scholarly journals The Role of Gibberellins in Regulation of Nitrogen Uptake and Physiological Traits in Maize Responding to Nitrogen Availability

2020 ◽  
Vol 21 (5) ◽  
pp. 1824
Author(s):  
Yubin Wang ◽  
Qingqing Yao ◽  
Yushi Zhang ◽  
Yuexia Zhang ◽  
Jiapeng Xing ◽  
...  

Modified gibberellin (GA) signaling leads to semi-dwarfism with low nitrogen (N) use efficiency (NUE) in crops. An understanding of GA-mediated N uptake is essential for the development of crops with improved NUE. The function of GA in modulating N uptake capacity and nitrate (NO3−) transporters (NRTs) was analyzed in the GA synthesis-deficient mutant zmga3ox grown under low (LN) and sufficient (SN) N conditions. LN significantly suppressed the production of GA1, GA3, and GA4, and the zmga3ox plants showed more sensitivity in shoots as well as LN stress. Moreover, the higher anthocyanin accumulation and the decrease of chlorophyll content were also recorded. The net NO3− fluxes and 15N content were decreased in zmga3ox plants under both LN and SN conditions. Exogenous GA3 could restore the NO3− uptake in zmga3ox plants, but uniconazole repressed NO3− uptake. Moreover, the transcript levels of ZmNRT2.1/2.2 were downregulated in zmga3ox plants, while the GA3 application enhanced the expression level. Furthermore, the RNA-seq analyses identified several transcription factors that are involved in the GA-mediated transcriptional operation of NRTs related genes. These findings revealed that GAs influenced N uptake involved in the transcriptional regulation of NRTs and physiological responses in maize responding to nitrogen supply.

Horticulturae ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 110
Author(s):  
Chunping Wang ◽  
Yifei Li ◽  
Wenqin Bai ◽  
Xiaomiao Yang ◽  
Hong Wu ◽  
...  

The molecular mechanisms underlying the variation in N-use efficiency (NUE) in pepper (Capsicum annuum L.) genotypes are poorly understood. In this work, two genotypes (750-1, low-N tolerant; ZCFB, low-N sensitive) with contrasting low-N tolerance were selected from 100 pepper cultivars on the basis of their relative leaf areas, shoot dry weights, root dry weights, and plant dry weights at the seedling stage. Subsequently, using RNA-Seq, the transcriptome of these two pepper genotypes under N starvation for 28 days was analyzed. We detected 2621/2470 and 3936/4218 different expressed genes (DEGs) in the leaves/roots of 750-1 and ZCFB, respectively. The changes in the expression of basic N metabolism genes were similar between 750-1 and ZCFB. However, different DEGs not directly involved in N metabolism were identified between the 750-1 and ZCFB cultivars. In 750-1, 110 unique DEGs were detected in the leaves, of which 103 were down-regulated, including genes associated with protein metabolism, photosynthesis, secondary metabolism, cell wall metabolism, stress response, and disease resistance. In ZCFB, 142 unique DEGs were detected in the roots, of which 117 were up-regulated, resulting in enhancement of processes such as protein degradation, secondary metabolites synthesis, lipid metabolism, endocytosis, the tricarboxylic acid cycle (TCA), transcriptional regulation, stress response, and disease resistance. Our results not only facilitate an understanding of the different regulatory process in low-N-tolerant and low-N-sensitive pepper cultivars, but also provide abundant candidate genes for improving the low-N tolerance of pepper cultivars.


2003 ◽  
Vol 141 (2) ◽  
pp. 221-230 ◽  
Author(s):  
A. Y. KAMARA ◽  
J. G. KLING ◽  
A. MENKIR ◽  
O. IBIKUNLE

Eighteen S1 lines of maize (Zea mays L.) derived from a low nitrogen tolerant pool and two inbred lines were evaluated for agronomic performance under moderate N conditions in the southern Guinea savannah of Nigeria. Generally, the breeding lines differed in yield, growth, vertical root-pulling resistance, N-uptake and N-use efficiency. Breeding lines with high vertical root-pulling resistance took up more N and utilized it more efficiently. They also showed better agronomic performance and recorded higher yields. Principal component and cluster analyses classified the breeding lines into six groups. The results of principal components analyses (PCA) suggest that the most important variables for the classification of the S1 lines were grain yield, plant height, total dry matter during the grain-filling period and at maturity, N-accumulation, N-uptake and N-use efficiency. Other important traits were days to silking, anthesis-silking interval, ears per plant, harvest index and vertical root-pulling resistance. Two groups containing a total of 14 S1 lines that had higher agronomic performance than others are recommended for further evaluation under severe N stress to ascertain their tolerance of low N stress before recombination to form a new population for the next cycle of selection.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 515
Author(s):  
Ying Ouyang ◽  
Gary Feng ◽  
Heidi Renninger ◽  
Theodor D. Leininger ◽  
Prem Parajuli ◽  
...  

Eucalyptus is one of the fastest growing hardwoods for bioenergy production. Currently, few modeling tools exist to simultaneously estimate soil hydrological processes, nitrogen (N) uptake, and biomass production in a eucalyptus plantation. In this study, a STELLA (Structural Thinking and Experiential Learning Laboratory with Animation)-based model was developed to meet this need. After the model calibration and validation, a simulation scenario was developed to assess eucalyptus (E. grandis × urophylla) annual net primary production (ANPP), woody biomass production (WBP), water use efficiency (WUE), and N use efficiency (NUE) for a simulation period of 20 years. Simulation results showed that a typical annual variation pattern was predicted for water use, N uptake, and ANPP, increasing from spring to fall and decreasing from fall to the following winter. Overall, the average NUE during the growth stage was 700 kg/kg. To produce 1000 kg eucalyptus biomass, it required 114.84 m3 of water and 0.92 kg of N. This study suggests that the STELLA-based model is a useful tool to estimate ANPP, WBP, WUE, and NUE in a eucalyptus plantation.


2020 ◽  
Author(s):  
Jie Wu ◽  
Zi-Sheng Zhang ◽  
Jing-Qiu Xia ◽  
Alamin Alfatih ◽  
Ying Song ◽  
...  

AbstractNitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavor in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the NIN-like protein OsNLP4 significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signaling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 is a master regulator of NUE in rice and sheds light on crop NUE improvement.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1241
Author(s):  
Peter Omara ◽  
Lawrence Aula ◽  
Fikayo B. Oyebiyi ◽  
Elizabeth M. Eickhoff ◽  
Jonathan Carpenter ◽  
...  

Biochar (B) has shown promise in improving crop productivity. However, its interaction with inorganic nitrogen (N) in temperate soils is not well-studied. The objective of this paper was to compare the effect of fertilizer N-biochar-combinations (NBC) and N fertilizer (NF) on maize (Zea mays L.) grain yield, N uptake, and N use efficiency (NUE). Trials were conducted in 2018 and 2019 at Efaw and Lake Carl Blackwell (LCB) in Oklahoma, USA. A randomized complete block design with three replications and ten treatments consisting of 50, 100, and 150 kg N ha−1 and 5, 10, and 15 Mg B ha−1 was used. At LCB, yield, N uptake, and NUE under NBC increased by 25%, 28%, and 46%, respectively compared to NF. At Efaw, yield, N uptake, and NUE decreased under NBC by 5%, 7%, and 19%, respectively, compared to NF. Generally, results showed a significant response to NBC at ≥10 Mg B ha−1. While results were inconsistent across locations, the significant response to NBC was evident at LCB with sandy loam soil but not Efaw with silty clay loam. Biochar application with inorganic N could improve N use and the yield of maize cultivated on sandy soils with poor physical and chemical properties.


2006 ◽  
Vol 290 (1-2) ◽  
pp. 115-126 ◽  
Author(s):  
Zhenan Hou ◽  
Pinfang Li ◽  
Baoguo Li ◽  
Jiang Gong ◽  
Yanna Wang

2014 ◽  
Vol 41 (2) ◽  
pp. 215 ◽  
Author(s):  
Jiayin Pang ◽  
Jairo A. Palta ◽  
Gregory J. Rebetzke ◽  
Stephen P. Milroy

Genotypic differences in early growth and nitrogen (N) uptake among 24 wheat (Triticum aestivum L.) genotypes were assessed in a field trial. At late tillering, large genetic variation was observed for shoot biomass (23–56 g m–2 ground area) and N uptake (1.1–1.8 g m–2 ground area). A strong correlation between aboveground biomass and N uptake was observed. Variation around this relationship was also found, with some genotypes having similar N uptake but large differences in aboveground biomass. A controlled environment experiment was conducted to investigate the underlying mechanisms for this variation in aboveground biomass using three vigorous genotypes (38–19, 92–11 and CV97) and a non-vigorous commercial cultivar (Janz). Vigorous genotypes had lower specific leaf N in the youngest fully expanded leaf than Janz. However, there was no difference in chlorophyll content, maximum Rubisco activity or the rate of electron transport per unit area. This suggests that Janz invested more N in non-photosynthetic components than the vigorous lines, which could explain the higher photosynthetic N use efficiency of the vigorous genotypes. The results suggest that the utilisation of wheat genotypes with high early vigour could improve the efficiency of N use for biomass production in addition to improving N uptake during early growth.


2008 ◽  
Vol 8 ◽  
pp. 394-399 ◽  
Author(s):  
Osumanu H. Ahmed ◽  
Aminuddin Hussin ◽  
Husni M. H. Ahmad ◽  
Anuar A. Rahim ◽  
Nik Muhamad Abd. Majid

Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP) and zeolite (Clinoptilolite) on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays) cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives) did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf) production of Swan (test crop). All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea.


1994 ◽  
Vol 74 (3) ◽  
pp. 479-484 ◽  
Author(s):  
D. E. McCullough ◽  
A. Aguilera ◽  
M. Tollenaar

An old maize (Zea mays L.) hybrid (Pride 5) has been shown to be less tolerant to N stress than a new maize hybrid (Pioneer 3902) during early phases of development. The objective of this study was to quantify the response of the two hybids to N supply in terms of N uptake, N partitioning, and photosynthetic N–use efficiency. Plants were grown under controlled-environment conditions until the 12-leaf stage at three levels of N supply (i.e., 15 mM N, 2.5 mM N, and 0.5 mM N) and were sampled at the 4-, 8-, and 12-leaf stages. Rates of N uptake per unit ground area were higher for Pioneer 3902 than for Pride 5 under maximum N stress during the 8- to 12-leaf phase, but rates were higher for Pride 5 at high N. Rates of N uptake per unit root weight were higher for Pioneer 3902 than for Pride 5 under both medium and low N supply. The old hybrid (Pride 5) partitioned more dry matter and N to leaves than the new hybrid under low N supply, but leaf N per unit leaf area was higher for the new hybrid. The new hybrid (Pioneer 3902) maintained greater rates of leaf photosynthesis per unit leaf N regardless of N supply. Consequently, results indicate that the higher N-use efficiency of Pioneer 3902 under low N supply is associated with higher N uptake and a higher leaf N per unit leaf area. Key words:Zea mays L., dry matter accumulation, photosynthesis, leaf N


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