scholarly journals Relationship of Nitrogen Use Efficiency with the Activities of Enzymes Involved in Nitrogen Uptake and Assimilation of Finger Millet Genotypes Grown under Different Nitrogen Inputs

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Nidhi Gupta ◽  
Atul K. Gupta ◽  
Vikram S. Gaur ◽  
Anil Kumar
Keyword(s):  
Nitrogen Uptake ◽  
Nitrogen Use Efficiency ◽  
Finger Millet ◽  
High Nitrogen ◽  
Nitrogen Use ◽  
Nitrogen Uptake Efficiency ◽  
Yield Parameters ◽  
Use Efficiency ◽  
Low Nitrogen ◽  
Nitrogen Conditions

Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour) PRM-1 (brown), PRM-701 (golden), and PRM-801 (white) grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH) at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

Optimising Fertilisation Strategy for Nitrogen Uptake Efficiency

2020 ◽  
Author(s):  
Daniel McKay Fletcher ◽  
Siul Ruiz ◽  
Simon Duncan ◽  
Dave Chadwick ◽  
David Jone ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Nitrogen Use Efficiency ◽  
Numerical Experiments ◽  
Water Movement ◽  
Nitrogen Transport ◽  
Nitrogen Species ◽  
Nitrogen Use ◽  
Nitrogen Uptake Efficiency ◽  
Uptake Efficiency ◽  
Use Efficiency

<p>Sufficient nitrogen fertilisation is essential for obtaining the crop yields required to feed the growing population. Moreover, nitrogen applied to fields is often lost to a number of processes including denitrification, surface run-off and leaching. These processes can damage the local ecology and contaminate water supplies. Additionally, nitrogen lost as ammonia gas and the large energy input required to synthesize ammonia are both large contributors to global greenhouse gas emissions. Choosing fertilisation strategies to optimise the proportion of nitrogen taken up by crops (nitrogen use efficiency) can reduce the production of ammonia and the pollution of water supplies.</p><p>We developed a mathematical model that describes the movement of water and multiple nitrogen species in soil at the field scale over a growing season. The model was then used to assess the nitrogen use efficiency of varying fertilisation strategies. We consider the effects of a number of biological, chemical, and physical processes including: root growth, root uptake, the transformation of nitrogen between different nitrogen species, and the effect of soil water movement on nitrogen transport. The resulting model is comprised of a coupled system of partial and ordinary differential equations that describe the mathematical interplay between nitrogen transport, water movement, and root uptake, which were solved numerically using a finite element approach. Numerical experiments were conducted to determine how nitrogen uptake efficiency was affected by different fertilisation strategies. We examine numerous cases by varying the quantity of fertiliser applied to the soil and the fertiliser application times.</p><p>The numerical experiments suggest that, under uniform rainfall rates, the optimal fertilisation times (within the bounds of typical times found in agriculture) can result in 25% more nitrogen uptake than the worst strategies. However, there were large time periods, 28 days for the first application and 10 days for the second, which resulted in close-to-optimal nitrogen use efficiency. The results of this study, in addition to crop health and past and predicted rainfall, could be taken into consideration by farmers while choosing fertilisation times to optimise nitrogen uptake efficiency.</p>

Responses of two rice cultivars differing in seedling-stage nitrogen use efficiency to growth under low-nitrogen conditions

2009 ◽  
Vol 326 (1-2) ◽  
pp. 291-302 ◽  
Author(s):  
Wei Ming Shi ◽  
Wei Feng Xu ◽  
Su Mei Li ◽  
Xue Qiang Zhao ◽  
Gang Qiang Dong
Keyword(s):  
Nitrogen Use Efficiency ◽  
Seedling Stage ◽  
Rice Cultivars ◽  
Nitrogen Use ◽  
Use Efficiency ◽  
Low Nitrogen ◽  
Nitrogen Conditions

scholarly journals Nitrogen Uptake Efficiency, Mediated by Fine Root Growth, Early Determines Temporal and Genotypic Variations in Nitrogen Use Efficiency of Winter Oilseed Rape

2021 ◽  
Vol 12 ◽  
Author(s):  
Victor Vazquez-Carrasquer ◽  
Anne Laperche ◽  
Christine Bissuel-Bélaygue ◽  
Michaël Chelle ◽  
Céline Richard-Molard
Keyword(s):  
Genetic Variability ◽  
Root Growth ◽  
Nitrogen Uptake ◽  
Nitrogen Use Efficiency ◽  
Fine Root ◽  
Nitrogen Use ◽  
Nitrogen Uptake Efficiency ◽  
Uptake Efficiency ◽  
Fine Root Growth ◽  
Use Efficiency

Maintaining seed yield under low N inputs is a major issue for breeding, which requires thoroughly exploiting the genetic diversity of processes related to Nitrogen Use Efficiency (NUE). However, dynamic analysis of processes underlying genotypic variations in NUE in response to N availability from sowing to harvest are scarce, particularly at the whole-plant scale. This study aimed to dynamically decipher the contributions of Nitrogen Uptake Efficiency (NUpE) and Nitrogen Utilization Efficiency (NUtE) to NUE and to identify traits underlying NUpE genetic variability throughout the growth cycle of rapeseed. Three experiments were conducted under field-like conditions to evaluate seven genotypes under two N conditions. We developed NUE_DM (ratio of total plant biomass to the amount of N available) as a new proxy of NUE at harvest, valid to discriminate genotypes from the end of inflorescence emergence, and N conditions as early as the beginning of stem elongation. During autumn growth, NUpE explained up to 100% of variations in NUE_DM, validating the major role of NUpE in NUE shaping. During this period, under low N conditions, up to 53% of the plant nitrogen was absorbed and NUpE genetic variability resulted not from differences in Specific N Uptake but in fine-root growth. NUtE mainly contributed to NUE_DM genotypic variation during the reproductive phase under high-N conditions, but NUpE contribution still accounted for 50–75% after flowering. Our study highlights for the first time NUpE and fine-root growth as important processes to optimize NUE, which opens new prospects for breeding.

scholarly journals Morphological and physiological plasticity response to low nitrogen stress in black cottonwood (Populus deltoides Marsh.)

2021 ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Qinjun Huang ◽  
Changjun Ding ◽  
Weixi Zhang ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Nitrogen Use Efficiency ◽  
Root Biomass ◽  
Populus Deltoides ◽  
Leaf Traits ◽  
Nitrogen Level ◽  
Nitrogen Use ◽  
Use Efficiency ◽  
Normal Nitrogen ◽  
Low Nitrogen

AbstractIt is important to evaluate nitrogen use efficiency and nitrogen tolerance of trees in order to improve their productivity. In this study, both were evaluated for 338 Populus deltoides genotypes from six provenances. The plants were cultured under normal nitrogen (750 μM NH4NO3) and low nitrogen (5 μM NH4NO3) conditions for 3 months. Growth, chlorophyll content and glutamine synthetase activity of each genotype were measured. Under low nitrogen, heights, ground diameter, leaf area, leaf and root biomass, and chlorophyll contents were significantly lower than those under normal nitrogen level. Correlation analysis showed that nutrient distribution changed under different nitrogen treatments. There was a negative correlation between leaf traits and root biomass under normal nitrogen level, however, the correlation became positive in low nitrogen treatment. Moreover, with the decrease of nitrogen level, the negative correlation between leaf morphology and chlorophyll levels became weakened. The growth of the genotypes under the two treatments was evaluated by combining principal component analysis with a fuzzy mathematical membership function; the results showed that leaf traits accounted for a large proportion of the variation in the evaluation model. According to the results of comprehensive evaluation of plants under the two treatments, the 338 P. deltoides genotypes could be divided into nine categories, with wide genotypic diversity in nitrogen use efficiency and low nitrogen tolerance. As a result, 26 N-efficient genotypes and 24 N-inefficient genotypes were selected. By comparative analysis of their morphological and physiological traits under the two treatments, leaf traits could be significant indicators for nitrogen use efficiency and nitrogen tolerance, which is of considerable significance for breeding poplar varieties with high nitrogen use efficiencies.

scholarly journals Adaptation Mechanism of Roots to Low and High Nitrogen Revealed by Proteomic Analysis

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Wei Xin ◽  
Lina Zhang ◽  
Jiping Gao ◽  
Wenzhong Zhang ◽  
Jun Yi ◽  
...  
Keyword(s):  
Root Growth ◽  
Nitrogen Use Efficiency ◽  
Root Morphology ◽  
Nitrogen Availability ◽  
Rice Root ◽  
Global Changes ◽  
High Nitrogen ◽  
Nitrogen Use ◽  
Rice Roots ◽  
Use Efficiency

Abstract Background Nitrogen-based nutrients are the main factors affecting rice growth and development. Root systems play an important role in helping plants to obtain nutrients from the soil. Root morphology and physiology are often closely related to above-ground plant organs performance. Therefore, it is important to understand the regulatory effects of nitrogen (N) on rice root growth to improve nitrogen use efficiency. Results In this study, changes in the rice root traits under low N (13.33 ppm), normal N (40 ppm) and high N (120 ppm) conditions were performed through root morphology analysis. These results show that, compared with normal N conditions, root growth is promoted under low N conditions, and inhibited under high N conditions. To understand the molecular mechanism underlying the rice root response to low and high N conditions, comparative proteomics analysis was performed using a tandem mass tag (TMT)-based approach, and differentially abundant proteins (DAPs) were further characterized. Compared with normal N conditions, a total of 291 and 211 DAPs were identified under low and high N conditions, respectively. The abundance of proteins involved in cell differentiation, cell wall modification, phenylpropanoid biosynthesis, and protein synthesis was differentially altered, which was an important reason for changes in root morphology. Furthermore, although both low and high N can cause nitrogen stress, rice roots revealed obvious differences in adaptation to low and high N. Conclusions These results provide insights into global changes in the response of rice roots to nitrogen availability and may facilitate the development of rice cultivars with high nitrogen use efficiency through root-based genetic improvements.

Nitrogen Use Efficiency and Nitrogen Uptake of Canola under Diverse Environments

2008 ◽  
Vol 100 (2) ◽  
pp. 285 ◽  
Author(s):  
Y. Gan ◽  
S. S. Malhi ◽  
S. Brandt ◽  
F. Katepa-Mupondwa ◽  
C. Stevenson
Keyword(s):  
Nitrogen Uptake ◽  
Nitrogen Use Efficiency ◽  
Nitrogen Use ◽  
Use Efficiency

A computational history and outlook of nitrogen use efficiency and precipitation-optimal fertilisation timings in agriculture

2021 ◽  
Author(s):  
Daniel McKay Flecher ◽  
Siul Ruiz ◽  
Tiago Dias ◽  
Katherine Williams ◽  
Chiara Petroselli ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Nitrogen Uptake ◽  
Nitrogen Use Efficiency ◽  
Nitrogen Efficiency ◽  
Nitrogen Use ◽  
Plant Nitrogen ◽  
Nitrogen Fertilisation ◽  
Plant Nitrogen Uptake ◽  
Use Efficiency ◽  
Rainfall Patterns

<p>Half of the nitrogen applied to arable-fields is lost through several processes linked to soil moisture. Low soil moisture limits nitrogen mobility reducing nitrogen-uptake while wetter conditions can increase nitrogen leaching. Rainfall ultimately governs soil moisture and the fate of nitrogen in soil. However, the interaction between rainfall and nitrogen use efficiency (NUE) remains poorly understood.</p> <p>We developed a field-scale modelling platform that describes coupled water and nitrogen transport, root growth and uptake, rainfall, the nitrogen-cycle and leaching to assess the NUE of split fertilisations with realistic rainfall patterns. The model was solved for every possible split fertilisation timing in 200+ growing seasons to determine optimal timings. Two previous field trials regarding rainfall and NUE had contrasting results: wetter years have enhanced fertiliser loss and drier years reduced plant nitrogen uptake. By choosing appropriate fertilisation timings in the model we could recreate the two contrasting trends and maintain variability in the data. However, we found by choosing other fertilisation timings we could mitigate the leaching in wetter years. Optimised timings could increase plant nitrogen uptake by up to 35% compared to the mean in dry years. Plant uptake was greatest under drier conditions due to mitigated leaching, but less likely to occur due to low nitrogen mobility. Optimal fertilisation timings varied dramatically depending on the rainfall patterns. Historic and projected rainfall patterns from 1950-2069 were used in the model. We found optimal NUE has a decrease from 2022-2040 due to increased heavy rainfall events and optimal fertilisation timings are later in the season but varied largely on a season-to-season basis.</p> <p>The results are a step towards achieving improved nitrogen efficiency in agriculture by using the ‘at the right time’ agronomic-strategy in the ‘4Rs’ of improved nitrogen fertilisation. Our results can help determine nitrogen fertilisation timings in changing climates.</p>

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