scholarly journals Physiological aspects of sun and shade leaves of Lithraea molleoides (Vell.) Engl. (Anacardiaceae)

2007 ◽  
Vol 50 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Jaqueline Dias ◽  
José Antonio Pimenta ◽  
Moacyr Eurípedes Medri ◽  
Maria Regina Torres Boeger ◽  
Claudinei Toledo de Freitas
Keyword(s):  
Stomatal Conductance ◽  
Nutrient Concentration ◽  
Physiological Parameter ◽  
The Sun ◽  
Chlorophyll B ◽  
Sun And Shade Leaves ◽  
Lower Light ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

The aim of this work was to compare the physiological parameters of sun and shade leaves of a specimen of L. molleoides. The higher-positional leaves, classified as sun leaves, presented similar photosynthetic rate, lower chlorophyill contents (a, b and total), same a chlorophyll /b chlrorophyll rate, lower transpiratory rate, same stomatal conductance and intercellular concentration of CO2 as the lower-positional leaves, classified as shade leaves. Nutrient concentration, except for Ca and Mg, was the same for both sun and shade leaves.The physiological parameter responses indicated that although receiving lower light intensity, the shade leaves had the same capacity to grow and develop as the sun leaves.

scholarly journals I. On the causes and ecological significance of stomatal frequency, with special reference to the woodland flora

1928 ◽  
Vol 216 (431-439) ◽  
pp. 1-65 ◽  
Keyword(s):  
Comparative Anatomy ◽  
The Sun ◽  
Ecological Significance ◽  
Apparent Discrepancy ◽  
Stomatal Frequency ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Numerical Variation ◽  
Shade Leaves ◽  
Sun Leaves

Though numerous investigators have recorded observations on the number of stomata present in various species, comparatively little is known respecting the causes of their numerical variation. Studies on the “sun” and “shade” leaves of woodland plants brought to light the striking differences which the numerical frequency of stomata may exhibit in leaves of the same species when growing in different environments and even in different leaves of the same individual. Various hypotheses have been put forward to explain the larger number of stomata in sun-leaves. These will be considered later, but we may note here the apparent discrepancy with the observations of Ziegeler that the leaves of the more xerophytic Carices possess fewer stomata than the leaves of those species characteristic of damper habitats. Spitzer obtained similar results from an examination of the Grasses and Adamson appears to have arrived at a similar conclusion with regard to the various species of Veronica studied by him (“Comparative anatomy of the leaves of certain species of Veronica,” Veronica " ‘Linn. Soc. Jour., Bot.,’ vol. XL, pp. 247-274, 1912).

scholarly journals Does selective logging affect the leaf structure of a late successional species?

Rodriguésia ◽  
2012 ◽  
Vol 63 (2) ◽  
pp. 419-427 ◽  
Author(s):  
Guilherme Rodrigues Rabelo ◽  
Denise Espellet Klein ◽  
Maura Da Cunha
Keyword(s):  
Leaf Area ◽  
Structural Characteristics ◽  
Selective Logging ◽  
Leaf Structure ◽  
The Sun ◽  
Seasonally Dry ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

The anatomical characteristics of both sun and shade leaves of Alseis pickelii were investigated in order to evaluate the consequences of selective logging (in seasonally dry Atlantic Forest) on the leaf structure of this species. Fully expanded sun and shade leaves were collected in two distinct stands of tabuleiro forest; a stand of recently logged forest and an unlogged stand. Only leaves from the unlogged stand revealed significantly different magnitudes of response to light regimes, producing leaves with structural characteristics associated with different levels of irradiance. The sun leaves from this stand had a thicker adaxial surface, mesophyll, palisade and spongy parenchyma, a secondary cell wall of fibers and a lower leaf area compared with the shade leaves. However, in the logged stand, the leaf cuticles of sun and shade leaves showed no significant differences, although the leaf area of the sun leaves was higher than the shade leaves. According to these data, we concluded that the unlogged stand produced typical "sun" and "shade" leaves. In contrast, leaves from the logged stand showed a lower variation of types, where neither typical "sun" nor typical "shade" leaves were produced, suggesting lower leaf plasticity of this late successional tree in this area.

scholarly journals Similar temperature dependence of photosynthetic parameters in sun and shade leaves of three tropical tree species

2020 ◽  
Vol 40 (5) ◽  
pp. 637-651 ◽  
Author(s):  
Georgia G Hernández ◽  
Klaus Winter ◽  
Martijn Slot
Keyword(s):  
Stomatal Conductance ◽  
Tropical Forests ◽  
Vapor Pressure Deficit ◽  
Net Photosynthesis ◽  
Carbon Uptake ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves ◽  
Temperature Responses

Abstract Photosynthetic carbon uptake by tropical forests is of critical importance in regulating the earth’s climate, but rising temperatures threaten this stabilizing influence of tropical forests. Most research on how temperature affects photosynthesis focuses on fully sun-exposed leaves, and little is known about shade leaves, even though shade leaves greatly outnumber sun leaves in lowland tropical forests. We measured temperature responses of light-saturated photosynthesis, stomatal conductance, and the biochemical parameters VCMax (maximum rate of RuBP carboxylation) and JMax (maximum rate of RuBP regeneration, or electron transport) on sun and shade leaves of mature tropical trees of three species in Panama. As expected, biochemical capacities and stomatal conductance were much lower in shade than in sun leaves, leading to lower net photosynthesis rates. However, the key temperature response traits of these parameters—the optimum temperature (TOpt) and the activation energy—did not differ systematically between sun and shade leaves. Consistency in the JMax to VCMax ratio further suggested that shade leaves are not acclimated to lower temperatures. For both sun and shade leaves, stomatal conductance had the lowest temperature optimum (~25 °C), followed by net photosynthesis (~30 °C), JMax (~34 °C) and VCMax (~38 °C). Stomatal conductance of sun leaves decreased more strongly with increasing vapor pressure deficit than that of shade leaves. Consistent with this, modeled stomatal limitation of photosynthesis increased with increasing temperature in sun but not shade leaves. Collectively, these results suggest that modeling photosynthetic carbon uptake in multi-layered canopies does not require independent parameterization of the temperature responses of the biochemical controls over photosynthesis of sun and shade leaves. Nonetheless, to improve the representation of the shade fraction of carbon uptake dynamics in tropical forests, better understanding of stomatal sensitivity of shade leaves to temperature and vapor pressure deficit will be required.

scholarly journals Seasonal Variation of Tannin and Nutrient in Aegiceras corniculatum Leaves in Zhangjiang Mangrove Ecosystem

2015 ◽  
Vol 9 (1) ◽  
pp. 143-148
Author(s):  
Minshen Huang ◽  
Lihua Zhang ◽  
Shudong Wei ◽  
Qi Zeng ◽  
Haichao Zhou ◽  
...  
Keyword(s):  
Condensed Tannins ◽  
Insect Pests ◽  
Mangrove Ecosystem ◽  
Plant Diseases ◽  
The Sun ◽  
Aegiceras Corniculatum ◽  
Significant Difference ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

Seasonal dynamics of total phenolics (TP), extractable condensed tannins (ECT), protein-bound condensed tannins (PBCT), fiber-bound condensed tannins (FBCT), total condensed tannins (TCT) and nitrogen contents in sun and shade leaves of Aegiceras corniculatum were studied in the Zhangjiang Estuary, Fujian Province, China. The contents of TP, ECT and TCT in the sun leaves were significantly higher than those in the shade leaves through the season. The N content in sun leaves was higher than that in shade leaves in the autumn, while it was lower in the summer, and there was no significant difference in the winter and spring. With the respect to the P through the year, P content in the sun leaves was different between seasons, with the highest in winter and the lowest in summer. In addition, the TP:N and ECT:N ratios in sun leaves were significantly higher than those in shade leaves except in autumn. High tannin levels and TP:N and ECT:N ratios in the sun leaves not only can reduce oxidative stress, but also improve the ability of resisting plant diseases and insect pests.

Influence of CO2 and SO2 on Growth and Structure of Photosystem II of the Chinese Tung-Oil Tree Aleurites montana

1996 ◽  
Vol 51 (7-8) ◽  
pp. 441-453 ◽  
Author(s):  
P. He ◽  
A. Radunz ◽  
K. P. Bader ◽  
G. H. Schmid
Keyword(s):  
Photosystem Ii ◽  
Chlorophyll Content ◽  
Soluble Sugars ◽  
Soluble Proteins ◽  
Bisphosphate Carboxylase ◽  
Light Harvesting Complex ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

Three months old plants of the Chinese tung-oil tree Aleurites montana were cultivated for 4 months in air containing an increased amount of 700 ppm CO2. During the exposure to 700 ppm CO2 the plants exhibited a considerably stronger growth (30-40% ) in comparison to the control plants (grown in normal air). In these CO2-plants during the entire analyzing period the amount of soluble proteins, of soluble sugars and the chlorophyll content were lower than in control plants. The protein content, referred to leaf area, increased during this time in both plant types by approx. 50% but with a different time course. The increase is faster in CO2-plants compared to control plants, and ends up with similar values in both plants after 4 months. No difference is seen between sun and shade leaves. The chlorophyll content in both sun and shade leaves is 20% lower in CO2-plants. Whereas the chlorophyll content in sun leaves stays constant during developm ent, it has increased in shade leaves by 20% at the end of the 4 months period. The content of soluble sugars is lower in CO2-plants compared to control plants. The difference is bigger in sun leaves than in shade leaves. The ribulose 1.5-bisphosphate carboxylase/oxygenase content almost doubles within the experimentation period, but seems to be subject to large variations. CO2-plants contain in general less ribulose 1.5-bisphosphate carboxylase/oxygenase than control plants. The content of coupling factor of photophosphorylation is 20% lower in CO2-plants when compared to control plants and remains during development more constant in CO2-plants. The molecular structure of the photosystem II-complex undergoes under the influence of the increased CO2-content a quantitative modification. The light harvesting complex (LHCP) and the extrinsic peptide with the molecular mass of 33 kDa increase in CO2-plants. Gassing with SO2 (0.3 ppm in air) leads to a strong damage of the plants. The damaging influence is already seen after 6 days and leads to a partial leaf-shedding of the tree. In the visually still intact remaining leaves the chlorophyll content referred to unit leaf area decreases by 63%, that of soluble sugars by 65%, the content of soluble proteins and that of Rubisco decrease by 26% and 36% respectively. The light harvesting complex and the chlorophyll- binding peptides (43 and 47 kDa) increase whereas the extrinsic peptides decrease. It looks as if the simultaneous application of SO2 (0.3 ppm) and increased CO2 (700 ppm) releaves the damaging effect of SO2. Plant growth does not exhibit a difference in comparison to control plants. Soluble proteins and chlorophyll increase by 27% and 33% and the ribulose 1.5-bisphosphate carboxylase/oxygenase content as well as that of soluble sugars increases by 18 respectively 14%. The peptide composition of photosystem II shows a quantitative modification. The LHCP increases and the chlorophyll-binding peptides and the peptides with a molecular mass smaller than 24 kDa are reduced. The quantity of extrinsic peptides appears unchanged. Ribulose 1,5-bisphosphate carboxylase/oxygenase and the CF1-complex of Aleurites are immunochemically only partially identical to the corresponding enzymes of Nicotiana tabacum as demonstrated by tandem-cross-immune electrophoresis.

scholarly journals Effect of Light on the Photosynthesis, Pigment Content and Stomatal Density of Sun and Shade Leaves of Vernonia Amygdalina

2018 ◽  
Vol 7 (4.30) ◽  
pp. 209 ◽  
Author(s):  
Aisha Idris ◽  
Alona C. Linatoc ◽  
Aisha M. Aliyu ◽  
Surayya M. Muhammad ◽  
Mohd Fadzelly Bin Abu Bakar
Keyword(s):  
Gas Exchange ◽  
Light Intensity ◽  
Stomatal Density ◽  
Photosynthetic Pigment ◽  
Vernonia Amygdalina ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves ◽  
Effect Of Light

Light affects the growth and development of plants by influencing the physical appearance of one leaf as well as the appearance of the whole plant. Plant photosynthesis, stomata density, and pigment contents are all influenced by light The objective of this research is to determine the effect of light on the photosynthesis, pigment content and stomatal density of Sun and Shade Leaves of Vernonia amygdalina. Gas exchange was measured using Li-6400 and the data obtained was used to create a light response curve where parameters including light saturation point (LSP), light compensation point (LCP) and apparent quantum yield were estimated. Photosynthetic pigment were quantified spectrophotometrically.  Moreover, the stomatal density was counted under light microscope, after making a nail polish impression of the leaf. The results discovered shows that as the light intensity increases, the gas exchange and stomatal density increases while the photosynthetic pigment of the studied plant decreases (P<0.05). In addition, LSP and LCP increases with increasing light intensity. Besides, statistically significant negative correlation (P<0.05) was achieved among stomatal density and transpiration rate thereby leading to a conclusion that sun leaves of Vernonia amygdalina contribute the highest assimilation rate to the plant than shade leaves. Yet, the higher stomatal density of sun leaves provides water saving to the plant.

Sun and shade leaves: clues to how salal (Gaultheriashallon) responds to overstory stand density

1991 ◽  
Vol 21 (3) ◽  
pp. 300-305 ◽  
Author(s):  
N. J. Smith
Keyword(s):  
Leaf Area Index ◽  
Relative Density ◽  
Leaf Area ◽  
Stand Density ◽  
Leaf Biomass ◽  
Area Index ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

Salal (Gaultheriashallon Pursh) leaf biomass, leaf area index, specific leaf area, and leaf morphology were examined in 13 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands from 37 destructively measured 1-m2 quadrats. In response to light and stand overstory density, salal shoots produced either mainly sun leaves or mainly shade leaves. Sun leaves were associated with sunflecks in open-grown or variably stocked stands. Shade leaves were associated with diffuse light under denser stands. Sun-leaf quadrats had mean specific leaf areas less than 90 cm2/g; shade-leaf quadrats had mean specific leaf areas greater than 90 cm2/g. Sun leaves were narrower, with average leaf widths less than 5 cm. Quadrat salal leaf biomass and leaf area index peaked at Curtis' metric relative density 5.9, which corresponded to an availability of 15% of global photosynthetically active radiation. Sun-leaf quadrats occurred below relative density 5; shade-leaf quadrats occurred above relative density 4. A mixture of sun- and shade-leaf quadrats occurred between about relative density 4 and 5, depending on the uniformity of stocking.

A comparative study of leaf thickness among southern Appalachian hardwoods

1981 ◽  
Vol 59 (8) ◽  
pp. 1393-1396 ◽  
Author(s):  
Stanley B. Carpenter ◽  
Naomi D. Smith
Keyword(s):  
Displacement Transducer ◽  
Linear Displacement ◽  
Leaf Thickness ◽  
Quercus Alba ◽  
Southern Appalachian ◽  
Sun And Shade Leaves ◽  
Sun And Shade ◽  
Quercus Stellata ◽  
Shade Leaves ◽  
Sun Leaves

A linear displacement transducer was used to measure the leaf thickness of sun and shade leaves collected from trees growing in the mountain and eastern coalfield region of Kentucky. Leaf thickness measurements are presented for 64 southern Appalachian forest species which occupy all strata of the forest communities. Leaf thickness varied from 117.1 μm in Hydrangea arborescans to 473.9 μm in Ilex opaca. In all species sun leaves were thicker than shade leaves. Species considered tolerant of shade had significantly thicker sun and shade leaves than intolerant species when shrubs were included. When shrubs were excluded the sun and shade leaves of tolerant species were thinner than sun and and shade leaves of intolerant species. For all species including shrubs, sun leaf thickness for the tolerant, medium, and intolerant classes averaged 220.1, 183.5, and 213.3 μm, respectively. Although there appeared to be differences in leaf thickness between species inhabiting xeric and mesic sites, these differences were not statistically significant. Variation in sun leaf thickness within the genus Quercus ranged from 130.6 μm in Quercus alba to 306.5 μm in Quercus stellata. Shrub species generally had the thickest leaf blades.

scholarly journals Die unterschiedliche Synthese der lipophilen Plastidenchinone in Sonnen- und Schattenblättern von Fagus silvatica L. / The Unequal Synthesis of the Lipophilic Plastidquinones in Sun- and Shade Leaves of Fagus silvatica L.

1971 ◽  
Vol 26 (8) ◽  
pp. 832-842 ◽  
Author(s):  
H. K. Lichtenthaler
Keyword(s):  
Chlorophyll A ◽  
Vitamin K ◽  
Leaf Development ◽  
Steady Increase ◽  
Redox Systems ◽  
Sun And Shade Leaves ◽  
Fagus Silvatica ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

The synthesis of plastidquinones was studied from leaf development until autumnal leaf degeneration in sun and shade leaves of Fagus silvatica and compared with chlorophyll and carotinoid synthesis.1. The lipoquinone content of Fagus chloroplasts increases steadily with increasing age of leaf tissue. This lipoquinone accumulation takes place in sun and shade leaves, it is however much more expressed in sun leaves. On a chlorophyll or a leaf square (100 cm2) basis the latter possess a several times (3 to 9 x) higher lipoquinone content than shade leaves.2. The augmentation of the plastidquinone level in both leaf types is mainly due to the synthesis of the reduced benzoquinone forms, plastohydroquinone 45 and the chromanol a-tocopherol. The larger part of the reduced lipoquinones represent excess amounts which are deposited extrathylakoidal in the osmiophilic plastoglobuli of the plastid stroma.3. The oxidized benzoquinones, plastoquinone 45 and α-tocoquinone, as well as the naphthoquinone vitamin K1 (phylloquinone) are present in much lower concentration. Their synthesis parallels that of chlorophylls and carotinoids. They are formed either not in excess (vitamin K1) or in very low excess amounts (α-tocoquinone, plastoquinone) . These oxidized quinone forms are in turn preferably located together with chlorophylls and carotinoids in the photochemically active thylakoids.4. The production of excess plastidquinones (mainly reduced benzoquinones) starts very early during leaf development. The main synthesis phase begins after the end of chlorophyll and thylakoid synthesis and continues in senescent Fagus leaves during the breakdown of chlorophyll and thylakoids until the early yellow stage of sun and shade leaves. In senescent leaves the level of the oxidized benzoquinones, plastoquinone and α-tocoquinone, increases slowly by oxidation of plastohydroquinone and α-tocopherol, respectively.5. The differences between sun and shade leaves in the total and relative amounts of the various lipid classes such as chlorophylls, carotinoids, benzoquinones and the naphthoquinone K1 (100 cm2 leaf square, dry weight or chlorophyll a as reference system) are not yet significant in May, several days after leaf unfolding, but get established thereafter.6. By August the benzoquinone content of sun leaves reaches even that of chlorophyll a, whereas in shade leaves the lipophilic benzoquinones make up only 20 to 30% of the chlorophyll a content. Shade leaves exhibit a benzoquinone level which is little lower than that of carotinoids. Sun leaves, in contrast, contain a benzoquinone content which is by ca. 4 times higher than the carotinoid content. The ratio benzoquinones to vitamin K1 amounts 60 - 70 in shade leaves and 100 - 120; n sun leaves. In addition the two lipophilic redox systems plastoquinone/plastohydroquinone 45 and α-tocoquinone/α-tocopherol are present in sun leaves to a higher extent in the reduced state (84% and 96%) than in shade leaves (60% and 90% respectively).7. From the results it is assumed, that the steady increase of the benzoquinone level with increasing age of plant tissue may be correlated with thylakoid turn-over. The possibility, that the enormous benzoquinone accumulation in sun leaves is mainly caused by higher light intensities in connection with a reduced protein synthesis is discussed.

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