Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.607
Filtrar
1.
PLoS One ; 15(8): e0238151, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833990

RESUMO

Bacteria often possess relatively flexible genome structures and adaptive genetic variants that allow survival in unfavorable growth conditions. Bacterial survival tactics in disadvantageous microenvironments include mutations that are beneficial against threats in their niche. Here, we report that the aerobic rice bacterial pathogen Burkholderia glumae BGR1 changes a specific gene for improved survival in static culture conditions. Static culture triggered formation of colony variants with deletions or point mutations in the gene bspP (BGLU_RS28885), which putatively encodes a protein that contains PDC2, PAS-9, SpoIIE, and HATPase domains. The null mutant of bspP survived longer in static culture conditions and produced a higher level of bis-(3'-5')-cyclic dimeric guanosine monophosphate than the wild type. Expression of the bacterial cellulose synthase regulator (bcsB) gene was upregulated in the mutant, consistent with the observation that the mutant formed pellicles faster than the wild type. Mature pellicle formation was observed in the bspP mutant before pellicle formation in wild-type BGR1. However, the population density of the bspP null mutant decreased substantially when grown in Luria-Bertani medium with vigorous agitation due to failure of oxalate-mediated detoxification of the alkaline environment. The bspP null mutant was less virulent and exhibited less effective colonization of rice plants than the wild type. All phenotypes caused by mutations in bspP were recovered to those of the wild type by genetic complementation. Thus, although wild-type B. glumae BGR1 prolonged viability by spontaneous mutation under static culture conditions, such genetic changes negatively affected colonization in rice plants. These results suggest that adaptive gene sacrifice of B. glumae to survive unfavorable growth conditions is not always desirable as it can adversely affect adaptability in the host.


Assuntos
Adaptação Biológica/genética , Burkholderia/genética , Burkholderia/metabolismo , Burkholderia/patogenicidade , Regulação Bacteriana da Expressão Gênica/genética , Genoma Bacteriano/genética , Genômica/métodos , Mutação , Oryza/microbiologia , Doenças das Plantas/microbiologia , Percepção de Quorum/genética , Virulência/genética
2.
PLoS Pathog ; 16(8): e1008326, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32804988

RESUMO

CRISPR/Cas has become the state-of-the-art technology for genetic manipulation in diverse organisms, enabling targeted genetic changes to be performed with unprecedented efficiency. Here we report on the first establishment of robust CRISPR/Cas editing in the important necrotrophic plant pathogen Botrytis cinerea based on the introduction of optimized Cas9-sgRNA ribonucleoprotein complexes (RNPs) into protoplasts. Editing yields were further improved by development of a novel strategy that combines RNP delivery with cotransformation of transiently stable vectors containing telomeres, which allowed temporary selection and convenient screening for marker-free editing events. We demonstrate that this approach provides superior editing rates compared to existing CRISPR/Cas-based methods in filamentous fungi, including the model plant pathogen Magnaporthe oryzae. Genome sequencing of edited strains revealed very few additional mutations and no evidence for RNP-mediated off-targeting. The high performance of telomere vector-mediated editing was demonstrated by random mutagenesis of codon 272 of the sdhB gene, a major determinant of resistance to succinate dehydrogenase inhibitor (SDHI) fungicides by in bulk replacement of the codon 272 with codons encoding all 20 amino acids. All exchanges were found at similar frequencies in the absence of selection but SDHI selection allowed the identification of novel amino acid substitutions which conferred differential resistance levels towards different SDHI fungicides. The increased efficiency and easy handling of RNP-based cotransformation is expected to accelerate molecular research in B. cinerea and other fungi.


Assuntos
Botrytis/fisiologia , Sistemas CRISPR-Cas , Edição de Genes , Oryza/microbiologia , Doenças das Plantas/microbiologia , Ribonucleoproteínas/antagonistas & inibidores , Telômero/genética , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Oryza/genética , Doenças das Plantas/genética , Ribonucleoproteínas/genética
3.
J Oleo Sci ; 69(9): 1031-1041, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788512

RESUMO

To accelerate the fermentation rate and reduce the adverse effects of undesirable microorganism contamination on rice noodle quality, the pure inoculum fermentation method was used to produce fermented rice noodles. The results indicated that the pure inoculum fermented rice slurry required 10 h to reach a stable pH value. While, the pH value of the natural, pure and natural inoculum fermented rice slurries required 54, 18 and 20 h to stabilize, respectively. Free amino acids and lactic acid concentrations of the pure inoculum fermented rice slurry were higher than those of the natural and natural inoculum fermented rice slurries. The pure inoculum fermentation modified the proximate composition and lowered the pasting viscosities of the rice flour. The texture, cooking and eating qualities of the pure inoculum fermented rice noodles were similar to those of the natural fermented ones. In addition, the pure inoculum fermented rice noodles had higher relative contents of aldehydes than other fermented rice noodles and thus had a better flavor. Therefore, pure inoculum fermentation accelerated the fermentation rate and improved the rice noodle flavor while maintaining the texture, cooking and eating qualities of the rice noodles.


Assuntos
Fermentação , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Lactobacillus plantarum/metabolismo , Oryza/química , Oryza/microbiologia , Aldeídos/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio , Paladar , Fatores de Tempo
4.
J Biosci Bioeng ; 130(3): 311-318, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32487498

RESUMO

Methane-oxidizing bacteria (MOB) possess the metabolic potential to assimilate the highly potent greenhouse gas, CH4, and can also synthesize valuable products. Depending on their distinct and fastidious metabolic pathways, MOB are mainly divided into Type I and Type II; the latter are known as producers of polyhydroxyalkanoate (PHA). Despite the metabolic potential of MOB to synthesize PHA, the ecophysiology of MOB, especially under high CH4 flux conditions, is yet to be understood. Therefore, in this study, a rice paddy soil receiving a high CH4 flux from underground was used as an inoculum to enrich MOB using fed-batch operation, then the enriched Type II MOB were characterized. The transitions in the microbial community composition and CH4 oxidation rates were monitored by 16S rRNA gene amplicon sequencing and degree of CH4 consumption. With increasing incubation time, the initially dominant Methylomonas sp., affiliated with Type I MOB, was gradually replaced with Methylocystis sp., Type II MOB, resulting in a maximum CH4 oxidation rate of 1.40 g-CH4/g-biomass/day. The quantification of functional genes encoding methane monooxygenase, pmoA and PHA synthase, phaC, by quantitative PCR revealed concomitant increases in accordance with the Type II MOB enrichment. These increases in the functional genes underscore the significance of Type II MOB to mitigate greenhouse gas emission and produce PHA.


Assuntos
Metano/metabolismo , Methylococcaceae/metabolismo , Oryza/metabolismo , Oryza/microbiologia , Técnicas de Cultura Celular por Lotes , Methylococcaceae/genética , Methylococcaceae/crescimento & desenvolvimento , Microbiota , Oxirredução , Oxigenases/genética , RNA Ribossômico 16S/genética , Solo/química
5.
Ecotoxicol Environ Saf ; 201: 110804, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502907

RESUMO

Phenanthrene (PHE) is harmful to human health and is difficult to be eliminated from environment. In this study, an aerobic bacterium capable of use PHE as a sole carbon source and energy was isolated and classified as Klebsiella sp. PD3 according to 16S rDNA analysis. The degradation efficiency of PHE reached to about 78.6% after 12 days of incubation with strain PD3. Identification of metabolites formed during PHE degradation process by this strain was carried out by GC-MS. The first degradation step of PHE by PD3 was proposed to generate 1-hydroxy-2-naphthoic acid. Two subsequent different routes for the metabolism of 1-hydroxy-2-naphthoic acid were proposed. Strain PD3 also showed two plant growth promoting properties like phosphate solubilization and ACC deaminase activity. Inoculation with Klebsiella sp. PD3 significantly improved growth performance, biomass production, seed germination rate, photosynthetic capacity, antioxidant levels, relative water content and chlorophyll accumulation in rice (Oryza sativa L.) plants under PHE stress conditions in comparison with non-inoculation treatment. Moreover, PD3-inoculated rice showed lower ROS accumulation, ethylene production, ACC content, ACC oxidase activity and electrolyte leakage under PHE treatment compared to non-inoculated ones. The combination use of rice plants and strain PD3 was also shown to enhance the removal efficiency of PHE from the soil and decline the PHE accumulation in plants. Synergistic use of plants and bacteria with PHE degradation ability and PGPR attributes to remediate the PHE-contaminated soil will be an important and effective way in the phytoremediation of PHE-contaminated soils.


Assuntos
Adaptação Fisiológica , Klebsiella/metabolismo , Oryza/crescimento & desenvolvimento , Fenantrenos/análise , Microbiologia do Solo , Poluentes do Solo/análise , Biodegradação Ambiental , Clorofila/metabolismo , Etilenos/metabolismo , Klebsiella/isolamento & purificação , Oryza/metabolismo , Oryza/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Fenantrenos/metabolismo , Solo/química , Poluentes do Solo/metabolismo
6.
Int J Syst Evol Microbiol ; 70(7): 4171-4178, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32552985

RESUMO

A novel Gram-stain-negative strain, designated ZYY5T, was isolated from rice roots. Results of 16S rRNA gene analysis indicated that strain ZYY5T was a member of the genus Dickeya, with a highest similarity to Dickeya zeae DSM 18068T (98.5%). The major fatty acids were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0 and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). Multi-locus sequence analysis using five concatenated genes (16S rRNA, atpD, infB, recA and gyrB) and phylogenomic analysis based on 2940 core gene sequences showed that strain ZYY5T formed a robust cluster with strains EC1, ZJU1202, DZ2Q, NCPPB 3531 and CSL RW192, while separated from the other strains of D. zeae. The orthologous average nucleotide identity (ANI) and digital DNA-DNAhybridization (dDDH) values among these six strains ranged from 96.8-99.9% and 73.7-99.8%, which supported that they were belonged to the same species. However, strain ZYY5T shared 58.4 of dDDH and 94.5% of ANI values with type strain D. zeae DSM 18068T, which were lower than the proposed species boundary cut-off for dDDH and ANI. The genomic analysis revealed that strain ZYY5T contained virulence-associated genes, which is same as the phylogenetic-related strains of the genus Dickeya. Based on the results of the polyphasic approaches, we propose that strain ZYY5T represents a novel species in the genus Dickeya, for which the name Dickeya oryzae sp. nov. (=JCM 33020 T=ACCC 61554 T) is proposed. Strains EC1, ZJU1202, DZ2Q, NCPPB 3531 and CSL RW192 should also be classified in the same genomospecies of D. oryzae same as ZYY5T.


Assuntos
Enterobacteriaceae/classificação , Oryza/microbiologia , Filogenia , Raízes de Plantas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Enterobacteriaceae/isolamento & purificação , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
PLoS One ; 15(6): e0233911, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479550

RESUMO

Promoters are very important for transcriptional regulation and gene expression, and have become invaluable tools for genetic engineering. Owing to the characteristics of obligate biotrophs, molecular research into obligate biotrophic fungi is seriously lagging behind, and very few of their endogenous promoters have been developed. In this study, a WY7 fragment was predicted in the genome of Oidium heveae Steinmann using PromoterScan. Its promoter function was verified with transient transformations (Agrobacterium tumefaciens-mediated transformation, ATMT) in Nicotiana tabacum cv. Xanthi nc. The analysis of the transcription range showed that WY7 could regulate GUS expression in both monocots (Zea mays Linn and Oryza sativa L. spp. Japonica cv. Nipponbare) and dicots (N. tabacum and Hylocereus undulates Britt). The results of the quantitative detection showed that the GUS transient expression levels when regulated by WY7 was more than 11.7 times that of the CaMV 35S promoter in dicots (N. tabacum) and 5.13 times that of the ACT1 promoter in monocots (O. sativa). GUS staining was not detected in the T1 generation of the WY7-GUS transgenic N. tabacum. This showed that WY7 is an inducible promoter. The cis elements of WY7 were predicted using PlantCARE, and further experiments indicated that WY7 was a low temperature- and salt-inducible promoter. Soluble proteins produced by WY7-hpa1Xoo transgenic tobacco elicited hypersensitive responses (HR) in N. tabacum leaves. N. tabacum transformed with pBI121-WY7-hpa1Xoo exhibited enhanced resistance to the tobacco mosaic virus (TMV). The WY7 promoter has a lot of potential as a tool for plant genetic engineering. Further in-depth studies will help to better understand the transcriptional regulation mechanisms of O. heveae.


Assuntos
Fungos/genética , Regulação Fúngica da Expressão Gênica , Engenharia Genética/métodos , Doenças das Plantas/prevenção & controle , Regiões Promotoras Genéticas , Fungos/patogenicidade , Genoma Fúngico , Hevea/genética , Hevea/microbiologia , Interações Hospedeiro-Patógeno/genética , Magnoliopsida/genética , Magnoliopsida/microbiologia , Oryza/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Plantas Geneticamente Modificadas , Tabaco/genética , Tabaco/microbiologia , Transformação Genética , Zea mays/genética , Zea mays/microbiologia
8.
Arch Microbiol ; 202(9): 2419-2428, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32591911

RESUMO

For sustainable agriculture in saline soil, extensive exploitation of salt-tolerant plant growth-promoting (PGP) bacteria and other symbiotic bacteria is required. This study was carried out to evaluate the efficiency of native salt-tolerant rice rhizobacteria for plant growth promotion under salt stress. A total of 188 bacteria were screened for assessing salt-tolerant capacity and nine isolates tolerating 12% NaCl (w/v) concentration were selected. Biochemical and molecular identification revealed that the salt-tolerant bacteria belonged to Bacillus sp, Exiguobacterium sp, Enterobacter sp, Lysinibacillus sp, Stenotrophomonas sp, Microbacterium sp, and Achromobacter sp. The increase in NaCl concentration from 2 to 4% decreases the PGP activities such as IAA production, P solubilization, K solubilization, and nitrate reduction. The effects of inoculation of salt-tolerant bacteria on the growth and different physiological properties of rice (Oryza sativa) were studied. It was found that the salinity affected the root and shoot length of the control plants; however, bacterial inoculant were found to effectively promote the growth of paddy under salinity stress. Further, bacterial inoculants substantially enhanced total chlorophyll, proline, total phenol, and oxidative damage such as electrolyte leakage and membrane stability index under salt stress. This study suggests that salt-tolerant PGP bacteria may be used for cultivation of O. sativa in salinized agricultural lands.


Assuntos
Fenômenos Fisiológicos Bacterianos , Oryza/microbiologia , Estresse Salino , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , Clorofila/metabolismo , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , Salinidade , Plantas Tolerantes a Sal/microbiologia , Solo/química , Simbiose/fisiologia
9.
Proc Natl Acad Sci U S A ; 117(28): 16649-16659, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32586957

RESUMO

Low availability of nitrogen (N) is often a major limiting factor to crop yield in most nutrient-poor soils. Arbuscular mycorrhizal (AM) fungi are beneficial symbionts of most land plants that enhance plant nutrient uptake, particularly of phosphate. A growing number of reports point to the substantially increased N accumulation in many mycorrhizal plants; however, the contribution of AM symbiosis to plant N nutrition and the mechanisms underlying the AM-mediated N acquisition are still in the early stages of being understood. Here, we report that inoculation with AM fungus Rhizophagus irregularis remarkably promoted rice (Oryza sativa) growth and N acquisition, and about 42% of the overall N acquired by rice roots could be delivered via the symbiotic route under N-NO3 - supply condition. Mycorrhizal colonization strongly induced expression of the putative nitrate transporter gene OsNPF4.5 in rice roots, and its orthologs ZmNPF4.5 in Zea mays and SbNPF4.5 in Sorghum bicolor OsNPF4.5 is exclusively expressed in the cells containing arbuscules and displayed a low-affinity NO3 - transport activity when expressed in Xenopus laevis oocytes. Moreover, knockout of OsNPF4.5 resulted in a 45% decrease in symbiotic N uptake and a significant reduction in arbuscule incidence when NO3 - was supplied as an N source. Based on our results, we propose that the NPF4.5 plays a key role in mycorrhizal NO3 - acquisition, a symbiotic N uptake route that might be highly conserved in gramineous species.


Assuntos
Proteínas de Transporte de Ânions/metabolismo , Glomeromycota/fisiologia , Micorrizas/fisiologia , Nitrogênio/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Transporte de Ânions/genética , Regulação da Expressão Gênica de Plantas , Nitratos/metabolismo , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Sorghum/genética , Sorghum/metabolismo , Sorghum/microbiologia , Zea mays/genética , Zea mays/metabolismo , Zea mays/microbiologia
10.
Arch Microbiol ; 202(8): 2169-2179, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32519022

RESUMO

Bacillus methylotrophicus has been demonstrated to promote growth of various plants, whereas the promoting effect of B. methylotrophicus on rice growth has been rarely reported. In this study, B. methylotrophicus DD-1, capable of efficiently promoting the growth of rice, was isolated from the root soil of rice plants. The isolate exhibited potassium-solubilizing (1.18 mg/L), Indole-3-acetic acid (IAA) (87.26 mg/L), Gibberellic acid (GA) (25.91 mg/L) and Siderophore production activity (52.32%). As indicated from the result, plant growth parameters (e.g., dry weight, tiller number, root and shoot length) of rice seedlings treated with the isolate DD-1 were more effective than those of the control group in pot and soilless culture experiments. Moreover, the adsorption capacity of rice roots which were soaked in the bacterial suspension of isolate increased with the increase in concentration and absorption time. In sterilized and unsterilized soil, conformation of root colonization activity by bacterial isolate established by its nearer existence to the rice root. Thus, the B. methylotrophicus DD-1 enhances plant growth promotion by multifarious growth promoting and root colonization traits, thereby augmenting potassium level in soil. Henceforth, the potential bacterium could be exploited for the development of biological fertilizer, leading towards sustainable agronomy.


Assuntos
Bacillus/fisiologia , Oryza/microbiologia , Raízes de Plantas/microbiologia , Plântula/microbiologia , Microbiologia do Solo , Bacillus/isolamento & purificação , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/crescimento & desenvolvimento , Desenvolvimento Vegetal , Plântula/crescimento & desenvolvimento , Sideróforos/metabolismo
11.
Int J Food Microbiol ; 330: 108667, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32531666

RESUMO

Fusarium fujikuroi species complex (FFSC) species are commonly encountered infecting rice, but knowledge of the diversity and toxigenic potential of the species is lacking in Brazil, the largest rice-producing country outside Asia. One hundred FFSC isolates obtained from national rice were identified using morphology and phylogeny of TEF, CAL and TUB genes. Eight previously known and one novel Fusarium species were identified. Three species accounted for around 60% of the strains: F. fujikuroi (n = 23), F. proliferatum (n = 22) and F. verticillioides (n = 16). The less frequent species were F. volatile (n = 8), F. anthophilum (n = 6), F. pseudocircinatum (n = 4), F. sterilihyphosum (n = 2) and F. begoniae (n = 1). The novel Fusarium species was represented by 18 isolates. All species produced at least one of the analyzed mycotoxins [beauvericin (BEA), fumonisins (FBs), moniliformin (MON) and enniatins (ENNs)]. BEA was produced by all species but F. verticillioides. The FBs (mainly FB1) were produced mostly by F. fujikuroi, F. proliferatum and F. verticillioides. F. begoniae and F. verticillioides did not produce ENNs and F. sterilihyphosum and F. begoniae did not produce MON, while the other species produced MON and ENNs. Our results add new knowledge of the diversity, geographical distribution and host range of FFSC species.


Assuntos
Fusarium/química , Fusarium/classificação , Oryza/microbiologia , Biodiversidade , Brasil , Fusarium/genética , Fusarium/isolamento & purificação , Especificidade de Hospedeiro , Micotoxinas/análise , Filogenia , Venenos/análise
12.
Chemosphere ; 256: 127157, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470740

RESUMO

Microcystins released by cyanobacteria affect crop growth and productivity, and even food safety. Plant hormones play a vital role in regulating growth, development and stress response in plants. Therefore, we studied the response of hormones including abscisic acid (ABA), indole-3-acetic acid (IAA), Zeatin (ZT) and gibberellin (GA3) as well as hormone balances (IAA/ABA, ZT/ABA and GA/ABA) to cyanobacterial extract containing microcystins (1, 10, 100 and 1000 µg/L) during stress and recovery periods. Low concentration microcystins (1 µg/L) promoted growth of rice seedlings by increasing levels of IAA, ZT and GA3 and maintaining hormone balances. In addition, the up-regulation of OsYUCCA1 increased IAA level in rice roots by promoting IAA biosynthesis. High concentrations microcystins (10, 100 or1000 µg/L) inhibited growth of rice seedlings by reducing levels of IAA, ZT and GA3 and ratios of IAA/ABA, ZT/ABA and GA/ABA due to increased ABA level. The increase in ABA in rice seedlings induced by high concentrations MCs was resulted from up-regulation of OsNCED1, OsNCED3, OsNCED4 and OsZEP to enhance ABA biosynthesis, and was controlled by up-regulating expression levels of OsABAox1-3 for enhancing ABA catabolism as negative feedback. The highest concentration of MCs (1000 µg/L) caused irreversible damage to metabolisms of IAA and ABA, partly resulting in unrecoverable inhibition on rice growth. All results demonstrate that "low-concentration promotion and high-concentration inhibition" of microcystins was associated with changes in hormone levels and balances by affecting their metabolisms, and could be helpful for guiding agricultural irrigation with microcystin contaminated water.


Assuntos
Cianobactérias/metabolismo , Microcistinas/toxicidade , Oryza/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Plântula/metabolismo , Ácido Abscísico/metabolismo , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Extratos Vegetais , Raízes de Plantas/metabolismo , Zeatina/metabolismo
13.
Yi Chuan ; 42(5): 506-518, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32431301

RESUMO

The root-associated bacterial microbiota is closely related to life activities of land plants, and its composition is affected by geographic locations and plant genotypes. However, the influence of plant genotypes on root microbiota in rice grown in northern China remains to be explained. In this study, we performed 16S rRNA gene amplicon sequencing to generate bacterial community profiles of two representative rice cultivars, Nipponbare and IR24. They are planted in Changping and Shangzhuang farms in Beijing and have reached the reproductive stage. We compared their root microbiota in details by Random Forest machine learning algorithm and network analysis. We found that the diversity of rice root microbiota was significantly affected by geographic locations and rice genotypes. Nipponbare and IR24 showed distinct taxonomic composition of the root microbiota and the interactions between different bacteria. Moreover, the root bacteria could be used as biomarkers to distinguish Nipponbare from IR24 across regions. Our study provides a theoretical basis for the in-depth understanding of rice root microbiota in Northern China and the improvement of rice breeding from the perspective of the interaction between root microorganisms and plants.


Assuntos
Bactérias/classificação , Microbiota , Oryza/microbiologia , Raízes de Plantas/microbiologia , China , RNA Ribossômico 16S
14.
Nat Commun ; 11(1): 2114, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32355217

RESUMO

Most plants associate with beneficial arbuscular mycorrhizal (AM) fungi that facilitate soil nutrient acquisition. Prior to contact, partner recognition triggers reciprocal genetic remodelling to enable colonisation. The plant Dwarf14-Like (D14L) receptor conditions pre-symbiotic perception of AM fungi, and also detects the smoke constituent karrikin. D14L-dependent signalling mechanisms, underpinning AM symbiosis are unknown. Here, we present the identification of a negative regulator from rice, which operates downstream of the D14L receptor, corresponding to the homologue of the Arabidopsis thaliana Suppressor of MAX2-1 (AtSMAX1) that functions in karrikin signalling. We demonstrate that rice SMAX1 is a suppressor of AM symbiosis, negatively regulating fungal colonisation and transcription of crucial signalling components and conserved symbiosis genes. Similarly, rice SMAX1 negatively controls strigolactone biosynthesis, demonstrating an unexpected crosstalk between the strigolactone and karrikin signalling pathways. We conclude that removal of SMAX1, resulting from D14L signalling activation, de-represses essential symbiotic programmes and increases strigolactone hormone production.


Assuntos
Proteínas de Arabidopsis/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Micorrizas/fisiologia , Oryza/microbiologia , Proteínas de Plantas/fisiologia , Simbiose , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Furanos/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Compostos Heterocíclicos com 3 Anéis/metabolismo , Homozigoto , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lactonas/metabolismo , Família Multigênica , Oryza/genética , Filogenia , Proteínas de Plantas/genética , Raízes de Plantas/microbiologia , Piranos/metabolismo , RNA-Seq , Transdução de Sinais
15.
Int J Syst Evol Microbiol ; 70(5): 3300-3308, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375931

RESUMO

A Gram-stain-positive, non-motile, creamy-white actinobacterium, which has an elementary branching rod-coccus life cycle was isolated from the rhizosphere soil of rice (Oryza sativa L.) collected from Northeast Agricultural University in Harbin, Heilongjiang province, north-east PR China, and its taxonomic status was examined by using a polyphasic approach. Results from the 16S rRNA gene sequence study showed that the isolate, designated strain NEAU-CX67T, belonged to the genus Rhodococcus and formed a cluster with Rhodococcus maanshanensis DSM 44675T, Rhodococcus kronopolitis NEAU-ML12T and Rhodococcus tukisamuensis JCM 11308T (98.3, 98.1 and 97.7% gene sequence similarity, respectively). The major fatty acids were C16 : 0, 10-methyl C18 : 0, C18 : 1 ω9c and C16 : 1 ω7c. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major isoprenoid quinone was MK-8(H2). Whole-cell hydrolysates contained meso-diaminopimelic acid. Arabinose, galactose and ribose were detected as diagnostic sugars from whole-cell hydrolysates. Mycolic acids were detected. The genomic DNA G+C content of strain NEAU-CX67T was 64.6 mol%. Strain NEAU-CX67T exhibited low average nucleotide identity and digital DNA-DNA hybridization values with R. maanshanensis DSM 44675T (92.1 and 45.4 %) and R. tukisamuensis JCM 11308T (81.9 and 24.4 %). On the basis of results of phylogenetic, genotypic, physiological and chemotaxonomic analysis, strain NEAU-CX67T is considered to represent a novel species of the genus Rhodococcus for which the name Rhodococcus oryzae sp. nov. is proposed. The type strain is NEAU-CX67T (=DSM 107701T=CCTCC AB 2018233T).


Assuntos
Oryza/microbiologia , Filogenia , Rizosfera , Rhodococcus/classificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodococcus/isolamento & purificação , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
16.
J Biosci Bioeng ; 130(1): 63-70, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32265130

RESUMO

Japanese sake production involves three processes: rice koji fermentation, seed mash fermentation, and main mash fermentation. Traditional seed mash (kimoto) production utilizes natural lactic acid produced by lactic acid bacteria for pure cultures of only sake yeast, preventing the growth of wild yeast and other unwanted bacteria. Recently, because kimoto production requires substantial time and labor, sake yeast mass-cultured in usual liquid medium has been used as a seed mash alternative. Sake quality is highly similar to that of kimoto, suggesting that they share similar component profiles. However, comparative component analyses of sake brewed with kimoto and sake brewed with cultured yeast are lacking. In this study, a time-course analysis of hydrophilic compounds in the main mash brewed with kimoto and with cultured yeast as well as a sensory evaluation of the products were performed. As a result, differences in various compounds and in umami taste level between sake brewed with kimoto and cultured yeast were detected. This is the first comparative analysis of changes in the component profile during sake main mash brewing using kimoto seed mash and cultured sake yeast; our results clarify the effects of kimoto seed mash on main mash brewing and sake quality.


Assuntos
Bebidas Alcoólicas/análise , Aromatizantes/química , Leveduras/metabolismo , Bebidas Alcoólicas/microbiologia , Fermentação , Aromatizantes/metabolismo , Humanos , Ácido Láctico/análise , Ácido Láctico/metabolismo , Lactobacillales/metabolismo , Oryza/química , Oryza/metabolismo , Oryza/microbiologia , Sementes/química , Sementes/metabolismo , Sementes/microbiologia , Paladar
17.
Nat Commun ; 11(1): 1608, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32231209

RESUMO

The emerging resistance of crop pathogens to fungicides poses a challenge to food security and compels discovery of new antifungal compounds. Here, we show that mono-alkyl lipophilic cations (MALCs) inhibit oxidative phosphorylation by affecting NADH oxidation in the plant pathogens Zymoseptoria tritici, Ustilago maydis and Magnaporthe oryzae. One of these MALCs, consisting of a dimethylsulfonium moiety and a long alkyl chain (C18-SMe2+), also induces production of reactive oxygen species at the level of respiratory complex I, thus triggering fungal apoptosis. In addition, C18-SMe2+ activates innate plant defense. This multiple activity effectively protects cereals against Septoria tritici blotch and rice blast disease. C18-SMe2+ has low toxicity in Daphnia magna, and is not mutagenic or phytotoxic. Thus, MALCs hold potential as effective and non-toxic crop fungicides.


Assuntos
Cátions/farmacologia , Produtos Agrícolas/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Substâncias Protetoras/farmacologia , Animais , Ascomicetos/efeitos dos fármacos , Cátions/química , Daphnia/efeitos dos fármacos , Descoberta de Drogas , Grão Comestível/microbiologia , Fibroblastos/efeitos dos fármacos , Fungicidas Industriais/química , Humanos , Mitocôndrias/efeitos dos fármacos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Substâncias Protetoras/química , Triticum/microbiologia , Ustilago/efeitos dos fármacos
18.
High Blood Press Cardiovasc Prev ; 27(3): 251-258, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32266706

RESUMO

INTRODUCTION: Ischemic heart disease is closely associated with many risk factors. Germinated brown rice extract (GBR) has potent antioxidant activities for alleviating the factors for developing heart failure such as hypertension and diabetes mellitus. AIM: The objective of the present study was to determine the cardio-protective effects of GBR and to elucidate the mechanisms underlying these effects in a model of simulated myocardial ischemic/ reperfusion injury (sI/R). METHODS: An in vitro study was performed on cultured rat cardiomyoblasts (H9c2) exposed to sI/R. The expression of apoptosis and signaling proteins was assessed using Western blot analyses. Eighteen New Zealand White rabbits were divided into 3 groups and the left circumflex coronary artery was ligated to induce myocardial ischemia. Heart functions were monitored by electrocardiography and echocardiography 0, 30, and 60 days after coronary artery ligation. RESULTS: GBR consumption group showed significantly improved cardiac function and reduced the heart rate, along with reduced mean arterial pressure and plasma glucose level. Also, GBR showed good scavenging activity, pretreatment with GBR inhibited I/R induced apoptosis by suppressing the production of caspase 3 and p38 MAPK. CONCLUSIONS: These results suggest that intake of germinated brown rice may effectively to protect cell proliferation and apoptosis and may provide important nutrients to prevent heart failure due to myocardial ischemia.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Oryza/microbiologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/isolamento & purificação , Caspase 3/metabolismo , Linhagem Celular , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fermentação , Hemodinâmica/efeitos dos fármacos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Coelhos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Função Ventricular Esquerda/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
19.
Int J Syst Evol Microbiol ; 70(5): 3111-3116, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32250236

RESUMO

Two Gram-stain-positive, rod-shaped, non-motile, non-spore-forming, catalase-negative bacteria, designated strains SG162T and NK01, were isolated from Japanese rice grain silage and total mixed ration silage, respectively. They were initially identified as Lactobacillus buchneri based on the 16S rRNA gene sequence similarities. However, the two strains were separated into a distinct clade from L. buchneri DSM 20057T (=JCM 1115T) through whole-genome sequence-based characterization, forming an infraspecific subgroup together with strains CD034 and S42, whose genomic sequences were available in the public sequence database. Strains within the subgroup shared 99.4-99.7 % average nucleotide identity (ANI) and 97.5-99.0 % digital DNA-DNA hybridization (dDDH) with each other, albeit 96.9-97.0 % ANI and 76.0-76.6 % dDDH against DSM 20057T. Strains SG162T and NK01 could utilize more substrates as sole carbon sources than DSM 20057T, potentially owing to the abundance of genes involved in carbon metabolism, especially the Entner-Doudoroff pathway. The inability of γ-aminobutyric acid (GABA) production was evidenced by the lack of glutamate decarboxylase and glutamate/GABA antiporter genes in the new subgroup strains. Strain SG162T grew at 10-45 °C (optimum, 30 °C), pH 3.5-8.0, and 0-8 % (w/v) NaCl. Its genomic DNA G+C content was 44.1 mol%. The predominant fatty acids were C16 : 0, C19 : 0 cyclo ω8c, and summed feature 8. On the basis of the polyphasic characterization findings, strains SG162T and NK01 represent a novel subspecies of L. buchneri, for which the name Lactobacillus buchneri subsp. silagei subsp. nov. is proposed. The type strain is SG162T (=JCM 32599T=DSM 107969T), and strains CD034 and S42 are also transferred to L. buchneri subsp. silagei.


Assuntos
Lactobacillus/classificação , Oryza/microbiologia , Filogenia , Silagem/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Grão Comestível/microbiologia , Ácidos Graxos/química , Genes Bacterianos , Japão , Lactobacillus/isolamento & purificação , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
20.
PLoS One ; 15(4): e0232115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32339192

RESUMO

Crop diseases are responsible for considerable yield losses worldwide and particularly in sub-Saharan Africa. To implement efficient disease control measures, detection of the pathogens and understanding pathogen spatio-temporal dynamics is crucial and requires the use of molecular detection tools, especially to distinguish different pathogens causing more or less similar symptoms. We report here the design a new molecular diagnostic tool able to simultaneously detect five bacterial taxa causing important diseases on rice in Africa: (1) Pseudomonas fuscovaginae, (2) Xanthomonas oryzae, (3) Burkholderia glumae and Burkholderia gladioli, (4) Sphingomonas and (5) Pantoea species. This new detection tool consists of a multiplex PCR, which is cost effective and easily applicable. Validation of the method is presented through its application on a global collection of bacterial strains. Moreover, sensitivity assessment for the detection of all five bacteria is reported to be at 0.5 ng DNA by µl. As a proof of concept, we applied the new molecular detection method to a set of 256 rice leaves collected from 16 fields in two irrigated areas in western Burkina Faso. Our results show high levels of Sphingomonas spp. (up to 100% of tested samples in one field), with significant variation in the incidence between the two sampled sites. Xanthomonas oryzae incidence levels were mostly congruent with bacterial leaf streak (BLS) and bacterial leaf blight (BLB) symptom observations in the field. Low levels of Pantoea spp. were found while none of the 256 analysed samples was positive for Burkholderia or Pseudomonas fuscovaginae. Finally, many samples (up to 37.5% in one studied field) were positive for more than one bacterium (co-infection). Documenting co-infection levels are important because of their drastic consequences on epidemiology, evolution of pathogen populations and yield losses. The newly designed multiplex PCR for multiple bacterial pathogens of rice is a significant improvement for disease monitoring in the field, thus contributing to efficient disease control and food safety.


Assuntos
Burkholderia/genética , Coinfecção/diagnóstico , DNA Bacteriano/análise , Reação em Cadeia da Polimerase Multiplex/métodos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Pseudomonas/genética , Xanthomonas/genética , Burkholderia/isolamento & purificação , Burkholderia/patogenicidade , Burkina Faso/epidemiologia , Coinfecção/epidemiologia , Coinfecção/genética , DNA Bacteriano/genética , Incidência , Pseudomonas/isolamento & purificação , Pseudomonas/patogenicidade , Xanthomonas/isolamento & purificação , Xanthomonas/patogenicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA