The Effect of Leaf Nitrogen and Temperature on the CO2 Response of Photosynthesis in the C3 Dicot MChenopodium album L

1990 ◽  
Vol 17 (2) ◽  
pp. 135 ◽  
Author(s):  
RF Sage ◽  
TD Sharkey ◽  
RW Pearcy
Keyword(s):  
Chenopodium Album ◽  
Co2 Assimilation ◽  
Leaf Nitrogen ◽  
Leaf Temperature ◽  
Initial Slope ◽  
Leaf Nitrogen Content ◽  
Regeneration Capacity ◽  
High Nitrogen ◽  
Co2 Response ◽  
Rate Of Photosynthesis

The CO2 response of photosynthesis was studied in the C3 annual, Chenopodium album L. Both the initial slope of the photosynthetic CO2 response and the CO2 saturated rate of photosynthesis were linearly dependent on organic leaf nitrogen content. As leaf nitrogen increased or leaf temperature declined, the CO2 saturation point of photosynthesis declined. Increasing leaf temperature from 15 to 34°C stimulated the CO2-saturated rate of photosynthesis but had little effect on the initial slope of the photosynthetic CO2 response. According to the photosynthesis model of Sharkey (1985 Bot. Rev. 51: 53-105), these results indicate that as leaf nitrogen increased, the capacity for RuP2 carboxylase and RuP2 regeneration increased to a greater extent than the capacity of starch and sucrose synthesis to regenerate orthophosphate. As a result, in high nitrogen leaves, photosynthesis appeared to be limited by the capacity to regenerate phosphate at lower CO2 partial pressures than in low nitrogen leaves. In high nitrogen leaves, increasing temperature appeared to enhance the phosphate regeneration capacity to a greater extent than the capacity of RuP2 carboxylase. Consequently, while under cool conditions (<20°C), CO2 assimilation in normal atmospheric air appeared to be limited by the phosphate regeneration capacity, under warm conditions (34°C), RuP2 carboxylase capacity appeared to limit CO2 assimilation.

scholarly journals Physiological responses of two tropical weeds to shade: II. Leaf gas exchange and nitrogen content

1999 ◽  
Vol 34 (6) ◽  
pp. 952-961 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Nitrogen Content ◽  
Weed Management ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Co2 Assimilation ◽  
Leaf Nitrogen ◽  
High Irradiance ◽  
Leaf Nitrogen Content ◽  
Light Regimes ◽  
Stachytarpheta Cayennensis

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in the Brazilian Amazonia, Brazil, were grown in controlled environment cabinets under high (800-1000 µmol m-² s-¹) and low (200-350 µmol m-² s-¹) light regimes during a 40-day period. The objective was to determine the effect of shade on photosynthetic features and leaf nitrogen content of I. asarifolia and S. cayennensis. High-irradiance grown I. asarifolia leaves had significantly higher dark respiration and light saturated rates of photosynthesis than low-irradiance leaves. No significant differences for these traits, between treatments, were observed in S. cayennensis. Low-irradiance leaves of both species displayed higher CO2 assimilation rates under low irradiance. High-irradiance grown leaves of both species had less nitrogen per unit of weight. Low-irradiance S. cayennensis had more nitrogen per unit of leaf area than high-irradiance plants; however, I. asarifolia showed no consistent pattern for this variable through time. For S. cayennensis, leaf nitrogen content and CO2 assimilation were inversely correlated to the amount of biomass allocated to developing reproductive structures. These results are discussed in relation to their ecological and weed management implications.

Fruit presence negatively affects photosynthesis by reducing leaf nitrogen in almond

2014 ◽  
Vol 41 (8) ◽  
pp. 884 ◽  
Author(s):  
Sebastian Saa ◽  
Patrick H. Brown
Keyword(s):  
Nitrogen Concentration ◽  
Carbon Assimilation ◽  
Leaf Nitrogen ◽  
Leaf Temperature ◽  
Leaf Nitrogen Content ◽  
Assimilation Rate ◽  
Specific Leaf Weight ◽  
Leaf Weight ◽  
Carbon Assimilation Rate ◽  
The Impact

Fruit presence often positively and seldom negatively affects leaf carbon assimilation rate in fruit-trees. In almond (Prunus dulcis (Mill.) DA Webb) the presence of fruit often results in the death of the fruit bearing spurs. The mechanism of this effect is unclear, but may be a consequence of diminished carbon assimilation rate in leaves adjacent to fruit and the subsequent depletion of nutrient and carbohydrates reserves. This study evaluated the influence of fruit on leaf carbon assimilation rate and leaf nitrogen throughout the season. Carbon assimilation rate (Aa), rubisco carboxylation capacity at leaf temperature (Vcmax@Tleaf), maximum rate of RubP regeneration at leaf temperature (Jmax@Tleaf), leaf nitrogen on a mass basis (N%) and area basis (Na), and specific leaf weight data were recorded. Fruit presence negatively affected leaf nitrogen concentration by a reduction in specific leaf weight and leaf nitrogen content. The impact of fruit presence on carbon assimilation rate was predominantly associated with the negative effect of fruit on Na and resulted in a significant reduction in Jmax@Tleaf and therefore in Aa, especially after full leaf and fruit expansion. The reduction in leaf area, leaf nitrogen, reduced Jmax@Tleaf and decreased carbon assimilation rate in the presence of fruit explains the negative effects of fruit presence on spur vitality.

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.

Acclimation by the Thylakoid Membranes to Growth Irradiance and the Partitioning of Nitrogen Between Soluble and Thylakoid Proteins

1988 ◽  
Vol 15 (2) ◽  
pp. 93 ◽  
Author(s):  
JR Evans
Keyword(s):  
Electron Transport ◽  
High Efficiency ◽  
Co2 Assimilation ◽  
Thylakoid Membranes ◽  
Leaf Nitrogen ◽  
Cytochrome F ◽  
Leaf Nitrogen Content ◽  
Carboxylase Activity ◽  
The Relationship ◽  
Shade Plants

Three characteristics of shade plants are reviewed. Firstly, they have relatively more chlorophyll b and the associated light-harvesting chlorophyll a/b-protein complex (LHC). Two currently accepted reasons for this are not supported by quantitative analysis. Instead, the reduced protein cost of complexing chlorophyll in LHC and the turnover of the 32 kDa herbicide binding protein are considered. Secondly, shade plants have low electron transport capacities per unit of chlorophyll. This is primarily related to a reduction in the amount of electron transport components such as the cytochrome f complex and the ATPase. The nitrogen cost of the thylakoid membranes per unit of light absorbed is thereby reduced, but the irradiance range over which light is used with high efficiency is also reduced. Thirdly, shade plants have less RuP2 carboxylase and other soluble proteins for a given amount of chlorophyll. However, while the ratio of RuP2 carboxylase protein to thylakoid protein declined, the ratio of the RuP2 carboxylase activity to electron transport activity increased. For several species, the relationship between the rate of CO2 assimilation and leaf nitrogen content depends on the irradiance during growth.

scholarly journals Estimating the Leaf Nitrogen Content with a New Feature Extracted from the Ultra-High Spectral and Spatial Resolution Images in Wheat

2021 ◽  
Vol 13 (4) ◽  
pp. 739
Author(s):  
Jiale Jiang ◽  
Jie Zhu ◽  
Xue Wang ◽  
Tao Cheng ◽  
Yongchao Tian ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Precision Agriculture ◽  
Field Experiments ◽  
Mean Squared Error ◽  
Growing Season ◽  
Leaf Nitrogen ◽  
Textural Analysis ◽  
Hyperspectral Images ◽  
Leaf Nitrogen Content ◽  
New Feature

Real-time and accurate monitoring of nitrogen content in crops is crucial for precision agriculture. Proximal sensing is the most common technique for monitoring crop traits, but it is often influenced by soil background and shadow effects. However, few studies have investigated the classification of different components of crop canopy, and the performance of spectral and textural indices from different components on estimating leaf nitrogen content (LNC) of wheat remains unexplored. This study aims to investigate a new feature extracted from near-ground hyperspectral imaging data to estimate precisely the LNC of wheat. In field experiments conducted over two years, we collected hyperspectral images at different rates of nitrogen and planting densities for several varieties of wheat throughout the growing season. We used traditional methods of classification (one unsupervised and one supervised method), spectral analysis (SA), textural analysis (TA), and integrated spectral and textural analysis (S-TA) to classify the images obtained as those of soil, panicles, sunlit leaves (SL), and shadowed leaves (SHL). The results show that the S-TA can provide a reasonable compromise between accuracy and efficiency (overall accuracy = 97.8%, Kappa coefficient = 0.971, and run time = 14 min), so the comparative results from S-TA were used to generate four target objects: the whole image (WI), all leaves (AL), SL, and SHL. Then, those objects were used to determine the relationships between the LNC and three types of indices: spectral indices (SIs), textural indices (TIs), and spectral and textural indices (STIs). All AL-derived indices achieved more stable relationships with the LNC than the WI-, SL-, and SHL-derived indices, and the AL-derived STI was the best index for estimating the LNC in terms of both calibration (Rc2 = 0.78, relative root mean-squared error (RRMSEc) = 13.5%) and validation (Rv2 = 0.83, RRMSEv = 10.9%). It suggests that extracting the spectral and textural features of all leaves from near-ground hyperspectral images can precisely estimate the LNC of wheat throughout the growing season. The workflow is promising for the LNC estimation of other crops and could be helpful for precision agriculture.

Estimation of tomato leaf nitrogen content using continuum-removal spectroscopy analysis technique

2012 ◽  
Author(s):  
Yongjun Ding ◽  
Minzan Li ◽  
Lihua Zheng ◽  
Hong Sun
Keyword(s):  
Nitrogen Content ◽  
Leaf Nitrogen ◽  
Tomato Leaf ◽  
Leaf Nitrogen Content ◽  
Spectroscopy Analysis ◽  
Analysis Technique ◽  
Continuum Removal

scholarly journals Effect of fluorescence characteristics and different algorithms on the estimation of leaf nitrogen content based on laser-induced fluorescence lidar in paddy rice

2017 ◽  
Vol 25 (4) ◽  
pp. 3743 ◽  
Author(s):  
Jian Yang ◽  
Jia Sun ◽  
Lin Du ◽  
Biwu Chen ◽  
Zhenbing Zhang ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Laser Induced Fluorescence ◽  
Leaf Nitrogen ◽  
Paddy Rice ◽  
Leaf Nitrogen Content ◽  
Fluorescence Characteristics

scholarly journals Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

2010 ◽  
Vol 67 (6) ◽  
pp. 624-632 ◽  
Author(s):  
Keila Rego Mendes ◽  
Ricardo Antonio Marenco
Keyword(s):  
Gas Exchange ◽  
Nitrogen Content ◽  
Leaf Area ◽  
Tree Species ◽  
Leaf Traits ◽  
Leaf Nitrogen ◽  
Dry Season ◽  
Leaf Thickness ◽  
Rainfall Regime ◽  
Leaf Nitrogen Content

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

Estimation of litchi ( Litchi chinensis Sonn.) leaf nitrogen content at different growth stages using canopy reflectance spectra

2016 ◽  
Vol 80 ◽  
pp. 182-194 ◽  
Author(s):  
Dan Li ◽  
Congyang Wang ◽  
Wei Liu ◽  
Zhiping Peng ◽  
Siyu Huang ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Leaf Nitrogen ◽  
Reflectance Spectra ◽  
Growth Stages ◽  
Canopy Reflectance ◽  
Leaf Nitrogen Content ◽  
Litchi Chinensis ◽  
Different Growth Stages
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