Photosynthetic potential of sun and shade Viola 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.

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Regenerative Succession of Tristaniopsis laurina and Acmena smithii in Riparian Warm Temperate Rain-Forest in Victoria, in Relation to Light and Nutrient Regimes

Australian Journal of Botany ◽

10.1071/bt9900111 ◽

1990 ◽

Vol 38 (2) ◽

pp. 111 ◽

Cited By ~ 10

Author(s):

DR Melick

Keyword(s):

Dark Respiration ◽

Ecological Status ◽

Photon Flux ◽

Light Conditions ◽

Growth Responses ◽

Low Light ◽

Light Regimes ◽

Temperate Rain Forest ◽

Warm Temperate ◽

Regenerative Succession

Tristaniopsis laurina and Acmena smithii often form a dominant association in riparian warm temperate rainforest communities in Victoria. The photosynthetic and morphological responses of seedlings of these species to varied light regimes, and the growth responses of seedlings in different nutrient regimes were examined in the laboratory. Acmena smithii was the most shade tolerant, having the lowest light compensation points, dark respiration rates and greater increases in leaf area ratio under low light conditions. Tristaniopsis laurina consistently demonstrated greater maximum rates of leaf photosynthesis at higher photon flux densities. In response to increased nutrients, T. laurina seedlings showed a marked increase in growth and a decrease in root/shoot ratios, while A. smithii demonstrated relatively small growth increases and showed an increase in root/shoot ratios. These results are discussed in relation to the ecological status of these species within the rainforest communities.

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Interactions entre mitochondries et chloroplastes dans la cellule. II. Action du DBMIB, de l'antimycine A et du FCCP sur la spore de Funaria hygrometrica

Canadian Journal of Botany ◽

10.1139/b77-193 ◽

1977 ◽

Vol 55 (12) ◽

pp. 1650-1659 ◽

Cited By ~ 4

Author(s):

D. Chevallier ◽

R. Douce ◽

F. Nurit

Keyword(s):

Cytochrome Oxidase ◽

Dark Respiration ◽

High Light ◽

Light Conditions ◽

Oxygen Production ◽

Low Light ◽

Funaria Hygrometrica ◽

Light Intensities

The effect of DBMIB, antimycine A, and FCCP on respiration and photosynthesis of intact chlorophyllic moss (Funaria hygrometrica) spore was investigated.Antimycine A (1 μM) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values), and stimulated photosynthesis at low light intensities (below the saturation plateau values).DBMIB (3 μM) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 μM) partially inhibited oxygen production at high light intensities. In this case, the inhibition observed was partially relieved by 1 μM antimycine A or 30 μM of KCN; higher concentration of FCCP totally inhibited the oxygen production.It seems likely, therefore, that in the chlorophyllic moss spore the cytochrome oxidase pathway is not functioning under high light intensities and that this inhibition of respiration is attributable to the low cytoplasmic ADP:ATP ratio.

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Engineering the phototropin photocycle improves photoreceptor performance and plant biomass production

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1902915116 ◽

2019 ◽

Vol 116 (25) ◽

pp. 12550-12557 ◽

Cited By ~ 6

Author(s):

Jaynee E. Hart ◽

Stuart Sullivan ◽

Paweł Hermanowicz ◽

Jan Petersen ◽

L. Aranzazú Diaz-Ramos ◽

...

Keyword(s):

Plant Growth ◽

Biomass Production ◽

Plant Biomass ◽

Targeted Mutagenesis ◽

Light Conditions ◽

In Planta ◽

Low Light ◽

Light Regimes ◽

Plant Biomass Production

The ability to enhance photosynthetic capacity remains a recognized bottleneck to improving plant productivity. Phototropin blue light receptors (phot1 and phot2) optimize photosynthetic efficiency in Arabidopsis thaliana by coordinating multiple light-capturing processes. In this study, we explore the potential of using protein engineering to improve photoreceptor performance and thereby plant growth. We demonstrate that targeted mutagenesis can decrease or increase the photocycle lifetime of Arabidopsis phototropins in vitro and show that these variants can be used to reduce or extend the duration of photoreceptor activation in planta. Our findings show that slowing the phototropin photocycle enhanced several light-capturing responses, while accelerating it reduced phototropin’s sensitivity for chloroplast accumulation movement. Moreover, plants engineered to have a slow-photocycling variant of phot1 or phot2 displayed increased biomass production under low-light conditions as a consequence of their improved sensitivity. Together, these findings demonstrate the feasibility of engineering photoreceptors to manipulate plant growth and offer additional opportunities to enhance photosynthetic competence, particularly under suboptimal light regimes.

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Decoding the gene co-expression network underlying the ability of Gevuina avellana Mol. to live in diverse light conditions

10.1101/240572 ◽

2017 ◽

Author(s):

E Ostria-Gallardo ◽

A Ranjan ◽

Y Ichihashi ◽

LJ Corcuera ◽

NR Sinha

Keyword(s):

Carbon Assimilation ◽

Photosynthetic Performance ◽

Light Energy ◽

Photosynthetic Parameters ◽

List Type ◽

Light Conditions ◽

Photochemical Process ◽

Gevuina Avellana ◽

Wide Range ◽

Photosynthetic Responses

SummaryGevuina avellana Mol. (Proteaceae) is a typical tree from the South American temperate rainforest. Although this species mostly regenerates in shaded understories, it exhibits an exceptional ecological breadth, being able to live under a wide range of light conditions. Here we studied the genetic basis regulating physiological acclimation of the photosynthetic responses of G. avellana under contrasting light conditions.We analyzed carbon assimilation and light energy used for photochemical process in plants acclimated to contrasting light conditions. Also, we used a transcriptional profile of leaf primordia from G. avellana saplings growing under different light environments to identify the gene co-expression network underpinning photosynthetic performance and light-related processes.The photosynthetic parameters revealed optimal performance regardless of light conditions. Strikingly, the mechanism involved in dissipation of excess light energy showed no significant differences between high and low-light acclimated plants. The gene co-expression network defined a community structure consistent with the photochemical responses, including genes involved mainly in assembly and functioning of photosystems, photoprotection, and retrograde signaling.Our ecophysiological genomics approach provides an understanding of the molecular regulatory mechanisms that allows this tree to have an optimal balance between photochemical, photoprotective and antioxidant performance in the diverse light habitats it encounters in nature.

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Photosynthetic Responses of Anthurium × ‘Red’ under Different Light Conditions

Plants ◽

10.3390/plants10050857 ◽

2021 ◽

Vol 10 (5) ◽

pp. 857

Author(s):

Lingyan Chen ◽

Muhammad Waqqas Khan Tarin ◽

Heqiang Huo ◽

Yushan Zheng ◽

Jianjun Chen

Keyword(s):

Photosynthetic Activity ◽

Chlorophyll Concentration ◽

Photon Flux ◽

Total Chlorophyll ◽

Light Conditions ◽

Photosynthetic Photon Flux ◽

Low Light ◽

Plant Photosynthesis ◽

Photosynthetic Responses ◽

Indoor Conditions

Light is an essential energy source for plant photosynthesis, although it can also be a stress-causing element. Therefore, the current research was aimed to compare photosynthetic responses of Anthurium × ‘Red’ leaves at different positions (bottom old leaf, 1; center mature leaf, 2; top expanded leaf, 3) established under three photosynthetic photon flux densities (PPFDs): 550 μmol·m−2·s−1 as high (H), 350 μmol·m−2·s−1 as medium (M), and 255 μmol·m−2·s−1 as low (L). After six months, all the replicates were relocated to interior rooms with a PPFD of 30 μmol·m−2·s−1. There were no significant differences in chlorophyll concentration of the old leaf among treatments, before (Day 0) and after shifting the plants to interior rooms (Day 30). The total chlorophyll concentrations of the mature and top leaves increased significantly. In greenhouse conditions, H and M treatments did not show any significant change for net photosynthetic rate (Pn) at various leaf positions. However, M2 exhibited an improved Pn in the interior conditions. Plants grown under M treatment were greener and had bigger leaves compared to other treatments. Our study reveals that Anthurium × ‘Red’ photosynthesis responses to different light conditions varied distinctly. However, M treatment can keep the plants looking green by accumulating enough energy for indoor conditions, and middle and lower leaves may be triggered to restore photosynthetic activity under low light or indoor conditions.

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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

Brazilian Journal of Biology ◽

10.1590/s1519-69842010000100011 ◽

2010 ◽

Vol 70 (1) ◽

pp. 75-83 ◽

Cited By ~ 14

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.

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Salinity Tolerance of Four Hardy Ferns from the Genus Dryopteris Adans. Grown under Different Light Conditions

Agronomy ◽

10.3390/agronomy11010049 ◽

2020 ◽

Vol 11 (1) ◽

pp. 49

Author(s):

Piotr Salachna ◽

Rafał Piechocki

Keyword(s):

Light Stress ◽

Leaf Damage ◽

Light Conditions ◽

Reduced Height ◽

Individual Taxon ◽

Necrotic Spots ◽

Sun And Shade ◽

Tolerance To Salinity ◽

Leaf Greenness ◽

Ground Part

Hardy ferns form a group of attractive garden perennials with an unknown response to abiotic stresses. The aim of this study was to evaluate the tolerance of three species of ferns of Dryopteris genus (D. affinis, D. atrata and D. filix-mas) and one cultivar (D. filix-mas cv. “Linearis-Polydactylon”) to salinity and light stress. The plants were grown in full sun and shade and watered with 50 and 100 mM dm−3 NaCl solution. All taxa treated with 100 mM NaCl responded with reduced height, leaf greenness index and fresh weight of the above-ground part. In D. affinis and D. atrata salinity caused leaf damage manifested by necrotic spots, which was not observed in the other two taxa. The effect of NaCl depended on light treatments and individual taxon. D. affinis and D. atrata were more tolerant to salinity when growing under shade. Contrary to that, D. filix-mas cv. “Linearis-Polydactylon” seemed to show significantly greater tolerance to this stress under full sun. Salt-treated D. filix-mas cv. “Linearis-Polydactylon” plants accumulated enhanced amounts of K+ in the leaves, which might be associated with the taxon’s tolerance to salinity. Among the investigated genotypes, D. filix-mas cv. “Linearis-Polydactylon” seemed the most and D. affinis and D. atrata the least tolerant to salinity and light stress.

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

Zeitschrift für Naturforschung C ◽

10.1515/znc-1986-5-618 ◽

1986 ◽

Vol 41 (5-6) ◽

pp. 597-603 ◽

Cited By ~ 33

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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