scholarly journals Relative Abundance of Ureides and Nitrate in Plant Tissues of Soybean as a Quantitative Assay of Nitrogen Fixation

1982 ◽  
Vol 70 (1) ◽  
pp. 1-6 ◽  
Author(s):  
David F. Herridge
Keyword(s):  
Nitrogen Fixation ◽  
Relative Abundance ◽  
Quantitative Assay ◽  
Plant Tissues

scholarly journals Phosphate solubilizing bacteria stimulate wheat rhizosphere and endosphere biological nitrogen fixation by improving phosphorus content

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9062
Author(s):  
Yongbin Li ◽  
Qin Li ◽  
Guohua Guan ◽  
Sanfeng Chen
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Available P ◽  
Plant Tissues ◽  
Diazotrophic Bacteria ◽  
Total N ◽  
P Content ◽  
Soil Available P ◽  
Biological Nitrogen ◽  
Total P

Phosphate (P) availability often limits biological nitrogen fixation (BNF) by diazotrophic bacteria. In soil, only 0.1% of the total P is available for plant uptake. P solubilizing bacteria can convert insoluble P to plant-available soluble P (ionic P and low molecular-weight organic P). However, limited information is available about the effects of synergistic application of diazotrophic bacteria and P solubilizing bacteria on the nitrogenase activity of rhizosphere and nifH expression of endosphere. In this study, we investigated the effects of co-inoculation with a diazotrophic bacterium (Paenibacillus beijingensis BJ-18) and a P-solubilizing bacterium (Paenibacillus sp. B1) on wheat growth, plant and soil total N, plant total P, soil available P, soil nitrogenase activity and the relative expression of nifH in plant tissues. Co-inoculation significantly increased plant biomass (length, fresh and dry weight) and plant N content (root: 27%, shoot: 30%) and P content (root: 63%, shoot: 30%). Co-inoculation also significantly increased soil total N (12%), available P (9%) and nitrogenase activity (69%) compared to P. beijingensis BJ-18 inoculation alone. Quantitative real-time PCR analysis showed co-inoculation doubled expression of nifH genes in shoots and roots. Soil nitrogenase activity and nifH expression within plant tissues correlated with P content of soil and plant tissues, which suggests solubilization of P by Paenibacillus sp. B1 increased N fixation in soils and the endosphere. In conclusion, P solubilizing bacteria generally improved soil available P and plant P uptake, and considerably stimulated BNF in the rhizosphere and endosphere of wheat seedlings.

scholarly journals Identification of Native Microorganisms of the Amazon Rhizosphere to Speed up the Decomposition Process of Agro-Industrial Organic Waste

2021 ◽  
Vol 10 (9) ◽  
pp. 473-483
Author(s):  
Ocampo-Guevara Jhon-Alexander ◽  
Vega Espinoz Johana Jazmín ◽  
Rivera González Johanna Rivera ◽  
Carlos Jacome
Keyword(s):  
Organic Matter ◽  
Nitrogen Fixation ◽  
Metabolic Activity ◽  
Organic Waste ◽  
Organic Matter Content ◽  
Degradation Process ◽  
Matter Content ◽  
Uniform Structure ◽  
Plant Tissues ◽  
Speed Up

Agribusiness is one of the areas with the greatest impact, which, due to the processes involved within this area, generates waste that, given its composition, is used in optimal materials to be used for degradation methods in the production of composting, different microorganisms such as Pseudomonas, Bacillus, Aspergillus help in the decomposition of waste from agribusiness, the metabolic activity of these microorganisms allows the degradation of animal and plant tissues such as cellulose, starch, pectin, proteins, agar that intervene in nitrification and nitrogen fixation processes, for the degradation process it is necessary to carry out in composting beds of organic waste isolated with strains of the rhizosphere from the natural forest of CIPCA the strains use the dimensions of 4 x 1 x 1 giving a city layer of 4𝑚3 or about 640 kg of organic rough which are covered with geo mucosa, surrounded by gutters to collect leachate two produced by the effect of degradation, this process of degradation of organic matter allows to obtain a product with characteristics such as earthy odor, texture and uniform structure, where a pH close to neutral was registered in the control beds, gradually increasing from that moment with slightly alkaline values where it does not present characteristics of the initial organic matter, reducing the volume by 35%, for this the objective is to maintain Controller of certain parameters of temperature, humidity, pH, compost ratio and organic matter content.

scholarly journals Long-term warming effects on the microbiome and nitrogen fixation associated with the moss Racomitrium lanuginosum in Icelandic tundra

2019 ◽  
Author(s):  
Ingeborg J. Klarenberg ◽  
Christoph Keuschnig ◽  
Ana J. Russi Colmenares ◽  
Denis Warshan ◽  
Anne D. Jungblut ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
The Arctic ◽  
Gene Copy ◽  
Nitrogen Fixing ◽  
Moss Species

AbstractBacterial communities form the basis of biogeochemical processes and determine plant growth and health. Mosses, an abundant plant group in Arctic ecosystems, harbour diverse bacterial communities that are involved in nitrogen fixation and carbon cycling. Global climate change is causing changes in aboveground plant biomass and shifting species composition in the Arctic, but little is known about the response of the moss microbiome. Here, we studied the total and potentially active bacterial community associated with Racomitrium lanuginosum, a common moss species in the Arctic, in response to 20-year in situ warming in an Icelandic heathland. We evaluated changes in moss bacterial community composition and diversity. Further, we assessed the consequences of warming for nifH gene copy numbers and nitrogen-fixation rates. Long-term warming significantly changed both the total and the potentially active bacterial community structure. The relative abundance of Proteobacteria increased, while the relative abundance of Cyanobacteria and Acidobacteria decreased. While warming did not affect nitrogen-fixation rates and nifH gene abundance, we did find shifts in the potentially nitrogen-fixing community, with Nostoc decreasing and non-cyanobacterial diazotrophs increasing in relative abundance. Our data suggests that the moss microbial community and the potentially nitrogen-fixing taxa are sensitive to future warming.

Diversity and abundance of termites along an altitudinal gradient in Khao Kitchagoot National Park, Thailand

2006 ◽  
Vol 22 (5) ◽  
pp. 609-612 ◽  
Author(s):  
Tetsushi Inoue ◽  
Yoko Takematsu ◽  
Akinori Yamada ◽  
Yuichi Hongoh ◽  
Toru Johjima ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Relative Abundance ◽  
National Park ◽  
Altitudinal Gradient ◽  
Feeding Habits ◽  
Carbon Mineralization ◽  
Terrestrial Ecosystems ◽  
Tropical Soils ◽  
Species Assemblage ◽  
Metabolic Processes

Termites are dominant invertebrates in tropical soils (Wood & Sands 1978) and are important mediators of decomposition in terrestrial ecosystems (Abe & Matsumoto 1979, Lawton et al. 1996, Lee & Wood 1971, Matsumoto & Abe 1979, Wood & Sands 1978, Yamada et al. 2005). Furthermore, these processes, such as carbon mineralization and nitrogen fixation, are dependent on the species assemblage structure of the termite community (Lawton et al. 1996, Yamada et al. 2005, 2006). Feeding habits of termites reflect their metabolic processes. The three major isopteran groups – wood-feeders, fungus-growers (fungus-growing wood/litter feeders), soil-feeders – appear to play very different roles in the decomposition process (Tayasu et al. 1997, Wood 1976, Wood & Sands 1978, Yamada et al. 2005). Consequently, the relative abundance of each feeding group provides useful information on the function of the termite assemblage in an ecosystem.

scholarly journals ​Diversity of Non-heterocystous Cyanobacteria in Paddy Field Soil

2021 ◽  
Author(s):  
Anitha Rajasekaran ◽  
Usha Raja
Keyword(s):  
Nitrogen Fixation ◽  
Soil Ph ◽  
Relative Abundance ◽  
Paddy Field ◽  
Natural Habitat ◽  
Axenic Culture ◽  
Soil Samples ◽  
Field Soil ◽  
Paddy Field Soil ◽  
Diversity Study

Paddy field soil is a natural habitat for many Cyanobacteria. Generally Heterocystous form dominate the nitrogen deficient soil. Non-heterocystous forms are also known to fix nitrogen. The diversity and the distribution of these forms vary. 20 Soil samples were serial diluted in BG-11 devoid of nitrogen supplement. Later the colonies were streaked to obtain axenic culture. The soil pH was also determined to study the effect on the diversity. The relative abundance of the BGA species was determined .Diversity of non-heterocystous form in the paddy field was found to be dominated by filamentous BGA, Lynbgya by 21%, Oscillatoria and Phormidium by 17% and colonial form Chrococcus sp by 12.5% Followed by Myxosarcina sp., 8%, while Aphanocapsa sp., Chlorogloea sp., Crinaluim sp., Gleocapsa sp, Plectonema sp. and Schizothrix sp., were 4%. A majority of the non-heterocystous BGA were found in the soil which had a pH ranging between 8.2-8.6. Diversity study of non-heterocystous BGA can help in understanding the distribution and further aid in the study of nitrogen fixation in these forms.

scholarly journals An experimental workflow identifies nitrogenase proteins ready for expression in plant mitochondria

2019 ◽  
Author(s):  
S. Okada ◽  
C. M. Gregg ◽  
R. S. Allen ◽  
A. Menon ◽  
D. Hussain ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Relative Abundance ◽  
Nitrogen Fertilizer ◽  
Nitrogenase Activity ◽  
Klebsiella Oxytoca ◽  
Plant Mitochondria ◽  
Fold Increase ◽  
Mitochondrial Targeting ◽  
Targeting Peptide ◽  
Nif Proteins

AbstractIndustrial nitrogen fertilizer is intrinsic to modern agriculture yet expensive and environmentally harmful. We aim to reconstitute bacterial nitrogenase function within plant mitochondria to reduce nitrogen fertilizer usage. Many nitrogen fixation (Nif) proteins are required for biosynthesis and function of the mature nitrogenase enzyme, and these will need to be correctly processed and soluble within mitochondria as a pre-requisite for function. Here we present our workflow that assessed processing, solubility and relative abundance of 16 Klebsiella oxytoca Nif proteins targeted to the plant mitochondrial matrix using an Arabidopsis mitochondrial targeting peptide (MTP). The functional consequence of the N-terminal modifications required for mitochondrial targeting of Nif proteins was tested using bacterial nitrogenase assays. We found that despite the use of the same constitutive promoter and MTP, MTP::Nif processing and relative abundance in plant leaf varied considerably. Assessment of solubility for all MTP::Nif proteins found NifF, M, N, S, U, W, X, Y and Z were soluble, while NifB, E, H, J, K, Q and V were mostly insoluble. Although most Nif proteins tolerated the N-terminal extension as a consequence of mitochondrial processing, this extension in NifM reduced nitrogenase activity to 10% of controls. Using proteomics, we detected a ∼50-fold increase in the abundance of NifM when it contained the N-terminal MTP extension, which may account for this reduction seen in nitrogenase activity. Based on plant mitochondrial processing and solubility, and retention of function in a bacterial assay, our workflow has identified that NifF, N, S, U, W, Y and Z satisfied all these criteria. Future work can now focus on improving these parameters for the remaining Nif components to assemble a complete set of plant-ready Nif proteins for reconstituting nitrogen fixation in plant mitochondria.

Microscopy studies of powdery mildew on summer squash

1991 ◽  
Vol 49 ◽  
pp. 520-521
Author(s):  
John S. Gardner ◽  
W. M. Hess
Keyword(s):  
Powdery Mildew ◽  
Tip Growth ◽  
Hyphal Growth ◽  
Plant Tissues ◽  
Vegetative Hypha ◽  
Powdery Mildews ◽  
Summer Squash ◽  
Conidial Formation ◽  
Polar Tip Growth ◽  
Short Conidiophore

Powdery mildews are characterized by the appearance of spots or patches of a white to grayish, powdery, mildewy growth on plant tissues, entire leaves or other organs. Ervsiphe cichoracearum, the powdery mildew of cucurbits is among the most serious parasites, and the most common. The conidia are formed similar to the process described for Ervsiphe graminis by Cole and Samson. Theconidial chains mature basipetally from a short, conidiophore mother-cell at the base of the fertile hypha which arises holoblastically from the conidiophore. During early development it probably elongates by polar-tip growth like a vegetative hypha. A septum forms just above the conidiophore apex. Additional septa develop in acropetal succession. However, the conidia of E. cichoracearum are more doliform than condia from E. graminis. The purpose of these investigations was to use scanning electron microscopy (SEM) to demonstrate the nature of hyphal growth and conidial formation of E. cichoracearum on field-grown squash leaves.

Localization of acid phosphatases in root cap of rice plant

1991 ◽  
Vol 49 ◽  
pp. 224-225
Author(s):  
Y. R. Chen ◽  
Y. F. Huang ◽  
W. S. Chen
Keyword(s):  
Rice Plant ◽  
Developmental Stages ◽  
Uranyl Acetate ◽  
Root Cap ◽  
Plant Tissues ◽  
Acid Phosphatases ◽  
Root Tips ◽  
Buffer Solution ◽  
Cacodylate Buffer ◽  
Ethanol Series

Acid phosphatases are widely distributed in different tisssues of various plants. Studies on subcellular localization of acid phosphatases show they might be present in cell wall, plasma lemma, mitochondria, plastid, vacuole and nucleus. However, their localization in rice cell varies with developmental stages of cells and plant tissues. In present study, acid phosphatases occurring in root cap are examined.Sliced root tips of ten-day-old rice(Oryza sativa) seedlings were fixed in 0.1M cacodylate buffer containing 2.5% glutaraldehyde for 2h, washed overnight in same buffer solution, incubated in Gomori's solution at 37° C for 90min, post-fixed in OsO4, dehydrated in ethanol series and finally embeded in Spurr's resin. Sections were doubly stained with uranyl acetate and lead citrate, and observed under Hitachi H-600 at 75 KV.

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