treating paraShu with antibiotics boosted Nrf2 signaling in the gut, and that global Nrf2 activation mirrored the effects of removing bacteria from paraShu. This raises the possibility that the removal of commensal bacteria suppresses the seizure-like manifestations through augmented antioxidant responses. Since bacterial removal during development was critical for suppression of adult paraShu phenotypes, our research sets the stage for subsequent studies, aiming to elucidate the interplay between commensal bacteria and the developing nervous system in conditions predisposed to the hyperexcitable nervous system.
Asunto(s)
Convulsiones , Canales de Sodio Activados por Voltaje , Animales , Convulsiones/genética , Canales de Sodio Activados por Voltaje/genética , Canales de Sodio Activados por Voltaje/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/microbiología , Fenotipo , Mutación , Acetobacter/genética , Acetobacter/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Simbiosis/genética , Microbioma GastrointestinalRESUMEN
Tripartite interactions among plants, fungi, and bacteria are critical for maintaining plant growth and fitness, and volatile organic compounds (VOCs) play a significant role in these interactions. However, the functions of VOCs within the niche of mycoheterotrophic plants, which represent unique types of interactions, remain poorly understood. Gastrodia elata, a mycoheterotrophic orchid species, forms a symbiotic relationship with specific Armillaria species, serving as a model system to investigate this intriguing issue. Rahnella aceris HPDA25 is a plant growth-promoting bacteria isolated from G. elata, which has been found to facilitate the establishment of G. elata-Armillaria symbiosis. In this study, using the tripartite symbiotic system of G. elata-Armillaria gallica-R. aceris HPDA25, we investigate the role of VOCs in the interaction among mycoheterotrophic plants, fungi, and bacteria. Our results showed that 33 VOCs of HPDA25-inducible symbiotic G. elata elevated compared to non-symbiotic G. elata, indicating that VOCs indeed play a role in the symbiotic process. Among these, 21 VOCs were accessible, and six active VOCs showed complete growth inhibition activities against A. gallica, while R. aceris HPDA25 had no significant effect. In addition, three key genes of G. elata have been identified that may contribute to the increased concentration of six active VOCs. These results revealed for the first time the VOCs profile of G. elata and demonstrated its regulatory role in the tripartite symbiotic system involving G. elata, Armillaria, and bacteria.
Asunto(s)
Armillaria , Gastrodia , Simbiosis , Compuestos Orgánicos Volátiles , Simbiosis/fisiología , Compuestos Orgánicos Volátiles/metabolismo , Gastrodia/microbiología , Gastrodia/metabolismo , Gastrodia/genética , Armillaria/metabolismo , Armillaria/genéticaRESUMEN
Microbial dysbiosis may manifest as inflammation both orally and in the gastrointestinal tract. Altered oral and gut microbiota composition and decreased diversity have been shown in inflammatory bowel disease (IBD) and periodontal disease (PD). Recent studies have verified transmission of oral opportunistic microbes to the gut. Prebiotics, probiotics, or dietary interventions are suggested to alleviate IBD symptoms in addition to medicinal treatment. Lingonberries contain multiple bioactive molecules, phenolics, which have a broad spectrum of effects, including antimicrobial, anti-inflammatory, antioxidant, anti-proteolytic, and anti-cancer properties. An all-natural product, fermented lingonberry juice (FLJ), is discussed as a potential natural anti-inflammatory substance. FLJ has been shown in clinical human trials to promote the growth of oral lactobacilli, and inhibit growth of the opportunistic oral pathogens Candida, Streptococcus mutans, and periodontopathogens, and decrease inflammation, oral destructive proteolysis (aMMP-8), and dental microbial plaque load. Lactobacilli are probiotic and considered also beneficial for gut health. Considering the positive outcome of these oral studies and the fact that FLJ may be swallowed safely, it might be beneficial also for the gut mucosa by balancing the microbiota and reducing proteolytic inflammation.
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Antiinflamatorios , Jugos de Frutas y Vegetales , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Humanos , Antiinflamatorios/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Enfermedades Inflamatorias del Intestino/microbiología , Enfermedades Inflamatorias del Intestino/dietoterapia , Fermentación , Vaccinium vitis-Idaea , Boca/microbiología , Probióticos/administración & dosificación , Disbiosis , SimbiosisRESUMEN
Soybean plants form symbiotic nitrogen-fixing nodules with specific rhizobia bacteria. The root hair is the initial infection site for the symbiotic process before the nodules. Since roots and nodules grow in soil and are hard to perceive, little knowledge is available on the process of soybean root hair deformation and nodule development over time. In this study, adaptive microrhizotrons were used to observe root hairs and to investigate detailed root hair deformation and nodule formation subjected to different rhizobia densities. The result showed that the root hair curling angle increased with the increase of rhizobia density. The largest curling angle reached 268° on the 8th day after inoculation. Root hairs were not always straight, even in the uninfected group with a relatively small angle (<45°). The nodule is an organ developed after root hair curling. It was inoculated from curling root hairs and swelled in the root axis on the 15th day after inoculation, with the color changing from light (15th day) to a little dark brown (35th day). There was an error between observing the diameter and the real diameter; thus, a diameter over 1 mm was converted to the real diameter according to the relationship between the perceived diameter and the real diameter. The diameter of the nodule reached 5 mm on the 45th day. Nodule number and curling number were strongly related to rhizobia density with a correlation coefficient of determination of 0.92 and 0.93, respectively. Thus, root hair curling development could be quantified, and nodule number could be estimated through derived formulation.
Asunto(s)
Glycine max , Raíces de Plantas , Nódulos de las Raíces de las Plantas , Simbiosis , Glycine max/microbiología , Glycine max/crecimiento & desarrollo , Raíces de Plantas/microbiología , Simbiosis/fisiología , Nódulos de las Raíces de las Plantas/microbiología , Rhizobium/fisiología , Fijación del NitrógenoRESUMEN
Recent theoretical advances in the One Health approach have suggested that cancer pathologies should be given greater consideration, as cancers often render their hosts more vulnerable to infectious agents, which could turn them into super spreaders within ecosystems. Although biologically plausible, this hypothesis has not yet been validated experimentally. Using a community of cnidarians of the Hydra genus (Hydra oligactis, Hydra viridissima, Hydra vulgaris) and a commensal ciliate species (Kerona pediculus) that colonizes them, we tested whether tumoral polyps of H. oligactis, compared to healthy ones, played an amplifying role in the number of ciliates, potentially resulting in a higher likelihood of infection for other community members through spillovers. Our results indicate that K. pediculus has a higher proliferation rate on tumoral polyps of H. oligactis than on healthy ones, which results in the infestation of other hydras. However, the magnitude of the spillover differed between recipient species. This study provides to our knowledge the first elements of proof of concept that tumoral individuals in communities could act as super spreaders of symbionts within and between species, and thus affect biotic interactions and dynamics in ecosystems.
Asunto(s)
Hydra , Neoplasias , Simbiosis , Animales , Hydra/microbiología , Hydra/fisiología , Salud Única , Ecosistema , Cilióforos/fisiologíaRESUMEN
Candidatus Patescibacteria, also known as candidate phyla radiation (CPR), including the class-level uncultured clade JAEDAM01 (formerly a subclass of Gracilibacteria/GN02/BD1-5), are ubiquitous in activated sludge. However, their characteristics and relationships with other organisms are largely unknown. They are believed to be episymbiotic, endosymbiotic or predatory. Despite our understanding of their limited metabolic capacity, their precise roles remain elusive due to the difficulty in cultivating and identifying them. In previous research, we successfully recovered high-quality metagenome-assembled genomes (MAGs), including a member of JAEDAM01 from activated sludge flocs. In this study, we designed new probes to visualize the targeted JAEDAM01-associated MAG HHAS10 and identified its host using fluorescence in situ hybridization (FISH). The FISH observations revealed that JAEDAM01 HHAS10-like cells were located within dense clusters of Zoogloea, and the fluorescence brightness of zoogloeal cells decreased in the vicinity of the CPR cells. The Zoogloea MAGs possessed genes related to extracellular polymeric substance biosynthesis, floc formation and nutrient removal, including a polyhydroxyalkanoate (PHA) accumulation pathway. The JAEDAM01 MAG HHAS10 possessed genes associated with type IV pili, competence protein EC and PHA degradation, suggesting a Zoogloea-dependent lifestyle in activated sludge flocs. These findings indicate a new symbiotic relationship between JAEDAM01 and Zoogloea.
Asunto(s)
Aguas del Alcantarillado , Simbiosis , Aguas Residuales , Zoogloea , Aguas del Alcantarillado/microbiología , Zoogloea/genética , Zoogloea/metabolismo , Aguas Residuales/microbiología , Hibridación Fluorescente in Situ , Metagenoma , FilogeniaRESUMEN
Mycorrhizal fungi, a category of fungi that form symbiotic relationships with plant roots, can participate in the induction of plant disease resistance by secreting phosphatase enzymes. While extensive research exists on the mechanisms by which mycorrhizal fungi induce resistance, the specific contributions of phosphatases to these processes require further elucidation. This article reviews the spectrum of mycorrhizal fungi-induced resistance mechanisms and synthesizes a current understanding of how phosphatases mediate these effects, such as the induction of defense structures in plants, the negative regulation of plant immune responses, and the limitation of pathogen invasion and spread. It explores the role of phosphatases in the resistance induced by mycorrhizal fungi and provides prospective future research directions in this field.
Asunto(s)
Resistencia a la Enfermedad , Micorrizas , Enfermedades de las Plantas , Micorrizas/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/genética , Monoéster Fosfórico Hidrolasas/metabolismo , Plantas/microbiología , Plantas/inmunología , Simbiosis , Raíces de Plantas/microbiología , Inmunidad de la PlantaRESUMEN
Rhizobia interact with leguminous plants in the soil to form nitrogen fixing nodules in which rhizobia and plant cells coexist. Although there are emerging studies on rhizobium-associated nitrogen fixation in cereals, the legume-rhizobium interaction is more well-studied and usually serves as the model to study rhizobium-mediated nitrogen fixation in plants. Rhizobia play a crucial role in the nitrogen cycle in many ecosystems. However, rhizobia are highly sensitive to variations in soil conditions and physicochemical properties (i.e. moisture, temperature, salinity, pH, and oxygen availability). Such variations directly caused by global climate change are challenging the adaptive capabilities of rhizobia in both natural and agricultural environments. Although a few studies have identified rhizobial genes that confer adaptation to different environmental conditions, the genetic basis of rhizobial stress tolerance remains poorly understood. In this review, we highlight the importance of improving the survival of rhizobia in soil to enhance their symbiosis with plants, which can increase crop yields and facilitate the establishment of sustainable agricultural systems. To achieve this goal, we summarize the key challenges imposed by global climate change on rhizobium-plant symbiosis and collate current knowledge of stress tolerance-related genes and pathways in rhizobia. And finally, we present the latest genetic engineering approaches, such as synthetic biology, implemented to improve the adaptability of rhizobia to changing environmental conditions.