338 Nitrogen Use Efficiency Is Proportionally More Improved When Young Bulls Are Ranked on Residual Body Gain Rather Than on Residual Feed Intake

Abstract Animals with superior feed efficiency (FE) may also have an improved nitrogen use efficiency (NUE), which would be beneficial to economic profitability while reducing environmental impacts. When genetically selecting animals on FE, it is preferable to use residual traits [e.g. residual feed intake (RFI) or residual body gain (RG)] rather than ratios because of their predictable genetic outcomes. We studied the relationship of RFI and RG with NUE, estimated from the validated 15N abundance in plasma, across two contrasted diets based on corn or grass silages. We evaluated FE of 588 (half by diet) Charolais bulls (545 ± 57 kg BW) from 12 experimental cohorts (different farms and periods) over 200 days. Before the end of the FE test, plasma was sampled and analyzed for δ 15N. NUE was related to FE through simple-linear models with variables previously corrected for the cohort and diet effects. The models’ slopes were standardized according to FE deviation in order to compare the response of NUE to FE between indices. Higher NUE was related to higher FE (P < 0.001), showing positive correlations with RG (r=-0.40) and negative with RFI (r=0.29). However, the standardized slope of NUE to RG was significantly higher (+28%; P < 0.05) than that of NUE to RFI. This stronger NUE relation to RG compared to RFI could reflect a higher potential of RG animals to deposit N as compared to a more conservational N metabolism in RFI individuals. Regarding diets, and despite the correction of NUE and FE for this effect, the slopes of NUE to FE were numerically (P > 0.05) higher (-16% and +36%; for RG and RFI) in corn-based diets, which agrees with superior NUE observed in corn-vs-grass diets. Results suggested that superior RG animals may present proportionally higher NUE than superior RFI animals, with even better results in corn-vs-grass diets.

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Genetic Engineering and Genome Editing for Improving Nitrogen Use Efficiency in Plants

Cells ◽

10.3390/cells10123303 ◽

2021 ◽

Vol 10 (12) ◽

pp. 3303

Author(s):

Vadim G. Lebedev ◽

Anna A. Popova ◽

Konstantin A. Shestibratov

Keyword(s):

Genome Editing ◽

Nitrogen Use Efficiency ◽

Nitrogen Availability ◽

Global Climate ◽

Biomass Accumulation ◽

Limiting Factors ◽

Unintended Effects ◽

Nitrogen Use ◽

N Metabolism ◽

Use Efficiency

Low nitrogen availability is one of the main limiting factors for plant growth and development, and high doses of N fertilizers are necessary to achieve high yields in agriculture. However, most N is not used by plants and pollutes the environment. This situation can be improved by enhancing the nitrogen use efficiency (NUE) in plants. NUE is a complex trait driven by multiple interactions between genetic and environmental factors, and its improvement requires a fundamental understanding of the key steps in plant N metabolism—uptake, assimilation, and remobilization. This review summarizes two decades of research into bioengineering modification of N metabolism to increase the biomass accumulation and yield in crops. The expression of structural and regulatory genes was most often altered using overexpression strategies, although RNAi and genome editing techniques were also used. Particular attention was paid to woody plants, which have great economic importance, play a crucial role in the ecosystems and have fundamental differences from herbaceous species. The review also considers the issue of unintended effects of transgenic plants with modified N metabolism, e.g., early flowering—a research topic which is currently receiving little attention. The future prospects of improving NUE in crops, essential for the development of sustainable agriculture, using various approaches and in the context of global climate change, are discussed.

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Recent Advances on Nitrogen Use Efficiency in Rice

Agronomy ◽

10.3390/agronomy11040753 ◽

2021 ◽

Vol 11 (4) ◽

pp. 753

Author(s):

Sichul Lee

Keyword(s):

Nitrogen Use Efficiency ◽

Oryza Sativa L ◽

N Fertilization ◽

World Population ◽

Nitrogen Use ◽

Complex Processes ◽

N Metabolism ◽

Use Efficiency ◽

Future Demands ◽

Global Population

Rice (Oryza sativa L.) is a daily staple food crop for more than half of the global population and improving productivity is an important task to meet future demands of the expanding world population. The application of nitrogen (N) fertilization improved rice growth and productivity in the world, but excess use causes environmental and economic issues. One of the main goals of rice breeding is reducing N fertilization while maintaining productivity. Therefore, enhancing rice nitrogen use efficiency (NUE) is essential for the development of sustainable agriculture and has become urgently needed. Many studies have been conducted on the main steps in the use of N including uptake and transport, reduction and assimilation, and translocation and remobilization, and on transcription factors regulating N metabolism. Understanding of these complex processes provides a base for the development of novel strategies to improve NUE for rice productivity under varying N conditions.

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Integrated genomics, physiology and breeding approaches for improving nitrogen use efficiency in potato: translating knowledge from other crops

Functional Plant Biology ◽

10.1071/fp17303 ◽

2018 ◽

Vol 45 (6) ◽

pp. 587 ◽

Cited By ~ 12

Author(s):

Jagesh K. Tiwari ◽

Darren Plett ◽

Trevor Garnett ◽

Swarup K. Chakrabarti ◽

Rajesh K. Singh

Keyword(s):

Nitrogen Use Efficiency ◽

N Uptake ◽

Production Costs ◽

Environmental Damage ◽

Nitrogen Use ◽

N Metabolism ◽

Use Efficiency ◽

High Production ◽

Food And Nutritional Security ◽

Integrated Genomics

Potato plays a key role in global food and nutritional security. Potato is an N fertiliser-responsive crop, producing high tuber yields. However, excessive use of N can result in environmental damage and high production costs, hence improving nitrogen use efficiency (NUE) of potato plants is one of the sustainable options to address these issues and increase yield. Advanced efforts have been undertaken to improve NUE in other plants like Arabidopsis, rice, wheat and maize through molecular and physiological approaches. Conversely, in potato, NUE studies have predominantly focussed on agronomy or soil management, except for a few researchers who have measured gene expression and proteins relevant to N uptake or metabolism. The focus of this review is to adapt knowledge gained from other plants to inform investigation of N metabolism and associated traits in potato with the aim of improving potato NUE using integrated genomics, physiology and breeding methods.

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Effects of replacing soybean meal with dried rumen digesta on feed intake, digestibility of nutrients, rumen fermentation and nitrogen use efficiency in Thai cattle fed on rice straw

Livestock Science ◽

10.1016/j.livsci.2014.09.008 ◽

2014 ◽

Vol 169 ◽

pp. 71-77 ◽

Cited By ~ 8

Author(s):

A. Cherdthong ◽

M. Wanapat ◽

A. Saenkamsorn ◽

N. Waraphila ◽

W. Khota ◽

...

Keyword(s):

Rice Straw ◽

Soybean Meal ◽

Nitrogen Use Efficiency ◽

Feed Intake ◽

Rumen Fermentation ◽

Nitrogen Use ◽

Use Efficiency

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Faculty Opinions recommendation of Leaf-level nitrogen use efficiency: definition and importance.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717964300.793465842 ◽

2012 ◽

Author(s):

Christian Körner

Keyword(s):

Nitrogen Use Efficiency ◽

Nitrogen Use ◽

Leaf Level ◽

Use Efficiency

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Faculty Opinions recommendation of PvNAC1 and PvNAC2 Are Associated with Leaf Senescence and Nitrogen Use Efficiency in Switchgrass.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726131278.793514339 ◽

2016 ◽

Author(s):

Elizabeth Hood

Keyword(s):

Leaf Senescence ◽

Nitrogen Use Efficiency ◽

Nitrogen Use ◽

Use Efficiency

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ROLE OF CONSERVATION AGRICULTURE IN IMPROVING PRODUCTION WATER AND NITROGEN EFFICIENCY OF WHEAT UNDER RAINFED CONDITIONS

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v51i4.1093 ◽

2020 ◽

Vol 51 (4) ◽

pp. 1139-1148

Author(s):

Othman & et al.

Keyword(s):

Crop Rotation ◽

Nitrogen Use Efficiency ◽

Agricultural Research ◽

Research Work ◽

Conservation Agriculture ◽

Nitrogen Efficiency ◽

Research Station ◽

Wheat Varieties ◽

Nitrogen Use ◽

Use Efficiency

The research work was conducted in Izra’a Research station, which affiliated to the General Commission for Scientific Agricultural Research (GCSAR), during the growing seasons (2016 – 2017; 2017 – 2018), in order to evaluate the response of two durum wheat verities (Douma3 and Cham5) and two bread wheat varieties (Douma4 and Cham6) to Conservation Agriculture (CA) as a full package compared with Conventional Tillage system (CT) under rainfed condition using lentils (Variety Edleb3) in the applied crop rotation. The experiment was laid according to split-split RCBD with three replications. The average of biological yield, grain yield, rainwater use efficiency and nitrogen use efficiency was significantly higher during the first growing season, under conservation agriculture in the presence of crop rotation, in the variety Douma3 (7466 kg. ha-1, and 4162kg. ha-1, 19.006 kg ha-1 mm-1, 39.62 kg N m-2respectively). The two varieties Douma3 and Cham6 are considered more responsive to conservation agriculture system in the southern region of Syria, because they recorded the highest grain yields (2561, 2385 kg ha-1 respectively) compared with the other studied varieties (Cham5 and Douma4) (1951 and 1724 kg ha-1 respectively). They also exhibited the highest values of both rainwater and nitrogen use efficiency.

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