scholarly journals Evidence of higher photosynthetic plasticity in the early successional Guazuma ulmifolia Lam. compared to the late successional Hymenaea courbaril L. grown in contrasting light environments

2010 ◽  
Vol 70 (1) ◽  
pp. 75-83 ◽  
Author(s):  
MT. Portes ◽  
DSC. Damineli ◽  
RV. Ribeiro ◽  
JAF. Monteiro ◽  
GM. Souza
Keyword(s):  
Photosynthetic Characteristics ◽  
Light Conditions ◽  
Response Curves ◽  
Low Light ◽  
Light Harvesting Complexes ◽  
Chl A ◽  
Hymenaea Courbaril ◽  
Photosynthetic Plasticity ◽  
Successional Species ◽  
Guazuma Ulmifolia

The present study investigated changes in photosynthetic characteristics of Guazuma ulmifolia Lam. (early successional species) and Hymenaea courbaril L. (late successional species) grown in contrasting light conditions as a way of assessing photosynthetic plasticity. Early successional species typically inhabit gap environments being exposed to variability in multiple resources, hence it is expected that these species would show higher photosynthetic plasticity than late successional ones. In order to test this hypothesis, light and CO2 response curves and chlorophyll content (Chl) were measured in plants grown in high and low light environments. G. ulmifolia presented the highest amounts of both Chl a and b, especially in the low light, and both species presented higher Chl a than b in both light conditions. The Chl a/b ratio was higher in high light leaves of both species and greater in G. ulmifolia. Taken together, these results evidence the acclimation potential of both species, reflecting the capacity to modulate light harvesting complexes according to the light environment. However, G. ulmifolia showed evidence of higher photosynthetic plasticity, as indicated by the greater amplitude of variation on photosynthetic characteristics between environments shown by more significant shade adjusted parameters (SAC) and principal component analysis (PCA). Thus, the results obtained were coherent with the hypothesis that the early successional species G. ulmifolia exhibits higher photosynthetic plasticity than the late successional species H. courbaril.

scholarly journals Photosynthetic performance and growth responses of Liriope muscari (Decne.) L.H. Bailey (Asparagaceae) planted within poplar forests having different canopy densities

2020 ◽  
Author(s):  
jiaojiao zhang ◽  
Ling Zhu ◽  
Xu Zhang ◽  
Jian Zhou
Keyword(s):  
Forest Edge ◽  
Photosynthetic Performance ◽  
Photosynthetic Characteristics ◽  
Growth Responses ◽  
Apparent Quantum Yield ◽  
Low Light ◽  
Adaptation Mechanism ◽  
Physiological Basis ◽  
Chl A ◽  
Point Light

Abstract Background: Liriope muscari (Decne.) L.H. Bailey is a valuable horticultural and medicinal plant that grows under a range of light intensities, from high to low, in the understories of shrubs. To understand how this species adapts to these various environments, we selected two groups of lilyturf growing under poplar trees at two different spacings. Each group was divided into three types, open field, forest edge and shaded forest with high, medium and low irradiance levels, respectively, and then we examined their photosynthetic characteristics, physiology and biomasses. Results: Light saturation point, light compensation point and in situ net photosynthetic rate ( P N ) were highest in lilyturf growing under high light. In contrast, lilyturf growing under low light had a higher apparent quantum yield and Chl a and b contents, indicating that they adapted to low light. Although the leaves of lilyturf growing under low light were small, their root tubers were heavier. Conclusions: The research demonstrates the eco-physiological basis of lilyturf’s shade adaptation mechanism as indicated by photosynthetic activity, chlorophyll fluorescence, Chl a, Chl b and Car contents when grown under different irradiances. We believe that lilyturf is a shade-tolerant plant suitable for planting in undergrowth, but attention should be paid to the canopy density of the forest when interplanting. The findings presented here advance our understanding of the photosynthetic characteristics of understory plants and may assist in the optimization of irradiances in the future.

scholarly journals Interactive effects of temperature and light during deep convection: a case study on growth and condition of the diatom Thalassiosira weissflogii

2014 ◽  
Vol 72 (6) ◽  
pp. 2061-2071 ◽  
Author(s):  
B. Walter ◽  
J. Peters ◽  
J. E. E. van Beusekom ◽  
M. A. St. John
Keyword(s):  
Primary Production ◽  
Deep Convection ◽  
Growth Conditions ◽  
Interactive Effects ◽  
Light Conditions ◽  
Thalassiosira Weissflogii ◽  
Pulsed Light ◽  
Low Light ◽  
Chl A ◽  
The North

Abstract Aim of this study was to expose phytoplankton to growth conditions simulating deep winter convection in the North Atlantic and thereby to assess changes in physiology enabling their survival. Growth rate, biochemical composition, and photosynthetic activity of the diatom Thalassiosira weissflogii were determined under two different light scenarios over a temperature range of 5–15°C to simulate conditions experienced by cells during winter deep convection. These metrics were examined under a low light scenario (20 µmol m−2 s−1, 12/12 h light/dark), and compared with a scenario of short light pulses of a higher light intensity (120 µmol m−2 s−1, 2/22 h light/dark). Both experimental light conditions offered the same daily light dose. No growth was observed at temperatures below 8°C. Above 8°C, growth rates were significantly higher under low light conditions compared with those of short pulsed light exposures, indicating a higher efficiency of light utilization. This could be related to (i) a higher content of Chl a per cell in the low light trial and/or (ii) a more efficient transfer of light energy into growth as indicated by constantly low carbohydrate levels. In contrast, pulsed intense light led to an accumulation of carbohydrates, which were catabolized during the longer dark period for maintaining metabolism. Light curves measured via Chl a fluorescence indicated low light assimilation for the algae exposed to short pulsed light. We postulate that our trial with short light pluses did not provide sufficient light to reach full light saturation. In general, photosynthesis was more strongly affected by temperature under pulsed light than under low light conditions. Our results indicate that model estimates of primary production in relation to deep convection, which are based on average low light conditions, not considering vertical transportation of algae will lead to an overestimation of in situ primary production.

Photosynthetic potential of sun and shade Viola species

1984 ◽  
Vol 62 (6) ◽  
pp. 1273-1278 ◽  
Author(s):  
William F. Curtis
Keyword(s):  
Dark Respiration ◽  
Photosynthetic Performance ◽  
Light Conditions ◽  
Low Light ◽  
Light Regimes ◽  
Photosynthetic Plasticity ◽  
Photosynthetic Potential ◽  
Photosynthetic Responses ◽  
Sun And Shade ◽  
Meadow Species

The photosynthetic responses of a forest floor violet (Viola blanda) and a related meadow species (Viola flmbriatula) grown under controlled conditions were measured to test the prediction that these two species were photosynthetically shade and sun adapted, respectively. Based on their low photosynthetic and dark respiration rates, and low light saturation and compensation points, both violets can be classified as shade-tolerant. The forest species was photosynthetically and morphologically inflexible when grown under high light conditions, which led to chlorosis and greatly decreased photosynthetic performance. Conversely, the meadow species was both photosynthetically and morphologically flexible; its photosynthetic performance allowed it to grow well under both high and low light regimes. As a consequence, morphological flexibility may play a greater role than physiological (i.e., photosynthetic) plasticity in regulating the distribution of these two violets under field conditions.

scholarly journals Net Carbon Exchange Rate of Fragaria Species, Synthetic Octoploids, and Derived Germplasm

2012 ◽  
Vol 137 (3) ◽  
pp. 202-209 ◽  
Author(s):  
Rebecca M. Harbut ◽  
J. Alan Sullivan ◽  
John T.A. Proctor ◽  
Harry J. Swartz
Keyword(s):  
Exchange Rate ◽  
Light Response ◽  
Research Station ◽  
Carbon Exchange ◽  
Light Conditions ◽  
Response Curves ◽  
Low Light ◽  
Light Response Curves ◽  
Single Leaf ◽  
Net Carbon Exchange

The net carbon exchange rate (NCER) of Fragaria species, synthetic octoploids [SO (interspecific hybrids)], F1 (SO × cultivar), and first outcross [OC1 (F1 × cultivar)] hybrids were evaluated in both field and greenhouse conditions. Plants were grown in a field trial at the Elora Research Station in Ontario, Canada, for one season and then plants were dug and moved into a greenhouse where the trial was repeated during the next season. Single leaf photosynthesis measurements and light response curves were generated at different stages of plant development. Photosynthetic capacity of the species was related to the ecological background of the species with sun-adapted species having higher rates compared with the shade-adapted species. The Fragaria species and introgressed hybrids (F1 and OC1) had significantly higher NCERs compared with the cultivars with rates 28% and 23% higher, respectively. Species and hybrids also appear to have increased adaptability to both high and low light conditions. These increases in NCER may be a heterotic effect because NCER of the hybrids were consistently higher compared with the midparent values and in some cases, they were higher than the high parent. These results suggest that the introgression of lower-ploidy Fragaria species into the cultivated strawberry (Fragaria ×ananassa) may lead to increased NCER and light adaptability.

scholarly journals Photosynthetic performance and growth responses of Liriope muscari (Decne.) L.H. Bailey (Asparagaceae) planted within poplar forests having different canopy densities

2020 ◽  
Author(s):  
jiaojiao zhang ◽  
Ling Zhu ◽  
Xu Zhang ◽  
Jian Zhou
Keyword(s):  
Forest Edge ◽  
Photosynthetic Performance ◽  
Photosynthetic Characteristics ◽  
Growth Responses ◽  
Apparent Quantum Yield ◽  
Low Light ◽  
Adaptation Mechanism ◽  
Physiological Basis ◽  
Chl A ◽  
Point Light

Abstract Background: Liriope muscari (Decne.) L.H. Bailey is a valuable horticultural and medicinal plant that grows under a range of light intensities, from high to low, in the understories of shrubs. To understand how this species adapts to these various environments, we selected two groups of lilyturf growing under poplar trees at two different spacings. Each group was divided into three types, open field, forest edge and shaded forest with high, medium and low irradiance levels, respectively, and then we examined their photosynthetic characteristics, physiology and biomasses. Results: Light saturation point, light compensation point and in situ net photosynthetic rate (PN) were highest in lilyturf growing under high light. In contrast, lilyturf growing under low light had a higher apparent quantum yield and Chl a and b contents, indicating that they adapted to low light. Although the leaves of lilyturf growing under low light were small, their root tubers were heavier. Conclusions: The research demonstrates the eco-physiological basis of lilyturf’s shade adaptation mechanism as indicated by photosynthetic activity, chlorophyll fluorescence, Chl a, Chl b and Car contents when grown under different irradiances. We believe that lilyturf is a shade-tolerant plant suitable for planting in undergrowth, but attention should be paid to the canopy density of the forest when interplanting. The findings presented here advance our understanding of the photosynthetic characteristics of understory plants and may assist in the optimization of irradiances in the future.

scholarly journals Photosynthetic performance and growth responses of Liriope muscari (Decne.) L.H. Bailey (Asparagaceae) planted within poplar forests having different canopy densities

2020 ◽  
Author(s):  
jiaojiao zhang ◽  
Ling Zhu ◽  
Xu Zhang ◽  
Jian Zhou
Keyword(s):  
Forest Edge ◽  
Photosynthetic Performance ◽  
Photosynthetic Characteristics ◽  
Growth Responses ◽  
Apparent Quantum Yield ◽  
Low Light ◽  
Adaptation Mechanism ◽  
Physiological Basis ◽  
Chl A ◽  
Point Light

Abstract Background: Liriope muscari (Decne.) L.H. Bailey is a valuable horticultural and medicinal plant that grows under a range of light intensities, from high to low, in the understories of shrubs. To understand how this species adapts to these various environments, we selected two groups of lilyturf growing under poplar trees at two different spacings. Each group was divided into three types, open field, forest edge and shaded forest with high, medium and low irradiance levels, respectively, and then we examined their photosynthetic characteristics, physiology and biomasses. Results: Light saturation point, light compensation point and in situ net photosynthetic rate (PN) were highest in lilyturf growing under high light. In contrast, lilyturf growing under low light had a higher apparent quantum yield and Chl a and b contents, indicating that they adapted to low light. Although the leaves of lilyturf growing under low light were small, their root tubers were heavier. Conclusions: The research demonstrates the eco-physiological basis of lilyturf’s shade adaptation mechanism as indicated by photosynthetic activity, chlorophyll fluorescence, Chl a, Chl b and Car contents when grown under different irradiances. We believe that lilyturf is a shade-tolerant plant suitable for planting in undergrowth, but attention should be paid to the canopy density of the forest when interplanting. The findings presented here advance our understanding of the photosynthetic characteristics of understory plants and may assist in the optimization of irradiances in the future.

scholarly journals Superradiance of bacteriochlorophyll c aggregates in chlorosomes of green photosynthetic bacteria

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomáš Malina ◽  
Rob Koehorst ◽  
David Bína ◽  
Jakub Pšenčík ◽  
Herbert van Amerongen
Keyword(s):  
Photosynthetic Bacteria ◽  
Excitation Energy Transfer ◽  
Light Conditions ◽  
Dipole Strength ◽  
Low Light ◽  
Light Harvesting Complexes ◽  
Green Photosynthetic Bacteria ◽  
Self Assembling ◽  
Excitonic Interactions ◽  
Potential Use

AbstractChlorosomes are the main light-harvesting complexes of green photosynthetic bacteria that are adapted to a phototrophic life at low-light conditions. They contain a large number of bacteriochlorophyll c, d, or e molecules organized in self-assembling aggregates. Tight packing of the pigments results in strong excitonic interactions between the monomers, which leads to a redshift of the absorption spectra and excitation delocalization. Due to the large amount of disorder present in chlorosomes, the extent of delocalization is limited and further decreases in time after excitation. In this work we address the question whether the excitonic interactions between the bacteriochlorophyll c molecules are strong enough to maintain some extent of delocalization even after exciton relaxation. That would manifest itself by collective spontaneous emission, so-called superradiance. We show that despite a very low fluorescence quantum yield and short excited state lifetime, both caused by the aggregation, chlorosomes indeed exhibit superradiance. The emission occurs from states delocalized over at least two molecules. In other words, the dipole strength of the emissive states is larger than for a bacteriochlorophyll c monomer. This represents an important functional mechanism increasing the probability of excitation energy transfer that is vital at low-light conditions. Similar behaviour was observed also in one type of artificial aggregates, and this may be beneficial for their potential use in artificial photosynthesis.

scholarly journals Photosynthetic performance and growth responses of Liriope muscari (Decne.) L.H. Bailey (Asparagaceae) planted within poplar forests having different canopy densities

2019 ◽  
Author(s):  
jiaojiao zhang ◽  
Jian Zhou ◽  
Ling Zhu ◽  
Xu Zhang
Keyword(s):  
Light Response ◽  
Forest Edge ◽  
Photosynthetic Performance ◽  
Photosynthetic Characteristics ◽  
Growth Responses ◽  
Apparent Quantum Yield ◽  
Low Light ◽  
Physiological Basis ◽  
Chl A ◽  
Point Light

Abstract Background: Liriope muscari (Decne.) L.H. Bailey is a valuable horticultural and medicinal plant that grows under a range of light intensities, from high to low, in the understories of shrubs. To understand how this species adapts to these various environments, we selected two groups of lilyturf growing under poplar trees at two different spacings. Each group was divided into three types, open field, forest edge and shaded forest with high, medium and low irradiance levels, respectively, and then we examined their photosynthetic characteristics, physiology and biomasses. Results: Light saturation point, light compensation point and in situ net photosynthetic rate (PN) were highest in lilyturf growing under high. In contrast, lilyturf growing under low light had a higher apparent quantum yield and Chl a and b contents, indicating that they adapted to low light. Although the leaves of lilyturf growing under low light were small, their root tubers were heavier. Conclusions: The novelty of this research is the demonstration of the eco-physiological basis of lilyturf's shade adaptation mechanisms indicated by photosynthetic activity, chlorophyll fuorescence, Chla, Chlb and Car contents and grown in different irradiance. We believe that lilyturf is a shade-tolerant plant suitable for planting in undergrowth, but attention should be paid to the canopy density of the forest when interplanting.The findings presented here advance our understanding of the photosynthetic characteristics of understory plants and may assist in the optimization of irradiances in the furture. Keywords: chlorophyll fluorescence; diurnal course; light acclimation; light response curve; soil characteristics; path analysis.

Changes in the Stoichiometry of Photosystem II Components as an Adaptive Response to High-Light and Low-Light Conditions during Growth

1986 ◽  
Vol 41 (5-6) ◽  
pp. 597-603 ◽  
Author(s):  
Aloysius Wild ◽  
Matthias Höpfner ◽  
Wolfgang Rühle ◽  
Michael Richter
Keyword(s):  
Photosystem Ii ◽  
Functional Organization ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Molar Ratio ◽  
Light Conditions ◽  
Low Light ◽  
Pigment System ◽  
Transport Chain ◽  
The One

The effect of different growth light intensities (60 W·m-2, 6 W·m-2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light conditions was found. For P-680 as well as for Oᴀ and Oв protein the molar ratio between high-light and low-light plants was 1.4 whereas the respective concentrations per chlorophyll showed some variations for P-680 and Oᴀ on the one and Oв protein on the other hand.In addition to the study of photosystem II components, the concentrations of PQ, Cyt f, and P-700 were measured. The light regime during growth had no effect on the amount of P-700 per chlorophyll but there were large differences with respect to PQ and Cyt f. The molar ratio for Cyt f and PQ between high- and low-light leaves was 2.2 and 1.9, respectively.Two models are proposed, showing the functional organization of the pigment system and the electron transport chain in thylakoids of high-light and low-light leaves of mustard plants.

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