Pigment Ratios Research Articles

Effects of AMPK on Apoptosis and Energy Metabolism of Gastric Smooth Muscle Cells in Rats with Diabetic Gastroparesis.

This study aimed to investigate the effect of AMPK on apoptosis and energy metabolism of gastric smooth muscle cells in diabetic rats and to explore the role of AMPK in the pathogenesis of diabetic gastroparesis (DGP). After establishment of a diabetic rat model, rats were divided into normal control (NC), 4-week (DM4W), 6-week (DM6W), and 8-week (DM8W) diabetic model groups. The gastric residual pigment ratio, intestinal transit rate, and intestinal propulsion rate in each group were detected to confirm the successful establishment of the DGP model. The spontaneous contraction in isolated gastric smooth muscle strips of the NC and DM8W groups was experimentally observed. The expression of phospho-AMPK, AMPK, phospho-LKB1, LKB1, phospho-TAK1, TAK1, and CaMMKβ in rat gastric smooth muscle tissues was detected by western blot analysis; ADP, AMP, ATP contents, and the energy charge were detected using Elisa; and apoptosis of gastric smooth muscle cells was detected by flow cytometry. The rat gastric smooth muscle cells were cultured in vitro, and treated with an AMPK inhibitor and an agonist. At 24 and 48 h, the effects of AMPK on apoptosis and energy metabolism of gastric smooth muscle cells were observed. Reduced spontaneous contractions, AMPK activation, cell apoptosis, and energy metabolism disorders were observed in gastric smooth muscle tissues of a diabetic rat, and AMPK activation was associated with an increased ratio of ADP/ATP, AMP/ATP, LKB1 activity, and CaMMKβ expression. From in vitro cell culture experiments, we found that AMPK activation of high-glucose conditions promoted cell apoptosis. Inhibition of AMPK had no obvious effect on apoptosis at the early stage with high glucose, but the inhibitory effect was significant at the late stage with high glucose. AMPK can regulate both mitochondrial metabolism and glycolysis pathways under high-glucose conditions. During the early stage with high glucose, AMPK was the main promotion factor of the mitochondrial metabolism pathway, but did not increase the ATP production, AMPK also promoted the glycolysis pathway. During the late stage with high glucose, AMPK was a major inhibitor of the mitochondrial pathway, and still played a role in promoting the glycolytic pathway, which acted as the main regulator. Apoptosis and energy metabolism disorders were present in gastric smooth muscle cells during the occurrence of DGP. Under high-glucose condition, AMPK was activated, which can promote apoptosis, change the energetic metabolism pathway of cells, inhibit mitochondrial energy metabolism, and promote glycolysis.

Diurnal regulation of photosynthetic light absorption, electron transport and carbon fixation in two contrasting oceanic environments

Abstract. Understanding the dynamics of marine phytoplankton productivity requires mechanistic insight into the non-linear coupling of light absorption, photosynthetic electron transport and carbon fixation in response to environmental variability. In the present study, we examined the variability of phytoplankton light absorption characteristics, light-dependent electron transport and 14C-uptake rates over a 48 h period in the coastal subarctic north-east (NE) Pacific. We observed an intricately coordinated response of the different components of the photosynthetic process to diurnal irradiance cycles, which acted to maximize carbon fixation, while simultaneously preventing damage by excess absorbed light energy. In particular, we found diurnal adjustments in pigment ratios, excitation energy transfer to reaction centre II (RCII), the capacity for non-photochemical quenching (NPQ), and the light efficiency (α) and maximum rates (Pmax) of RCII electron transport (ETRRCII) and 14C uptake. Comparison of these results from coastal waters to previous observations in offshore waters of the subarctic NE Pacific provides insight into the effects of iron limitation on the optimization of photosynthesis. Under iron-limited, low-biomass conditions, there was a significant reduction of iron-rich photosynthetic units per chlorophyll a, which was partly offset by higher light absorption and electron transport per photosystem II (PSII). Iron deficiency limited the capacity of phytoplankton to utilize peak midday irradiance for carbon fixation and caused an upregulation of photoprotective mechanisms, including NPQ, and the decoupling of light absorption, electron transport and carbon fixation. Such decoupling resulted in an increased electron requirement (Φe,C) and decreased quantum efficiency (ΦC) of carbon fixation at the iron-limited station. In both coastal and offshore waters, Φe,C and ΦC correlated strongly to NPQ, albeit with a significantly different slope. We discuss the implications of our results for the interpretation of bio-optical data and the parameterization of numerical productivity models, both of which are vital tools in monitoring marine photosynthesis over large temporal and spatial scales.

Temperature Regulation in Colored Infrared-Transparent Polyethylene Textiles

Summary Effectively regulating heat flow between the human body and its environment not only increases thermal comfort but also presents a novel and potentially cost-effective approach to reducing building energy consumption. Infrared property-engineered textiles have been shown to passively regulate radiative heat dissipation for effective cooling and warming of the human body. However, a lack of dyes that can tune the textile color without compromising the infrared properties remains a major impediment to textile commercialization. Here, we report a new strategy utilizing inorganic nanoparticles as a coloring component for scalable brightly colored, infrared-transparent textiles. The as-fabricated composite textiles not only show a high infrared transparency of ∼80% and a passive cooling effect of ∼1.6°C–1.8°C but also exhibit intense visible colors with good stability against washing. This facile coloration approach will promote the commercialization of radiative cooling textiles in temperature-regulating wearable applications for effective energy savings.

A New Method to Purify Hydroxyl Monascus Red Pigment by Retrogradation of Both Pigments and Maize Amylopectin

In monascus red pigment (MRP) products, there exist many components such as polypeptides, amino acids, polysaccharide, and citrinin (toxin). The existence of those components lowers the purity of pigments and brings a great security problem. Hydroxyl MRP has been found in products of China and other countries. This paper presents a new method to isolate hydroxyl MRP by retrograded maize amylopectin (MA) and proposes the mechanism involved based on investigation of Xray‐diffraction, IR and ¹³C solid NMR spectra. The research results have shown that the optimum retrogradation parameters for purification of hydroxyl MRP are as follows: the ratio of pigments and MA is 1:1, autoclaving temperature 120 °C and time, 20 min, aging temperature 4 °C and time needed, 48 h. Most non‐pigment components without hydroxyls in the samples are dissolved in solution when retrograded MA containing MRP has been hydrolyzed by amylase with only MA and MRP left in the precipitatate. Such precipitation can redissolve in aqueous KOH to open hydrogen bond and the MA in solution can be distilled by ethanol in neutral pH, and then the purified pigments in solution can be concentrated and dried. Every 100 g MA can isolate 68.0 g MRP. The results of IR and ¹³C solid NMR have indicated that hydrogen bonds might form between C7 of pigment and C1 of MA, also, C10 of pigment and C3 or C2 of MA. Retrogradation is surely a simple, inexpensive, and valid method to isolate pigments with hydroxyl groups and citrinin.

Analyzing carotenoids of snow algae by Raman microspectroscopy and high-performance liquid chromatography.

We tested the potential of Raman microspectroscopy to determine carotenoid pigments - both primary (lutein, beta-carotene) and secondary (astaxanthin) carotenoids - in the different species and life-cycle stages of snow algae from the order Chlamydomonadales (Chlorophyta). We compared the performance of Raman spectrometry to a reference method of biological pigment analysis, high-performance liquid chromatography (HPLC). The three main carotenoid Raman bands of the astaxanthin-rich red cysts were located at 1520, 1156 and 1006 cm-1. The shifts (orange aplanozygotes and green motile cells with flagella) in the position of the ν1(CC) Raman band of the polyenic chain is consistent with the expected changes in the ratios of the various carotenoid pigments. Flagellated green cells commonly contain lutein as a major carotenoid, together with minor amounts of β‑carotene and varying amounts of antheraxanthin, violaxanthin and neoxanthin. Aplanozygotes contain mixtures of both primary and secondary carotenoids. In most cases, the ν1(CC) band is an overlapping set of bands, which is due to the signal of all carotenoid pigments in the sample, and a deconvolution along with the band position shifts (mainly ν1) could be used to characterize the mixture of carotenoids. However, the ability of Raman spectroscopy to discriminate between structurally slightly differing carotenoid pigments or several carotenoids in an admixture in an unknown biological system remains limited.

Evaluation of the functional state of peach varieties (Prunus persica Mill.) when exposed hydrothermal stress to plants

The article presents data on the change in the ratio of pigments and fluorescence of chlorophyll in peach leaves in the optimal period of vegetation and under hydrothermal stress. When determining the resistance of a peach to unfavorable environmental factors, methods based on laboratory, fixed changes in the physiological and biochemical processes occurring in plants are used. In the period of inadequate water availability, the water deficit in peach leaves increased to an average of 15%, while less stable - an increase in the parameter to 18% was observed. It is shown that the xeromorphic character of the leaf apparatus is associated with a slight change in the anatomical characteristics of the leaf (the thickness of the leaf blade before and after the drought), which determines the permanence of the turgor. In this case, in the leaves of resistant varieties, the loss of turgor is insignificant (LSD (p ≤0.05) = 7.24); the thickness of the leaf fluctuates within 0.20 mm. On the background of stress impact, a clear varietal difference was shown, which allowed us to develop a scale for a comparative assessment of the resistance of peach varieties and clones. During the active growth of the assimilation surface, an increase in the amount of green pigments in the leaves of experimental plants was noted. Perspective varieties of peach contain significantly higher amounts of chlorophylls compared to other varieties (LSD (p ≤0.05) = 0.30). Under unfavorable conditions, in these varieties the ratio of the sum of chlorophylls to carotenoids is higher, which is confirmed by their more developed adaptive potential. Reorganization of the pigmentary apparatus during the period of hydrothermal stress is accompanied by an increase in the coefficient of photosynthetic activity (Kf_n) and a decrease in the fluorescence level (F_T) of chlorophyll. Thus, the water deficit, pigment composition and fluorescence of chlorophyll make it possible to identify the resistance of peach varieties and clones to the action of hydrothermal stressors. Based on the results of the studies, the most resistant varieties and clones of peaches have been identified for the humid subtropics of Russia (Larisa, Early bloy, Medin red, Slavutich, Donetskij zheltij, Vanity and Form 1).

Phytoplankton response in growth, photophysiology and community structure to iron and light in the Polar Frontal Zone and Antarctic waters

Availability of dissolved iron and light are both regulating factors for primary productivity in high (macro)nutrient, low chlorophyll regions of the Southern Ocean. Here, using on-board iron/light incubation experiments conducted in 2015 in the Atlantic sector of the Southern Ocean, we show that irradiance limited significant phytoplankton growth (in chlorophyll-a and particulate organic carbon) north of the Polar Front (46 °S 08 °E), while iron addition resulted in growth stimulation even at low light levels in the Antarctic zone (65 °S 0 °E). The phytoplankton community in the Polar Frontal Zone showed a greater functional diversity than the one in the Antarctic Zone. The community structure changed over the course of the incubations in response to increased iron and light. The observed increase in chlorophyll-a under high light in the Polar Frontal Zone was driven predominantly by an increase in pico-(0.2–2 µm) and large (> 5 µm) nanophytoplankton. Pigment fingerprinting indicated an increase in the contribution of diatoms and Phaeocystis over the course of the incubation. In contrast, in the Antarctic Zone, the increase in chlorophyll-a after iron enrichment was predominantly due to an increase in the contribution of diatoms and large nanophytoplankton. The photochemical efficiency (Fv/Fm) was low at both sites at the beginning of the incubations, but increased upon iron fertilization in both water masses, indicating stress relief. However, the acclimation strategies fundamentally differed between the two communities. The ratio of photoprotective versus light-harvesting pigments increased under high light in the Polar Frontal Zone independent of iron enrichment, whereas this ratio declined upon iron enrichment in the Antarctic Zone even under high light. At the same time, the functional cross section of photosystem II (σPSII) decreased upon iron enrichment in the Antarctic Zone, but not in the Polar Frontal Zone. Our experiments support the need to take biogeographical differences between Southern Ocean water masses into account when interpreting ecosystem dynamics.

Effect of Lachancea thermotolerans on the Formation of Polymeric Pigments during Sequential Fermentation with Schizosaccharosmyces pombe and Saccharomyces cerevisiae.

Anthocyanins in red grape musts may evolve during the winemaking process and wine aging for several different reasons; colour stability and evolution is a complex process that may depend on grape variety, winemaking technology, fermentative yeast selection, co-pigmentation phenomena and polymerization. The condensation of flavanols with anthocyanins may occur either with the flavylium ion or with the hemiacetal formation in order to produce oligomers and polymers. The kinetics of the reaction are enhanced by the presence of metabolic acetaldehyde, promoting the formation of pyranoanthocyanin-type dimers or flavanol-ethyl-anthocyanin structures. The experimental design carried out using white must corrected with the addition of malvidin-3-O-glucoside and flavanols, suggests that non-Saccharomyces yeasts are able to provide increased levels of colour intensity and larger polymeric pigment ratios and polymerization indexes. The selection of non-Saccharomyces genera, in particular Lachancea thermotolerans and Schizosaccharomyces pombe in sequential fermentation, have provided experimental wines with increased fruity esters, as well as producing wines with potential pigment compositions, even though there is an important reduction of total anthocyanins.

Introgression of UfCyt c6, a thylakoid lumen protein from a green seaweed Ulva fasciata Delile enhanced photosynthesis and growth in tobacco

Cytochromes are important components of photosynthetic electron transport chain. Here we report on genetic transformation of Cytochrome c6 (UfCyt c6) gene from Ulva fasciata Delile in tobacco for enhanced photosynthesis and growth. UfCyt c6 cDNA had an open reading frame of 330bp encoding a polypeptide of 109 amino acids with a predicted molecular mass of 11.65kDa and an isoelectric point of 5.21. UfCyt c6 gene along with a tobacco petE transit peptide sequence under control of CaMV35S promoter was transformed in tobacco through Agrobacterium mediated genetic transformation. Transgenic tobacco grew normal and exhibited enhanced growth as compared to wild type (WT) and vector control (VC) tobacco. Transgenic tobacco had higher contents of photosynthetic pigments and better ratios of photosynthetic pigments. The tobacco expressing UfCyt c6 gene exhibited higher photosynthetic rate and improved water use efficiency. Further activity of the water-splitting complex, photosystem II quantum yield, photochemical quenching, electron transfer rate, and photosynthetic yield were found comparatively higher in transgenic tobacco as compared to WT and VC tobacco. Alternatively basal quantum yield of non-photochemical processes in PSII and non-photochemical quenching were estimated lower in tobacco expressing UfCyt c6 gene. As a result of improved photosynthetic performance the transgenic tobacco had higher contents of sugar and starch, and exhibited comparatively better growth. To the best of our knowledge this is the first report on expression of UfCyt c6 gene from U. fasciata for improved photosynthesis and growth in tobacco.

Pigment configuration in the light-harvesting protein of the xanthophyte alga Xanthonema debile.

The soil chromophyte alga Xanthonema (X.) debile contains only non-carbonyl carotenoids and Chl-a. X. debile has an antenna system denoted Xanthophyte light-harvesting complex (XLH) that contains the carotenoids diadinoxanthin, heteroxanthin, and vaucheriaxanthin. The XLH pigment stoichiometry was calculated by chromatographic techniques and the pigment-binding structure studied by resonance Raman spectroscopy. The pigment ratio obtained by HPLC was found to be close to 8:1:2:1 Chl-a:heteroxanthin:diadinoxanthin:vaucheriaxanthin. The resonance Raman spectra suggest the presence of 8-10 Chl-a, all of which are 5-coordinated to the central Mg, with 1-3 Chl-a possessing a macrocycle distorted from the relaxed conformation. The three populations of carotenoids are in the all-trans configuration. Vaucheriaxanthin absorbs around 500-530nm, diadinoxanthin at 494nm and heteroxanthin at 487nm at 4.5K. The effective conjugation length of heteroxanthin and diadinoxanthin has been determined as 9.4 in both cases; the environment polarizability of the heteroxanthin and diadinoxanthin binding pockets is 0.270 and 0.305, respectively.

Comparison of phytotoxic effects of bio-synthesised copper oxide nanoparticle and ionic copper on Elodea canadensis

ABSTRACTThis study aims to investigate the phytotoxic effects of both Punica granatum peel extract directed copper oxide nanoparticles (CuONPs) and copper nitrate on Elodea canadensis. The CuONPs were characterised by UV–visible spectroscopy (UV-Vis), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FT-IR) Spectroscopy. The ratio of photosynthetic pigments, total soluble protein, malondialdehyde (MDA), catalase (CAT), ascorbate peroxidase (APX), and copper accumulation in the E. canadensis was determined to evaluate the phytotoxicity of the CuONPs and copper nitrate on E. canadensis. The significant improvements were observed in the growth rate of E. canadensis, chlorophyll a and b, carotenoid contents, and total soluble protein in the E. canadensis when it was exposed to the CuONPs. Additionally, CAT and APX activities and MDA contents were enhanced by accumulation of the CuONPs into the E. canadensis. These results suggested that oxidative stress was alleviated, owing to the result of an increase in the antioxidants such as CAT and APX, with an increase in the concentration of the CuONPs. Finally, the findings of this study show that copper nitrate has many negative effects on E. canadensis compared bio-synthesised CuONPs.

Properties of Color Polymer Cement Mortar according to Polymer-binder ratio and Dosage of Pigment

Properties of Color Polymer Cement Mortar according to Polymer-binder ratio and Dosage of Pigment

Effects of aged ZnO NPs and soil type on Zn availability, accumulation and toxicity to pea and beet in a greenhouse experiment

Most studies have assessed the toxicity of pristine NPs to plants without considering the likely changes that these NPs will undergo during their residence time in the soil. In this study, we assessed the effects of ZnO NPs (3, 20, and 225 mg Zn kg−1 soil) aged for a year in soil and after a previous crop on the Zn availability in soil, leaf accumulation and toxicity to green pea (Pisum sativum L.) and beet root (Beta vulgaris L). The effects were compared to bulk ZnO and ZnSO4 in two agricultural soils with different pH under greenhouse conditions. The Zn concentration in the plant leaf was 6–12-fold higher in acidic than in calcareous soil that could explain the different effects on plants caused by Zn applications depending on soil type. Thus, in acidic soil, ZnO NPs promoted ROS generation in both plant species with increases from 47% to 130%, increased the MDA content in pea up to 58 ± 8% in plant exposed to ZnSO4 at 225 mg Zn kg−1 soil and altered the ratio of photosynthetic pigments in beet between 12% and 41%, suggesting distressed chloroplast constituents. In calcareous soil, the changes seemed to be related to the supply of Zn in Zn deficient soils, whose principal effect was the 20–65% decrease of ROS levels in treated plants. The available and leaf Zn concentrations did not differ among Zn sources. Likewise, ZnO NPs showed comparable toxic or stimulatory effects to ZnO bulk and Zn salt, with some exceptions where Zn ion showed the highest phytotoxicity and effectiveness as a micronutrient. According to our results, we cannot affirm that NPs pose a higher potential environmental risk than their bulk counterparts after one-year of residence time in soil.

Protecting and stimulating effect on the degradation of eosin lakes. Part 1: Lead white and cobalt blue

An important problem encountered during the preservation of paintings and other artworks is the fading of the original colors due to exposure of the colorants to light. This fact is clearly evidenced in some of Vincent Van Gogh's paintings in which an organic red, eosin or geranium lake, is present.The identification of eosin and the characterization of its degradation products in paintings represents a challenge because of (i) the generally low concentration of the pigment remaining after an aging period of ca 100 years, (ii) the scarcity of the paint micro samples available for analysis and the difficulty of obtaining additional ones and (iii) the complexity of the degradation behavior of eosin when it is mixed with organic or inorganic pigments, binding media or varnish.This study presents an accelerated aging experiment of eosin paint models in order to understand better the discoloration process; more specifically the influence of different metals with which eosin forms complexes and of the presence of admixture pigments such as lead white and cobalt blue on the lightfastness of eosin is evaluated. Paint model samples were prepared using eosin, lead white, and cobalt blue in different mixing ratios and were characterized with several techniques before and after aging. The possible formation of intermediate molecular forms during the aging experiment and the influence of pigment ratios on the discoloration process were monitored at periodic intervals using a combination of UV–Visible and attenuated total Reflectance-Fourier transform infrared (ATR-FTIR) spectroscopies. Raman spectroscopy, scanning electron microscopy coupled to energy-dispersive X-ray analysis (SEM-EDX) and optical microscopy (OM) analyses were performed to gain information about the discoloration processes taking place within the paint models.Eosin precipitated on lead, aluminum and potassium/aluminum salts was used. These three lakes showed similar discoloration rates under light exposure. In contrast, the presence and relative abundance of the admixture pigments lead white and cobalt blue had a significant influence on the (speed of the) eosin discoloration process. The presence of lead white and cobalt blue appears to stimulate the eosin degradation. However, the cobalt blue shows less influence in the discoloration process, showing a protective effect during the first stages of the aging. This may be qualitatively explained in terms of the ability of lead white to scatter light towards eosin molecules and the absorption characteristics of cobalt blue in the green range of the electromagnetic spectrum, shielding eosin from incoming light.The color changes observed in the paint reconstructions are similar to discoloration phenomena visible in some Van Gogh paintings and can offer an explanation of the gradual discoloration process that took place over the years. These insights will be helpful to estimate the original hues color used/intended by the artist.

Circadian and irradiance effects on expression of antenna protein genes and pigment contents in dinoflagellate Prorocentrum donghaiense (Dinophycae)

PCP and acpPC are the two major antennae proteins that bind pigments in peridinin-containing dinoflagellates. The relationship between antennae proteins and cellular pigments at molecular level is still poorly understood. Here we identified and characterized the two antennae protein genes in dinoflagellate Prorocentrum donghaiense under different light conditions. The mature PCP protein was 32 kDa, while acpPC was a polyprotein each of 19 kDa. Both genes showed higher expression under low light than under high light, suggesting their possible role in a low light adaptation mechanism. The two genes showed differential diel expression rhythm, with PCP being more highly expressed in the dark than in the light period and acpPC the other way around. HPLC analysis of cellular pigments indicated a diel change of chlorophyll c2, but invariability of other pigments. A stable peridinin: chlorophyll a pigment ratio was detected under different light intensities and over the diel cycle, although the diadinoxanthin:chlorophyll a ratio increased significantly with light intensity. The results suggest that 1) PCP and acpPC genes are functionally distinct, 2) PCP and acpPC can function under low light as an adaptive mechanism in P. donghaiense, 3). the ratios of diadinoxanthin:chlorophyll a and peridinin: chlorophyll a can potentially be used as an indicator of algal photophysiological status and a pigment signature respectively under different light conditions in P. donghaiense.

Integrating aerial images for in-season nitrogen management in a corn field

Methods of determining in-season corn (Zea mays L.) nitrogen (N) requirements and yield estimates are needed for designing a resource-efficient corn production system that is both profitable and environmentally sustainable. The objectives of this study were to examine: (1) the role of spectral signatures of corn plants obtained by aerial images in examining the yield variability across various N treatments, (2) whether the images could be used to guide in-season N management decisions, and to predict in-season corn yield and corn yield loss, and (3) the influence of spatial resolution of imagery on the accuracy of corn yield prediction models. Twenty-four treatments evaluated were the combinations of eight fertilization times (at-planting (A), pre-planting (P)∗A, P∗A∗mid-season (M), P∗A∗late-season (L), PAML, AM, AL, and AML) and three at-planting N rates (11, 45, and 78 kg N ha−1). Visual and thermal images were collected from manned aircraft and geo-corrected for the analyses. Vegetation indices and ratios were derived from three waveband combinations of visual images, and they were examined in relation to yield. Two linear regression models - model 1 (based solely on imagery) and model 2 (based on imagery and information about elevation and N fertilizer application rate), were tested on their performances (in terms of coefficient of determination (R2) and root mean square error (RMSE)) for in-season corn yield prediction at four spatial resolutions (0.35, 0.5, 1, and 2 m px−1). Among individual wavebands, and vegetation indices and ratio, plant pigment ratio (PPR) at early growth stages were highly correlated to corn yield, particularly in the field that received limited N application. The correlation improved as the corn growth stage progressed, but weakened towards the end of the growing season. There were significant differences in PPR values between the treatments receiving the least and the most N application, and it was the amount of N applied at planting that created the most significant differences. The models for 0.35 to 1 m px−1 spatial resolutions did not show significant improvements in R2 over the lowest ground resolutions (2 m px−1) (differences in R2 ≤ 0.05). The model 2 showed higher R2 (up to 0.64 at tasseling stage) and lower RMSE than model 1. These results indicate that the models developed integrating spectral and spatial information from aerial imagery with the information about elevation and N application rate help improve in-season corn yield estimates under different N management practices.

Assessment of the color modulation and stability of naturally copigmented anthocyanin-grape colorants with different levels of purification

Grape skins or their by-products from wine production are rich sources of anthocyanins and various colorless phenolics, depending on the grape variety. Phenolics have strong antioxidant and anthocyanin stabilizing properties and help to produce functional anthocyanin colorants with improved stability. This study aimed to assess differences in color expression and stability of anthocyanin colorants from red grape varieties naturally copigmented and with different levels of purity and to compare them to synthetic FD&C Red No. 3. Model juice systems were prepared at pH 3.5 with anthocyanins and phenolic copigments extracted from four Vitis vinifera grape varieties (‘Tempranillo’, ‘Syrah’, ‘C. Sauvignon’, and ‘Graciano’) both crude and purified by C18 solid phase extraction. Attention was focused on differential colorimetry and phenolic composition related to the color. Degradation kinetics of total color were also studied during storage of 17 days in darkness at 25 °C. Grape variety significantly influenced pigment yield, proportion of acylation, and proportion of copigments:pigments ratios in crude extracts; purification modulated the copigment:pigment ratios. This proportion was related to perceptible color variability among colorants and to different stabilities. With the same pigment content, grape varieties richer in skin copigments and higher copigment/pigment ratios (‘Syrah’ and ‘Tempranillo’) produced more intensely colored crude extracts whose tonalities ranged from reddish (‘Graciano’) to red-bluish (‘Syrah’), depending on the proportion of acylation. Increasing the purity of the pigments diminished the color variability due to variety, making them less vivid and visually more similar to one another and also to the synthetic colorant. Degradation kinetic studies showed that unpurified grape colorants had higher color stability over time, with the greatest stabilizing effects achieved with varieties richer in skin flavonols (‘Tempranillo’ and ‘Syrah’).

Depth-Dependent Pigment Fluctuations in the Agarophyte Gracilaria corticata at Intertidal Waters

Red macroalgae from the genus Gracilaria (agarophytes) are of ecological and pharmaceutical importance particularly for agar production. In this study, the red, agarophyte alga Gracilaria corticata was investigated for fluctuations of main and accessory pigments and total carotenoids at two depths during its growing season. The alga was sampled from coastal waters in Brice coast, Chabahar, southern Iran, from December to March in shallow (2–3 m) and higher (5–6 m) depths. The accessory pigments (phycoerythrin, phycocyanin and alophycocyanin), chlorophyll a, and total carotenoids were extracted three times using appropriate solvents and estimated through spectroscopy (mg g−1 dry weight). All pigments of G. corticata increased with depth showing significant differences between the two depths (p < 0.05). Phycoerythrin and phycocyanin were utmost at a depth of 5–6 m in December and January. The highest allophycocyanin and chlorophyll a contents were found at a depth of 5–6 m in February, and total carotenoids were of greatest values at depths of 2–3 m and 5–6 m in March and February, respectively (p < 0.05). The pigment ratios (phycobilin/chlorophyll and total carotenoids/chlorophyll a) at the two depths displayed marked monthly variations (p < 0.05). The greatest phycobilin/chlorophyll a (0.4 ± 0.2418) was found in December (5–6 m) and the ratio of carotenoids/chlorophyll a (0.31 ± 0.0058) was highest in March (2–3 m). The remarkable increases in major and accessory pigments with depth could indicate maximum biomass and production of G. corticata, especially in the months of February and March, which is important for field harvesting operations.

挺水植物与浮叶植物光合荧光特性的差异

PDF HTML阅读 XML下载 导出引用 引用提醒 挺水植物与浮叶植物光合荧光特性的差异 DOI: 10.5846/stxb201704120652 作者: 作者单位: 南京大学生命科学学院,南京大学生命科学学院,南京大学生命科学学院,南京大学生命科学学院,南京大学生命科学学院,南京大学生命科学学院,南京大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 江苏省重点研发计划（现代农业项目）（BE2015357）；江苏省林业三新工程项目（LYSX[2015]16）；国家海洋局海洋公益性行业科研专项经费项目（201505023）；国家基础科学人才培养基金项目（J1210026）；中央高校基本科研业务经费项目（020814380026，020814380034） Photosynthetic characteristics differ between emergent and floating-leaved macrophytes Author: Affiliation: Nanjing University,Nanjing University,Nanjing University,Nanjing University,Nanjing University,Nanjing University,Nanjing University Fund Project: Fundamental Research Plan of Jiangsu Province (Modern Agriculture program, BE 2015357), Forestry “San-Xin” project of Jiangsu Province ( LYSX [2015] 16), The State Oceanic Administration of public welfare scientific research funding (201505023), National Undergraduate Innovation Program of China (J1210026), Fundamental Research Funds for the Central Universities (020814380026, 020814380034) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探讨自然生境中不同生活型水生植物光合生理特征的差异，选取4种挺水植物菖蒲（Acorus calamus L.）、再力花（Thalia dealbata Fraser）、梭鱼草（Pontederia cordata L.）、茭草（Zizania latifolia（Griseb.）Stapf），以及4种浮叶植物黄睡莲（Nymphaea mexicana Zucc.）、莼菜（Brasenia schreberi J.F.Gmel.）、金银莲花（Nymphoides indica（L.）O.Kuntze）、菱（Trapa bispinosa Roxb.）为研究对象，比较其叶绿素荧光参数、色素组成和比叶重的差异。研究发现，高光强下挺水植物电子传递速率（ETR）、非光化学淬灭（NPQ）等光合荧光参数、以及低光强下ETR拟合曲线的初始斜率（α）均值显著大于浮叶植物。不同挺水植物间光系统Ⅱ（PSⅡ）最大光化学效率（Fv/Fm）、ETR、NPQ、最大潜在电子传递速率（Ps）、最大电子传递速率（ETRm）及饱和光强（Em）变化幅度较大；不同浮叶植物间上述参数变化幅度较小。挺水植物叶绿素（Chls）、类胡萝卜素（Cars）含量均值也高于浮叶植物。但由于比叶重（SLW）的影响，不同水生植物间单位叶面积和单位叶鲜重色素含量的变化规律略有不同。挺水植物中再力花、梭鱼草光合能力较强，其光合荧光参数和色素比例均符合典型阳生型特征；菖蒲、茭草光合能力略弱，部分指标符合阴生型特征。4种浮叶植物各指标均符合阳生型特征。实验推测，挺水植物和浮叶植物由于叶片所处环境不同，其光合适应机制存在明显分化。挺水植物叶片所处环境异质性较大，因而不同物种之间光合参数适应范围也大；浮叶植物叶片所处环境相对均一，因而光合参数差异也小。浮叶植物也不依赖NPQ进行高光保护。在湿地植被恢复工具种筛选过程中应综合考虑环境异质性和不同物种光适应能力的差异。 Abstract:Emergent and floating-leaved macrophytes, two different life forms of primary producers in shallow lakes and riparian zones, play important roles in nutrient cycling and energy flow of aquatic ecosystems. To investigate the differences in photosynthetic characteristics between the two forms of macrophytes, chlorophyll fluorescence, pigment composition, and special leaf weight (SLW) of four emergent macrophytes (Acorus calamus L., Pontederia cordata L., Thalia dealbata Fraser, Zizania latifolia (Griseb.) Stapf) and four floating-leaved macrophytes (Nymphaea mexicana Zucc., Brasenia schreberi J. F. Gmel., Nymphoides indica (L.) O. Kuntze, Trapa bispinosa Roxb.) growing in natural habitats were compared. In general, emergent macrophytes showed higher electron transport rate (ETR) and non-photochemical quenching (NPQ) under high irradiation, as well as relatively higher initial slope (α) of ETR curve under low light, than did floating-leaved plants. Broader ranges on maximum quantum yield of PSⅡ (Fv/Fm), ETR, NPQ, maximum potential ETR (Ps), maximum ETR (ETRm) and saturating irradiance (Em) were also found among different species of emergent macrophytes. Average chlorophyll (Chls) and carotenoid (Cars) contents were also higher in emergent macrophytes than in floating-leaved ones. However, due to the discrepancy of SLW, the trends of pigment amount among species on a fresh matter basis differed from those per leaf area unit. Among the four emergent macrophytes, T. dealbata and P. cordata exhibited relatively higher photosynthetic ability, and all fluorescence parameters together with pigment ratios (Chl a/b, Chls/Cars) indicated they belonged to the sun type. However, A. calamus and Z. latifolia exhibited relatively lower photosynthetic ability, and part of the parameters were closer to the shade type. All four floating-leaved species exhibited as sun type. This suggests that the heterogeneity of environments contributes to the discrepancy of leaf photosynthetic abilities. Emergent leaves grow in highly diverse environments, so their photosynthetic parameters have broad ranges, whereas the environments for floating leaves are relatively stable, so their parameters are limited to small ranges. It may not be necessary for floating-leaved macrophytes to develop NPQ and internal heat dissipation to prevent high irradiation damage. In conclusion, special attention should be paid to both environmental heterogeneity and discrepancy of adaptation abilities when selecting aquatic macrophytes for wetland restoration. 参考文献 相似文献 引证文献

Biochemical Adaptation of Scots Pine (Pinus sylvestris L.) to Technogenic Pollution

We have investigated changes in the complex of biochemical parameters reflecting the disturbance of the homeostatic state and the activity of the adaptive reactions in Pinus sylvestris L. under the conditions of technogenic pollution. Disorders of the physiological state of trees growing under the effect of the excessive accumulation of pollutant elements result in changes in a number of parameters: a decrease in the ratio of protein and nonprotein nitrogen fractions in the needles by 52%; a decrease in the total phosphorus and its acid-soluble fraction by 40 and 63%, respectively; a decrease in carbon concentration by 31%; and a decrease in the amount of chlorophyll a, chlorophyll b, and carotenoids based on the weight of one needle by 23, 40, and 42%, respectively. The activation of protective reactions of pine is proven by an increase in the amount of ascorbic acid in needles by 48%; in the amount of water-soluble phenolic compounds by 29%; in the ratio of Chl. a/Chl. b by 35%; in the ratio of green pigments to yellow by 40%; and in the level of water- and alcohol-soluble proteins 40 and 30%, respectively. The highest activity of biochemical protection components was recorded in trees growing near the Shelekhovsky industrial center, the emissions of which contain a large amount of fluorides and polycyclic aromatic hydrocarbons (PAHs).