scholarly journals Digital imaging approaches for phenotyping whole plant nitrogen and phosphorus response in Brachypodium distachyon

2014 ◽  
Vol 56 (8) ◽  
pp. 781-796 ◽  
Author(s):  
Richard Poiré ◽  
Vincent Chochois ◽  
Xavier R. R. Sirault ◽  
John P. Vogel ◽  
Michelle Watt ◽  
...  
Keyword(s):  
Digital Imaging ◽  
Brachypodium Distachyon ◽  
Nitrogen And Phosphorus ◽  
Plant Nitrogen ◽  
Phosphorus Response ◽  
Whole Plant

Systemic control of nodule formation by the plant N demand requires autoregulation dependent and independent mechanisms

2021 ◽  
Author(s):  
Marjorie Pervent ◽  
Ilana Lambert ◽  
Marc Tauzin ◽  
Alicia Karouani ◽  
Martha Nigg ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nodule Formation ◽  
Atmospheric Nitrogen ◽  
Plant Nitrogen ◽  
Systemic Signaling ◽  
Systemic Control ◽  
Whole Plant ◽  
Strong Control ◽  
Mutant Genes ◽  
N Demand

Abstract In legumes interacting with rhizobia the formation of symbiotic organs involved in the acquisition of atmospheric nitrogen is depending of the plant nitrogen (N) demand. We used Medicago truncatula plants cultivated in split-root systems to discriminate between responses to local and systemic N signalings. We evidenced a strong control of nodule formation by systemic N-signaling but obtained no clear evidence of a local control by mineral nitrogen. Systemic signaling of the plant N demand controls numerous transcripts involved in the root transcriptome reprogramming associated to early rhizobia interaction and nodule formation. SUNN has an important role in this control but major systemic N signaling responses remained active in the sunn mutant. Genes involved in the activation of nitrogen fixation are regulated by systemic N signaling in the mutant, explaining why the hypernodulation phenotype is not associated to a higher nitrogen fixation of the whole plant. The control of the transcriptome reprogramming of nodule formation by systemic N signaling requires other pathway(s) that parallel the SUNN/CLE pathway.

scholarly journals Impact of plant functional group and species removals on soil and plant nitrogen and phosphorus across a retrogressive chronosequence

2019 ◽  
Vol 108 (2) ◽  
pp. 561-573 ◽  
Author(s):  
David A. Wardle ◽  
Michael J. Gundale ◽  
Paul Kardol ◽  
Marie‐Charlotte Nilsson ◽  
Nicolas Fanin
Keyword(s):  
Functional Group ◽  
Nitrogen And Phosphorus ◽  
Plant Functional Group ◽  
Plant Nitrogen

Biological nutrient removal model No.1 (BNRM1)

2004 ◽  
Vol 50 (6) ◽  
pp. 69-70 ◽  
Author(s):  
A. Seco ◽  
J. Ribes ◽  
J. Serralta ◽  
J. Ferrer
Keyword(s):  
Nutrient Removal ◽  
Volatile Fatty Acids ◽  
Wastewater Treatment Plants ◽  
Biological Nutrient Removal ◽  
Model Parameters ◽  
Nitrogen And Phosphorus ◽  
Hindered Settling ◽  
Whole Plant ◽  
Bacterial Groups ◽  
Removal Model

This paper presents the results of the work carried out by the CALAGUA Group on Mathematical Modelling of Biological Treatment Processes: the Biological Nutrient Removal Model No.1. This model is based on a new concept for dynamic simulation of wastewater treatment plants: a unique model can be used to design, simulate and optimize the whole plant, as it includes most of the biological and physico-chemical processes taking place in all treatment operations. The physical processes included are: settling and clarification processes (flocculated settling, hindered settling and thickening), volatile fatty acids elutriation and gasÐliquid transfer. The chemical interactions included comprise acidÐbase processes, where equilibrium conditions are assumed. The biological processes included are: organic matter, nitrogen and phosphorus removal; acidogenesis, acetogenesis and methanogenesis. Environmental conditions in each operation unit (aerobic, anoxic or anaerobic) will determine which bacterial groups can grow. Thus, only the model parameters related to bacterial groups able to grow in any of the operation units of a specific WWTP will require calibration. One of the most important advantages of this model is that no additional analysis with respect to ASM2d is required for wastewater characterization. Some applications of this model have also been briefly explained in this paper.

Symbiotic Nitrogen Fixation by Coralloid Roots of the Cycad Macrozamia riedlei: Physiological Characteristics and Ecological Significance

1976 ◽  
Vol 3 (3) ◽  
pp. 349 ◽  
Author(s):  
J Halliday ◽  
JS Pate
Keyword(s):  
Nitrogenase Activity ◽  
Natural Habitat ◽  
Natural Populations ◽  
Molar Ratio ◽  
Fixation Rate ◽  
Plant Nitrogen ◽  
Blue Green Algae ◽  
C2h2 Reduction ◽  
Whole Plant ◽  
Coralloid Roots

'Coralloid' roots containing blue-green algae occur commonly on the upper root stocks of M. riedlei in natural habitat in Western Australia. Each coralloid mass persists for several seasons; replacement sets form at irregular intervals, especially after fire. 15N2 and acetylene reduction assays demonstrate that coralloid roots fix nitrogen at physiologically significant rates. C2H2 reduction rates by coralloid roots are higher in winter than in summer. Performance is positively correlated with rainfall; soil temperature appears to be of lesser importance. Diurnal fluctuations in nitrogenase activity occur. Calibration using 15N2 gives a molar ratio of C2H2 reduced : N2 fixed of 5.8 : 1. The seasonal average of C2H2 reduction of 14.8 nmol per g fresh wt coralloid root per min is then equivalent to 37.6 g N per kg fresh wt per year, a fixation rate potentially capable of doubling coralloid root nitrogen once in every 8 weeks, and whole plant nitrogen every 8-11 years. Returns of fixed nitrogen in two natural populations of Macrozamia are estimated by compounding measurements of biomass of host and symbiotic organs with the seasonal average for coralloid fixation rate. The values obtained (18.8 and 18.6 kg N ha-1 year-1) indicate that Macrozamia contributes significantly to the nitrogen economy of its ecosystem.

scholarly journals A Proficiency Testing Program for the Agricultural Laboratory Analysis Industry

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 456G-457
Author(s):  
Robert O. Miller ◽  
Steven E. Newman ◽  
Janice Kotuby-Amacher
Keyword(s):  
Proficiency Testing ◽  
Performance Testing ◽  
Internal Quality ◽  
Nitrogen And Phosphorus ◽  
Testing Program ◽  
Plant Nitrogen ◽  
Plant Samples ◽  
Accuracy And Precision ◽  
Internal Quality Assurance ◽  
Canadian Provinces

The accuracy of soil and plant analytical results are occasionally called into question by laboratory clientele. Although laboratories generally conduct internal quality assurance procedures, there are few external performance testing programs for the industry. In 1994, a proficiency testing program was initiated for soil and plant samples for agricultural laboratories in the western United States to provide an external quality control for the lab industry. The program involves the quarterly exchange of soil and plant samples on which soil salinity, soil fertility, and plant nutrition analyses are conducted. One hundred laboratories are annually enrolled in the program from 24 states and Canadian provinces. Results of 3 years of the program indicate soil nitrate, soil pH, extractable potassium, soil and organic matter are reproducible within 10% between laboratories. Soil-extractable phosphorus (by five methods), soil-extractable boron, and soluble chloride were only reproducible within 15% to 20% between laboratories. Plant nitrogen and phosphorus results were consistent across samples, laboratories, and methods. Variability in plant nitrate increased with decreasing tissue concentrations. Overall accuracy and precision of reported results, based on the use of NIST certified reference botanical samples, were excellent for N, P, K, Ca, and Cu. Generally, for any given analysis, the results of ≈10% of the laboratories exceed two standard deviations from the mean. Overall, significant improvement was noted in the laboratory industry proficiency through the course of the program.

scholarly journals Role of Methylotrophy During Symbiosis Between Methylobacterium nodulans and Crotalaria podocarpa

2005 ◽  
Vol 18 (10) ◽  
pp. 1061-1068 ◽  
Author(s):  
Philippe Jourand ◽  
Adeline Renier ◽  
Sylvie Rapior ◽  
Sergio Miana de Faria ◽  
Yves Prin ◽  
...  
Keyword(s):  
Root Nodule ◽  
Wild Type Strain ◽  
Plant Biomass ◽  
Root Nodules ◽  
Methylotrophic Bacterium ◽  
Plant Nitrogen ◽  
Affected Plant ◽  
Whole Plant ◽  
Fixation Capacity

Some rare leguminous plants of the genus Crotalaria are specifically nodulated by the methylotrophic bacterium Methylobacterium nodulans. In this study, the expression and role of bacterial methylotrophy were investigated during symbiosis between M. nodulans, strain ORS 2060T, and its host legume, Crotalaria podocarpa. Using lacZ fusion to the mxaF gene, we showed that the methylotroph genes are expressed in the root nodules, suggesting methylotrophic activity during symbiosis. In addition, loss of the bacterial methylotrophic function significantly affected plant development. Indeed, inoculation of M. nodulans nonmethylotroph mutants in C. podocarpa decreased the total root nodule number per plant up to 60%, decreased the whole-plant nitrogen fixation capacity up to 42%, and reduced the total dry plant biomass up to 46% compared with the wild-type strain. In contrast, inoculation of the legume C. podocarpa with nonmethylotrophic mutants complemented with functional mxa genes restored the symbiotic wild phenotype. These results demonstrate the key role of methylotrophy during symbiosis between M. nodulans and C. podocarpa.

Preliminary investigation of the potential of four tropical emergent macrophytes for treatment of pre-treated pulp and papermill wastewater in Kenya

2003 ◽  
Vol 48 (5) ◽  
pp. 223-231 ◽  
Author(s):  
M.A. Abira ◽  
H.W. Ngirigacha ◽  
J.J.A. van Bruggen
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Preliminary Investigation ◽  
Dry Weight ◽  
Batch Reactors ◽  
Nitrogen And Phosphorus ◽  
Emergent Macrophytes ◽  
Paper Mills ◽  
Plant Nitrogen ◽  
Appropriate Treatment

The potential of four aquatic macrophytes for treatment of wastewater in constructed wetlands was investigated in bucket mesocosms at Pan African Paper Mills (E.A) Limited. The buckets were operated as semi-continuous batch reactors with reversed vertical flow for a period of 3 months. Four treatments were applied involving two hydraulic retention times (HRT) and two wastewater concentrations. Plants appeared healthier and greener in treatments at HRT5 than at HRT10. Cyperus immensus and Typha domingensis had higher biomass gain compared to the other two species. Plant nitrogen and phosphorus content, based on dry weight, was lower at the end of the experiment than at the beginning in all treatments for all species. The removal efficiency achieved for COD ranged from 10 to 55% for planted buckets at HRT5 and 15 to 65% at HRT10 for similar buckets. The mean percentage COD removal in unplanted buckets was significantly lower than in planted ones. TSS removal efficiency ranged from 44-86%. Buckets planted with Typha exhibited the highest removal efficiency in all treatments. Those at HRT5 showed significantly higher removal efficiencies than those at HRT10 for all species. The results indicate that the plants are suitable for use in constructed wetlands for treatment of the wastewater provided the appropriate treatment is applied.

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