scholarly journals Structural and photosynthetic re-acclimation to low light in C4 maize leaves that developed under high light

2019 ◽  
Vol 124 (3) ◽  
pp. 437-445 ◽  
Author(s):  
Takayuki Yabiku ◽  
Osamu Ueno
Keyword(s):  
High Light ◽  
Energetic Cost ◽  
C3 Plants ◽  
Leaf Mass Per Area ◽  
Low Light ◽  
Chlorophyll Contents ◽  
Kranz Anatomy ◽  
Mature Leaves ◽  
Maize Leaves ◽  
Shade Leaves

Abstract Background and Aims C4 plants have higher photosynthetic capacity than C3 plants, but this advantage comes at an energetic cost that is problematic under low light. In the crop canopy, lower leaves first develop under high light but later experience low light because of mutual shading. To explore the re-acclimation of C4 leaves to low light, we investigated the structural and physiological changes of the leaves of maize plants grown in shaded pots. Methods Plants were first grown under high light, and then some of them were shaded (20 % of sunlight) for 3 weeks. Four types of leaves were examined: new leaves that developed under low light during shading (L), new leaves that developed under high light (H), mature leaves that developed under high light before shading and were then subjected to low light (H–L) and mature leaves that always experienced high light (H–H). Key Results The leaf mass per area, nitrogen and chlorophyll contents per unit leaf area, chlorophyll a/b ratio and activities of C3 and C4 photosynthetic enzymes were lower in H–L than in H–H leaves and in L than in H leaves. Unlike L leaves, H–L leaves maintained the thickness and framework of the Kranz anatomy of H leaves, but chloroplast contents in H–L leaves were reduced. This reduction of chloroplast contents was achieved mainly by reducing the size of chloroplasts. Although grana of mesophyll chloroplasts were more developed in L leaves than in H leaves, there were no differences between H–L and H–H leaves. The light curves of photosynthesis in H–L and L leaves were very similar and showed traits of shade leaves. Conclusions Mature maize leaves that developed under high light re-acclimate to low-light environments by adjusting their biochemical traits and chloroplast contents to resemble shade leaves but maintain the anatomical framework of sun leaves.

scholarly journals 152 Environmental Factors Affect the Growth and Transpiration Rate of Potted Oriental Cymbidium (Cymbidium goeringii)

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 416A-416
Author(s):  
Keun Ho Cho ◽  
Beyoung Hwa Kwack ◽  
Moo Ryong Huh ◽  
Chiwon W. Lee
Keyword(s):  
Wind Velocity ◽  
Transpiration Rate ◽  
Leaf Temperature ◽  
High Light ◽  
High Humidity ◽  
Low Light ◽  
Medium Temperature ◽  
Chlorophyll Contents ◽  
Cymbidium Goeringii ◽  
Carbohydrate Levels

The biomass yield, transpiration rate, and chlorophyll contents in Cymbidium goeringii plants grown under various light, temperature, and humidity conditions were investigated. Two-year-old plants potted in pine-bark medium were grown for 12 weeks during the summer months in polyethylene film-covered mini-greenhouses having four different environmental conditions: a) closed house (CH) with high humidity (95.1% RH), high light (800 μmol·m–2·s–1) and high temperature (37.5 °C), b) ventilated house (VH) with low humidity (41.4% RH), high light (800 μmol·m–2·s–1), and medium temperature (31.5 °C), c) shaded closed house (SCH) with high humidity (91.0% RH), low light (110 μmol·m–2·s–1) and medium temperature (33.3 °C), and d) shaded ventilated house (SVH) with medium humidity (61.5% RH), low light (110 μmol·m–2·s–1) and low temperature (30.5 °C). Plants grown in CH produced leaf chlorosis with 50% shorter leaves and 40% lower relative growth rate (7.9 mg/g fresh weight per day) compared to plants grown in SVH. Cymbidium plants grown in SCH or SVH showed higher leaf and root dry weights as compared to those grown in CH or VH. Leaf chlorophyll-a and -b contents as well as carbohydrate levels were the highest in plants grown in SVH, indicating the benefits of shading and ventilation. The rate of transpiration showed a quadratic response to increasing levels of leaf temperature (r2 = 0.81), wind velocity (r2 = 0.82), and vapor pressure deficit (VPD, r2 = 0.91). Regression analysis revealed that the maximum transpiration rate occurred at 25.4 °C leaf temperature, 2.1 m/s wind velocity, and 2.3 kPa VPD in this experiment.

scholarly journals Epistatic Interactions Influencing Anthocyanin Gene Expression in Capsicum annuum

2007 ◽  
Vol 132 (6) ◽  
pp. 824-829 ◽  
Author(s):  
Gordon J. Lightbourn ◽  
John R. Stommel ◽  
Robert J. Griesbach
Keyword(s):  
Gene Expression ◽  
Light Intensity ◽  
Genetic Basis ◽  
High Light ◽  
Anthocyanin Content ◽  
Anthocyanin Accumulation ◽  
Light Conditions ◽  
Low Light ◽  
Mature Leaves ◽  
Anthocyanin Concentration

Anthocyanin pigmentation in leaves, flowers, and fruit imparts violet to black color and enhances both ornamental and culinary appeal. Shades of violet to black pigmentation in Capsicum annuum L. are attributed to anthocyanin accumulation. Anthocyanin production is markedly influenced by numerous environmental factors, including temperature and light stress. The objective of this study was to determine the genetic basis for differences in C. annuum anthocyanin content in response to varying environments. Growth experiments conducted under controlled environment conditions demonstrated that anthocyanin concentration was significantly higher in mature leaves in comparison with immature leaves under high light (435 μmol·s−1·m−2) conditions. High (30 °C day/25 °C night) versus low (20 °C day/15 °C night) temperature had no significant effect on anthocyanin concentration regardless of leaf maturity stage. Foliar anthocyanin concentration in plants grown under short days (10 h) with low light intensity (215 μmol·s−1·m−2) was significantly less than under long days (16 h) with low light. Under high light intensity, daylength had no effect on anthocyanin content. Three structural genes [chalcone synthase (Chs), dihydroflavonol reductase (Dfr), anthocyanin synthase (Ans)] and three regulatory genes (Myc, MybA , Wd40) were selected for comparison under inductive and noninductive environmental conditions for anthocyanin accumulation. Expression of Chs, Dfr, and Ans was significantly higher in mature leaves in comparison with younger leaves. Consistent with anthocyanin concentration, temperature had no effect on structural gene expression, whereas light positively influenced expression. Under low light conditions, temperature had no effect on Myc, MybA , and Wd40 expression; whereas under high light conditions, temperature only had an effect on MybA expression. The study of anthocyanin leaf pigmentation in C. annuum under inductive and noninductive environments provides a new approach for elucidating the molecular genetic basis of epistatic gene interactions and the resulting phenotypic plasticity.

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.

scholarly journals Effects of alkalinity and salinity at low and high light intensity on hydrogen isotope fractionation of long-chain alkenones produced by <i>Emiliania huxleyi</i>

2017 ◽  
Vol 14 (24) ◽  
pp. 5693-5704 ◽  
Author(s):  
Gabriella M. Weiss ◽  
Eva Y. Pfannerstill ◽  
Stefan Schouten ◽  
Jaap S. Sinninghe Damsté ◽  
Marcel T. J. van der Meer
Keyword(s):  
Light Intensity ◽  
Environmental Conditions ◽  
Hydrogen Isotope ◽  
Isotope Fractionation ◽  
Emiliania Huxleyi ◽  
High Light Intensity ◽  
High Light ◽  
Light Conditions ◽  
Low Light ◽  
Long Chain

Abstract. Over the last decade, hydrogen isotopes of long-chain alkenones have been shown to be a promising proxy for reconstructing paleo sea surface salinity due to a strong hydrogen isotope fractionation response to salinity across different environmental conditions. However, to date, the decoupling of the effects of alkalinity and salinity, parameters that co-vary in the surface ocean, on hydrogen isotope fractionation of alkenones has not been assessed. Furthermore, as the alkenone-producing haptophyte, Emiliania huxleyi, is known to grow in large blooms under high light intensities, the effect of salinity on hydrogen isotope fractionation under these high irradiances is important to constrain before using δDC37 to reconstruct paleosalinity. Batch cultures of the marine haptophyte E. huxleyi strain CCMP 1516 were grown to investigate the hydrogen isotope fractionation response to salinity at high light intensity and independently assess the effects of salinity and alkalinity under low-light conditions. Our results suggest that alkalinity does not significantly influence hydrogen isotope fractionation of alkenones, but salinity does have a strong effect. Additionally, no significant difference was observed between the fractionation responses to salinity recorded in alkenones grown under both high- and low-light conditions. Comparison with previous studies suggests that the fractionation response to salinity in culture is similar under different environmental conditions, strengthening the use of hydrogen isotope fractionation as a paleosalinity proxy.

scholarly journals Physiological responses of two tropical weeds to shade: I. Growth and biomass allocation

1999 ◽  
Vol 34 (6) ◽  
pp. 944-952 ◽  
Author(s):  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Leaf Area ◽  
Weed Management ◽  
Dry Mass ◽  
High Light ◽  
Low Light ◽  
Light Regimes ◽  
Leaf Dry Mass ◽  
Lower Ability ◽  
Total Plant ◽  
Plant Dry Mass

Ipomoea asarifolia (Desr.) Roem. & Schultz (Convolvulaceae) and Stachytarpheta cayennensis (Rich) Vahl. (Verbenaceae), two weeds found in pastures and crop areas in Brazilian Amazonia, 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. For both species leaf dry mass and leaf area per total plant dry mass, and leaf area per leaf dry mass were higher for low-light plants, whereas root mass per total plant dry mass was higher for high-light plants. High-light S. cayennensis allocated significantly more biomass to reproductive tissue than low-light plants, suggesting a probably lower ability of this species to maintain itself under shaded conditions. Relative growth rate (RGR) in I. asarifolia was initially higher for high-light grown plants and after 20 days started decreasing, becoming similar to low-light plants at the last two harvests (at 30 and 40 days). In S. cayennensis, RGR was also higher for high-light plants; however, this trend was not significant at the first and last harvest dates (10 and 40 days). These results are discussed in relation to their ecological and weed management implications.

scholarly journals Effects of microhabitat on leaf traits in Digitalis grandiflora L. (Veronicaceae) growing at forest edge and interior

2014 ◽  
Vol 66 (2) ◽  
pp. 615-627
Author(s):  
J. Kołodziejek
Keyword(s):  
Soil Moisture ◽  
Leaf Area ◽  
Stomatal Density ◽  
Leaf Traits ◽  
Dry Mass ◽  
Forest Edge ◽  
Leaf Mass Per Area ◽  
Forest Interior ◽  
The Mean ◽  
Shade Leaves

The morphological, anatomical and biochemical traits of the leaves of yellow foxglove (Digitalis grandiflora Mill.) from two microhabitats, forest interior (full shade under oak canopy) and forest edge (half shade near shrubs), were studied. The microhabitats differed in the mean levels of available light, but did not differ in soil moisture. The mean level of light in the forest edge microhabitat was significantly higher than in the forest interior. Multivariate ANOVA was used to test the effects of microhabitat. Comparison of the available light with soil moisture revealed that both factors significantly influenced the morphological and anatomical variables of D. grandiflora. Leaf area, mass, leaf mass per area (LMA), surface area per unit dry mass (SLA), density and thickness varied greatly between leaves exposed to different light regimes. Leaves that developed in the shade were larger and thinner and had a greater SLA than those that developed in the half shade. In contrast, at higher light irradiances, at the forest edge, leaves tended to be thicker, with higher LMA and density. Stomatal density was higher in the half-shade leaves than in the full-shade ones. LMA was correlated with leaf area and mass and to a lesser extent with thickness and density in the forest edge microsite. The considerable variations in leaf density and thickness recorded here confirm the very high variation in cell size and amounts of structural tissue within species. The leaf plasticity index (PI) was the highest for the morphological leaf traits as compared to the anatomical and biochemical ones. The nitrogen content was higher in the ?half-shade leaves? than in the ?shade leaves?. Denser leaves corresponded to lower nitrogen (N) contents. The leaves of plants from the forest edge had more potassium (K) than leaves of plants from the forest interior on an area basis but not on a dry mass basis; the reverse was true for phosphorus.

scholarly journals Nighttime Temperatures and Sunlight Intensities Interact to Influence Anthocyanin Biosynthesis and Photooxidative Sunburn in “Fuji” Apple

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaomin Xue ◽  
Ying Duan ◽  
Jinzheng Wang ◽  
Fengwang Ma ◽  
Pengmin Li
Keyword(s):  
Light Intensity ◽  
Low Temperatures ◽  
Anthocyanin Biosynthesis ◽  
High Light ◽  
Anthocyanin Accumulation ◽  
Low Light ◽  
Low Light Intensity ◽  
Apple Peel ◽  
Fuji Apple ◽  
Nighttime Temperatures

Light and low temperatures induce anthocyanin accumulation, but intense sunlight causes photooxidative sunburn. Nonetheless, there have been few studies of anthocyanin synthesis under different sunlight intensities and low nighttime temperatures. Here, low nighttime temperatures followed by low light intensity were associated with greater anthocyanin accumulation and the expression of anthocyanin biosynthesis genes in “Fuji” apple peel. UDP-glucose flavonoid-3-O-glucosyltransferase (UFGT) activity was positively associated with anthocyanin enrichment. Ascorbic acid can be used as an electron donor of APX to scavenge H2O2 in plants, which makes it play an important role in oxidative defense. Exogenous ascorbate altered the anthocyanin accumulation and reduced the occurrence of high light–induced photooxidative sunburn by removing hydrogen peroxide from the peel. Overall, low light intensity was beneficial for the accumulation of anthocyanin and did not cause photooxidative sunburn, whereas natural light had the opposite effect on the apple peel at low nighttime temperatures. This study provides an insight into the mechanisms by which low temperatures induce apple coloration and high light intensity causes photooxidative sunburn.

scholarly journals THE POTENTIAL OF MATURE PANDAN LEAVES AS A SOURCE OF CHLOROPHYLL FOR NATURAL FOOD COLORANTS

2020 ◽  
Vol 31 (2) ◽  
pp. 127-137
Author(s):  
Chatarina Lilis Suryani ◽  
◽  
Tutik Dwi Wahyuningsih ◽  
Supriyadi Supriyadi ◽  
Umar Santoso ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Primary Source ◽  
Dry Weight ◽  
Natural Food ◽  
Food Colorants ◽  
Chlorophyll Contents ◽  
Leaf Maturity ◽  
Mature Leaves ◽  
Natural Colorants ◽  
Four Levels

Plant leaves are the primary source of natural colorants for food, mainly due to their chlorophyll content. However, the plant types and the degree of leaf maturity determine the quality and quantity of the chlorophyll. This study aimed to determine the best maturity level of pandan (Pandanus amaryllifolius Roxb.) leaves that serves as potential source of chlorophyll for natural food colorants. Eighty three pandan plants obtained from six different farming locations in Bantul Regency, Yogyakarta, Indonesia were used as samples. The leaves were grouped into four levels of maturity using descriptive statistics based on their morphology, anatomy, color, and chlorophyll contents. The results showed that the average number of leaves ranged from 20-24 leaves per plant (at 95% confidence interval), and 96.4% of the plant had a maximum of 24 leaves. The leaf maturity was grouped into (1) young, (2) medium, (3) mature, and (4) over mature, corresponding to leaf number 1-6, 7-12, 13-18, and 19-24, respectively. The higher the leaf maturity, the higher the chlorophyll content. However, the over mature leaves were only slightly different from the mature ones. In addition, pandan leaves have specific flavor and contain carotenoid, phenolic, and flavonoid substances. Anatomically, the mesophyll’s size was greatest in the mature leaves, while the size of chloroplast was not significantly different from medium to over mature leaves. Based on the chlorophyll content and mesophyll size, it was concluded that mature pandan leaves were the best source of chlorophyll, containing chlorophyll of 623.08 mg/100 g dry weight (DW).

scholarly journals Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin Strongylocentrotus intermedius

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8001 ◽  
Author(s):  
Jiangnan Sun ◽  
Xiaomei Chi ◽  
Mingfang Yang ◽  
Jingyun Ding ◽  
Dongtao Shi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Foraging Behavior ◽  
Sea Urchins ◽  
High Light Intensity ◽  
High Light ◽  
Strongylocentrotus Intermedius ◽  
Low Light ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Significant Difference

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

Sign in / Sign up

Export Citation Format

Share Document