Use Efficiency Of Wheat Research Articles

The δ2H and δ18O isotopic evidence for hydraulic redistribution by Alnus acuminata in an agricultural landscape

Understanding of the process of hydraulic redistribution in agricultural landscapes is important for informing agroforestry design and agricultural management. The measurement of hydraulic lift and redistribution in the field is still a challenge. Due to the robustness of stable isotope analysis, we hypothesized that the measurement and analysis of the natural abundance of stable isotopes δ2H and δ1⁸O, in the twigs of agroforestry trees, stems of wheat intercrop, rain, and soil water coupled to an isotopic mixing modeling by IsoSource supplemented with other physiological crop parameters, would estimate the extent of hydraulic redistribution in intercropping, and inform the design of an agroforestry system. There are still many plant species that have not been investigated for their potential hydraulic redistribution yet, and Alnus acuminata is among them, therefore this study aimed to contribute to filling that gap. The field experiment was conducted in an Andic soil of the northern Rwanda highlands to address the extent of water efflux redistribution from tree roots of Alnus acuminata to the wheat intercrop across bench terraces. The study involved the measurement of the natural abundance of stable isotopes δ2H, and δ1⁸O of the tree twigs, soil and wheat stems at distances of 1, 3, 5, and 7 m from the tree lines of Alnus acuminata, and of rainwater. The isotopic mixing modeling was supplemented by measuring both specific leaf area (SLA) and carbon discrimination (Δ13C) in the wheat leaf. We noted a significant (p < 0.01) gradient in the depletion of wheat xylem water δ2H and δ18O signatures moving further away from the tree lines. Based on the wheat value of δ2H, the isoSource indicated that the trees may have contributed the wheat water up to 64.3 ± 2.6% at 5 m from the trees, and the values of both the SLA (cm2 g–1) and ∆13C (‰) of wheat leaf indicated the water use efficiency of wheat significantly improved around the trees up to 3 m away from the trees with 140.10 ± 3.74 cm2 g–1, 149.56 ± 3.43 cm2 g–1 and 20.6 ± 0.1‰, 20.8 ± 0.1‰ at 1 m and 3 m for SLA and ∆13C respectively. We concluded that Alnus acuminata exhibits significant hydraulic redistribution in the field.

Changes in phosphorus-related performance attributes of dryland winter wheat cultivars released between the 1940s and 2010s in Shaanxi Province, China.

Water and nutrients are two main determinants of wheat yield, which are vital for maintaining high crop yields. In the present study, the effects of water and phosphate fertilization on wheat yield, photosynthetic parameters, water productivity and phosphate use efficiency were investigated. Five dryland wheat cultivars from the 1940s to the 2010s that are widely cultivated in Shaanxi Province, China, were used. Experiments were conducted from 2019 to 2022 using two irrigation levels (normal rainfall and no precipitation after the reviving stage) and two phosphorus application levels (0 and 100 kg ha-1). Compared with old cultivars ('Mazha'), the grain yield of modern cultivars ('Changhan 58') was 89.24% higher and was closely correlated with chlorophyll index, leaf area index, photosynthetic rate and tillers. With the replacement of cultivars, the phosphorus content, water potential and phosphatase activity of wheat leaves increased. Considering water-phosphorus interactions, the water use efficiency and phosphorus use efficiency of wheat showed a significant positive correlation. Our findings indicate that modern wheat cultivars are more responsive to phosphorus. Further analysis revealed that modern varieties have evolved two phosphorus absorption strategies in response to phosphorus deficiency - namely, the formation of a phosphorus supply source, which may result in larger numbers of green organs; and an increase in phosphorus sinks, which tended to activation and transport of plant phosphorus. Our results may thus contribute to water conservation, increased yields and the development of strategies for efficient phosphorus fertilization. © 2024 Society of Chemical Industry.

Zinc-Oxide-Nanoparticles in Conjugation with Zn-Solubilizing Bacteria Improve Zn Biofortification and Nitrogen Use Efficiency in Wheat

Zinc-Oxide-Nanoparticles in Conjugation with Zn-Solubilizing Bacteria Improve Zn Biofortification and Nitrogen Use Efficiency in Wheat

Precision nitrogen management strategies and high yielding genotypes for enhanced growth, yield, economics, and nitrogen use efficiency in wheat

Current agricultural production systems face challenges of poor economic returns, soil fatigue and negative environmental outcomes from excess use of nitrogenous fertilizers, especially in wheat production under middle gangetic plains. To overcome these challenges, the current study was conducted to optimize nitrogen management in different wheat genotypes with precision nitrogen management tools and approaches. The field experiment was laid out in split-plot design, with three genotypes assigned to the main plot and six nitrogen management practices to the sub-plot. The soil of the experimental field was sandy loam in texture, with low levels of organic carbon and available nitrogen, and medium levels of available phosphorus and potassium. Results revealed that the HD-2967 genotype outperformed others in terms of growth, grain yield (4.7 and 4.81 t ha−1), gross return (1417.41 and 1505.48 US$ ha−1), net return (953.43 and 1019.76 US$ ha−1), and B-C ratio (2.04 and 2.08) in 2015-16 and 2016-17, respectively. Among the nitrogen management practices, application of 150 kg N ha−1 in three equal splits demonstrated improved crop growth, grain yield (4.7 and 4.81 t ha−1), and economic returns (gross return, 1500.40 and 1607.65 US$ ha−1, net return, 1025.40 and 1110.38 US$ ha−1 and B: C ratio, 2.17 and 2.23) in 2015-16 and 2016-17, respectively. However, it resulted in higher nitrogen losses. Green seeker guided N application significantly reduced apparent nitrogen losses compared to all other nitrogen applied treatments. These findings provide valuable insights for optimizing wheat production by selecting appropriate genotypes and implementing precision nitrogen management techniques to enhance yield, profitability, and environmental sustainability.

TabHLH27 orchestrates root growth and drought tolerance to enhance water use efficiency in wheat.

Cultivating high-yield wheat under limited water resources is crucial for sustainable agriculture in semiarid regions. Amid water scarcity, plants activate drought response signaling, yet the delicate balance between drought tolerance and development remains unclear. Through genome-wide association studies and transcriptome profiling, we identified a wheat atypical basic helix-loop-helix (bHLH) transcription factor (TF), TabHLH27-A1, as a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat. TabHLH27-A1/B1/D1 knock-out reduced wheat drought tolerance, yield, and water use efficiency (WUE). TabHLH27-A1 exhibited rapid induction with polyethylene glycol (PEG) treatment, gradually declining over days. It activated stress response genes such as TaCBL8-B1 and TaCPI2-A1 while inhibiting root growth genes like TaSH15-B1 and TaWRKY70-B1 under short-term PEG stimulus. The distinct transcriptional regulation of TabHLH27-A1 involved diverse interacting factors such as TaABI3-D1 and TabZIP62-D1. Natural variations of TabHLH27-A1 influence its transcriptional responses to drought stress, with TabHLH27-A1Hap-II associated with stronger drought tolerance, larger root system, more spikelets, and higher WUE in wheat. Significantly, the excellent TabHLH27-A1Hap-II was selected during the breeding process in China, and introgression of TabHLH27-A1Hap-II allele improved drought tolerance and grain yield, especially under water-limited conditions. Our study highlights TabHLH27-A1's role in balancing root growth and drought tolerance, providing a genetic manipulation locus for enhancing WUE in wheat.

Overexpression of rice OsNRT1.1A/OsNPF6.3 enhanced the nitrogen use efficiency of wheat under low nitrogen conditions.

Overexpression of OsNRT1.1A promotes early heading and increases the tolerance in wheat under nitrogen deficiency conditions. The application of inorganic nitrogen (N) fertilizers is a major driving force for crop yield improvement. However, the overuse of fertilizers significantly raises production costs and leads to environmental problems, making it critical to enhance crop nitrogen use efficiency (NUE) for the sake of sustainable agriculture. In this study, we created a series of transgenic wheat lines carrying the rice OsNRT1.1A gene, which encodes a nitrate transporter, to investigate its possible application in improving NUE in wheat. The transgenic wheat exhibited traits such as early maturation that were highly consistent with the overexpression of OsNRT1.1A in Arabidopsis and rice. However, we also observed that overexpression of the OsNRT1.1A gene in wheat can facilitate the growth of roots under low N conditions but has no effect on other aspects of growth and development under normal N conditions. Thus, it may lead to the improvement of wheat low N tolerance,which is different from the effects reported in other plants. A field trial analysis showed that transgenic wheat exhibited increased grain yield per plant under low N conditions. Moreover, transcriptome analysis indicated that OsNRT1.1A increased the expression levels of N uptake and utilization genes in wheat, thereby promoting plant growth under low N conditions. Taken together, our results indicated that OsNRT1.1A plays an important role in improving NUE in wheat with low N availability.

Impact of cultivation methods and fertilization by EM (Effective microorganisms) and /or compost on Productivity and water use efficiency of wheat (Triticum aestivum L.)

Impact of cultivation methods and fertilization by EM (Effective microorganisms) and /or compost on Productivity and water use efficiency of wheat (Triticum aestivum L.)

Effect of a QTL on wheat chromosome 5B associated with enhanced root dry mass on transpiration and nitrogen uptake under contrasting drought scenarios in wheat.

A sufficient nitrogen supply is crucial for high-quality wheat yields. However, the use of nitrogen fertilization can also negatively influence ecosystems due to leaching or volatile atmospheric emissions. Drought events, increasingly prevalent in many crop production areas, significantly impact nitrogen uptake. Breeding more efficient wheat varieties is necessary to achieve acceptable yields with limited nitrogen and water. Crop root systems play a crucial role as the primary organ for absorbing water and nutrients. To investigate the impact of an enhanced root system on nitrogen and water use efficiency in wheat under various irrigation conditions, this study conducted two experiments using precision phenotyping platforms for controlled drought stress treatment. Experiment 1 involved four contrasting winter wheat genotypes. It included the Chinese variety Ning0604, carrying a quantitative trait locus (QTL) on chromosome 5B associated with a higher root dry biomass, and three elite German varieties, Elixer, Genius, and Leandrus. Experiment 2 compared near-isogenic lines (NIL) of the three elite varieties, each containing introgressions of the QTL on chromosome 5B linked to root dry mass. In both experiments, nitrogen partitioning was tracked via isotope discrimination after fertilization with 5 Atom % 15N-labeled KNO3-. In experiment 1 the quantification by 15N isotope discrimination revealed significantly (p < 0.05) higher nitrogen derived from fertilizer in the root organ for Ning0604 than those of the three German varieties. In experiment 2, two out of three NILs showed a significantly (p < 0.05) higher uptake of N derived from fertilizer than their respective recipient line under well-watered conditions. Furthermore, significantly lower transpiration rates (p < 0.1) were observed in one NIL compared to its respective recipient. The combination of the DroughtSpotter facility coupled with 15N tracer-based tracking of N uptake and remobilization extends the insight into the impact of genetically altered root biomass on wheat NUE and WUE under different water availability scenarios. The study shows the potential for how a modified genetic constitution of the locus on wheat chromosome 5B can reduce transpiration and enhance N uptake. The dependence of the observations on the recipient and water availability suggests a need for further research to investigate the interaction with genetic background traits.

Effects of Polymer Conditioner and Nitrogen Fertilizer Application on Nitrogen Absorption and Utilization of Drip-Irrigated Wheat in Arid Areas

Nitrogen (N), an important element for crop growth, has a great impact on dry matter weight and yield. Currently, improving N fertilizer use rate is an urgent problem to be solved in agricultural production in the world. In this field experiment, a self-developed water-soluble polymer material (PPM) with water retention and slow-release characteristics was combined with different doses of N fertilizer (N300 (100% N), PN300 (PPM + 100% N), PN240 (PPM + 80% N), PN180 (PPM + 60% N), CK (no N and PPM)) to analyze the impacts on N uptake and use efficiency of wheat plants. The results showed that the combined application of PPM and N fertilizer significantly improved yield, plant height, biomass, and N uptake and use efficiency of drip irrigated wheat, and the PN240 group had the highest N use rate. In addition, the PN300 group had the highest yield. N use efficiency in the PN240 group was 40.23% higher than that in the N300 group. Therefore, the combined application of PPM and N fertilizer, especially PN240, can reduce the N fertilizer application rate by increasing N use efficiency. This study provides technical reference for improving the N use efficiency of drip-irrigated wheat in arid areas.

Effect of Tillage, Residue, Irrigation and Nitrogen on Growth, Yield and Nitrogen Use Efficiency of Wheat in an Inceptisol

Effect of Tillage, Residue, Irrigation and Nitrogen on Growth, Yield and Nitrogen Use Efficiency of Wheat in an Inceptisol

Drone Multispectral Imaging Captures the Effects of Soil Nmin on Canopy Structure and Nitrogen Use Efficiency in wheat

Drone Multispectral Imaging Captures the Effects of Soil Nmin on Canopy Structure and Nitrogen Use Efficiency in wheat

Enhancing phosphorus use efficiency in wheat grown on alkaline calcareous soils

Phosphorus (P) use efficiency is crucial for sustainable wheat production, particularly on alkaline calcareous soils. This study investigates the relative importance of two factors; P acquisition efficiency (PAE) and P utilization efficiency (PUtE), in determining P use efficiency (PUE) in wheat. A field trial with ten wheat genotypes was conducted under two P levels (no P application and P application at 110 kg P2O5 ha−1). Results revealed significant genetic variability in PUE, PAE, and PUtE among wheat genotypes under varying P availabilities. Genotypes MK-4 and MK-8 exhibited superior PUE, making them ideal candidates for soils with differing P levels. PAE played a more substantial role in influencing PUE, with PUtE contributing less to the variability. The findings underscore the importance of improving PAE, particularly for wheat genotypes grown in P-deficient conditions. Moreover, selecting genotypes with lower grain P concentration can enhance PUtE, contributing to improved PUE. These insights can improve breeding efforts and crop management practices to enhance P use efficiency in wheat, ultimately reducing production costs and fertilizer demand, especially in P-limited alkaline calcareous soils.

Effect of tillage, residue and nitrogen management on yield, water and nitrogen use efficiency of wheat (Triticum aestivum)

A two-year field study was carried out during winter (rabi) seasons of 2020–21 and 2021–22 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi with the aim of examining the impacts of various methods of tillage, residue management and nitrogen (N) application on wheat (Triticum aestivum L.) yield, water use efficiency (WUE), and nitrogen use efficiency in terms of Partial Factor Productivity of Nitrogen (PFPN). The study utilized a split-split plot design with 3 replications, where the main plot consisted of two tillage systems [conventional tillage (CT) and no tillage (NT)], the subplot comprised 2 residue levels [maize residue @5 t/ ha (R+) and no residue (R0)], and the sub-sub plot involved 3 N levels [60, 120, and 180 kg N/ha, representing 50% (N60 kg N/ha), 100% (N120 kg N/ha), and 150% (N180 kg N/ha)] respectively. The results indicated that both tillage and residue management considerably influenced the grain and biomass yield of wheat. Over the two years, NT exhibited a 7% higher WUE compared to CT, but the change was insignificant. However, in years with lower rainfall, crop residue mulching had a significant positive impact on WUE, while in years with higher rainfall; its effect on WUE was insignificant. Moreover, tillage practices had a considerable effect on the PFPN. In the year 2020–21, PFPN under NT was 3.59% higher than under CT, and in the year 2021–22, it was 2.06% higher. Furthermore, with an increase in N levels, WUE showed a substantial increase, while PFPN decreased.

Effects of different mulch materials on the photosynthetic characteristics, yield, and soil water use efficiency of wheat in Loess tableland

Due to the lack of precipitation and poor temporal and spatial stability in the Loess Plateau for a long time, it is necessary to adopt mulching technology to support the stable and high yield of wheat cultivation system. This study aims at exploring different mulching materials on the soil water content, photosynthetic characteristics, wheat yield, and yield components of winter wheat in the gully region of the Loess Plateau. The results showed that the traditional flat soil water content is the lowest in the seedling stage. In the jointing stage and heading stage of many crop water requirements, ridge film mulching treatment can effectively promote the growth of wheat and increase the water use efficiency. The leaf area index (LAI) of different treatments wheat showed a trend of increasing first and then decreasing. In the jointing stage, ordinary mulching film (T1) and liquid mulching film (T3) had the highest LAI content, which were 3.78 and 3.71 respectively. The Pn and Gs in wheat flag leaves of T3 treatment is higher than that of CK throughout the entire growth period, and T3 significantly increased Ci and WUEi in different growth stage. And the grain number per panicle and grain weight of T3 treatment were 24.44 and 41.00 g, which were 19.3% and 5.4% higher than CK, respectively. Through the actual production calculation of the final harvest, the ridge film mulching has a significant increase in production compared with the CK. The yield of T3 treatment was 4980.25 kg hm−2, which was 29.37% higher than CK. It was significantly different from CK (P < 0.05). Based on the comprehensive analysis, the ridge film mulching treatment significantly affected the soil water content and wheat yield. And the liquid mulching film had the best effect. Exploring the impact of different covering techniques on the wheat cultivation system in the Loess Plateau region, to promote the scientific promotion of this technology.

Straw mulch decreased nitrogen fertilizer requirements via regulating soil moisture and temperature to improve physiology, nitrogen, and water use efficiency of wheat

AbstractThe infrequent rainfall caused drought‐prone conditions, particularly in semiarid regions of China, where most of the precipitation occurs in summer season. Thus, the summer rainwater conservation is very important for winter wheat (Triticum aestivum) production. Therefore, a 2‐year field experiment was conducted on straw mulch along with nitrogen (N) fertilizer to improve physiology, nitrogen use efficiency (NUE), wheat yield, and water use efficiency (WUE). Maize (Zea mays) was a rotated crop after wheat, and therefore, maize straw mulch (S1, 0 kg ha−1; S2, 4500 kg ha−1; S3, 9000 kg ha−1) was in the main plots, and N fertilizer (N1, 0 kg ha−1; N2, 192 kg ha−1 [80%]; N3, 240 kg ha−1 [100%]) was in the subplots. The interaction of S3N3 and S3N2 produced 59.2% and 43.8% higher net photosynthesis and enhanced its characteristics at booting stage compared with that of S1N1. Higher Soil Plant Analysis Development (SPAD) values (49.1% and 41.0%) and leaf area (85.6% and 61.0%) were measured with S3N3 and S3N2 treatments at booting stage compared with S1N1. Both S3N2 and S3N3 had increased wheat N‐uptake (91% and 103%, respectively) compared to S1N1. While S3N3 and S3N2 enhanced soil moisture conservation, NUE (19.7% and 22.8%) and WUE (47.2% and 47.2%) improved the growth yield of wheat compared to S1N1. Higher wheat grain yield (7604 kg ha−1) was obtained from interaction of S3N2. Therefore, interaction of S3N2 is a viable approach for improving the winter wheat crop performance in terms of NUE, WUE, and wheat yield for semiarid areas in China.

Assessing the Effect of Irrigation Levels and Hydrogel on Growth and Yield of Wheat (Triticum aestivum L.)

One of the most essential inputs for agriculture is water. Moisture stress at critical growth stages in wheat severely effects the growth and yield. Hydrogel (water-absorbing polymer) can keep the appropriate moisture level at the root zone depth and protects the crop from adverse effect of moisture stress. The present trial was conducted during rabi season of 2020-21 to assess the performance of different hydrogels under different levels of irrigations on growth, yield, and water use efficiency of wheat. Results revealed that application of 3 irrigations recorded significantly maximum number of tillers per m2 at 90 Days After Sowing and at harvest. The application of Nano hydrogel @ 20 kg ha-1 significantly increased the number of tillers per m2 at 90 DAS and at harvest over control. Significantly maximum grain (26.1%) and straw (24.5%) yield were obtained with 3 irrigation levels over one irrigation. The Nano hydrogel increased grain (33.6%) and straw (22.9%) yield significantly over control. Water use efficiency significantly improved with one irrigation over 3 irrigation levels, application of Nano hydrogel @ 20 kg ha-1 significantly increased WUE.

Interactive effect of tillage, residue, nitrogen, and irrigation management on yield, radiation productivity and water productivity of winter wheat in semi-arid climate

Water, nutrients, and energy are the three main inputs in agricultural production and recently there has been a drop in the factor productivity of these inputs because of their improper management and deterioration of soil health. To maximize agricultural productivity while lowering strain on natural resources, the best synergistic combinations of tillage, residue, nitrogen, and water management should be identified for improving resource use efficiency of wheat. Hence, an attempt has been made to evaluate the impact of contrasting tillage, crop residue mulch, nitrogen, and irrigation interaction on yield, radiation productivity (RP), and water productivity (WP) of wheat in a split-factorial design. Results showed that wheat yield was higher under no-tillage (4.8%) than that of conventional tillage. Crop residue mulch (CRM) and higher nitrogen application enhanced RP, WP, and yield of wheat; although RP increased with increase in nitrogen application up to 100% recommended dose of nitrogen (RDN). CRM significantly reduced the seasonal evapotranspiration (6.0‒7.2%) as compared to residue removal treatment. Deficit irrigation enhanced the WP while it lowered the crop yield significantly. Therefore, wheat can be grown under no-tillage, CRM, 100% RDN with deficit irrigation to obtain higher WP but with full irrigation to obtain higher yield, and RP in the semiarid climate of India.

Site-Specific Fertilizer Management through Nutrient Expert: Productivity, Profitability and Efficiency of Wheat

A field experiment was conducted at Tikapur, Kailali located in Sudur-Pashim Province of Nepal from November 2021 to April 2022 to determine the effects of site-specific nutrient management practice son the yield, economics and resource use efficiency of wheat (cv: Vijay). Six fertilizer treatments were laid-out in a Randomized Complete Block Design. The treatment includes nitrogen omitted plot (N0), blanket recommendation (BR), Nutrient Expert based-NPK (NE), Nutrient Expert based nitrogen recommendation and farmers fertilizer practice for other fertilizers (NE-N), leaf color chart-based nitrogen recommendation (LCC-N) and farmers fertilizer practice (FFP). NE produced the highest yield compared to BR and FFP. Grain yield between NE and LCC was similar (p&gt;0.05). LCC-N produced the highest harvest index (0.46) and nitrogen use efficiency while they were the lowest in farmer-based practice. As with yield, NE produced higher gross revenue and benefit-cost ratio compared to farmers’ practice. Similarly, the maximum nitrogen uptake by grain and straw and soil residual N was observed in NE treated plot. These results suggested that NE based NPK management could increase yields, NUE and farm profit. However, similar benefits could also be achieved using either LCC based N management with 25 to 40% less N compared to NE. So, the fertilizer recommendation using NE-Wheat model in combination with LCC (if available to farmers) for N management could be suggested to the farmers for successful wheat cultivation.

Physiological traits and expression profile of genes associated with nitrogen and phosphorous use efficiency in wheat

Nitrogen (N) and phosphorous (P) play a very important role in the growth and development of wheat as well as major constituents of biological membranes. To meet the plant's nutritional demand these nutrients are applied in the form of fertilizers. But the plant can utilize only half of the applied fertilizer whereas the rest is lost through surface runoff, leaching and volatilization. Thus, to overcome the N/P loss we need to elucidate the molecular mechanism behind the N/P uptake. In our study, we used DBW16 (low NUE), and WH147 (high NUE) wheat genotypes under different doses of N, whereas HD2967 (low PUE) and WH1100 (high PUE) genotypes were studied under different doses of P. To check the effect of different doses of N/P, the physiological parameters like total chlorophyll content, net photosynthetic rate, N/P content, and N/PUE of these genotypes were calculated. In addition, gene expression of various genes involved in N uptake, utilization, and acquisition such as Nitrite reductase (NiR), Nitrate transporter 1/Peptide transporter family (NPF2.4/2.5), Nitrate transporter (NRT1) and NIN Like Protein (NLP) and induced phosphate starvation (IPS), Phosphate Transporter (PHT1.7) and Phosphate 2 (PHO2) acquisition was studied by quantitative real-time PCR. Statistical analysis revealed a lower percent reduction in TCC, NPR, and N/P content in N/P efficient wheat genotypes (WH147 & WH1100). A significant increase in relative fold expression of genes under low N/P concentration was observed in N/P efficient genotypes as compared to N/P deficient genotypes. Significant differences in physiological data and gene expression among N/ P efficient and deficient wheat genotypes could be useful for future improvement of N/P use efficiency.

Convergently selected NPF2.12 coordinates root growth and nitrogen use efficiency in wheat and barley.

Understanding the genetic and molecular function of nitrate sensing and acquisition across crop species will accelerate breeding of cultivars with improved nitrogen use efficiency (NUE). Here, we performed a genome-wide scan using wheat and barley accessions characterized under low and high N inputs that uncovered the NPF2.12 gene, encoding a homolog of the Arabidopsis nitrate transceptor NRT1.6 and other low-affinity nitrate transporters that belong to the MAJOR FACILITATOR SUPERFAMILY. Next, it is shown that variations in the NPF2.12 promoter correlated with altered NPF2.12 transcript levels where decreased gene expression was measured under low nitrate availability. Multiple field trials revealed a significantly enhanced N content in leaves and grains and NUE in the presence of the elite allele TaNPF2.12TT grown under low N conditions. Furthermore, the nitrate reductase encoding gene NIA1 was up-regulated in npf2.12 mutant upon low nitrate concentrations, thereby resulting in elevated levels of nitric oxide (NO) production. This increase in NO correlated with the higher root growth, nitrate uptake, and N translocation observed in the mutant when compared to wild-type. The presented data indicate that the elite haplotype alleles of NPF2.12 are convergently selected in wheat and barley that by inactivation indirectly contribute to root growth and NUE by activating NO signaling under low nitrate conditions.