scholarly journals Anaerobic Nitrogen-Fixing Consortia Consisting of Clostridia Isolated from Gramineous Plants

2004 ◽  
Vol 70 (5) ◽  
pp. 3096-3102 ◽  
Author(s):  
Kiwamu Minamisawa ◽  
Kiyo Nishioka ◽  
Taro Miyaki ◽  
Bin Ye ◽  
Takuya Miyamoto ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Wild Rice ◽  
Nitrogen Fixing ◽  
Naturally Occurring ◽  
Pioneer Plants ◽  
Wild Rice Species

ABSTRACT We report here the existence of anaerobic nitrogen-fixing consortia (ANFICOs) consisting of N2-fixing clostridia and diverse nondiazotrophic bacteria in nonleguminous plants; we found these ANFICOs while attempting to overcome a problem with culturing nitrogen-fixing microbes from various gramineous plants. A major feature of ANFICOs is that N2 fixation by the anaerobic clostridia is supported by the elimination of oxygen by the accompanying bacteria in the culture. In a few ANFICOs, nondiazotrophic bacteria specifically induced nitrogen fixation of the clostridia in culture. ANFICOs are widespread in wild rice species and pioneer plants, which are able to grow in unfavorable locations. These results indicate that clostridia are naturally occurring endophytes in gramineous plants and that clostridial N2 fixation arises in association with nondiazotrophic endophytes.

scholarly journals Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species

2001 ◽  
Vol 67 (11) ◽  
pp. 5285-5293 ◽  
Author(s):  
Adel Elbeltagy ◽  
Kiyo Nishioka ◽  
Tadashi Sato ◽  
Hisa Suzuki ◽  
Bin Ye ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Wild Rice ◽  
Fluorescent Protein ◽  
In Planta ◽  
Cultivated Rice ◽  
Phenotypic Properties ◽  
Rice Varieties ◽  
Bacterial Populations ◽  
Rdna Sequences ◽  
Wild Rice Species

ABSTRACT Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum,Ideonella, Enterobacter, andAzospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2gas incorporation assays. Therefore, we conclude thatHerbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis.

scholarly journals Enterobacter oryzae sp. nov., a nitrogen-fixing bacterium isolated from the wild rice species Oryza latifolia

2009 ◽  
Vol 59 (7) ◽  
pp. 1650-1655 ◽  
Author(s):  
G. Peng ◽  
W. Zhang ◽  
H. Luo ◽  
H. Xie ◽  
W. Lai ◽  
...  
Keyword(s):  
Wild Rice ◽  
Nitrogen Fixing ◽  
Wild Rice Species ◽  
Oryza Latifolia

scholarly journals Enterobacter oryzae sp. nov., a nitrogen-fixing bacterium isolated from the wild rice species Oryza latifolia

2009 ◽  
Vol 59 (10) ◽  
pp. 2646-2646
Author(s):  
Guixiang Peng ◽  
Zhiyuan Tan ◽  
Huifen Luo ◽  
Weihao Lai ◽  
Wu Zhang ◽  
...  
Keyword(s):  
Wild Rice ◽  
Nitrogen Fixing ◽  
Wild Rice Species ◽  
Oryza Latifolia

scholarly journals Expression of the nifH Gene of a Herbaspirillum Endophyte in Wild Rice Species: Daily Rhythm during the Light-Dark Cycle

2005 ◽  
Vol 71 (12) ◽  
pp. 8183-8190 ◽  
Author(s):  
Mu You ◽  
Tomohiro Nishiguchi ◽  
Asami Saito ◽  
Tsuyoshi Isawa ◽  
Hisayuki Mitsui ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Wild Rice ◽  
Nifh Gene ◽  
Living Cells ◽  
Daily Rhythm ◽  
Gene Transcript ◽  
In Planta ◽  
Rt Pcr ◽  
Free Living ◽  
Wild Rice Species

ABSTRACT The expression of nitrogenase genes of Herbaspirillum sp. B501 associated in shoot (leaf and stem) of wild rice, Oryza officinalis, was studied by means of reverse transcription-PCR (RT-PCR) targeted at the nifH gene. RT-PCR analyses indicate that nifH transcript was detected exclusively from nitrogen-fixing cells of gfp-tagged strain B501gfp1 in both free-living and endophytic states by using a constitutive gfp gene transcript as a positive control. Transcription of nifH and nitrogen fixation in free-living cells were induced maximally at a 2% O2 concentration and repressed in free air (21% O2). nifH transcription was monitored in the endophytic cells by using total RNA extracted from B501gfp1-inoculated wild rice plants during daily light-dark cycles. The level of nifH transcription in planta varied dramatically, with a maximum during the light period. Moreover, the light radiation enhanced nifH expression even in free-living cells grown in culture. These results suggest that in planta nitrogen fixation by the endophyte shows a daily rhythm determined by the plant's light environment.

scholarly journals Plasmids Related to the Symbiotic Nitrogen Fixation Are Not Only Cooperated Functionally but Also May Have Evolved over a Time Span in Family Rhizobiaceae

2020 ◽  
Vol 12 (11) ◽  
pp. 2002-2014
Author(s):  
Ling-Ling Yang ◽  
Zhao Jiang ◽  
Yan Li ◽  
En-Tao Wang ◽  
Xiao-Yang Zhi
Keyword(s):  
Nitrogen Fixation ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Symbiotic Nitrogen Fixation ◽  
Gene Families ◽  
Time Span ◽  
Soil Conditions ◽  
Gene Gain ◽  
Nitrogen Fixing ◽  
Pan Genome

Abstract Rhizobia are soil bacteria capable of forming symbiotic nitrogen-fixing nodules associated with leguminous plants. In fast-growing legume-nodulating rhizobia, such as the species in the family Rhizobiaceae, the symbiotic plasmid is the main genetic basis for nitrogen-fixing symbiosis, and is susceptible to horizontal gene transfer. To further understand the symbioses evolution in Rhizobiaceae, we analyzed the pan-genome of this family based on 92 genomes of type/reference strains and reconstructed its phylogeny using a phylogenomics approach. Intriguingly, although the genetic expansion that occurred in chromosomal regions was the main reason for the high proportion of low-frequency flexible gene families in the pan-genome, gene gain events associated with accessory plasmids introduced more genes into the genomes of nitrogen-fixing species. For symbiotic plasmids, although horizontal gene transfer frequently occurred, transfer may be impeded by, such as, the host’s physical isolation and soil conditions, even among phylogenetically close species. During coevolution with leguminous hosts, the plasmid system, including accessory and symbiotic plasmids, may have evolved over a time span, and provided rhizobial species with the ability to adapt to various environmental conditions and helped them achieve nitrogen fixation. These findings provide new insights into the phylogeny of Rhizobiaceae and advance our understanding of the evolution of symbiotic nitrogen fixation.

scholarly journals Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Phosphate Solubilization ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Promising Tool ◽  
A Genome ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.

Identification and diversity of functional centromere satellites in the wild rice species Oryza brachyantha

2013 ◽  
Vol 21 (8) ◽  
pp. 725-737 ◽  
Author(s):  
Chuandeng Yi ◽  
Wenli Zhang ◽  
Xibin Dai ◽  
Xing Li ◽  
Zhiyun Gong ◽  
...  
Keyword(s):  
Wild Rice ◽  
Wild Rice Species ◽  
Oryza Brachyantha ◽  
In The Wild

Isolation and Identification of a Functional Centromere Element in the Wild Rice Species Oryza granulata with the GG Genome

2015 ◽  
Vol 42 (12) ◽  
pp. 699-702 ◽  
Author(s):  
Chuandeng Yi ◽  
Mingsen Wang ◽  
Wei Jiang ◽  
Derong Wang ◽  
Yong Zhou ◽  
...  
Keyword(s):  
Wild Rice ◽  
Isolation And Identification ◽  
Wild Rice Species ◽  
In The Wild ◽  
Oryza Granulata

Nitrogen fixation

1976 ◽  
Vol 274 (934) ◽  
pp. 341-358 ◽  
Keyword(s):  
Nitrogen Fixation ◽  
Metabolic Regulation ◽  
Higher Plants ◽  
Focal Point ◽  
Nitrogenase Activity ◽  
Nitrogen Fixing ◽  
Blue Green Algae ◽  
International Biological Programme ◽  
The 1960S ◽  
Biological Programme

The International Biological Programme served as a focal point for studies on biological nitrogen fixation during the 1960s. The introduction of the acetylene reduction technique for measuring nitrogenase activity in the field led to estimates becoming available of the contribution of lichens, blue-green algae, nodulated non-legumes and bacterial-grass associations, as well as of legumes. Other studies carried out on the physiology and biochemistry of the process led to the eventual purification and characterization of the nitrogenase enzyme. These studies, collectively, provided the springboard for current work, so essential in view of the present energy crisis, on how to increase the use and efficiency of nitrogen-fixing plants, on the metabolic regulation of the nitrogenase enzyme and on the genetics of the nitrogen-fixing process, both in higher plants and in free-living micro-organisms.

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