scholarly journals GmVTL1a is an iron transporter on the symbiosome membrane of soybean with an important role in nitrogen fixation

2020 ◽  
Vol 228 (2) ◽  
pp. 667-681 ◽  
Author(s):  
Ella M. Brear ◽  
Frank Bedon ◽  
Aleksandr Gavrin ◽  
Igor S. Kryvoruchko ◽  
Ivone Torres‐Jerez ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Iron Transporter ◽  
Symbiosome Membrane

scholarly journals Soybean Yellow Stripe-like7 is a symbiosome membrane peptide transporter essential for nitrogen fixation

2020 ◽  
Author(s):  
A Gavrin ◽  
PC Loughlin ◽  
EM Brear ◽  
OW Griffith ◽  
F Bedon ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Metal Transport ◽  
Peptide Transporter ◽  
Excess Iron ◽  
Symbiosome Membrane ◽  
Transporter Family ◽  
Membrane Peptide ◽  
Mature Nodule ◽  
Yellow Stripe

ABSTRACTLegumes form a symbiosis with rhizobia that convert atmospheric nitrogen (N2) to ammonia which they provide to the plant in return for a carbon and nutrient supply. Nodules, developed as part of the symbiosis, harbor rhizobia which are enclosed in the plant-derived symbiosome membrane (SM), to form a symbiosome. In the mature nodule all exchanges between the symbionts occur across the SM. Here we characterize GmYSL7, a member of Yellow stripe-like family which is localized to the SM in soybean nodules. It is expressed specifically in nodule infected cells with expression peaking soon after nitrogenase becomes active. Although most members of the family transport metal complexed with phytosiderophores, GmYSL7 does not. It transports oligopeptides of between four and 12 amino acids. Silencing of GmYSL7 reduces nitrogenase activity and blocks development when symbiosomes contain a single bacteroid. RNAseq of nodules in which GmYSL7 is silenced suggests that the plant initiates a defense response against the rhizobia. There is some evidence that metal transport in the nodules is dysregulated, with upregulation of genes encoding ferritin and vacuolar iron transporter family and downregulation of a gene encoding nicotianamine synthase. However, it is not clear whether the changes are a result of the reduction of nitrogen fixation and the requirement to store excess iron or an indication of a role of GmYSL7 in regulation of metal transport in the nodules. Further work to identify the physiological substrate for GmYSL7 will allow clarification of this role.One sentence summaryGmYSL7 is a symbiosome membrane peptide transporter that is essential for symbiotic nitrogen fixation that when silenced blocks symbiosome development.

scholarly journals Transcription of ENOD8 in Medicago truncatula Nodules Directs ENOD8 Esterase to Developing and Mature Symbiosomes

2008 ◽  
Vol 21 (4) ◽  
pp. 404-410 ◽  
Author(s):  
Laurent Coque ◽  
Purnima Neogi ◽  
Catalina Pislariu ◽  
Kimberly A. Wilson ◽  
Christina Catalano ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Immunoblot Analysis ◽  
Nodule Formation ◽  
Nitrogenous Compounds ◽  
Symbiosome Membrane ◽  
The Matrix ◽  
And Function ◽  
Infected Nodule

In Medicago truncatula nodules, the soil bacterium Sinorhizobium meliloti reduces atmospheric dinitrogen into nitrogenous compounds that the legume uses for its own growth. In nitrogen-fixing nodules, each infected cell contains symbiosomes, which include the rhizobial cell, the symbiosome membrane surrounding it, and the matrix between the bacterium and the symbiosome membrane, termed the symbiosome space. Here, we describe the localization of ENOD8, a nodule-specific esterase. The onset of ENOD8 expression occurs at 4 to 5 days postinoculation, before the genes that support the nitrogen fixation capabilities of the nodule. Expression of an ENOD8 promoter–gusA fusion in nodulated hairy roots of composite transformed M. truncatula plants indicated that ENOD8 is expressed from the proximal end of interzone II to III to the proximal end of the nodules. Confocal immunomicroscopy using an ENOD8-specific antibody showed that the ENOD8 protein was detected in the same zones. ENOD8 protein was localized in the symbiosome membrane or symbiosome space around the bacteroids in the infected nodule cells. Immunoblot analysis of fractionated symbiosomes strongly suggested that ENOD8 protein was found in the symbiosome membrane and symbiosome space, but not in the bacteroid. Determining the localization of ENOD8 protein in the symbiosome is a first step in understanding its role in symbiosome membrane and space during nodule formation and function.

scholarly journals GmVTL1 is an iron transporter on the symbiosome membrane of soybean with an important role in nitrogen fixation

2020 ◽  
Author(s):  
Ella M. Brear ◽  
Frank Bedon ◽  
Aleksandr Gavrin ◽  
Igor S. Kryvoruchko ◽  
Ivone Torres-Jerez ◽  
...  
Keyword(s):  
Lotus Japonicus ◽  
List Type ◽  
Symbiotic Relationships ◽  
Iron Transporter ◽  
Symbiosome Membrane ◽  
Transporter Family ◽  
Root Transformation ◽  
Carbon Substrates ◽  
Infected Cells

SummaryLegumes establish symbiotic relationships with soil bacteria (rhizobia), housed in nodules on plant roots. The plant supplies carbon substrates and other nutrients to the bacteria in exchange for fixed nitrogen. The exchange occurs across a plant-derived symbiosome membrane (SM), which encloses rhizobia to form a symbiosome. Iron supplied by the plant is crucial for the rhizobial enzyme nitrogenase that catalyses N2 fixation, but the SM iron transporter has not been identified.We use complementation of yeast and plant mutants, real-time PCR, hairy root transformation, microscopy and proteomics to demonstrate the role of soybean GmVTL1 and 2.Both are members of the vacuolar iron transporter family and homologous to Lotus japonicus SEN1 (LjSEN1), previously shown to be essential for N2 fixation. GmVTL1 expression is enhanced in nodule infected cells and both proteins are localised to the SM.GmVTL1 and 2 transport iron in yeast and GmVTL1 restores N2 fixation when expressed in the Ljsen1 mutant.Three GmVTL1 amino acid substitutions that reduce iron transport in yeast also block N2 fixation in Ljsen1 plants.We conclude GmVTL1 is responsible for transport of iron across the SM to bacteroids and plays a crucial role in the N2-fixing symbiosis.

scholarly journals Medicago truncatula esn1 Defines a Genetic Locus Involved in Nodule Senescence and Symbiotic Nitrogen Fixation

2013 ◽  
Vol 26 (8) ◽  
pp. 893-902 ◽  
Author(s):  
Jiejun Xi ◽  
Yuhui Chen ◽  
Jin Nakashima ◽  
Suo-min Wang ◽  
Rujin Chen
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Truncatula ◽  
Symbiotic Nitrogen Fixation ◽  
Genetic Locus ◽  
Forward Genetics ◽  
Host Cells ◽  
Nodule Development ◽  
Marker Genes ◽  
Symbiosome Membrane ◽  
Nodule Senescence

Symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti results in the formation on the host roots of new organs, nodules, in which biological nitrogen fixation takes place. In infected cells, rhizobia enclosed in a plant-derived membrane, the symbiosome membrane, differentiate to nitrogen-fixing bacteroids. The symbiosome membrane serves as an interface for metabolite and signal exchanges between the host cells and endosymbionts. At some point during symbiosis, symbiosomes and symbiotic cells are disintegrated, resulting in nodule senescence. The regulatory mechanisms that underlie nodule senescence are not fully understood. Using a forward genetics approach, we have uncovered the early senescent nodule 1 (esn1) mutant from an M. truncatula fast neutron-induced mutant collection. Nodules on esn1 roots are spherically shaped, ineffective in nitrogen fixation, and senesce early. Atypical among fixation defective mutants isolated thus far, bacteroid differentiation and expression of nifH, Leghemoglobin, and DNF1 genes are not affected in esn1 nodules, supporting the idea that a process downstream of bacteroid differentiation and nitrogenase gene expression is affected in the esn1 mutant. Expression analysis shows that marker genes involved in senescence, macronutrient degradation, and remobilization are greatly upregulated during nodule development in the esn1 mutant, consistent with a role of ESN1 in nodule senescence and symbiotic nitrogen fixation.

Factors controlling nitrogen fixation in temperate seagrass beds

2015 ◽  
Vol 525 ◽  
pp. 41-51 ◽  
Author(s):  
PLM Cook ◽  
V Evrard ◽  
RJ Woodland
Keyword(s):  
Nitrogen Fixation ◽  
Seagrass Beds

NEW CLOVER CULTIVARS FOR WAIKATO DAIRY PASTURE: ESTABLISHMENT, PRODUCTION AND NITROGEN FIXATION DURING THE FIRST YEAR

1988 ◽  
pp. 207-211
Author(s):  
S.F. Ledgard ◽  
G.J. Brier ◽  
R.N. Watson
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Dairy Cow ◽  
Red Clover ◽  
First Year ◽  
Buried Seed

Clover cultivars grown with ryegrass were compared in an establishment year under dairy cow grazing. There was no difference in total annual productton but summer production was greater with Pawera red clover and with Kopu or Pitau white clovers. Clovers differed little in the proportion of nitrogen fixed, except during summer when values were highest for Pawera. Pawera was less prone to nematode attack than white clover cultivars but was more susceptible to clover rot. Resident clovers and high buried seed levels (e.g., 11-91 kg/ha) made introduction of new clover cultivars difficult. Sown clovers established best (50-70% of total clover plants) when drilled into soil treated with dicamba and glyphosate. Keywords: white clover, red clover, nematodes. nitrogen fixation, pasture renovation

Reduction of Growth and Symbiotic Nitrogen Fixation in Soybean as Affected by the Site of Simulated Acid Rain Application.

1997 ◽  
Vol 66 (4) ◽  
pp. 596-602 ◽  
Author(s):  
Xianyu WANG ◽  
Makoto TSUDA ◽  
Tetsuro TANIYAMA
Keyword(s):  
Nitrogen Fixation ◽  
Acid Rain ◽  
Symbiotic Nitrogen Fixation ◽  
Simulated Acid Rain

A Study on the Farmers’ Awareness and Acceptance of Biofertilizers in Kottayam District

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 425-431
Author(s):  
Subin Thomas ◽  
Dr. M. Nandhini
Keyword(s):  
Organic Matter ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Nutrient Cycle ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting ◽  
Structured Questionnaire ◽  
Area Data

Biofertilizers are fertilizers containing microorganisms that promote plant growth by improving the supply of nutrients to the host plant. The supply of nutrients is improved naturally by nitrogen fixation and solubilizing phosphorus. The living microorganisms in biofertilizers help in building organic matter in the soil and restoring the natural nutrient cycle. Biofertilizers can be grouped into Nitrogen-fixing biofertilizers, Phosphorous-solubilizing biofertilizers, Phosphorous-mobilizing biofertilizers, Biofertilizers for micro nutrients and Plant growth promoting rhizobacteria. This study conducted in Kottayam district was intended to identify the awareness and acceptance of biofertilizers among the farmers of the area. Data have been collected from 120 farmers by direct interviews with structured questionnaire.

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