Root and Stem Nodule Bacteria of Legumes

Sadowsky, Michael J.; Graham, Peter

doi:10.1007/0-387-30742-7_25

Cited by 13 publications

(15 citation statements)

References 258 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The vast diversity of the α-subdivision is clearly evident through the lifestyle differences among its members making them important in agricultural, medical and industrial fields. Such examples include the animal and human intracellular pathogens ( Rickettsia , Bartonella , and Brucella ) [1-3], the plant pathogens and symbiotic soil bacteria ( Agrobacterium , Sinorhizobium , Mesorhizobium , and Bradyrhizobium ) [1,4-6], the Drosophila endosymbiont ( Wolbachia ) [1] and a number of other free-living bacteria occupying a wide variety of ecological niches [1]. Furthermore, this group exhibits a wide spectrum of characteristics in terms of morphology (spiral, rod, stalked), metabolism (phototrophs, heterotrophs, and chemolithotrophs), physiology and cell division mechanisms [1,7,8].…”

Section: Introductionmentioning

confidence: 99%

Signature proteins that are distinctive of alpha proteobacteria

Kainth

Gupta

2005

BMC Genomics

View full text Add to dashboard Cite

Background: The alpha (α) proteobacteria, a very large and diverse group, are presently characterized solely on the basis of 16S rRNA trees, with no known molecular characteristic that is unique to this group. The genomes of three α-proteobacteria, Rickettsia prowazekii (RP), Caulobacter crescentus (CC) and Bartonella quintana (BQ), were analyzed in order to search for proteins that are unique to this group.

show abstract

Section: Introductionmentioning

confidence: 99%

Signature proteins that are distinctive of alpha proteobacteria

Kainth

Gupta

2005

BMC Genomics

View full text Add to dashboard Cite

show abstract

“…without inoculation of rhizobial strains were studied (Naeem et al, 2004;Wielbo et al, 2010). All developed nodules had an indeterminate shape, which is the typical morphology of a Trifolium-Rhizobium symbiosis (Sadowsky and Graham, 2006;Gage, 2004). It is very likely that the peak of nodule abundance was reached at the time of sampling, because the plant was in the flowering stage where most nitrogen is needed (Malhi et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, it has been often postulated that the inter-and intra-species diversity of rhizobia, which are able to form nodules with selected legumes, strongly depend on environmental conditions like soil pH and water content or biogeography. For example, it was shown that R. etli as microsymbiont of beans can be replaced by R. tropici under acidic conditions (Anyango et al, 1995;Sadowsky and Graham, 2006) and that diversity of rhizobia infecting chickpea (Alexandre et al, 2009) or Lotus corniculatus (Sotelo et al, 2011) depends on the investigated biogeographic region. Moreover, annual legumes like T. arvense face the problem that the symbiosis must be established each year again (Sessitsch et al, 2002).…”

Section: S Schulz Et Al: Diversity Pattern Of Nitrogen Fixing Micromentioning

confidence: 99%

“…Moreover, annual legumes like T. arvense face the problem that the symbiosis must be established each year again (Sessitsch et al, 2002). However, with each passing year the rhizobial population might increase, as they are released from the nodules at the end of each growing season (Sadowsky and Graham, 2006) dominated by those ecotypes which form the most efficient symbiosis related to the particular plant cultivar and the given environmental conditions.…”

Section: S Schulz Et Al: Diversity Pattern Of Nitrogen Fixing Micromentioning

confidence: 99%

See 1 more Smart Citation

Diversity pattern of nitrogen fixing microbes in nodules of <i>Trifolium arvense</i> (L.) at different initial stages of ecosystem development

et al. 2013

View full text Add to dashboard Cite

Abstract. Legumes can be considered as pioneer plants during ecosystem development, as they form a symbiosis with different nitrogen fixing rhizobia species, which enable the plants to grow on soils with low available nitrogen content. In this study we compared the abundance and diversity of nitrogen fixing microbes based on the functional marker gene nifH, which codes for a subunit of the Fe-protein of the dinitrogenase reductase, in nodules of different size classes of Trifolium arvense (L.). Additionally, carbon and nitrogen contents of the bulk soil and plant material were measured. Plants were harvested from different sites, reflecting 2 (2a) and 5 (5a) yr of ecosystem development, of an opencast lignite mining area in the south of Cottbus, Lower Lusatia (Germany) where the artificial catchment "Chicken Creek" was constructed to study the development of terrestrial ecosystems. Plants from the 5a site revealed higher amounts of carbon and nitrogen, although nifH gene abundances in the nodules and carbon and nitrogen contents between the two soils did not differ significantly. Analysis of the nifH clone libraries showed a significant effect of the nodule size on the community composition of nitrogen fixing microbes. Medium sized nodules (2–5 mm) contained a uniform community composed of Rhizobium leguminosarum bv. trifolii, whereas the small nodules (<2 mm) consisted of a diverse community including clones with non-Rhizobium nifH gene sequences. Regarding the impact of the soil age on the community composition a clear distinction between the small and the medium nodules can be made. While clone libraries from the medium nodules were pretty similar at both soil ages, soil age had a significant effect on the community compositions of the small nodules, where the proportion of R. leguminosarum bv. trifolii increased with soil age.

show abstract

“…These ambitious goals require a complete understanding of the symbiotic relationship. Whilst decades of research have led to a solid understanding of the genetics and metabolism of SNF from the bacterial perspective (Dunn, 2014;MacLean et al, 2007;Sadowsky et al, 2013;Udvardi & Poole, 2013), our knowledge remains incomplete.…”

Section: Introductionmentioning

confidence: 99%

Proline auxotrophy in Sinorhizobium meliloti results in a plant-specific symbiotic phenotype

diCenzo¹,

Zamani²,

Cowie³

et al. 2015

Microbiology

View full text Add to dashboard Cite

In order to effectively manipulate rhizobium-legume symbioses for our benefit, it is crucial to first gain a complete understanding of the underlying genetics and metabolism. Studies with rhizobium auxotrophs have provided insight into the requirement for amino acid biosynthesis during the symbiosis; however, a paucity of available L-proline auxotrophs has limited our understanding of the role of L-proline biosynthesis. Here, we examined the symbiotic phenotypes of a recently described Sinorhizobium meliloti L-proline auxotroph. Proline auxotrophy was observed to result in a host-plant-specific phenotype. The S. meliloti auxotroph displayed reduced symbiotic capability with alfalfa (Medicago sativa) due to a decrease in nodule mass formed and therefore a reduction in nitrogen fixed per plant. However, the proline auxotroph formed nodules on white sweet clover (Melilotus alba) that failed to fix nitrogen. The rate of white sweet clover nodulation by the auxotroph was slightly delayed, but the final number of nodules per plant was not impacted. Examination of white sweet clover nodules by confocal microscopy and transmission electron microscopy revealed the presence of the S. meliloti proline auxotroph cells within the host legume cells, but few differentiated bacteroids were identified compared with the bacteroid-filled plant cells of WT nodules. Overall, these results indicated that L-proline biosynthesis is a general requirement for a fully effective nitrogen-fixing symbiosis, likely due to a transient requirement during bacteroid differentiation.

show abstract

Root and Stem Nodule Bacteria of Legumes

Cited by 13 publications

References 258 publications

Signature proteins that are distinctive of alpha proteobacteria

Signature proteins that are distinctive of alpha proteobacteria

Diversity pattern of nitrogen fixing microbes in nodules of <i>Trifolium arvense</i> (L.) at different initial stages of ecosystem development

Proline auxotrophy in Sinorhizobium meliloti results in a plant-specific symbiotic phenotype

Contact Info

Product

Resources

About

Root and Stem Nodule Bacteria of Legumes

Cited by 13 publications

References 258 publications

Signature proteins that are distinctive of alpha proteobacteria

Signature proteins that are distinctive of alpha proteobacteria

Diversity pattern of nitrogen fixing microbes in nodules of &lt;i&gt;Trifolium arvense&lt;/i&gt; (L.) at different initial stages of ecosystem development

Proline auxotrophy in Sinorhizobium meliloti results in a plant-specific symbiotic phenotype

Contact Info

Product

Resources

About

Diversity pattern of nitrogen fixing microbes in nodules of <i>Trifolium arvense</i> (L.) at different initial stages of ecosystem development