scholarly journals Sucrose Synthase in Legume Nodules Is Essential for Nitrogen Fixation

1999 ◽  
Vol 120 (3) ◽  
pp. 867-878 ◽  
Author(s):  
Anthony J. Gordon ◽  
Frank R. Minchin ◽  
Caron L. James ◽  
Olga Komina
2009 ◽  
Vol 22 (12) ◽  
pp. 1565-1576 ◽  
Author(s):  
Estíbaliz Larrainzar ◽  
Stefanie Wienkoop ◽  
Christian Scherling ◽  
Stefan Kempa ◽  
Rubén Ladrera ◽  
...  

Regulation of symbiotic nitrogen fixation (SNF) during drought stress is complex and not yet fully understood. In the present work, the involvement of nodule C and N metabolism in the regulation of SNF in Medicago truncatula under drought and a subsequent rewatering treatment was analyzed using a combination of metabolomic and proteomic approaches. Drought induced a reduction of SNF rates and major changes in the metabolic profile of nodules, mostly an accumulation of amino acids (Pro, His, and Trp) and carbohydrates (sucrose, galactinol, raffinose, and trehalose). This accumulation was coincidental with a decline in the levels of bacteroid proteins involved in SNF and C metabolism, along with a partial reduction of the levels of plant sucrose synthase 1 (SuSy1). In contrast, the variations in enzymes related to N assimilation were found not to correlate with the reduction in SNF, suggesting that these enzymes do not have a role in the regulation of SNF. Unlike the situation in other legumes such as pea and soybean, the drought-induced inhibition of SNF in M. truncatula appears to be caused by impairment of bacteroid metabolism and N2-fixing capacity rather than a limitation of respiratory substrate.


1999 ◽  
Vol 47 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Antonio Ocaña ◽  
Juan Manuel Caba ◽  
Francisco Ligero ◽  
Carmen Lluch

The evolution of growth, nodulation, nitrogen fixation, and activities of root-nodule enzymes related to sucrose breakdown (sucrose synthase, alkaline invertase), pentose phosphate pathway (glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase), malate dehydrogenase, phosphoenolpyruvate carboxylase, and NADP-dependent isocitrate dehydrogenase, were followed over the complete life-cycle of faba bean in a growth chamber. The aim was to study the ontogenic changes of these parameters to obtain information on the carbon metabolism in nodules ofVicia faba, an amide-exporting legume. The maximum values of the relative growth rate and the specific acetylene-reducing activity were registered during the vegetative period. At pod-filling, the specific and total acetylene-reducing activity per plant declined in parallel with the enzyme activities of carbon metabolism. Contrary to reports for other legume species, inV. fabaroot nodule activity of sucrose synthase exceeded alkaline invertase values by 2-fold or more during the vegetative period. The activity of the two enzymes was similar at flowering and pod formation. The enzymes of carbon metabolism registered two maxima, one before and one after a trough (day 32), which marked the change from the vegetative to the reproductive period.


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

Author(s):  
S.F. Ledgard ◽  
G.J. Brier ◽  
R.N. Watson

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


GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 425-431
Author(s):  
Subin Thomas ◽  
Dr. M. Nandhini

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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