Pigment Ratios Research Articles

Estimation of some non-enzymatic antioxidants in leaves of Betula platyphylla Sukacz. and Larix sibirica Ledeb.

The study of plant stress tolerance in Mongolia is based on the estimation of morphological and physiological parameters without taking into consideration plant enzyme activity and non-enzymatic antioxidant contents. The latter parameters are more sensitive to various environmental stresses, and their accurate estimation would provide a means to monitor plant health and indirectly determine stress response. This paper presents our study of non-enzymatic antioxidants as chlorophylls (Chl a and Chl b), total carotenoids (TC), ascorbic acid, proline and malondialdehyde, a biomarker of oxidative stress in leaves of two plant species grown in urban and natural environments during the vegetation period. The results indicate that there was a significant decrease in pigments ratio (Chl a : Chl b and TC : (Chl а + Chl в)), and an increase in proline and malondialdehyde contents in urban plants.

Пигменты в донных отложениях зал. Анива (Охотское море)

The data of spectrophotometric determination of the content of plant pigments in the bottom sediments of Aniva bay (the Sea of Okhotsk) obtained in autumn 2013 are presented. The content of sedimentary pigments is shown to be quantitatively related to the hydrological characteristics of the water column and the typological indicators of bottom sediments. The content of chlorophyll a with phaeopigments in the sediments of the bay is generally characterized by values of the oligotrophic category. The pigment characteristics of the bottom sediments of the bay are represented by the values of indicators that differ significantly from those of functioning plant organisms due to the strong degradation of the pigment fund. The prevalence of the concentration of phaeopigments over chlorophyll a, an increase in the contribution of additional chlorophylls to their total amount, as well as an increase in total carotenoids compared to chlorophyll a were noted. The ecological interpretation of the data obtained on pigments and pigment ratios gives an idea of the mechanism of interaction between production and destruction processes in water bodies, which gives to the pigment characteristics meaning of integral ecosystem indicators.

Анатомо-морфологические и физиологические особенности талломов цианолишайника Peltigera praetextata (Florke ex Sommerf.) Zopf разных онтогенетических состояний

The goal of this study is to describe the cyanolichen Peltigera praetextata ontogenesis stages and reveal some of their morphological, anatomical, and physiological features. This paper analyzes 300 P. praetextata thalli taken in 2019 from aspen trunks in the aspen-spruce communities of the middle taiga territory in Kivach Nature Reserve (62°15'15.9'N, 33°58'746.1"E) from permanent sample plots. The authors determined the ontogenetic state of each thallus based on morphology and anatomy data using the concept of a discrete approach to the description of ontogenesis (Suetina, 2001). They registered the following thalli parameters: length, width, presence and length of rhizines, presence and width of veins, presence of phyllidia and apothecia, number of notches and lobes, shape, edge curl, and surface tomentum. They studied the anatomical parameters (thallus total thickness, tomentum thickness, cortical layer, algal layer and medulla thickness, algae cell size) using sections of thalli samples in all ontogenetic states from the apical, medial, and basal parts in triplicate. They measured the content of photosynthetic pigments spectrophotometrically with preparation of alcoholic extracts. To assess the parameters of the water regime of thalli having different ontogenetic states, the authors calculated a specific thallus mass (STM) and water holding capacity (WHC). They made a statistical data measurement using one-way ANOVA and regression analysis. They also calculated the coefficient of variation (CV) to assess the variability of the features under study. The study identified four periods and 12 ontogenetic states of P. praetextata: latent (sp), pre-generative (pr, prt, j, iml, im2, im3, vl, v2), generative (g), and post-generative (ss, s). The values of the morphological and anatomical parameters of the thalli increase during their development. The early ontogenesis stages demonstrate the highest variability of the parameters. The highest variability of the thallus structures under study within the ontogenetic states is registered for the rhizine length, vein width, and medulla thickness, while the highest constancy is typical of the share of the algal layer in the thallus that varies within a very limited range (22-32%) and reaches the minimum values in the post-generative period. The mycobiont increases in volume through a medulla growth. The physiological characteristics of the P. praetextata thalli differ in various ontogenetic states, while the generative thalli characterized by a normal ratio of photosynthetic pigments, maximum water saturation, and maximum water holding capacity have the maximum values. Thus, at early development stages, the thalli demonstrate a lower ability to retain moisture and may represent a critical stage in a lichen life cycle. On the one hand, the revealed wide variability of the morphological and anatomical parameters of young thalli testifies to their high adaptability, but the physiological parameters of water saturation indicate the vulnerability of these stages. These parameters confirm the validity of the ontogenetic stages identified. The paper contains 5 Figures, 5 Tables and 55 References. The Authors declare no conflict of interest.

The effect of negative air temperatures and humidity on the photosynthetic apparatus functioning in some species of Oleaceae family

The characteristics of the photosynthetic apparatus functioning in the leaves of some evergreen species of Oleaceae family depending on the cold periods` weather conditions on the southern coast of Crimea are presented in this work. It has been revealed that changes in PSII are species-specific. Low air humidity in combination with negative air temperature promotes a significant decrease in frost resistance in the studied Olea and Osmantus genotypes. However, in Olea europea genotypes, changes in the PSII parameters under the simulation of winter desiccation approximated sublethal limits. The photosynthetic apparatus in L. lucidum species was more sensitive to a decrease in air temperature under conditions of relatively high air humidity. The development of the stress state in this species was accompanied by an increase in energy losses in the process of energy transfer from light-harvesting complexes. With the onset of frosty weather, a significant decrease in the chlorophyll a/b ratio was noted in all the studied genotypes. After the stress pressure, Olea europea cultivars and Osmantus spp. showed an increase in chlorophyll amount, in contrast to L. lucidum, in which the ratio of photosynthetic pigments remained low.

Purification and use of carotenoid standards to quantify cis-trans geometrical carotenoid isomers in plant tissues.

Reverse-phase high-performance liquid chromatography (HPLC) is a preferred method used to identify and quantify carotenoids. Here, we describe a straightforward, reliable, and cost-effective protocol to purify and develop individual carotenoid standards for absolute quantification of carotenoids, including selected cis-trans (geometric) isomers. Analytical techniques to extract, purify and collect individual carotenoids using an HPLC system equipped with a Diode Array Detector (DAD) and fraction collector are described. Carotenoids were separated and identified by their characteristic ultraviolet-visible (UV-Vis) absorption spectra and individually isolated based on their retention times using a C30 column. This chapter outlines how to prepare standard calibration curves using known quantities of purified and/or commercially available carotenoids. A series of molar extinction and slope coefficients for phytoene, phytofluene, ζ-carotene, neurosporene, pro-lycopene, all trans-lycopene, lutein, β-carotene, zeaxanthin, antheraxanthin, violaxanthin, neoxanthin, capsanthin, capsorubin and β-cryptoxanthin are defined to enable absolute quantification of their abundance in plant, animal, and bacterial tissues. Different approaches for reporting carotenoid abundance by absolute concentration, relative composition, and/or using ratios of different pigments are provided as a convenient resource for carotenoid researchers.

Изменение фотосинтетической активности Sorbus gorodkovii Pojark. в зоне воздействия железных дорог

The photosynthetic pigments content in the leaves and the state of Sorbus gorodkovii and on the railway stations areas in the cities of the Murmansk region were studied. It was revealed that the least weakened specimens are found in the city of Polyarnye Zori. The largest share of strongly weakened plants was noted in Apatity and Olenegorsk. Dead wood was found in Murmansk, Olenegorsk and Kandalaksha. The content of photosynthetic pigments in the assimilating organs of Sorbus gorodkovii in all studied habitats, except for Apatity and Olenegorsk, is comparable to the background. A change in the ratio of pigments in the direction of an increase in chlorophyll a and a decrease in the proportion of chlorophyll b and carotenoids was found, which was not associated with the impact of railway transport.

Characterisation and Bioactivity Analysis of Peridinin-Chlorophyll a-Protein (PCP) Isolated from Symbiodinium tridacnidorum CS-73

Peridinin-Chlorophyll a-Proteins (PCP) are the major light harvesting proteins in photosynthetic dinoflagellates. PCP shows great variation in protein length, pigment ratio, sequence, and spectroscopic properties. PCP conjugates (PerCP) are widely used as fluorescent probes for cellular and tissue analysis in the biomedical field. PCP consists of a peridinin carotenoid; thereby, it can potentially be used as a bioactive compound in pharmaceutical applications. However, the biological activities of PCP are yet to be explored. In this study, we extracted, purified, and partially characterised the PCP from Symbiodinium tridacnidorum (CS-73) and explored its antioxidant, anti-cancer and anti-inflammation bioactivities. The PCP was purified using an ÄKTA™ PURE system and predicted to be of 17.3 kDa molecular weight (confirmed as a single band on SDS-PAGE) with an isoelectric point (pI) 5.6. LC-MS/MS and bioinformatic analysis of purified PCP digested with trypsin indicated it was 164 amino acids long with >90% sequence similarity to PCP of SymA3.s6014_g3 (belonging to clade A of Symbiodinium sp.) confirmed with 59 peptide combinations matched across its protein sequence. The spectroscopic properties of purified PCP showed a slight shift in absorption and emission spectra to previously documented analysis in Symbiodinium species possibly due to variation in amino acid sequences that interact with chl a and peridinin. Purified PCP consisted of a 19-amino-acid-long signal peptide at its N terminal and nine helixes in its secondary structure, with several protein binding sites and no DNA/RNA binding site. Furthermore, purified PCP exhibited antioxidant and in vitro anti-inflammation bioactivities, and anti-cancer activities against human metastatic breast adenocarcinoma (MDA-MB-231) and human colorectal (HTC-15) cancer cell lines. Together, all these findings present PCP as a promising candidate for continued investigations for pharmaceutical applications to cure chronic diseases, apart from its existing application as a fluorescent-probe.

Variability of bio-optical properties in nearshore waters of the estuary and Gulf of St. Lawrence: Absorption and backscattering coefficients

The inherent optical properties and the optically significant constituents in nearshore zones of the Estuary and Gulf of St. Lawrence (EGSL), eastern Canada, were systematically investigated. Dry-mass concentrations of dissolved organic carbon (DOC), phytoplankton pigments, and suspended particulate matter (SPM) were determined together with the absorption coefficients of chromophoric dissolved organic matter, acdom; non-algal particles, anap; phytoplankton, aphy; and particulate backscattering coefficient, bbp. The sampling design allowed analysis at different spatial scales and considered some intra-regional differences in distinctive zones (subregions) of the EGSL's north shore (separated by ∼ 102 km), as well as within subregions (samples separated by ∼ 100–101 km). Temporal analysis focused on seasonal variability (sampling time separated by ∼ 101–102 days). Optical indices, such as the spectral slopes of acdom and anap, pigment ratios, mass-specific absorption and backscattering coefficients, and particulate matter fractioning (inorganic and organic) allowed a detailed characterization of the dissolved organic matter pool and provided useful information about particulate matter assemblages. The acdom was highly correlated with DOC and was found to have a conservative mixing behavior as the dominant process controlling its distribution, although differences among and within subregions were noted and related to differences in local river endmembers and seasonality. The acdom also dominated the absorption budget, even in long wavelengths of the visible range (e.g., 550 nm). Despite the highly light-absorptive characteristic of the waters, phytoplankton biomass was not negligeable, as shown by the chlorophyll-a (Chla) concentrations means that were almost always greater than 1 mg m−3. Analysis of the spectral shape of aphy and pigment ratios revealed a seasonal modulation in the composition of phytoplankton assemblages and photoacclimation. The optical properties of particulate matter showed a very dispersed relationship when compared to dry-mass concentration proxies in the study area, but the extremely low SPM-specific bbp values encountered were explained by the organic-rich characteristic of the nearshore zones of the EGSL. Short-term variability (atmospheric events) and the hydrodynamical regime also resulted in substantial variability in the optical properties of these areas. Overall, we provide a general parametrization for the relationships among the investigated inherent optical properties and dry-mass concentrations, which, in turn, will provide a baseline for tuning and developing regional remote sensing algorithms for the retrieval of biogeochemically relevant constituents of the water.

Effects of spectral light quality on the growth, productivity, and elemental ratios in differently pigmented marine phytoplankton species

The recent advancement in LED technology led many incubator manufacturers and research labs to switch to these more efficient, yet spectrally restricted, light sources. Potential effects of commercially available broad range “white” light systems on phytoplankton growth, productivity, light absorption spectra, and cellular composition have not yet been characterized but could affect our interpretation of lab-based projections on responses to environmental changes. In this study, we investigated such effects using cultures of Prochlorococcus marinus, Synechococcus sp., and Thalassiosira weissflogii grown under three different commercially available LED lights as well as one fluorescent growth light. Photosynthetically active radiation was equal for each species, while photosynthetically usable radiation differed among the combinations of species and treatments. Growth rate was unaffected across species, yet all species displayed changes in cellular carbon, nitrogen, and chlorophyll a quotas as a direct response to the different light spectra. 14C-based primary productivity was also affected in P. marinus and T. weissflogii. Analysis of pigment ratios and photophysiological data indicated changes in the photoacclimation state between different light environments. The results of this study show that these species undergo changes in underlying cellular metabolism which in turn affect cellular composition while keeping specific growth constant. The data presented here illustrate ecophysiological responses of differently pigmented species when grown under different artificial growth light spectra. These cellular acclimation responses should be considered when designing laboratory-based incubation experiments, especially when comparing responses to specific changes in environmental conditions, or when implementing physiological parameters, derived from laboratory experiments, into numerical models.

Ionic liquid-based multi-stage sugaring-out extraction of lactic acid from simulated broth and actual lignocellulosic fermentation broth

In this study, ionic liquid-based sugaring-out extraction was developed to separate lactic acid from the synthetic solution and actual lignocellulosic fermentation broth. Except for [EOHmim]BF4, the ILs with BF4− and OTF− anion can form aqueous two-phase system (ATPS) with the aid of saccharides. With the same kind of saccharides, the ATPS formation ability of ILs could be promoted by increasing the side-chain length of ILs in the order of [Hmim]BF4 ≈ [Bmim]BF4 ˃ [Emim]BF4 due to the decrease in ILs’ kosmotropicity. On the other hand, for the same type of ILs, an ATPS was formed more easily with glucose than with xylose. When IL concentration varied from 35% (w/w) to 40% (w/w) at a low glucose concentration of 15% (w/w), an interesting phase reversal was observed. When lactic acid was undissociated at pH 2.0, 51.8% LA and 92.3% [Bmim]BF4 were partitioned to the top phase, and 97.0% glucose to the bottom phase using an ATPS consisting of 25% (w/w) glucose and 45% (w/w) IL. The total recovery of LA would increase to 89.0% in three-stage sugaring-out extraction from synthetic solution. In three-stage sugaring-out extraction from the filtered and unfiltered fermentation broth obtained via simultaneous saccharification and co-fermentation (SSCF) of acid-pretreated corn stover by the microbial consortium, the total recovery of LA was 89.5% and 89.8%, respectively. Furthermore, the total removal ratio of cells and pigments from the unfiltered broth was 68.4% and 65.4%, respectively. The results support IL-based sugaring-out extraction as a potential method for the recovery of lactic acid from actual fermentation broth.Graphical

Aerial high-throughput phenotyping of peanut leaf area index and lateral growth

Leaf area index (LAI) is the ratio of the total one-sided leaf area to the ground area, whereas lateral growth (LG) is the measure of canopy expansion. They are indicators for light capture, plant growth, and yield. Although LAI and LG can be directly measured, this is time consuming. Healthy leaves absorb in the blue and red, and reflect in the green regions of the electromagnetic spectrum. Aerial high-throughput phenotyping (HTP) may enable rapid acquisition of LAI and LG from leaf reflectance in these regions. In this paper, we report novel models to estimate peanut (Arachis hypogaea L.) LAI and LG from vegetation indices (VIs) derived relatively fast and inexpensively from the red, green, and blue (RGB) leaf reflectance collected with an unmanned aerial vehicle (UAV). In addition, we evaluate the models’ suitability to identify phenotypic variation for LAI and LG and predict pod yield from early season estimated LAI and LG. The study included 18 peanut genotypes for model training in 2017, and 8 genotypes for model validation in 2019. The VIs included the blue green index (BGI), red-green ratio (RGR), normalized plant pigment ratio (NPPR), normalized green red difference index (NGRDI), normalized chlorophyll pigment index (NCPI), and plant pigment ratio (PPR). The models used multiple linear and artificial neural network (ANN) regression, and their predictive accuracy ranged from 84 to 97%, depending on the VIs combinations used in the models. The results concluded that the new models were time- and cost-effective for estimation of LAI and LG, and accessible for use in phenotypic selection of peanuts with desirable LAI, LG and pod yield.

Quantitative characterization of the spreading and adhesion of styrene-butadiene latex binder in the dried pigment coating layer

In low-latex-content pigmented coatings, the spreading of latex particles and their adhesion to pigment is a crucial determinant of the structure and properties of the coating layer. In spite of its importance, analytical techniques to evaluate the latex spreading and adhesion in pigment coating layer has not been established. This study presents a new analytical technique for the quantitative analysis of the spreading and adhesion of latex binder in the coating structure, based on cross-sectional image analysis. This analytical technique enabled to assess the microscopic details of binding ability of latex binders, including the length distribution of pigment–binder interface. Novel parameters and methods were developed and used to investigate the coating layers prepared using different glass transition temperature (Tg) latexes and dried or dry-sintered under various conditions. The spreading and adhesion of binders within the coating layer was numerically determined, which enabled objective and accurate analysis. The results showed that the spreading and adhesion of binders increased when a low-Tg latex was used or when the processing temperature was increased. The adhesion ratio and length distribution of pigment–binder interfaces plotted against the surface-area index showed a transition in the low binder spreading domain.

Наследственная обусловленность пигментного состава хвои представителей рода лиственница

The content and ratio of plastid pigments in the conifers of three species of the larch genus (Larix Mill.) were studied: Siberian larch (L. sibirica Ledeb.), Gmelin’s larch (L. Gmelinii (Rupr.) Rupr.), Sukachev’s larch (L. Sukaczewii Dylis). Their seed progeny is concentrated on a pilot site in the Sergachsky forestry of the Nizhny Novgorod region with geographical coordinates 55°32 ‘14,2” N 45°28’01,0” E and an absolute height of 160 m. The site is assigned to the zone of coniferous-broad-leaved forests (the third forest-growing zone) and is included in the area of coniferous-broad-leaved (mixed) forests of the European part of the Russian Federation. The content of chlorophyll a, chlorophyll b and carotenoids in the needles was determined by spectrophotometric method at wavelengths: 665 nm, 649 nm, 452,5 nm. Samples for research were prepared in accordance with the principle of a single logical difference and randomized sample formation. Phenotypic differences in the pigment composition of needles between representatives of these species were revealed. The pigment composition of Siberian larch is dominated by chlorophyll a (3,76 ± 0,12 mg/g), significantly less chlorophyll b (1,87 ± 0,07 mg/g) and even less carotenoids (0,59 ± 0,02 mg/g). The same is observed in the pigment composition of other larch species. The hereditary conditionality of the species specificity of Siberian larch, Gmelin’s larch and Sukachev’s larch was established for all the tested characteristics. The greatest influence (29,84 ± 1,61 %) on the formation of the total phenotypic dispersion was observed in the ratio of the content of chlorophyll-a to the content of carotenoids, the least (5,89 ± 2,16 %) — in the content of dry matter in the needles. Relatively high values were obtained for the proportion of carotenoids (26,74 ± 1,68 %) and the ratio of their content to the total of chlorophylls (26,39 ± 1,69 %). The studied species showed an unequal level of similarity or significant differences in the individual characteristics of the pigment composition of needles.

Contents of photosynthetic pigments and ratios of chlorophyll a/b and chlorophylls to carotenoids (a+b)/(x+c) in C<sub>4</sub> plants as compared to C<sub>3</sub> plants

The content of chlorophylls (Chl) (a+b), total carotenoids (x+c), and the pigment ratios of Chl a/b and Chls to carotenoids (a+b)/(x+c) of green leaves of five C4 plants were determined and compared to those of C3 plants. The C4 plants were: Pacific and Chinese silvergrass (Miscanthus floridulus and Miscanthus sinensis), sugar cane (Saccharum officinarum) as well as feed and sugar maize (Zea mays). The three C3 plants were beech, ginkgo, and oak. C4 plants possess higher values for the ratio Chl a/b (3.4-4.5) as compared to the C3 plants (2.6-3.3). Sugar maize had the highest values for Chl a/b (4.04-4.70) and exceptionally high contents of total carotenoids and consequently lower values for the ratio of (a+b)/(x+c) (mean: 3.75 ± 0.6). During autumnal senescence also C4 plants showed a faster decline of Chl b as compared to Chl a yielding high values for Chl a/b of 6 to 8. Chlorophylls declined faster than carotenoids yielding low (a+b)/(x+c) values below 1.0.

Light supply and mineral nutrition conditions as optimization factors for outdoor mass culture of carotenogenic microalga Dunaliella salina

The productivity characteristics of green halophilic algae Dunaliella salina during its pilot cultivation were compared between two nutrient media and under different illumination. Cultivation was carried out in ponds located in the greenhouse during summer season. Two main factors that determine rates of growth and pigments synthesis, as well as the pigments ratio in D. salina grown outdoors in summer, are light and temperature conditions. The mean productivity of D. salina culture grown in two nutrient media, differing in nutrients concentration, was the same, and the mean carotenoid accumulation rate was 30% higher when using Ben-Amotz medium (52 mg·m−2·day−1) than Johnson medium. D. salina cell illumination was decreased by pond shading or by doubling their depth. Both these methods allowed reducing the level of the stress impact on algal culture under extreme light and temperature conditions. Shading of the ponds resulted in an increase in biomass and carotenoid productivity by 30% and 50%. However, a two-fold increase in ponds depth proved to be a more effective technological method, which allowed for an increase in D. salina areal productivity both in biomass and carotenoids by a factor of 3.5–3.8. In conclusion, less concentrated medium and increasing culture depth may be recommended as the optimization factors for D. salina outdoor cultivation.

PROTECTION WITH A BIOACTIVE COMPOSITION BASED ON PLUMBAGIN (CERATOSTIGMA PLUMBAGINOIDES BUNGE) AND NA-ASCORBATE PIGMENTS AND PSII IN OXIDATIVE STRESS

The protective properties of Na-ascorbate and a bioactive composition (BAC) obtained on the basis of plumbagin from roots (Ceratostigma plumbaginoides Bunge) under the toxic effect of Zn2+ and Ni2+ on wheat seedlings (Triticum aestivum L.) were studied. The change in the characteristics of millisecond delayed fluorescence (msec DF Chl a) reflecting the state of PS II shows a decrease in the blocking of the activity of the electron transport chain (ETC) on the acceptor side under the action of Zn2+ and Ni2+ and on the donor side under the action of Ni2+. The resistance of Chl b 650 decreases and the resistance of carotenoids to this stress increases. The action of Na-asс and BAC changes the ratio of pigments. Na-asc restores the activity of the donor side and increases the work of the acceptor side of the ETC upon sequential action with Zn2+. The activity of the acceptor side of the ETC is restored with the simultaneous action of Na-asc with Ni2+. The effect of the BAC is manifested in the restoration of the activity of the donor side of the ETC PS II with sequential action with metals. The corrective effect of Na-asc and LHC is determined by their ability to neutralize reactive oxygen species formed under stress and to support the redox reactions of photosystems.

Monitoring fitness and productivity in cyanobacteria batch cultures

Cyanobacteria are key photosynthetic organisms in many aquatic ecosystems and hold great potential for sustainable green biotechnology. Growth of cyanobacteria in batch cultures is expected to be part of future biotechnological practices. However, the issue of correlating the dynamics of metabolic and photosynthetic parameters with the culture fitness during batch cultivation is still outstanding. In this paper we take advantage of a photobioreactor system to continuously track growth parameters of Synechocystis sp. PCC 6803, and to couple online culture monitoring with offline measurements of photosynthetic efficiency and biochemical and elemental cell composition under several light intensity and CO2 regimes. Light intensity determines the flux of energy into the photosynthetic system while CO2 concentrations determines the ability to capture this energy in chemical form. From this perspective, four distinct source-sink regimes were established and compared, which allowed us to reveal specific strategies to acclimate to both carbon and light limitation. As part of the measurements, room temperature excitation-emission spectra and elemental composition of Synechocystis cells were, for the first time, compared throughout the exponential and linear growth phases. In total, 39 parameters (out of 170 measured) were identified as highly correlating (R2 > 0.9) with growth rate or productivity under at least one tested cultivation condition, including concentrations and ratios of pigments or particular elements. For online fitness and productivity monitoring in cyanobacteria batch cultures, parameters such as photosynthesis and respiration rates and ratios, energy-dependent non-photochemical quenching (qE) or Zn and Mo concentration in the cultivation medium can be of interest.

Determination of the age of dry red wine by multivariate techniques using color parameters and pigments

Vintage is a decisive factor for market price of commercial bottled dry red wines. Aim of this study was to use color parameters and pigments for the prediction of the age of dry red wine by means of partial least squares (PLS) and multiple linear regression (MLR). Both models allow the prediction of the age accurately, with high coefficients of determination (R 2 ), and low enough root mean square error of cross-validation (RMSECV). Although less variables were required to obtain a successful MLR model, its prediction results were as accurate as the model obtained by PLS. The ratio of the first polymeric pigments (TFPP) and malvidin-3-glycoside was demonstrated to be a promising and practical chemical parameter for the rapid and simple age assessment of the dry red wines. • Significant pigmented polymers for wine age is analyzed by HPLC-DAD. • Color parameters and pigments highly correlated with dry red wine age are obtained. • PLS and MLR models are established to predict the vintage of dry red wine. • The predictive ability of dry red wine vintage of best PLS and MLR models is compared.

A pigment ratio index based on remotely sensed reflectance provides the potential for universal gross primary production estimation

Gross primary production (GPP) estimation usually involves a priori assumptions about biome-specific rules or climate controls, which hampers an objective analysis of driving mechanisms. Observation-based methods that are biome-invariant and globally uniform are thus highly desirable. To facilitate this, a reflectance index representing the ratio of chlorophyll to total pigments (R chl) was proposed to consider the variation of energy conversion efficiency driven by different pigment contents in the canopy. Experiments based on simulated reflectance spectra showed that R chl could explain over 83% of chlorophyll ratio dynamics. A model was then developed which approximates GPP as the product of R chl, the normalized difference vegetation index, the near-infrared reflectance, and the photosynthetically active radiation. The model is simple, fast, with definite physical meaning and independent of climatic parameters such as temperature and humidity. Validated with over one hundred thousand field measurements, the model exhibited comparable accuracy to biome- and climate-based GPP models (r = 0.74 for both types of models), demonstrating satisfactory performance. It also achieved significantly better results compared with a regression model excluding R chl, which emphasizes the important role of R chl. By avoiding circular analyses in mechanism studies on GPP variations, this model may extend our previous understanding of global terrestrial carbon uptake.

Effects of calcium-containing natural fertilizer on Camellia sinensis (L.) Kuntze

The effects of application of calcium-containing natural fertilizer on the functional state of the tea plant were studied. Application of calcium resulted weakening of the negative effects of high temperatures and water deficiency due to an increase in its heat resistance (on average by 30 - 40%), an increase in catalase activity (on average 5 - 10 %), as well as adaptive rearrangement of pigment ratio to increasing the content of carotenoids, chlorophylls and the their functional activity. In general, the more efficient functioning of the signaling intracellular network due to the calcium application provided better adaptability of plants to extreme conditions and more efficient recovery after subsequent rehydration, which in a whole contributed to an increase in shoot growth activity (on average 20%) and an increase in yield by an average of 27 - 33%.