scholarly journals Growth, Mineral Nutrients, Photosynthesis and Related Physiological Parameters of Citrus in Response to Nitrogen Deficiency

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1859
Author(s):  
Wei-Tao Huang ◽  
Yi-Zhi Xie ◽  
Xu-Feng Chen ◽  
Jiang Zhang ◽  
Huan-Huan Chen ◽  
...  
Keyword(s):  
N Uptake ◽  
Nutrient Balance ◽  
Photosynthetic Pigment ◽  
Nitrogen Deficiency ◽  
Photosynthetic Electron Transport ◽  
Dry Weight ◽  
Root Surface ◽  
Co2 Assimilation ◽  
N Concentration ◽  
N Deficiency

Limited data are available on the physiological responses of Citrus to nitrogen (N) deficiency. ‘Xuegan’ (Citrus sinensis (L.) Osbeck) and ‘Shantian pummelo’ (Citrus grandis (L.) Osbeck) seedlings were fertilized with nutrient solution at a N concentration of 0, 5, 10, 15 or 20 mM for 10 weeks. N deficiency decreased N uptake and N concentration in leaves, stems and roots and disturbed nutrient balance and homeostasis in plants, thus inhibiting plant growth, as well as reducing photosynthetic pigment levels and impairing thylakoid structure and photosynthetic electron transport chain (PETC) in leaves, hence lowering CO2 assimilation. The imbalance of nutrients intensified N deficiency’s adverse impacts on biomass, PETC, CO2 assimilation and biosynthesis of photosynthetic pigments. Citrus displayed adaptive responses to N deficiency, including (a) elevating the distributions of N and other elements in roots, as well as root dry weight (DW)/shoot DW ratio and root-surface-per-unit volume and (b) improving photosynthetic N use efficiency (PNUE). In general, N deficiency had less impact on biomass and photosynthetic pigment levels in C. grandis than in C. sinensis seedlings, demonstrating that the tolerance of C. grandis seedlings to N deficiency was slightly higher than that of C. sinensis seedlings, which might be related to the higher PNUE of the former.

scholarly journals Do plants use root-derived proteases to promote the uptake of soil organic nitrogen?

2020 ◽  
Vol 456 (1-2) ◽  
pp. 355-367
Author(s):  
Lucy M. Greenfield ◽  
Paul W. Hill ◽  
Eric Paterson ◽  
Elizabeth M. Baggs ◽  
Davey L. Jones
Keyword(s):  
Protease Activity ◽  
Organic Nitrogen ◽  
N Uptake ◽  
Root Surface ◽  
Organic N ◽  
Soil Organic Nitrogen ◽  
Poor Access ◽  
N Deficiency ◽  
Almost All ◽  
Soil Protein

Abstract Aims The capacity of plant roots to directly acquire organic nitrogen (N) in the form of oligopeptides and amino acids from soil is well established. However, plants have poor access to protein, the central reservoir of soil organic N. Our question is: do plants actively secrete proteases to enhance the breakdown of soil protein or are they functionally reliant on soil microorganisms to undertake this role? Methods Growing maize and wheat under sterile hydroponic conditions with and without inorganic N, we measured protease activity on the root surface (root-bound proteases) or exogenously in the solution (free proteases). We compared root protease activities to the rhizosphere microbial community to estimate the ecological significance of root-derived proteases. Results We found little evidence for the secretion of free proteases, with almost all protease activity associated with the root surface. Root protease activity was not stimulated under N deficiency. Our findings suggest that cereal roots contribute one-fifth of rhizosphere protease activity. Conclusions Our results indicate that plant N uptake is only functionally significant when soil protein is in direct contact with root surfaces. The lack of protease upregulation under N deficiency suggests that root protease activity is unrelated to enhanced soil N capture.

Evaluation of Maize Inbreds for Vegetative Nitrate Uptake and Assimilation

1989 ◽  
Vol 16 (2) ◽  
pp. 161 ◽  
Author(s):  
RT Weiland
Keyword(s):  
Nitrate Uptake ◽  
N Uptake ◽  
Dry Weight ◽  
Root Surface ◽  
Root Surface Area ◽  
Controlled Environment ◽  
Uptake Rates ◽  
Total Plant ◽  
Maize Inbreds ◽  
Hydroponic Conditions

Twelve maize (Zea mays L.) inbred lines were cultured under hydroponic conditions in a controlled environment room for evaluation of NO3--N uptake, subsequent translocation patterns and utilisation. Prior to harvest (8-10-leaf stage), inbred roots were exposed to 24 h of 10 atom % 15NO3--N. Differences for N contents and biomass were determined. Root dry weight (RDW) was significantly correlated (r = 0.93) with root surface area. Significant inbred differences were found when N content in the plant was based on RDW. When based on 15N during the 24 h, the amount of N absorbed varied between 30 and 71 mg per plant for the inbreds. Uptake rates ranged between 8.7 and 14.4 mg g-1 day-1 RDW. Nitrogen uptake over the 24 h based on RDW and total plant-N contents based on RDW were significantly (P< 0.001) correlated, implying that uptake rates were constant up to mid-vegetative stages for these genotypes. Of the 15N absorbed, between 30 and 61% was reduced by the inbreds and the amount reduced varied with plant tissue. The total amount reduced ranged between 0.72 and 1.25 mg g-1 dry weight.

scholarly journals Nitrogen Uptake Efficiency and Leaching Losses from Lysimeter-grown Citrus Trees Fertilized at Three Nitrogen Rates

1996 ◽  
Vol 121 (1) ◽  
pp. 57-62 ◽  
Author(s):  
J.P. Syvertsen ◽  
M.L. Smith
Keyword(s):  
N Uptake ◽  
Dry Weight ◽  
Fruit Yield ◽  
Fibrous Root ◽  
N Application ◽  
Nitrogen Uptake Efficiency ◽  
Uptake Efficiency ◽  
N Concentration ◽  
Application Rates ◽  
Leaf N

Four-year-old `Redblush' grapefruit (Citrus paradisi Macf.) trees on either the relatively fast-growing rootstock `Volkamer' lemon (VL) (C. volkameriana Ten. & Pasq.) or on the slower-growing rootstock sour orange (SO) (C. aurantium L.) were transplanted into 7.9-m3 drainage lysimeter tanks filled with native Candler sand, irrigated similarly, and fertilized at three N rates during 2.5 years. After 6 months, effects of N application rate and rootstock on tree growth, evapotranspiration, fruit yield, N uptake, and leaching were measured during the following 2 years. When trees were 5 years old, low, medium, and high N application rates averaged about 79,180, or 543 g N/tree per year and about 126,455, or 868 g N/tree during the following year. Recommended rates average about 558 g N/tree per year. A lysimeter tank with no tree and additional trees growing outside lysimeters received the medium N treatment. Nitrogen concentration in the drainage water increased with N rate and exceeded 10 mg·liter-1 for trees receiving the high rates and also for the no tree tank. Leachate N concentration and total N recovered was greater from trees on SO than from those on VL. Average N uptake efficiency of medium N rate trees on VL was 6870 of the applied N and 61 % for trees on SO. Nitrogen uptake efficiency decreased with increased N application rates. Trees outside lysimeters had lower leaf N and fruit yield than lysimeter trees. Overall, canopy volume and leaf N concentration increased with N rate, but there was no effect of N rate on fibrous root dry weight. Fruit yield of trees on SO was not affected by N rate but higher N resulted in greater yield for trees on VL. Rootstock had no effect on leaf N concentration, but trees on VI. developed larger canopies, had greater fibrous root dry weight, used more water, and yielded more fruit than trees on SO. Based on growth, fruit yield and N leaching losses, currently recommended N rates were appropriate for trees on the more vigorous VL rootstock but were 22% to 69 % too high for trees on SO.

Soil phosphorus supply affects nodulation and N:P ratio in 11 perennial legume seedlings

2011 ◽  
Vol 62 (11) ◽  
pp. 992 ◽  
Author(s):  
Jiayin Pang ◽  
Mark Tibbett ◽  
Matthew D. Denton ◽  
Hans Lambers ◽  
Kadambot H. M. Siddique ◽  
...  
Keyword(s):  
N Uptake ◽  
Dry Weight ◽  
Good Growth ◽  
P Availability ◽  
Soil P ◽  
Pasture Legumes ◽  
P Concentration ◽  
N Concentration ◽  
P Supply ◽  
N Status

Developing new perennial pasture legumes for low-P soils is a priority for Australian Mediterranean agro-ecosystems, where soil P availability is naturally low. As legumes tend to require higher P inputs than non-legumes, the ability of these plants to fix N2 under varying soil P levels must be determined. Therefore, the objective of this study was to investigate the influence of soil P supply on plant N status and nodule formation in 11 perennial legumes, including some novel pasture species. We investigated the effect of applying soil P, ranging from 0 to 384 μg P/g dry soil, on plant N status and nodulation in a glasshouse. Without exogenous P supply, shoot N concentration and N : P ratio were higher than at 6 μg P/g soil. Shoot N concentration and N : P ratio then changed little with further increase in P supply. There was a close positive correlation between the number of nodules and shoot P concentration in 7 of the 11 species. Total nodule dry weight and the percentage of plant dry weight that consisted of nodules increased when P supply increased from 6 to 48 μg P/g. Without exogenous P addition, N : P ratios partitioned into a two-group distribution, with species having a N : P ratio of either >70 or <50 g/g. We suggest that plants with a high N : P ratio may take up N from the soil constitutively, while those with a low N : P ratio may regulate their N uptake in relation to internal P concentration. The flexibility of the novel pasture legumes in this study to adjust their leaf N concentrations under different levels of soil P supplements other published evidence of good growth and high P uptake and P-use efficiency under low soil P supply and suggests their potential as pasture plants in low-P soils in Australian Mediterranean agro-ecosystems warrants further attention.

Nitrogen deficiency precludes a growth response to CO2 enrichment in C3 and C4 Panicum grasses

1998 ◽  
Vol 25 (5) ◽  
pp. 627 ◽  
Author(s):  
Oula Ghannoum ◽  
Jann P. Conroy
Keyword(s):  
Growth Response ◽  
Nitrogen Deficiency ◽  
Co2 Enrichment ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Co2 Assimilation ◽  
Initial Slope ◽  
Co2 Response ◽  
N Supply ◽  
N Deficiency

We investigated the interaction of nitrogen (N) supply and CO2 enrichment on the growth and photosynthesis of Panicum laxum (C3), P. coloratum (C4) and P. antidotale (C4). Plants were grown at ambient CO2 partial pressures (pa) of either 36 (low) or 71 (high) Pa, in potted soil supplied with 0 (low) or 60 (high) mg N kg-1 soil week-1. Elevated CO2 enhanced total plant dry mass of all three species by approximately 28% under high N supply, but had no effect on biomass accumulation under N deficiency. CO2 enrichment resulted in reductions of CO2 assimilation rates (A; measured at comparable pa) of P. laxum, indicating acclimation of photosynthesis. This acclimation, which was more pronounced under N stress, was unrelated to changes in leaf N or non-structural carbohydrate concentrations, because neither were affected by CO2 enrichment. In the C4 grasses grown at low N, A were fully saturated at the current ambient pa, whereas at high N, A increased slightly when CO2 was raised to 71 Pa. N deficiency reduced the initial slope of the CO2 response curve of A in P. antidotale, and this effect was more pronounced at high CO2. In conclusion, the preclusion of a growth response to CO2 enrichment by N deficiency was correlated with a strong inhibition of A in the C3 species, and the saturation of A at below current atmospheric pa in C4 species.

scholarly journals Seasonal Biomass and Nitrogen Accumulation of Rosa ‘Mariandel®’ Grown in Compost Amended Peat at Different Fertilization Rates

2007 ◽  
Vol 25 (4) ◽  
pp. 197-203
Author(s):  
Yosef Amha ◽  
Heike Bohne
Keyword(s):  
Linear Trend ◽  
N Uptake ◽  
Dry Weight ◽  
Nitrogen Accumulation ◽  
Significant Linear Trend ◽  
N Content ◽  
Total N ◽  
Weight Percentage ◽  
Fertilization Rates ◽  
N Concentration

Abstract The growth and nitrogen (N) uptake of Rosa ‘Mariandel®’ were evaluated at four fertilization rates: 0, 0.4, 0.8 and 1.2 g N/liter (0, 0.016, 0.032 and 0.048 oz/qt). Plants were harvested at 6-week intervals. New shoots in all treatments retained the highest relative dry weight percentage, apparently at the expense of root. The total N concentration, content, and uptake at 12 and 18 weeks, but not at 6 weeks, after potting were significantly (r2 &gt; 0.59; P = 0.0005) affected by rates of fertilization. Although DM in the old shoots of all treatments slightly increased over the first 6 weeks, the corresponding N content decreased due to translocation. Except in old shoots, a significant linear trend occurred between DM accumulation and N content but not with N concentration (at least up to 12 weeks). However, N concentration in most plant parts was significantly (P &lt; 0.05) correlated with the respective N content. Excluding N released from the substrate, plants in 0.4, 0.8 and 1.2 g N/liter treated pots received 80, 126 and 182 mg (0.003, 0.004 and 0.006 oz) N per week, respectively, as used Osmocote (15N–4P–7.5K–1.8Mg) showed a linear (r2 &gt; 0.99) N-releasing rate. The corresponding total mineralized N in each control pot was 96 mg (0.003 oz) and 140 mg (0.005 oz) over the first and the second 6-week interval. Overall, ‘Mariandel®’ grown in 0.8 and 1.2 g N/liter treated pots had the highest mean N concentration and content respectively.

scholarly journals Nitrite Concentration Effects on NO3-N Uptake and Reduction, Growth, and Fruit Yield in Strawberry

2001 ◽  
Vol 126 (5) ◽  
pp. 560-563 ◽  
Author(s):  
Rebecca L. Darnell ◽  
Gary W. Stutte
Keyword(s):  
Developmental Stages ◽  
N Uptake ◽  
Dry Weight ◽  
Fruit Yield ◽  
Concentration Effects ◽  
Stage Of Development ◽  
N Concentration ◽  
Uptake Rates ◽  
Vegetative And Reproductive Growth ◽  
Nr Activity

Strawberries (Fragaria xananassa Duch. .Osogrande.) were grown hydroponically with three NO3-N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO3-N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO3-N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO3-N concentration in the hydroponics system increased. Tissue NO3-. concentration also increased as external NO3-N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO3-N concentration on NR activities in leaves or roots during either stage of development. Leaf NR activity averaged ~360 nmol NO2 formed/g fresh weight (FW)/h over both developmental stages, while NR activity in roots was much lower, averaging ~115 nmol NO2 formed/g FW/h. Vegetative organ FW, dry weight (DW), and total fruit yield were unaffected by NO3-N concentration. These data suggest that the inability of strawberry to increase growth and fruit yield in response to increasing NO3-N concentrations is not due to limitations in NO3-N uptake rates, but rather to limitations in NO3 - reduction and/or assimilation in both roots and leaves.

scholarly journals Effects of Leachate Fertigation and the Addition of Hydrogen Peroxide on Growth and Nutrient Balance in Dracaena deremensis Potted Plants

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Pedro García-Caparrós ◽  
Cristina Velasquez Espino ◽  
María Teresa Lao
Keyword(s):  
Nutrient Solution ◽  
Soluble Sugar ◽  
Nutrient Balance ◽  
Treatment Plant ◽  
Dry Weight ◽  
Sugar Concentration ◽  
Control Treatment ◽  
Peat Moss ◽  
Clear Trend ◽  
Total Soluble Sugar

The reuse of drainages for cultivating more salt tolerant crops can be a useful tool especially in arid regions, where there are severe problems for crops water management. Dracaena deremensis L. plants were cultured in pots with sphagnum peat-moss and were subjected to three fertigation treatments for 8 weeks: control treatment or standard nutrient solution (D0), raw leachates from Chrysalidocarpus lutescens H. Wendl plants (DL) and the same leachate blending with H2O2 (1.2 M) at 1% (v/v) (DL + H2O2). After harvesting, ornamental and biomass parameters, leaf and root proline and total soluble sugar concentration and nutrient balance were assessed in each fertigation treatment. Plant height, leaf and total dry weight had the highest values in plants fertigated with leachates with H2O2, whereas root length, leaf number, RGB values and pigment concentration declined significantly in plants fertigated with leachates from C. lutescens with or without H2O2. The fertigation with leachates, regardless of the presence or absence of H2O2 increased root and leaf proline concentration. Nevertheless, root and leaf total soluble sugar concentration did not show a clear trend under the treatments assessed. Regarding nutrient balance, the addition of H2O2 in the leachate resulted in an increase in plant nutrient uptake and efficiency compared to the control treatment. The fertigation with leachates with or without H2O2 increased nitrogen and potassium leached per plant compared to plants fertigated with the standard nutrient solution. The reuse of drainages is a viable option to produce ornamental plants reducing the problematic associated with the water consumption and the release of nutrients into the environment.

scholarly journals Integrative Transcriptomic and Proteomic Analysis Reveals an Alternative Molecular Network of Glutamine Synthetase 2 Corresponding to Nitrogen Deficiency in Rice (Oryza sativa L.)

2021 ◽  
Vol 22 (14) ◽  
pp. 7674
Author(s):  
Ting Liang ◽  
Zhengqing Yuan ◽  
Lu Fu ◽  
Menghan Zhu ◽  
Xiaoyun Luo ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Oryza Sativa L ◽  
Alternative Pathway ◽  
Rice Variety ◽  
Nitrogen Deficiency ◽  
Primary Root ◽  
Phenotypic Characterization ◽  
Glutathione Metabolism ◽  
N Assimilation ◽  
N Deficiency

Nitrogen (N) is an essential nutrient for plant growth and development. The root system architecture is a highly regulated morphological system, which is sensitive to the availability of nutrients, such as N. Phenotypic characterization of roots from LY9348 (a rice variety with high nitrogen use efficiency (NUE)) treated with 0.725 mM NH4NO3 (1/4N) was remarkable, especially primary root (PR) elongation, which was the highest. A comprehensive analysis was performed for transcriptome and proteome profiling of LY9348 roots between 1/4N and 2.9 mM NH4NO3 (1N) treatments. The results indicated 3908 differential expression genes (DEGs; 2569 upregulated and 1339 downregulated) and 411 differential abundance proteins (DAPs; 192 upregulated and 219 downregulated). Among all DAPs in the proteome, glutamine synthetase (GS2), a chloroplastic ammonium assimilation protein, was the most upregulated protein identified. The unexpected concentration of GS2 from the shoot to the root in the 1/4N treatment indicated that the presence of an alternative pathway of N assimilation regulated by GS2 in LY9348 corresponded to the low N signal, which was supported by GS enzyme activity and glutamine/glutamate (Gln/Glu) contents analysis. In addition, N transporters (NRT2.1, NRT2.2, NRT2.3, NRT2.4, NAR2.1, AMT1.3, AMT1.2, and putative AMT3.3) and N assimilators (NR2, GS1;1, GS1;2, GS1;3, NADH-GOGAT2, and AS2) were significantly induced during the long-term N-deficiency response at the transcription level (14 days). Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that phenylpropanoid biosynthesis and glutathione metabolism were significantly modulated by N deficiency. Notably, many transcription factors and plant hormones were found to participate in root morphological adaptation. In conclusion, our study provides valuable information to further understand the response of rice roots to N-deficiency stress.

scholarly journals Biosolids Benefit Yield and Nitrogen Uptake in Winter Cereals without Excess Risk of N Leaching

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini
Keyword(s):  
Triticum Turgidum ◽  
N Uptake ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
N Leaching ◽  
Specific Rate ◽  
Mineral Fertilization ◽  
Hordeum Vulgare L ◽  
Mineral N ◽  
Winter Cereals

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.

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