The model symbiotic association between Medicago truncatula cv. Jemalong and Rhizobium meliloti strain 2011 leads to N-stressed plants when symbiotic N2 fixation is the main N source for plant growth

2008 ◽  
Vol 59 (13) ◽  
pp. 3509-3522 ◽  
Author(s):  
Delphine Moreau ◽  
Anne-Sophie Voisin ◽  
Christophe Salon ◽  
Nathalie Munier-Jolain
Keyword(s):  
Plant Growth ◽  
Medicago Truncatula ◽  
N2 Fixation ◽  
Rhizobium Meliloti ◽  
Symbiotic Association ◽  
Symbiotic N2 Fixation ◽  
N Source ◽  
Meliloti Strain

scholarly journals A New Medicago truncatula Line with Superior in Vitro Regeneration, Transformation, and Symbiotic Properties Isolated Through Cell Culture Selection

1997 ◽  
Vol 10 (3) ◽  
pp. 307-315 ◽  
Author(s):  
Beate Hoffmann ◽  
Toan Hanh Trinh ◽  
Jeffrey Leung ◽  
Adam Kondorosi ◽  
Eva Kondorosi
Keyword(s):  
Medicago Truncatula ◽  
In Vitro Selection ◽  
Rhizobium Meliloti ◽  
In Vitro Regeneration ◽  
Selection Procedure ◽  
Genetic System ◽  
Strain Specificity ◽  
Meliloti Strain ◽  
Symbiotic Properties

The understanding of how leguminous plants establish symbiosis with rhizobia is limited by the lack of genetic system in most legume plants. Here we propose a Medicago truncatula line suitable for genetic analysis of Medicago-Rhizobium meliloti symbiosis because of its high regeneration capacity and broad R. meliloti strain specificity. This line has been isolated by extensive in vitro screening of explants from several ecotypes of M. truncatula that are known to be autogamous and have small diploid genomes. One such derivative identified from ecotype 108-1 has gained the capacity to be readily regenerated in vitro. The derivative, called R108-1, like its parent, can establish effective symbiosis with several widely studied R. meliloti strains (Rm41, Rm2011, Rm1021, F51, and GR4). Importantly, the nodulation characteristics of the R108-1 line were not compromised by the in vitro selection procedure. We have further established the conditions for efficient transformation of R108-1 by co-cultivation with Agrobacterium tumefaciens. Thus, this in vitro-derived plant line has most of the favorable attributes, otherwise rare among legumes, of a complementary model plant system for investigating symbiosis at the genetic and the molecular levels.

Effect of glyphosate on symbiotic N2 fixation and nickel concentration in glyphosate-resistant soybeans

2010 ◽  
Vol 44 (2) ◽  
pp. 176-180 ◽  
Author(s):  
L.H.S. Zobiole ◽  
R.S. Oliveira ◽  
R.J. Kremer ◽  
J. Constantin ◽  
T. Yamada ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Nickel Concentration ◽  
Symbiotic N2 Fixation

Differential responses of the sunn4 and rdn1-1 super-nodulation mutants of Medicago truncatula to elevated atmospheric CO2

2021 ◽  
Author(s):  
Yunfa Qiao ◽  
Shujie Miao ◽  
Jian Jin ◽  
Ulrike Mathesius ◽  
Caixian Tang
Keyword(s):  
Nitrogen Fixation ◽  
Elevated Co2 ◽  
Medicago Truncatula ◽  
N2 Fixation ◽  
Sink Strength ◽  
Wild Type ◽  
Total N ◽  
Autoregulation Of Nodulation ◽  
Nodulation Mutants ◽  
Fixation Capacity

Abstract Background and Aims Nitrogen fixation in legumes requires tight control of carbon and nitrogen balance. Thus, legumes control nodule numbers via an autoregulation mechanism. ‘Autoregulation of nodulation’ mutants super-nodulate and are thought to be carbon-limited due to the high carbon-sink strength of excessive nodules. This study aimed to examine the effect of increasing carbon supply on the performance of super-nodulation mutants. Methods We compared the responses of Medicago truncatula super-nodulation mutants (sunn-4 and rdn1-1) and wild type to five CO2 levels (300-850 μmol mol -1). Nodule formation and N2 fixation were assessed in soil-grown plants at 18 and 42 days after sowing. Key results Shoot and root biomass, nodule number and biomass, nitrogenase activity and fixed-N per plant of all genotypes increased with increasing CO2 concentration and reached the maximum around 700 μmol mol -1. While the sunn-4 mutant showed strong growth-retardation compared to wild-type plants, elevated CO2 increased shoot biomass and total N content of rdn1-1 mutant up to two-fold. This was accompanied by a four-fold increase in nitrogen fixation capacity in the rdn1-1 mutant. Conclusions These results suggest that the super-nodulation phenotype per se did not limit growth. The additional nitrogen fixation capacity of the rdn1-1 mutant may enhance the benefit of elevated CO2 on plant growth and N2 fixation.

Symbiotic N2-fixation in alpine tundra: ecosystem input and variation in fixation rates among communities

Oecologia ◽  
1996 ◽  
Vol 108 (2) ◽  
pp. 345-350 ◽  
Author(s):  
William D. Bowman ◽  
James C. Schardt ◽  
Steven K. Schmidt
Keyword(s):  
N2 Fixation ◽  
Alpine Tundra ◽  
Symbiotic N2 Fixation ◽  
Tundra Ecosystem

scholarly journals Improvement Salt Tolerance of Safflower Plants by Endophytic Bacteria

2019 ◽  
Vol 5 ◽  
pp. 38-56 ◽  
Author(s):  
Khulod A. Hemida ◽  
Amany M.M. Reyad
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Endophytic Bacteria ◽  
Bacterial Species ◽  
Limiting Factors ◽  
Symbiotic Association ◽  
Bacterial Strains ◽  
Growth Promoters ◽  
Wide Range ◽  
Plant Salt Tolerance

Salinity is one of the most dangerous environmental limiting factors of the plant productivity. A wide range of adaptation strategies is required to overcome salinity stress. However, such strategies seem to be long drawn and cost-intensive. It has been confirmed in recent years that plant growth promoting endophytes (PGPEs) that have the ability to further build a symbiotic association with their host to improve host plant salt tolerance. In our investigation try to improve plant salt tolerance using different species of endophytic bacteria. From the total eight endophytic bacterial species were isolated from root, stem, and leaf of Carthamustinctorius (safflower) plant, two isolates were capable of using 1-aminocyclopropane-1-carboxylic acid (ACC) as a sole nitrogen source, and they are of positive results for (ACC) deaminase activity and indole-3-acetic acid (IAA) production. The bacterial isolates were identified using 16S ribosomal DNA technique as Bacillus cereus and Bacillus aerius and had accession numbers MG708176 and MG711593 respectively, by submitting their sequences in GenBank database. This study showed that the bacterial strains B. cereus and B. aerius are valuable biological plant growth promoters that could enhance salt tolerance in Safflower plants under 100, 200, and 300mMNaCl levels resulting in an increase in plant growth and ascorbate-glutathione redox cycle, in comparison with the non-inoculated controls. Our findings reported that the co-inoculation of the two selected endophytic bacteria strains were successfully isolated from Safflower seedlings significantly alleviated the harmful effects of salt stress, promoted plant growth and biomass yield.

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