Nodulation pattern and acetylene reduction (nitrogen fixation) activity of some highland and lowland Acacia species of Ethiopia

1998 ◽  
Vol 27 (1) ◽  
pp. 60-64 ◽  
Author(s):  
F. Assefa ◽  
D. Kleiner
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Acacia Species ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity

Seasonal patterns of nitrogen fixation in biological soil crusts from British Columbia’s Chilcotin grasslands

Botany ◽  
2013 ◽  
Vol 91 (9) ◽  
pp. 631-641 ◽  
Author(s):  
Kasia Caputa ◽  
Darwyn Coxson ◽  
Paul Sanborn
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
N Uptake ◽  
Summer Precipitation ◽  
Biological Soil Crusts ◽  
Winter Period ◽  
Late Winter ◽  
Nitrogen Fixation Activity ◽  
Soil Crusts ◽  
Fixation Activity

This study provides estimates of N2 fixation in biological soil crusts (BSCs) from shrub–steppe grasslands in British Columbia’s Chilcotin plateau. We identify key seasonal periods and environmental conditions during episodes of BSC nitrogen-fixation activity. Predicted nitrogen-fixation activity showed two peak periods: one during late winter and early spring snowmelt events, and the second during summer precipitation events. BSC nitrogen fixation, especially summer activity, was quite variable from year to year. The magnitude of predicted nitrogen fixation at the landscape level was dependent upon the ratio used to convert rates of acetylene reduction to nitrogen fixed. Using a theoretical ratio of 3:1, estimates of average annual BSC nitrogen fixation were 1.0 kg N·ha−1. However, using a conversion ratio of 0.06, obtained from side-by-side measurements of acetylene reduction and 15N uptake, annual estimates are 52 kg N·ha−1. These estimates are based on assessments of the aerial extent of dark BSC communities, which at the Farwell Canyon study site exceeded 50%. The fate of fixed nitrogen, especially during the late winter period, when underlying soils are frozen, remains unclear.

scholarly journals Root Distribution and Nitrogen Fixation Activity of Tropical Forage Legume American Jointvetch (Aeschynomene americanaL.) cv. Glenn under Waterlogging Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Manabu Tobisa ◽  
Masataka Shimojo ◽  
Yasuhisa Masuda
Keyword(s):  
Nitrogen Fixation ◽  
Root Distribution ◽  
Water Surface ◽  
Nitrogenase Activity ◽  
Soil Surface ◽  
Nodule Formation ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity ◽  
Net Assimilation ◽  
Waterlogging Treatment

We investigated the root distribution and nitrogen fixation activity of American jointvetch (Aeschynomene americanaL.) cv. Glenn, under waterlogging treatment. The plants were grown in pots under three different treatments: no waterlogging (control), 30 days of waterlogging (experiment 1), and 40 days of waterlogging (experiment 2). The plants were subjected to the treatments on day 14 after germination. Root dry matter (DM) weight distribution of waterlogged plants was shallower than controls after day 20 of waterlogging. Throughout the study period, the total root DM weight in waterlogged plants was similar to that in the controls. Enhanced rooting (adventitious roots) and nodule formation at the stem base were observed in waterlogged plants after day 20 of waterlogging. The average DM weight of individual nodules on the region of the stem between the soil surface and water surface of waterlogged plants was similar to that of individual taproot nodules in the controls. Waterlogged plants had slightly greater plant DM weight than the controls after 40 days of treatment. The total nitrogenase activity (TNA) of nodules and nodule DM weight were higher in waterlogged plants than in the controls. Waterlogged American jointvetch had roots with nodules both around the soil surface and in the area between the soil surface and water surface after 20 days of waterlogging, and they maintained high nitrogenase activity and net assimilation rate that resulted in an increased growth rate.

scholarly journals The effect of inoculation of pea plants with mycorrhizal fungi and Rhizobium on nitrogen and phosphorus assimilation

2011 ◽  
Vol 52 (No. 10) ◽  
pp. 435-440 ◽  
Author(s):  
M. Geneva ◽  
G. Zehirov ◽  
E. Djonova ◽  
N. Kaloyanova ◽  
G. Georgiev ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Mycorrhizal Fungi ◽  
Glomus Mosseae ◽  
Rhizobium Leguminosarum ◽  
Glomus Intraradices ◽  
Plant Biomass ◽  
Phosphorus Level ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity

The study evaluated the response of pea (Pisum sativum cv. Avola) to arbuscular mycorrhizal fungi (AM) species Glomus mosseae and Glomus intraradices and Rhizobium leguminosarum bv. viceae, strain D 293, regarding the growth, photosynthesis, nodulation and nitrogen fixation activity. Pea plants were grown in a glasshouse until the flowering stage (35 days), in 4 kg plastic pots using leached cinnamonic forest soil (Chromic Luvisols – FAO) at P levels 13.2 (P1) and 39.8 (P2) mg P/kg soil. The obtained results demonstrated that the dual inoculation of pea plants significantly increased the plant biomass, photosynthetic rate, nodulation, and nitrogen fixation activity in comparison with single inoculation with Rhizobium leguminosarum bv. viceae strain D 293. On the other hand, coinoculation significantly increased the total phosphorus content in plant tissue, acid phosphatase activity and percentage of root colonization. The effectiveness of coinoculation with Rhizobium leguminosarum and Glomus mosseae was higher at the low phosphorus level while the coinoculation with Glomus intraradices appeared to be the most effective at higher phosphorus level.

scholarly journals Digalactosyldiacylglycerol Synthase Gene MtDGD1 Plays an Essential Role in Nodule Development and Nitrogen Fixation

2019 ◽  
Vol 32 (9) ◽  
pp. 1196-1209
Author(s):  
Zaiyong Si ◽  
Qianqian Yang ◽  
Rongrong Liang ◽  
Ling Chen ◽  
Dasong Chen ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Essential Role ◽  
Symbiotic Nitrogen Fixation ◽  
Histochemical Staining ◽  
Nodule Development ◽  
Nodule Number ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity ◽  
Infected Cells ◽  
Nodule Symbiosis

Little is known about the genes participating in digalactosyldiacylglycerol (DGDG) synthesis during nodule symbiosis. Here, we identified full-length MtDGD1, a synthase of DGDG, and characterized its effect on symbiotic nitrogen fixation in Medicago truncatula. Immunofluorescence and immunoelectron microscopy showed that MtDGD1 was located on the symbiosome membranes in the infected cells. β-Glucuronidase histochemical staining revealed that MtDGD1 was highly expressed in the infection zone of young nodules as well as in the whole mature nodules. Compared with the control, MtDGD1-RNA interference transgenic plants exhibited significant decreases in nodule number, symbiotic nitrogen fixation activity, and DGDG abundance in the nodules, as well as abnormal nodule and symbiosome development. Overexpression of MtDGD1 resulted in enhancement of nodule number and nitrogen fixation activity. In response to phosphorus starvation, the MtDGD1 expression level was substantially upregulated and the abundance of nonphospholipid DGDG was significantly increased in the roots and nodules, accompanied by corresponding decreases in the abundance of phospholipids such as phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. Overall, our results indicate that DGD1 contributes to effective nodule organogenesis and nitrogen fixation by affecting the synthesis and content of DGDG during symbiosis.

scholarly journals Nitrogen Fertilization Reduces Nitrogen Fixation Activity of Diverse Diazotrophs in Switchgrass Roots

2020 ◽  
pp. PBIOMES-09-19-0
Author(s):  
Rahul A. Bahulikar ◽  
Srinivasa R. Chaluvadi ◽  
Ivone Torres-Jerez ◽  
Jagadish Mosali ◽  
Jeffrey L. Bennetzen ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Fertilization ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity

scholarly journals Influence of the Poly-3-Hydroxybutyrate (PHB) Granule-Associated Proteins (PhaP1 and PhaP2) on PHB Accumulation and Symbiotic Nitrogen Fixation in Sinorhizobium meliloti Rm1021

2007 ◽  
Vol 189 (24) ◽  
pp. 9050-9056 ◽  
Author(s):  
Chunxia Wang ◽  
Xiaoyan Sheng ◽  
Raymie C. Equi ◽  
Maria A. Trainer ◽  
Trevor C. Charles ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Sinorhizobium Meliloti ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dry Weight ◽  
Granule Formation ◽  
Maldi Tof ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity ◽  
Associated Proteins

ABSTRACT Sinorhizobium meliloti cells store excess carbon as intracellular poly-3-hydroxybutyrate (PHB) granules that assist survival under fluctuating nutritional conditions. PHB granule-associated proteins (phasins) are proposed to regulate PHB synthesis and granule formation. Although the enzymology and genetics of PHB metabolism in S. meliloti have been well characterized, phasins have not yet been described for this organism. Comparison of the protein profiles of the wild type and a PHB synthesis mutant revealed two major proteins absent from the mutant. These were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) as being encoded by the SMc00777 (phaP1) and SMc02111 (phaP2) genes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins associated with PHB granules followed by MALDI-TOF confirmed that PhaP1 and PhaP2 were the two major phasins. Double mutants were defective in PHB production, while single mutants still produced PHB, and unlike PHB synthesis mutants that have reduced exopolysaccharide, the double mutants had higher exopolysaccharide levels. Medicago truncatula plants inoculated with the double mutant exhibited reduced shoot dry weight (SDW), although there was no corresponding reduction in nitrogen fixation activity. Whether the phasins are involved in a metabolic regulatory response or whether the reduced SDW is due to a reduction in assimilation of fixed nitrogen rather than a reduction in nitrogen fixation activity remains to be established.

scholarly journals Biological Nitrogen Fixation and Denitrification in Rhizosphere of Potato Plants in Response to the Fertilization and Inoculation

2021 ◽  
Vol 5 ◽  
Author(s):  
Vitaliy V. Volkogon ◽  
Svitlana B. Dimova ◽  
Kateryna I. Volkogon ◽  
Vasyl P. Sidorenko ◽  
Mykola V. Volkogon
Keyword(s):  
Nitrogen Fixation ◽  
Green Manure ◽  
Crop Yields ◽  
Nitrogenase Activity ◽  
Farmyard Manure ◽  
Mineral Fertilizers ◽  
Potato Plants ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity ◽  
Fertilizer Rates

The study aim was to evaluate the potential nitrogen fixation and denitrification in the rhizosphere soil of potato plants, crop yield and output quality in response to the different fertilization systems and the inoculation with Azospirillum brasilense 410. Field stationary experiment was conducted between 2016 and 2019 with potato in a crop rotation system on leached chernozem soil. Farmyard manure, 40 t/ha, applied prior to potatoes planting promotes nitrogen fixation (0.8–2.0 times compared to control). However, it has also affected denitrification (in 1.4–2.2 times higher compared to control). The lowest rate of mineral fertilizers used in the experiment, N40P40K40, was shown as most environmentally feasible. Under its use the increase of soil nitrogenase activity and low denitrification levels were observed. Same trends were also noted for the medium fertilizer rate, N80P80K80. The highest doses of mineral fertilizers, N120P120K120, substantially affected the denitrification process and reduced the nitrogen fixation activity (in 1.9–2.2 times). The combination of manure with the medium fertilizers rate has also resulted in high denitrification levels, while the soil nitrogen fixation activity has restored only at flowering stage. Crop inoculation with A. brasilense combined with the manure application, has not affected studied processes. However, crop inoculation after the green manure intercropping has shown the growth of nitrogenase activity. Used on the mineral fertilizers background inoculation has activated nitrogen fixation and has ensured the decrease of denitrification levels, subject to the fertilization background. High fertilizer rates have hampered the inoculation efficiency. Inoculation has promoted crop yields on unfertilized and mineral backgrounds or following green manure. Crop inoculation following organic and the organo-mineral backgrounds had no significant effect, probably due to the competition for A. brasilense from microorganisms that have created a competitive environment for A. brasilense. Despite its environmental expediency, inoculation combined with the low fertilizer doses underperforms the action of inoculation combined with the medium fertilizer rates showing the latter as the compromise between the environmental requirements and crop productivity. The use of inoculation has promoted the accumulation of starch and ascorbic acid and has contributed to the reduction of nitrate contents in the tubers of inoculated plants.

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