Sporulation in root nodules of actinorhizal plants inoculated with pure cultured strains of Frankia

1991 ◽  
Vol 69 (7) ◽  
pp. 1471-1476 ◽  
Author(s):  
Suzanne Racette ◽  
John G. Torrey ◽  
R. Howard Berg
Keyword(s):  
Host Plants ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
High Magnification ◽  
Casuarina Equisetifolia ◽  
Light Microscope Level ◽  
Casuarina Glauca ◽  
Host Root ◽  
Spore Release ◽  
Thin Plastic

A low level of sporulation was seen to occur consistently within root nodules produced by inoculation with specific pure cultured strains of Frankia. The three Frankia strains, UFGCeI5 from Casuarina equisetifolia, UFGCgI1 from Casuarina glauca, and UFGMuI1 from Myrica pubescens, infect and produce root nodules on a range of actinorhizal host plants. Sporulation was detected in nodules of each host plant examined when the Frankia used for inoculation was one of these three strains. The amount of sporulation that occurred in any particular nodule was so low that it required identification in thin plastic sections prepared for examination at high magnification at the light microscope level. These strains, unlike other isolates studied, appear to be genetically predisposed to sporulate in the host root nodules. All three strains also show spontaneous spore release in culture. Key words: actinorhizal plants, endosymbiont, Frankia, sporulation.

scholarly journals Comparison of Nodule Induction in Legume and Actinorhizal Symbioses: The Induction of Actinorhizal Nodules Does Not Involve ENOD40

2003 ◽  
Vol 16 (9) ◽  
pp. 808-816 ◽  
Author(s):  
Carole Santi ◽  
Uritza von Groll ◽  
Ana Ribeiro ◽  
Maurizio Chiurazzi ◽  
Florence Auguy ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Host Plants ◽  
Root Nodule ◽  
Higher Plants ◽  
Expression Patterns ◽  
Lotus Japonicus ◽  
Casuarina Glauca ◽  
Actinorhizal Plant ◽  
Allocasuarina Verticillata ◽  
Actinorhizal Nodules

Two types of root nodule symbioses are known for higher plants, legume and actinorhizal symbioses. In legume symbioses, bacterial signal factors induce the expression of ENOD40 genes. We isolated an ENOD40 promoter from an actinorhizal plant, Casuarina glauca, and compared its expression pattern in a legume (Lotus japonicus) and an actinorhizal plant (Allocasuarina verticillata) with that of an ENOD40 promoter from the legume soybean (GmENOD402). In the actinorhizal Allocasuarina sp., CgENOD40-GUS and GmENOD40-2-GUS showed similar expression patterns in both vegetative and symbiotic development, and neither promoter was active during nodule induction. The nonsymbiotic expression pattern of CgENOD40-GUS in the legume genus Lotus resembled the nonsymbiotic expression patterns of legume ENOD40 genes however, in contrast to GmENOD40-2-GUS, CgENOD40-GUS was not active during nodule induction. The fact that only legume, not actinorhizal, ENOD40 genes are induced during legume nodule induction can be linked to the phloem unloading mechanisms established in the zones of nodule induction in the roots of both types of host plants.

Characterization of four defense-related genes up-regulated in root nodules of Casuarina glauca

Symbiosis ◽  
2009 ◽  
Vol 50 (1-2) ◽  
pp. 27-35 ◽  
Author(s):  
Patrícia Santos ◽  
Ana Fortunato ◽  
Inês Graça ◽  
Sandra Marina Martins ◽  
Maria Manuela Gouveia ◽  
...  
Keyword(s):  
Root Nodules ◽  
Casuarina Glauca

scholarly journals Alone Yet Not Alone: Frankia Lives Under the Same Roof With Other Bacteria in Actinorhizal Nodules

2021 ◽  
Vol 12 ◽  
Author(s):  
Faten Ghodhbane-Gtari ◽  
Timothy D’Angelo ◽  
Abdellatif Gueddou ◽  
Sabrine Ghazouani ◽  
Maher Gtari ◽  
...  
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
16S Rrna Gene ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
Rrna Gene ◽  
Plant Growth Promoting Bacteria ◽  
Metagenomic Sequencing ◽  
Plant Growth Promoting ◽  
Growth Promoting

Actinorhizal plants host mutualistic symbionts of the nitrogen-fixing actinobacterial genus Frankia within nodule structures formed on their roots. Several plant-growth-promoting bacteria have also been isolated from actinorhizal root nodules, but little is known about them. We were interested investigating the in planta microbial community composition of actinorhizal root nodules using culture-independent techniques. To address this knowledge gap, 16S rRNA gene amplicon and shotgun metagenomic sequencing was performed on DNA from the nodules of Casuarina glauca. DNA was extracted from C. glauca nodules collected in three different sampling sites in Tunisia, along a gradient of aridity ranging from humid to arid. Sequencing libraries were prepared using Illumina NextEra technology and the Illumina HiSeq 2500 platform. Genome bins extracted from the metagenome were taxonomically and functionally profiled. Community structure based off preliminary 16S rRNA gene amplicon data was analyzed via the QIIME pipeline. Reconstructed genomes were comprised of members of Frankia, Micromonospora, Bacillus, Paenibacillus, Phyllobacterium, and Afipia. Frankia dominated the nodule community at the humid sampling site, while the absolute and relative prevalence of Frankia decreased at the semi-arid and arid sampling locations. Actinorhizal plants harbor similar non-Frankia plant-growth-promoting-bacteria as legumes and other plants. The data suggests that the prevalence of Frankia in the nodule community is influenced by environmental factors, with being less abundant under more arid environments.

scholarly journals Preliminary Study on the Control of the Cottony-Cushion Scale (Icerya purchasii Maskell,) by Means of Insecticides

1969 ◽  
Vol 43 (4) ◽  
pp. 295-299
Author(s):  
Silverio Medina Gaud
Keyword(s):  
Natural Enemies ◽  
Host Plants ◽  
Casuarina Equisetifolia ◽  
Total Control ◽  
Preliminary Study

The cottony-cushion scale, Icerya purchasii Maskell, is one of the soft scales that attack a large variety of plants and trees in our Island. A series of host plants are listed and the insect is briefly described. Its distribution and natural enemies are also listed. Two insecticides, namely Parathion and Malathion, were tested for the control of the cottony-cushion scale in Australian pine, Casuarina equisetifolia Forst. Total control was obtained for all adult scales and crawlers with both insecticides, while in the checks both stages continued alive. It was found that the insecticides were not effective in the control of the eggs.

scholarly journals Molecular Methods for Assessement the Bacterial Communities from Different Type of Soils in Romania

2011 ◽  
Vol 39 (1) ◽  
pp. 64 ◽  
Author(s):  
Călina Petruţa CORNEA ◽  
Cătălina VOAIDEŞ ◽  
Matilda CIUCA ◽  
Vasilica STAN ◽  
Eugenia GAMENT ◽  
...  
Keyword(s):  
Plant Species ◽  
Host Plants ◽  
Root Nodules ◽  
Indigenous Populations ◽  
Most Probable Number ◽  
Organic Carbon Content ◽  
Bacterial Strains ◽  
Probable Number ◽  
Plate Counts ◽  
Fertilization Level

Rhizobia are soil bacteria that are capable to form nitrogen-fixing symbiosis with leguminous plants. This ability, as well as the diversity of microbial populations in the soil, and in the rhizosphere of host plants and non-host plants is influenced by several factors, including crop management. The aim of this work was the examination of the influence of some factors on indigenous populations of rhizobia in soils under different crop managements. The genetic diversity of rhizobial strains isolated directly from soil (free-living state) or from root nodules of three herbaceous perennial legumes was examined. The study was conducted in the experimental fields located in Moara Domnească area (South of Romania) and in the Brașov County. The characteristics of brown reddish soil were determined (nitrogen content, organic carbon content and pH). Counting of the rhizobia populations was done by most probable number estimation and by viable plate counts. Bacterial strains were isolated directly from soil samples or from root nodules of different plant species (Trifolium repens, T. pratense and Lotus corniculatus). The characterization of rhizobia was performed by DNA fingerprinting (ERIC PCR and BOX PCR) and the bacterial diversity of soils was examined by DGGE technique. The results revealed that the rhizobial diversity was significantly lower in soils under increased fertilization with N. A reduced intraspecific polymorphism was observed in the strains recovered from the same plant species (Trifolium spp.), whatever the origin of the plant (Moara Domnească or Brașov) but clear differences appeared to be related to the origin of nodules (red or white clover) as revealed by DNA fingerprints. However, various amplicon profiles were observed by DGGE when total DNA isolated from soils was examined, the differences being associated with the fertilization level.

An overview of actinorhizal plants in Africa

2011 ◽  
Vol 38 (9) ◽  
pp. 653 ◽  
Author(s):  
Maher Gtari ◽  
Jeffrey O. Dawson
Keyword(s):  
Native Species ◽  
Root Nodules ◽  
Alnus Glutinosa ◽  
Wildlife Habitat ◽  
Actinorhizal Plants ◽  
Current Status ◽  
Arid Zones ◽  
African Countries ◽  
Climatic Regions ◽  
Actinorhizal Species

A compilation and synthesis of information derived from plant databases and other sources on the occurrence, diversity and geographic distribution of actinorhizal plants in Africa is presented in this review. Actinorhizal plants are a specific group of non-leguminous, woody dicots having symbiotic, nitrogen-fixing root nodules that are induced on roots of actinorhizal plant species by soil actinomycetes of the genus Frankia. There is a lack of basic information on actinorhizal plants in Africa compared with other major land masses in the world. Results indicate that most, if not all, African countries and climatic regions have native or introduced actinorhizal species. A synthesis of available information indicates that there are six families, nine genera and 38 reported species of actinorhizal plants in Africa. Of these, 21 species are native and 17 are exotic. The families and corresponding number of species in each genus are: Betulaceae (native Alnus glutinosa (1), exotic Alnus (2)); Casuarinaceae (exotic Casuarina (5), exotic Allocasuarina (3), exotic Gymnostoma deplancheana (1)); Coriariaceae (native Coriaria myrtifolia (1)); Myricaceae (native Morella (19), exotic Morella cerifera (1)); Rhamnaceae (exotic Ceanothus caeruleus (1), exotic Colletia paradoxa (1)); and Elaeagnaceae (exotic Eleaegnus angustifolia (1)). Four reports of native, actinorhizal Ceanothus species in Africa found in the database were determined to be false, instead, being non-actinorhizal species. Widespread plantings of exotic Casuarinaceae have been introduced into tropical and arid zones of Africa as multipurpose trees, especially in arid regions where native species do not occur. There is a diverse assemblage of native species of Morella in Africa, mostly shrubs or small trees, which provide medicine, other useful chemicals and wildlife habitat. Many native Morella species are isolated in montane islands, apparently leading to greater speciation than in Eurasia from where the genus migrated into Africa. The current status and knowledge of African actinorhizal plants indicates a need to focus research on their biogeography, biology, ecology, genetics and use.

scholarly journals FrankiaDiversity in Host Plant Root Nodules Is Independent of Abundance or Relative Diversity ofFrankiaPopulations in Corresponding Rhizosphere Soils

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Seifeddine Ben Tekaya ◽  
Trina Guerra ◽  
David Rodriguez ◽  
Jeffrey O. Dawson ◽  
Dittmar Hahn
Keyword(s):  
Host Plant ◽  
Root Nodule ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Content Type ◽  
Rhizosphere Soils ◽  
Root Nodule Formation ◽  
Host Infection

ABSTRACTActinorhizal plants form nitrogen-fixing root nodules in symbiosis with soil-dwelling actinobacteria within the genusFrankia, and specificFrankiataxonomic clusters nodulate plants in corresponding host infection groups. In same-soil microcosms, we observed that some host species were nodulated (Alnus glutinosa,Alnus cordata,Shepherdia argentea,Casuarina equisetifolia) while others were not (Alnus viridis,Hippophaë rhamnoides). Nodule populations were represented by eight different sequences ofnifHgene fragments. Two of these sequences characterized frankiae inS. argenteanodules, and three others characterized frankiae inA. glutinosanodules. Frankiae inA. cordatanodules were represented by five sequences, one of which was also found in nodules fromA. glutinosaandC. equisetifolia, while another was detected in nodules fromA. glutinosa. Quantitative PCR assays showed that vegetation generally increased the abundance of frankiae in soil, independently of the target gene (i.e.,nifHor the 23S rRNA gene). Targeted Illumina sequencing ofFrankia-specificnifHgene fragments detected 24 unique sequences from rhizosphere soils, 4 of which were also found in nodules, while the remaining 4 sequences in nodules were not found in soils. Seven of the 24 sequences from soils represented >90% of the reads obtained in most samples; the 2 most abundant sequences from soils were not found in root nodules, and only 2 of the sequences from soils were detected in nodules. These results demonstrate large differences between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils.IMPORTANCEThe nitrogen-fixing actinobacteriumFrankiaforms root nodules on actinorhizal plants, with members of specificFrankiataxonomic clusters nodulating plants in corresponding host infection groups. We assessedFrankiadiversity in root nodules of different host plant species, and we related specific populations to the abundance and relative distribution of indigenous frankiae in rhizosphere soils. Large differences were observed between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils but rather results from plants potentially selecting frankiae from the soil for root nodule formation. These data also highlight the necessity of using a combination of different assessment tools so as to adequately address methodological constraints that could produce contradictory data sets.

Fine structure of Frankia in root nodules and isolation of Frankia from nodules of actinorhizal plants growing in Japan

1997 ◽  
Vol 43 (sup1) ◽  
pp. 1097-1100
Author(s):  
Hideo Sasakawa ◽  
Hiroshi Kawai ◽  
Norikatsu Takahashi ◽  
Sizuka Tanigawa ◽  
Toru Hiyoshi
Keyword(s):  
Fine Structure ◽  
Root Nodules ◽  
Actinorhizal Plants
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