scholarly journals Revisiting Why Plants Become N Deficient Under Elevated CO2: Importance to Meet N Demand Regardless of the Fed-Form

2021 ◽  
Vol 12 ◽  
Author(s):  
Maaya Igarashi ◽  
Yan Yi ◽  
Katsuya Yano
Keyword(s):  
Growth Rate ◽  
Plant Biomass ◽  
Nitrate Assimilation ◽  
Leaf Sheath ◽  
Nitrate Accumulation ◽  
N Limitation ◽  
N Supply ◽  
N Concentration ◽  
Guinea Grass ◽  
N Deficiency

An increase in plant biomass under elevated CO2 (eCO2) is usually lower than expected. N-deficiency induced by eCO2 is often considered to be a reason for this. Several hypotheses explain the induced N-deficiency: (1) eCO2 inhibits nitrate assimilation, (2) eCO2 lowers nitrate acquisition due to reduced transpiration, or (3) eCO2 reduces plant N concentration with increased biomass. We tested them using C3 (wheat, rice, and potato) and C4 plants (guinea grass, and Amaranthus) grown in chambers at 400 (ambient CO2, aCO2) or 800 (eCO2) μL L−1 CO2. In most species, we could not confirm hypothesis (1) with the measurements of plant nitrate accumulation in each organ. The exception was rice showing a slight inhibition of nitrate assimilation at eCO2, but the biomass was similar between the nitrate and urea-fed plants. Contrary to hypothesis (2), eCO2 did not decrease plant nitrate acquisition despite reduced transpiration because of enhanced nitrate acquisition per unit transpiration in all species. Comparing to aCO2, eCO2 remarkably enhanced water-use efficiency, especially in C3 plants, decreasing water demand for CO2 acquisition. As our results supported hypothesis (3) without any exception, we then examined if lowered N concentration at eCO2 indeed limits the growth using C3 wheat and C4 guinea grass under various levels of nitrate-N supply. While eCO2 significantly increased relative growth rate (RGR) in wheat but not in guinea grass, each species increased RGR with higher N supply and then reached a maximum as no longer N was limited. To achieve the maximum RGR, wheat required a 1.3-fold N supply at eCO2 than aCO2 with 2.2-fold biomass. However, the N requirement by guinea grass was less affected by the eCO2 treatment. The results reveal that accelerated RGR by eCO2 could create a demand for more N, especially in the leaf sheath rather than the leaf blade in wheat, causing N-limitation unless the additional N was supplied. We concluded that eCO2 amplifies N-limitation due to accelerated growth rate rather than inhibited nitrate assimilation or acquisition. Our results suggest that plant growth under higher CO2 will become more dependent on N but less dependent on water to acquire both CO2 and N.

Interactive effects of nitrogen and irradiance on growth and partitioning of dry mass and nitrogen in young tomato plants

2002 ◽  
Vol 29 (11) ◽  
pp. 1319 ◽  
Author(s):  
Corine C. de Groot ◽  
Leo F. M. Marcelis ◽  
Riki van den Boogaard ◽  
Hans Lambers
Keyword(s):  
Leaf Area ◽  
Dry Mass ◽  
High Irradiance ◽  
Interactive Effects ◽  
Tomato Plants ◽  
N Limitation ◽  
N Supply ◽  
N Concentration ◽  
Growth Irradiance ◽  
Dry Mass Partitioning

The interactive effects of irradiance and N on growth of young tomato plants (Lycopersicon esculentum Mill.) were studied. Plants were grown at 70 or 300 μmol photons m–2 s–1, hereafter referred to as 'low' and 'high' irradiance, and at a range of exponential N supply rates (70–370 mg g–1 d–1) or at a constant concentration in the nutrient solution of 12 mM NO3–. At both irradiance levels, leaf area ratio was more important than net assimilation rate (NAR) in explaining effects of N on growth at mild N limitation. However, at severe N limitation, NAR became the most important parameter, as indicated by calculated growth response coefficients. Furthermore, this study shows that N supply and growth irradiance interacted strongly. The decrease of specific leaf area with increasing N limitation and increasing growth irradiance correlated with increasing leaf dry mass percentage and starch concentration. Furthermore, at low irradiance, plants partitioned more dry mass to the stem. Dry mass partitioning to roots increased with decreasing plant N concentration, and this relation appeared to be independent of irradiance. Shading increased plant N concentration and decreased dry mass partitioning to roots. Also, the relationship between plant N concentration and N partitioning to different plant organs was largely independent of growth irradiance.

scholarly journals Effects of Nitrogen Supply on Growth and Nutrient Status of Containerized Crape Myrtle

1998 ◽  
Vol 16 (2) ◽  
pp. 98-104
Author(s):  
Raul I. Cabrera ◽  
Diana R. Devereaux
Keyword(s):  
Plant Biomass ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Maximum Growth ◽  
Shoot Biomass ◽  
Opposite Pattern ◽  
N Supply ◽  
N Concentration ◽  
Key Factor ◽  
Leaf N Concentration

Abstract Containerized crape myrtle (Lagerstroemia indica x fauriei ‘Tonto’) plants were grown over a 9-month period using complete nutrient solutions, except during overwintering, that differed in N concentration: 15, 30, 60, 120, 210, and 300 mg/liter. Plant shoot biomass, leaf area and canopy diameter increased with applied N concentrations ([N]a) up to 60 mg/liter, but higher levels caused significant depressions in all these parameters. Root biomass and plant height were depressed linearly with increases in [N]a. Regardless of final plant biomass, increases in [N]a significantly favored shoot over root growth, with ratios increasing from 1.9 to 5.4 for 15 to 300 mg/liter, respectively. Soluble salts in the medium, monitored via leachates, increased with N supply and were identified as a key factor involved in the yield reductions observed at the higher [N]a. Leaf N concentration increased with N supply, stabilizing at [N]a above 120 mg/liter; concentrations of 2.6–2.7% were associated with maximum growth. Calcium and iron concentrations in tissue followed the same response pattern as N, but sulfur (S) decreased significantly in an opposite pattern. Other nutrients did not respond to [N]a. Leaf tissue N:S ratios were more closely correlated with plant growth that either N or S alone, with maximum growth observed at a ratio of approximately 6:1. Higher N:S ratios produced sharp yield depressions.

scholarly journals Optimal Nitrogen Supply Ameliorates the Performance of Wheat Seedlings under Osmotic Stress in Genotype-Specific Manner

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 493 ◽  
Author(s):  
Tania Kartseva ◽  
Anelia Dobrikova ◽  
Konstantina Kocheva ◽  
Vladimir Alexandrov ◽  
Georgi Georgiev ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Wheat Variety ◽  
Growth And Yield ◽  
Physiological Status ◽  
Wheat Seedlings ◽  
Modern Variety ◽  
N Supply ◽  
N Assimilation ◽  
N Deficiency

Strategies and coping mechanisms for stress tolerance under sub-optimal nutrition conditions could provide important guidelines for developing selection criteria in sustainable agriculture. Nitrogen (N) is one of the major nutrients limiting the growth and yield of crop plants, among which wheat is probably the most substantial to human diet worldwide. Physiological status and photosynthetic capacity of two contrasting wheat genotypes (old Slomer and modern semi-dwarf Enola) were evaluated at the seedling stage to assess how N supply affected osmotic stress tolerance and capacity of plants to survive drought periods. It was evident that higher N input in both varieties contributed to better performance under dehydration. The combination of lower N supply and water deprivation (osmotic stress induced by polyethylene glycol treatment) led to greater damage of the photosynthetic efficiency and a higher degree of oxidative stress than the individually applied stresses. The old wheat variety had better N assimilation efficiency, and it was also the one with better performance under N deficiency. However, when both N and water were deficient, the modern variety demonstrated better photosynthetic performance. It was concluded that different strategies for overcoming osmotic stress alone or in combination with low N could be attributed to differences in the genetic background. Better performance of the modern variety conceivably indicated that semi-dwarfing (Rht) alleles might have a beneficial effect in arid regions and N deficiency conditions.

scholarly journals Effects of Photosynthetic Activity Radiation (PAR) on Green Mustard Plant Growth (Brassica rapa var. parachinensis L.)

2019 ◽  
Vol 20 (1) ◽  
pp. 19
Author(s):  
Ni Nyoman Ratini ◽  
I Wayan Supardi ◽  
Yuli Nurfadhillah
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Plant Height ◽  
Photosynthetic Activity ◽  
Plant Biomass ◽  
Vegetative Phase ◽  
Active Radiation ◽  
Blue Filter ◽  
Mustard Plant ◽  
Number Of Leaves

A research on the effect of photosynthetic active radiation (PAR) on the growth of green mustard plants has been conducted. The radiation source used is sunlight. Samples have been grouped as a sample which treated by red filter (P1), by orange filter (P2), by purple filter (P3), by green filter (P4), by blue filter (P5) and a sample without filter as a control (P0). Each sample consisted of four plants. The planting was carried out using polybags with compost media. Observations were made from the nursery phase to the slow vegetative phase (day 3rd, when all plants had grown shoots until day 63rd of the harvest). Parameters measured include light intensity, plant height and number of leaves. Measurement is done every three days. Also it measured plant biomass on the last day of observation (63rd day). The results showed that the intensity of each sample had an impact on the harvest. The best growth rate is obtained in P2, both in the nursery phase and fast vegetative phase i.e. 0.119 cm/day and 0.194 cm/day, respectively. While the highest growth rate was obtained in the P3 sample, namely the slow vegetative phase (0.035 cm/day). Overall the best planting results were obtained in P2 samples with plant height of 23.18 cm, number of leaves of 12 strands and plant biomass of 33.56 g.

scholarly journals Microstructural and physiological responses to cadmium stress under different nitrogen levels in Populus cathayana females and males

2020 ◽  
Vol 40 (1) ◽  
pp. 30-45 ◽  
Author(s):  
Miao Liu ◽  
Jingwen Bi ◽  
Xiucheng Liu ◽  
Jieyu Kang ◽  
Helena Korpelainen ◽  
...  
Keyword(s):  
Nitrogen Deficiency ◽  
Ion Homeostasis ◽  
N Availability ◽  
Cd Stress ◽  
Cd Accumulation ◽  
N Supply ◽  
Populus Cathayana ◽  
N Deficiency ◽  
Cellular Compartments ◽  
Cd Translocation

Abstract Although increasing attention has been paid to the relationships between heavy metal and nitrogen (N) availability, the mechanism underlying adaptation to cadmium (Cd) stress in dioecious plants has been largely overlooked. This study examined Cd accumulation, translocation and allocation among tissues and cellular compartments in Populus cathayana Rehder females and males. Both leaf Cd accumulation and root-to-shoot Cd translocation were significantly greater in females than in males under a normal N supply, but they were reduced in females and enhanced in males under N deficiency. The genes related to Cd uptake and translocation, HMA2, YSL2 and ZIP2, were strongly induced by Cd stress in female roots and in males under a normal N supply. Cadmium largely accumulated in the leaf blades of females and in the leaf veins of males under a normal N supply, while the contrary was true under N deficiency. Furthermore, Cd was mainly distributed in the leaf epidermis and spongy tissues of males, and in the leaf palisade tissues of females. Nitrogen deficiency increased Cd allocation to the spongy tissues of female leaves and to the palisade tissues of males. In roots, Cd was preferentially distributed to the epidermis and cortices in both sexes, and also to the vascular tissues of females under a normal N supply but not under N deficiency. These results suggested that males possess better Cd tolerance compared with females, even under N deficiency, which is associated with their reduced root-to-shoot Cd translocation, specific Cd distribution in organic and/or cellular compartments, and enhanced antioxidation and ion homeostasis. Our study also provides new insights into engineering woody plants for phytoremediation.

Nitrogen supply controls vegetative growth, biomass and nitrogen allocation for grapevine (cv. Shiraz) grown in pots

2015 ◽  
Vol 42 (1) ◽  
pp. 105 ◽  
Author(s):  
Aurélie Metay ◽  
Jessica Magnier ◽  
Nicolas Guilpart ◽  
Angélique Christophe
Keyword(s):  
Vegetative Growth ◽  
Limiting Factor ◽  
Dependent Manner ◽  
Leaf Emergence ◽  
N Supply ◽  
Secondary Axis ◽  
Axis Elongation ◽  
Primary Axis ◽  
N Deficiency ◽  
Area Expansion

Maintaining grapevine productivity with limited inputs is crucial in Mediterranean areas. Apart from water, nitrogen (N) is also an important limiting factor in grape growing. The effects of N deficiency on grapevine growth were investigated in this study. Two-year-old Vitis vinifera L.cv. Shiraz plants grafted on 110 R were grown in pots placed outside and exposed to various N supplies (0, 0.6, 1.2, 2.4 and 12 g plant–1) under well-watered conditions. At veraison, plants were harvested and organs separately dried, weighed and analysed for N. During plant growth, the length of the primary and secondary axes and the number of leaves on them were recorded. The N content of leaves was also analysed at three phenological stages (flowering, bunch closure and veraison). All growth processes were inhibited by N deficiency in an intensity-dependent manner. Quantitative relationships with N supply were established. Vegetative growth responded negatively to N stress when comparing control N supply with no N supply: primary axis elongation (–61%), leaf emergence on the primary axis (–47%), leaf emergence on the secondary axis (–94%) and lamina area expansion (–45%). Significant differences on the plant N status were observed from flowering onwards which might be useful for managing fertilisation.

scholarly journals How Nitrogen Supply Affects Growth and Nitrogen Uptake, Use Efficiency, and Loss from Citrus Seedlings

1996 ◽  
Vol 121 (1) ◽  
pp. 105-114 ◽  
Author(s):  
John D. Lea-Cox ◽  
James P. Syvertsen
Keyword(s):  
Plant Growth ◽  
N Uptake ◽  
Single Application ◽  
N Application ◽  
N Supply ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Use Efficiency ◽  
Complete Nutrient Solution ◽  
Leaf N

We examined how N supply affected plant growth and N uptake, allocation and leaching losses from a fine sandy soil with four Citrus rootstock species. Seedlings of `Cleopatra' mandarin (Citrus reticulata Blanco) and `Swingle' citrumelo (C. paradisi × P. trifoliata) were grown in a glasshouse in 2.3-liter pots of Candler fine sand and fertilized weekly with a complete nutrient solution containing 200 mg N/liter (20 mg N/week). A single application of 15NH415NO3(17.8% atom excess 15N) was substituted for a normal weekly N application when the seedlings were 22 weeks old (day O). Six replicate plants of each species were harvested at 0.5, 1.5, 3.5, 7, 11, and 30 days after 15N application. In a second experiment, NH4 NO3 was supplied at 18,53, and 105 mg N/week to 14-week-old `Volkamer' lemon (C. volkameriana Ten. & Pasq.) and sour orange (C. aurantium L.) seedlings in a complete nutrient solution for 8 weeks. A single application of 15NH415NO3 (23.0% 15N) was substituted at 22 weeks (day 0), as in the first experiment, and seedlings harvested 3,7, and 31 days after 15N application. Nitrogen uptake and partitioning were similar among species within each rate, but were strongly influenced by total N supply and the N demand by new growth. There was no 15N retranslocation to new tissue at the highest (105 mg N/week) rate, but N supplies below this rate limited plant growth without short-term 15N reallocation from other tissues. Leaf N concentration increased linearly with N supply up to the highest rate, while leaf chlorophyll concentration did not increase above that at 53 mg N/week. Photosynthetic CO2 assimilation was not limited by N in this study; leaf N concentration exceeded 100 mmol·m-2 in all treatments. Thus, differences in net productivity at the higher N rates appeared to be a function of increased leaf area, but not of leaf N concentration. Hence, N use efficiency decreased significantly over the range of N supply, whether expressed either on a gas-exchange or dry weight basis. Mean plant 15N uptake efficiencies after 31 days decreased from 60% to 47% of the 15N applied at the 18,20, and 53 mg N/week rates to less than 33% at the 105 mg N/week rate. Leaching losses increased with N rate, with plant growth rates and the subsequent N requirements of these Citrus species interacting with residual soil N and potential leaching loss.

scholarly journals (347) Identifying Common Reflectance Properties in Diverse Ornamental Species to Nondestructively Determine Nitrogen Status

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1060C-1060
Author(s):  
Jonathan M. Frantz ◽  
Dharmalingam S. Pitchay ◽  
Glen Ritchie ◽  
Heping Zhu
Keyword(s):  
Gray Mold ◽  
Production Cycle ◽  
Strongly Correlated ◽  
N Concentration ◽  
Derivative Analysis ◽  
Leaf Chlorosis ◽  
N Deficiency ◽  
Whole Plants ◽  
Ornamental Species

Nitrogen (N) is often supplied to plants in excess to minimize the possibility of encountering N deficiency that would reduce the plant quality due to leaf chlorosis and necrosis. This is not only costly, but it can reduce the quality of plants, predispose the plants to biotic stress such as Botrytisgray mold, and extend the production cycle. Several tools can be used to identify N deficiency in plants, and most are based on chlorophyll reflectance or transmittance. While sensitive when plants are experiencing N deficiency, spectral signals can saturate in an ample N supply and make it difficult to discern sufficient and supra-optimal N nondestructively. Three diverse ornamental species (begonia, Begoniacea×tuberhybrida; butterflybush, Buddlejadavidii; and geranium, Pelargonium×hortorum) were grown with a broad range of N supplied (1.8 to 58 mm) in three separate studies that resulted in a range of 1.8% to 6% tissue N concentration. Using a spectroradiometer, we measured reflectance from the whole plants twice over a period of 3 weeks. A first-derivative analysis of the data identified six wavebands that were strongly correlated to both begonia and butterflybush tissue N concentration (r2 ∼ 0.9), and two of these also correlated well to geranium N concentration. These wavebands did not correlate to chlorophyll peak absorbance, but rather blue, green, red, and far-red “edges” of known plant pigments. These wavebands hold promise for use as a nondestructive indicator of N status over a much broader range of tissue N concentration than current sensors can reliably predict.

A management experiment reveals the difficulty of altering seedling growth and palatable plant biomass by culling invasive deer

2017 ◽  
Vol 44 (8) ◽  
pp. 623
Author(s):  
David S. L. Ramsey ◽  
David M. Forsyth ◽  
Clare J. Veltman ◽  
Sarah J. Richardson ◽  
Robert B. Allen ◽  
...  
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
Relative Growth Rate ◽  
Forest Dynamics ◽  
Structural Equation ◽  
Plant Biomass ◽  
Bayesian Variable Selection ◽  
Seedling Height ◽  
Relative Growth ◽  
Foliar Biomass

Context There is concern that deer are shifting forests towards undesirable trajectories, and culling of deer is often advocated to mitigate these impacts. However, culling deer is expensive and sometimes controversial. To reliably ascertain whether such action is beneficial, management-scale experiments are needed. We conducted a management experiment to evaluate the benefits of culling deer in four New Zealand forests. Aims Our experiment tested the predictions that culling deer should increase (1) canopy tree seedling height relative growth rate (SHRGR), and (2) the foliar biomass of understorey species palatable to deer (FBP). Methods Each forest was divided into two 3600-ha areas, with deer culling randomly assigned to one area. Deer abundances were indexed using faecal pellet counts, and forest variables were measured at the start and end of the 8-year experiment. Deer were already at low abundance in one forest and were not culled there. We used structural equation modelling (SEM) with Bayesian variable selection to update our a priori graphical forest–deer model with data from all four forests. Key results Deer abundances were significantly reduced in one forest but increased or did not change in the other two forests in which deer culling occurred. Culling deer did not increase seedling height relative growth rate (SHRGR) or the foliar biomass of understorey species palatable to deer (FBP) in the three areas subject to deer culling compared with the three areas not subject to deer culling. SEM revealed no significant relationships between local-scale deer abundance and either SHRGR or FBP. Rather, tree basal area and the foliar biomass of unpalatable understorey species were important predictors of FBP and SHRGR, respectively, in some forests. Conclusions Our study revealed that culling deer, as currently practiced by New Zealand land managers, did not generate the desired responses in New Zealand forests, possibly due to deer not being culled to sufficiently low densities and/or because forest dynamics and abiotic drivers determined plant growth more than deer. Implications Managers should consider actions other than ineffective deer culling (e.g. creating canopy gaps) to alter the dynamics of New Zealand forests. Alternatively, managers will need to substantially increase culling effort above what is currently practised for this activity to substantially reduce deer populations and thus potentially alter forest dynamics.

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