scholarly journals Casuarina glauca Prenodule Cells Display the Same Differentiation as the Corresponding Nodule Cells

2000 ◽  
Vol 13 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Laurent Laplaze ◽  
Emile Duhoux ◽  
Claudine Franche ◽  
Thierry Frutz ◽  
Sergio Svistoonoff ◽  
...  
Keyword(s):  
Root Nodule ◽  
Common Ancestor ◽  
Cortical Cell ◽  
Cell Types ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Casuarina Glauca ◽  
Cell Divisions ◽  
Phylogenetic Studies ◽  
Infected Cells

Recent phylogenetic studies have implied that all plants able to enter root nodule symbioses with nitrogen-fixing bacteria go back to a common ancestor (D. E. Soltis, P. S. Soltis, D. R. Morgan, S. M. Swensen, B. C. Mullin, J. M. Dowd, and P. G. Martin, Proc. Natl. Acad. Sci. USA, 92:2647–2651, 1995). However, nodules formed by plants from different groups are distinct in nodule organogenesis and structure. In most groups, nodule organogenesis involves the induction of cortical cell divisions. In legumes these divisions lead to the formation of a nodule primordium, while in non-legumes they lead to the formation of a so-called prenodule consisting of infected and un-infected cells. Nodule primordium formation does not involve prenodule cells, and the function of prenodules is not known. Here, we examine the differentiation of actinorhizal prenodule cells in comparison to nodule cells with regard to both symbionts. Our findings indicate that prenodules represent primitive symbiotic organs whose cell types display the same characteristics as their nodule counterparts. The results are discussed in the context of the evolution of root nodule symbioses.

scholarly journals Stable Genetic Transformation and Heterologous Expression in the Nitrogen-fixing Plant Endosymbiont Frankia alni ACN14a

2018 ◽  
Author(s):  
Isaac Gifford ◽  
Summer Vance ◽  
Giang Nguyen ◽  
Alison M Berry
Keyword(s):  
Genetic Transformation ◽  
Root Nodule ◽  
Cell Types ◽  
Nitrogen Fixing ◽  
Chloramphenicol Resistance ◽  
Type Iv ◽  
Frankia Alni ◽  
Limited Culture ◽  
Nif Gene Cluster ◽  
Common Plant

Genus Frankia is comprised primarily of nitrogen-fixing actinobacteria that form root nodule symbioses with a group of hosts known as the actinorhizal plants. These plants are evolutionarily closely related to the legumes, which are nodulated by the rhizobia. Both host groups utilize homologs of nodulation genes for root-nodule symbiosis, derived from common plant ancestors. However the corresponding endosymbionts, Frankia and the rhizobia, are distantly related groups of bacteria, leading to questions of their symbiotic mechanisms and evolutionary history. To date, a stable system of genetic transformation has been lacking in Frankia. Here, we report the successful electrotransformation of Frankia alni ACN14a, by means of replicating plasmids expressing chloramphenicol-resistance for selection, and the use of GFP as a marker of gene expression. We have identified type IV methyl-directed restriction systems, highly-expressed in a range of actinobacteria, as a likely barrier to Frankia transformation and circumvented this barrier by using unmethylated plasmids, which allowed the transformation of F. alni as well as the maintenance of the plasmid. During nitrogen limitation, Frankia differentiates into two cell types: the vegetative hyphae and nitrogen-fixing vesicles. When the plasmid transformation system was used with expression of egfp under the control of the nif gene cluster promoter, it was possible to demonstrate by fluorescence imaging the expression of nitrogen fixation in vesicles but not hyphae in nitrogen-limited culture.

scholarly journals Simultaneous Identification of Brain Cell Type and Lineage via Single Cell RNA Sequencing

2021 ◽  
Author(s):  
Donovan J. Anderson ◽  
Florian M. Pauler ◽  
Aaron McKenna ◽  
Jay Shendure ◽  
Simon Hippenmeyer ◽  
...  
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
Expression Patterns ◽  
Cortical Cell ◽  
Cell Types ◽  
F1 Hybrids ◽  
Mouse Strains ◽  
Monoallelic Expression ◽  
Cell Divisions ◽  
Single Cell Rna Sequencing

ABSTRACTAcquired mutations are sufficiently frequent such that the genome of a single cell offers a record of its history of cell divisions. Among more common somatic genomic alterations are loss of heterozygosity (LOH). Large LOH events are potentially detectable in single cell RNA sequencing (scRNA-seq) datasets as tracts of monoallelic expression for constitutionally heterozygous single nucleotide variants (SNVs) located among contiguous genes. We identified runs of monoallelic expression, consistent with LOH, uniquely distributed throughout the genome in single cell brain cortex transcriptomes of F1 hybrids involving different inbred mouse strains. We then phylogenetically reconstructed single cell lineages and simultaneously identified cell types by corresponding gene expression patterns. Our results are consistent with progenitor cells giving rise to multiple cortical cell types through stereotyped expansion and distinct waves of neurogenesis. Compared to engineered recording systems, LOH events accumulate throughout the genome and across the lifetime of an organism, affording tremendous capacity for encoding lineage information and increasing resolution for later cell divisions. This approach can conceivably be computationally incorporated into scRNA-seq analysis and may be useful for organisms where genetic engineering is prohibitive, such as humans.

scholarly journals Cowpea symbiotic efficiency, pH and aluminum tolerance in nitrogen-fixing bacteria

2014 ◽  
Vol 71 (3) ◽  
pp. 171-180 ◽  
Author(s):  
Bruno Lima Soares ◽  
Paulo Avelar Ademar Ferreira ◽  
Silvia Maria de Oliveira-Longatti ◽  
Leandro Marciano Marra ◽  
Marcia Rufini ◽  
...  
Keyword(s):  
Aluminum Tolerance ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Symbiotic Efficiency

scholarly journals A Genome-Scale Metabolic Model of Anabaena 33047 to Guide Genetic Modifications to Overproduce Nylon Monomers

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 168
Author(s):  
John I. Hendry ◽  
Hoang V. Dinh ◽  
Debolina Sarkar ◽  
Lin Wang ◽  
Anindita Bandyopadhyay ◽  
...  
Keyword(s):  
Electron Transport ◽  
Pyruvate Decarboxylase ◽  
Metabolic Model ◽  
Cell Types ◽  
Economic Feasibility ◽  
Nitrogen Fixing ◽  
Design Algorithm ◽  
A Genome ◽  
Anabaena Sp ◽  
Genome Scale

Nitrogen fixing-cyanobacteria can significantly improve the economic feasibility of cyanobacterial production processes by eliminating the requirement for reduced nitrogen. Anabaena sp. ATCC 33047 is a marine, heterocyst forming, nitrogen fixing cyanobacteria with a very short doubling time of 3.8 h. We developed a comprehensive genome-scale metabolic (GSM) model, iAnC892, for this organism using annotations and content obtained from multiple databases. iAnC892 describes both the vegetative and heterocyst cell types found in the filaments of Anabaena sp. ATCC 33047. iAnC892 includes 953 unique reactions and accounts for the annotation of 892 genes. Comparison of iAnC892 reaction content with the GSM of Anabaena sp. PCC 7120 revealed that there are 109 reactions including uptake hydrogenase, pyruvate decarboxylase, and pyruvate-formate lyase unique to iAnC892. iAnC892 enabled the analysis of energy production pathways in the heterocyst by allowing the cell specific deactivation of light dependent electron transport chain and glucose-6-phosphate metabolizing pathways. The analysis revealed the importance of light dependent electron transport in generating ATP and NADPH at the required ratio for optimal N2 fixation. When used alongside the strain design algorithm, OptForce, iAnC892 recapitulated several of the experimentally successful genetic intervention strategies that over produced valerolactam and caprolactam precursors.

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.

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