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Chlorophyll is the primary pigment responsible for capturing light energy during photosynthesis, while carotenoids assist in light absorption and provide photoprotection by dissipating excess energy. Both pigments are essential for plant growth and development, playing distinct and complementary roles in maintaining photosynthetic efficiency and protecting plants from oxidative stress. Because of their function in photosynthesis and photoprotection, chlorophyll and carotenoid accumulation are strongly associated with light conditions, especially blue and red lights, which play key roles in regulating their metabolisms. Despite advancements in understanding pigment metabolism, there remains a limited comprehensive overview of how various parts of the light spectrum influence these pathways throughout the entire process. The effects of other spectral ranges of light, such as green light, far-red light, and UV, are not yet fully understood. This review aims to synthesize recent findings about the regulatory network of chlorophyll and carotenoid pathways under different light spectral bands, emphasizing the interplay between light-regulated transcription factors and genes involved in their biosynthesis and degradation. [ABSTRACT FROM AUTHOR] more...

The commercial development of Cavendish bananas still faces many obstacles, including the availability of seedlings/suckers at low prices, so technological substitution is needed to stimulate the growth of Cavendish banana suckers in the form of arbuscular mycorrhizal (AM) biological agents. The research aims to determine the correlation between AM doses and colonization levels, tissue nutrient concentrations, and photosynthetic pigments in Cavendish banana seedlings/suckers. It is also a novelty in this research study. The research was carried out in Parepare city at coordinates 3°59'30.204" S; 119°38'42.936" E using four AM doses as independent variables, namely 0 g, 5 g, 10 g, and 15 g pot-1. The variables observed (dependent variables) were the level of colonization, nutrient concentration in the tissue, and photosynthetic pigment content. Using Microsoft Excel software, statistical tests, regression, and correlation analyses were conducted to see the relationship between treatment (independent variable) and observed parameters (dependent variable). The research showed that AM dosage was positively correlated with the level of root colonization, the concentration of N, P, and K elements in the tissue, and the photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids). A dose AM of 15 g pot-1 gave a better effect on Cavendish banana suckers, which can be recommended for the development of Cavendish banana seedlings. [ABSTRACT FROM AUTHOR] more...

Light intensity and wind are critical environmental factors of abiotic stress on plants, triggering a considerable number of morphological and physiological responses. This study tested the hypothesis that different light and wind conditions (full sunlight ± wind, shade ± wind) would affect the leaf content of photosynthetic pigments and anthocyanins, as well as the plant height, the fresh and dry weight of the aboveground part, and Water-Use Efficiency on Ocimum basilicum plants. About 16 days after the application of the different conditions, all leaf pigments of the shaded plants exhibited increased contents compared to the lightened ones. Subsequently, this response was enhanced until the 39th day, which was the final day of the experiment. Furthermore, shaded plants grew taller, although their fresh and dry weight and Water-Use Efficiency were lower than that of the corresponding lightened ones. On the other hand, wind did not have any effect on pigment content. Concerning the plant growth indexes, reduced values were observed on the wind-treated plants. The above results demonstrate a considerable effect of light intensity while the applied wind seems to be mild enough to induce important plant responses, partially confirming the hypothesis studied. [ABSTRACT FROM AUTHOR] more...

Implementing nanofertilizers in cultivation to enhance food security is important and gaining great significance, as they have good properties to improve plant production, phytochemicals, and nutrient efficiency and thereby meet the demands of the increasing world population for food. This work demonstrated the impact of calcium carbonate nanoparticles (Ca-NPs) and Ca bulk at three concentrations (0, 100, and 200 mg L−1) on growth, productivity, photosynthetic pigments, phytochemical content, antioxidant activity enzymes, minerals, toxicity, and genomic DNA of lettuce plants. In this regard, Ca-NPs at a concentration of 200 mg L−1 reinforced the vegetative growth characteristics of lettuce plants, increasing head length by 15.7 and 19.2%, head diameter by 20.3 and 19.9%, head fresh weight by 54.4 and 52.9%, and production per hectare by 54.7 and 52.8% as compared to the control during the two growing seasons. Furthermore, the percentages of total chlorophyll (62.6 and 59.5%), carotenoids (48.4 and 56.5%), total phenolics (63.6 and 65.7%), total indoles (39.4 and 36.4%), vitamin C (39.7 and 39.6%), antioxidant activity (57.8 and 53.7%), nitrogen (70.5 and 67.5%), phosphorus (120 and 110.5%), potassium (33.0 and 33.2%), and calcium (67.14 and 63.2%) were also increased compared with the control during two consecutive growing seasons. Additionally, Ca-NPs and Ca bulk had an impact on the plants' genomic DNA compared to the control. In addition, lettuce plants treated with Ca-NPs were proven to be nontoxic and safe for humans by using the Microtox 500 analyzer. [ABSTRACT FROM AUTHOR] more...

In nature, seasonal changes bring about a rich variety of colors in leaves, especially during autumn, which captivates numerous observers and sparks scientific exploration. However, behind this phenomenon lie a series of intricate chemical changes and delicate adjustments in the molecular structure of pigments. This article delves into the chemical foundation of autumnal leaf coloration. [ABSTRACT FROM AUTHOR] more...

The main aim of this study is to identify physiological characteristics, including Chl a, b, total Chl "a+b" and carotenoids, in potato genotypes under the influence of lead (Pb+2) and cadmium (Cd+2) heavy metals. Two potato genotypes from the Netherlands, Riviera and Agria, were used in the study. Potato tubers were transferred to 2 kg compost pots and placed in a controlled environment with a 12 photoperiod, a day/night temperature of 25/19°C and a relative humidity of 75%. Since Pb+2 and Cd+2 poisoning was greater than in the control and different fractions of heavy metal residues in the substrate were transferred to plant organs, the amounts of these two metals in each treatment (outside the control) were measured. Plant pigments were extracted from fresh leaves in amounts ranging from 60 to 100 mg and these were then extracted into samples containing 80/20% (v/v) acetone/water with 0.5% w/v MgCO3 at room temperature for a full day. Photosynthetic pigments of each sample were extracted three times. The absorbances obtained at 663 nm, 644 nm and 452.5 nm for the maximum absorption of Chl a, Chl b and carotenoids, respectively, were used to measure the amount of chlorophyll and carotenoids. Differences between Pb+2 and Cd+2 and physiological markers were examined with the Duncan Multiple Range test. Information on Pb+2 and Cd+2 content in applications revealed wide variability. When potato genotype seedlings were exposed to varying levels of Pb+2 and Cd+2, the amount of chlorophyll and carotenoids in their leaves was lower than the control group. The results showed that there were significant and statistically significant changes in carotenoid and chlorophyll concentration at the LSD p = 0.01 level. Similar to Pb+2 and Cd+2 inhibiting plant growth, it had a negative effect on photosynthesis as well as chlorophyll and carotenoid contents. Moreover, these effects became more pronounced when the concentrations of two stress factors (Pb+2 and Cd+2) increased. [ABSTRACT FROM AUTHOR] more...

Pigments serve a multitude of functions in biology including light harvesting for photosynthesis, radiation protection, membrane support, and defense. The ubiquity of pigments—especially within extremophiles found in high-radiation, high-salinity, and dry environments—and their detectability via mission-ready techniques have elevated these molecules as promising targets in the search for evidence of life elsewhere. Moreover, the detection of pigments has been proposed as a "smoking gun" for extraterrestrial life as it has been suggested that these molecules cannot be generated abiotically. However, while pigments may hold promise as a biosignature, current understanding of their possible prebiotic origins remains understudied and uncertain. Better understanding of the abiotic synthesis of pigments is critical for evaluating the biogenicity of any pigment detected during missions, including by the Mars Perseverance rover or from returned samples. Compounding this uncertainty is the broad definition of pigment as it includes any compound capable of absorbing visible light and by itself does not specify a particular chemical motif. While not experimentally verified, there are promising prebiotic routes for generating pigments including hemes, chlorophylls, and carotenoids. Herein, we review the biochemistry of pigments, the inherent assumptions made when searching for these molecules in the field, their abiotic synthesis in industry and prebiotic reactions, prebiotically relevant molecules that can mimic their spectral signatures, and implications/recommendations for future work. [ABSTRACT FROM AUTHOR] more...

Copyright of Journal of Soil Science & Plant Nutrition / Toprak Bilimi ve Bitki Besleme Dergisi is the property of Soil Science Society of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

The present study was conducted to evaluate the effects of kaolin particle film on the quantitative and qualitative characteristics of important commercial varieties of apple trees (Golden Delicious and Red Delicious) in the orchards of Bonab and Shahre Jadide Sahand, East Azerbaijan. This experiment was randomized complete block design with 4 replications at 4 levels of thin membrane (control, 2, 4, 6%) on 2 apple cultivars (Golden Delicious and Red Delicious) in 2 locations for two years. The measured indicators included sunburn percentage, photosynthesis rate, total chlorophyll, chlorophyll b and chlorophyll a, fruit surface temperature, fruit firmness at harvest, leaf calcium and phosphorus levels, and yield. The results showed that with increasing levels of kaolin concentration in both regions and cultivars, the amount of damage, burn percentage and fruit surface temperature decreased. The lowest temperature limit (37.16 degrees Celsius) in the treatment with 4% concentration and the highest limit. The temperature (40.25 degrees Celsius) was observed in the control. The highest percentage of burn damage was related to the control treatment (19.95%) and the lowest was related to the 4% kaolin treatment (14.2%). Total chlorophyll, chlorophyll b and chlorophyll an indices, fruit firmness at harvest, fruit calcium content, photosynthesis rate and yield increased significantly with increasing kaolin levels. The highest amounts of chlorophyll b and a were observed, respectively, 0.97 and 1.95 mg per gram of fresh weight, and in the treatment of 2% and 4%, and the lowest amount of these plant pigments was observed in the control (chlorophyll b and a, respectively, 1.28 and 58/mg/g fresh weight). The highest amount of photosynthesis related to the treatment of 6% kaolin (9.44 mM CO2 m-2 g-1 ) and the lowest amount of photosynthesis was observed in the control treatment (7.92 mM CO2 m-2 g-1 ). The highest amount of calcium, phosphorus and yield (respectively 55/ 1 mg/kg, 0.154 mg/kg, 80.62 mg/kg) in the 4% kaolin treatment and the lowest of these values in the control (1.55 mg/kg, 0.154 mg/kg respectively) per kg, there was 67.67 kg) and there was no significant difference between the two regions and cultivars in this respect. [ABSTRACT FROM AUTHOR] more...

Diatoms are a group of marine algae that are responsible for a significant part of global oxygen production. Adapted to life in an aqueous environment dominated by the blue–green light, their major light-harvesting antennae—fucoxanthin–chlorophyll protein complexes (FCPs)—exhibit different pigment compositions than of plants. Despite extensive experimental studies, until recently the theoretical description of excitation energy dynamics in these complexes was limited by the lack of high-resolution structural data. In this work, we use the recently resolved crystallographic information of the FCP complex from Phaeodactylum tricornutum diatom [Wang et al., Science 363, 6427 (2019)] and quantum chemistry-based calculations to evaluate the chlorophyll transition dipole moments, atomic transition charges from electrostatic potential, and the inter-chlorophyll couplings in this complex. The obtained structure-based excitonic couplings form the foundation for any modeling of stationary or time-resolved spectroscopic data. We also calculate the inter-pigment Förster energy transfer rates and identify two quickly equilibrating chlorophyll clusters. [ABSTRACT FROM AUTHOR] more...

Transitions into the first excited state of carotenoids, Car S1, are optically forbidden in conventional one-photon excitation (OPE) but are possible via two-photon excitation (TPE). This can be used to quantify the amount of Car S1 to Chlorophyll (Chl) energy transfer in pigment–protein complexes and plants by observing the chlorophyll fluorescence intensity after TPE in comparison to the intensity observed after direct chlorophyll OPE. A parameter, Φ Coupling Car S1−Chl , can be derived that directly reflects relative differences or changes in the Car S1 → Chl energy transfer of different pigment–protein complexes and even living plants. However, very careful calibrations are necessary to ensure similar OPE and TPE excitation probabilities and transition energies. In plants, the exact same sample spot must be observed at the same time. All this is experimentally quite demanding. Φ Coupling Car S1−Chl also corrects intrinsically for direct chlorophyll TPE caused by larger chlorophyll excesses in the complexes, but recently it turned out that in certain TPE wavelengths ranges, its contribution can be quite large. Fortunately, this finding opens also the possibility of determining Φ Coupling Car S1−Chl in a much easier way by directly comparing values in TPE spectra observed at wavelengths that are either more dominated by Cars or Chls. This avoids tedious comparisons of OPE and TPE experiments and potentially allows measurement at even only two TPE wavelengths. Here, we explored this new approach to determine Φ Coupling Car S1−Chl directly from single TPE spectra and present first examples using known experimental spectra from Cars, Chl a, Chl b, LHC II, and PS 1. [ABSTRACT FROM AUTHOR] more...

The aim of this study was to determine the effect of plant spacing on the growth, yield and chemical composition of stevia grown in Poland. The variable factor was spacings of 50 cm × 30 cm, 45 cm × 25 cm and 30 cm × 30 cm. Seedlings were planted during the first ten days of June, and the plant material was harvested between the 10th and 20th of September. In July and September, seedlings were subjected to biometric measurements, and plant samples were taken for chemical analyses. Plants grown at 50 cm × 30 cm spacing were characterised by an increased content of reducing sugars, nitrates, phosphorous, potassium and magnesium, but the yield of the herb and leaves was smallest. The greatest yield of the herb and leaves was found for the 30 cm × 30 and 45 cm × 25 cm spacings with the lowest mass of single plants. Leaves from plants grown in the 30 cm × 30 cm spacing were also characterised as having the greatest concentration of dry mass and phenolic compounds and the lowest concentration of phosphorus and magnesium. Spacing did not significantly affect the biometric parameters of the plants in July, but in September, a difference was observed in the lateral width and total number of shoots. Spacing did not affect the plant pigment contents in the leaves of stevia. [ABSTRACT FROM AUTHOR] more...

The differential effects of cellular and ultrastructural characteristics on the optical properties of adaxial and abaxial leaf surfaces in the genus Tradescantia highlight the intricate relationships between cellular arrangement and pigment distribution in the plant cells. We examined hyperspectral and chlorophyll a fluorescence (ChlF) kinetics using spectroradiometers and optical and electron microscopy techniques. The leaves were analysed for their spectral properties and cellular makeup. The biochemical compounds were measured and correlated with the biophysical and ultrastructural features. The main findings showed that the top and bottom leaf surfaces had different amounts and patterns of pigments, especially anthocyanins, flavonoids, total phenolics, chlorophyll-carotenoids, and cell and organelle structures, as revealed by the hyperspectral vegetation index (HVI). These differences were further elucidated by the correlation coefficients, which influence the optical signatures of the leaves. Additionally, ChlF kinetics varied between leaf surfaces, correlating with VIS-NIR-SWIR bands through distinct cellular structures and pigment concentrations in the hypodermis cells. We confirmed that the unique optical properties of each leaf surface arise not only from pigmentation but also from complex cellular arrangements and structural adaptations. Some of the factors that affect how leaves reflect light are the arrangement of chloroplasts, thylakoid membranes, vacuoles, and the relative size of the cells themselves. These findings improve our knowledge of the biophysical and biochemical reasons for leaf optical diversity, and indicate possible implications for photosynthetic efficiency and stress adaptation under different environmental conditions in the mesophyll cells of Tradescantia plants. [ABSTRACT FROM AUTHOR] more...

The research explored Canna indica's ability to extract Cd in hydroponic conditions, determining its upper tolerance threshold and assessing Cd's impact on growth and biochemical properties. Plants were grown in 5L tanks containing nutrient solutions with varying Cd concentrations (0, 100, 200, 300, and 400 mg/L) for 18 days. Each treatment was performed in triplicate. Analysis of Cd content across roots, shoot, and leaves revealed high absorption rates of 89.5% to 96.8% efficiency for Cd treatments of 100–400 mg/L. Metrics like bioaccumulation coefficient (BAC), translocation factor (TF), and bio-concentration factor (BCF) were determined, indicating BAC > 1 across treatments, while TF was <1 for 100 mg/L and >1 for higher Cd treatments. Bio-concentration patterns varied with Cd concentration. Optimal Cd uptake occurred at 200–300 mg/L, declining notably at 400 mg/L. The study suggests C. indica's potential for phytoextraction up to 400 mg/L Cd contamination, but adverse effects emerged at ≥300 mg/L: reduced chlorophyll pigments, ascorbic acid, fresh/dry weights, and elevated leaf pH, indicating a Cd tolerance threshold of 300 mg/L for C. indica. [ABSTRACT FROM AUTHOR] more...

Anoectochilus roxburghii (Wall.) Lindl is a perennial herb of the Orchidaceae family; a yellow–green mutant and a yellow mutant were obtained from the wild type, thereby providing good material for the study of leaf color variation. Pigment content analysis revealed that chlorophyll, carotenoids, and anthocyanin were lower in the yellow–green and yellow mutants than in the wild type. Transcriptome analysis of the yellow mutant and wild type revealed that 78,712 unigenes were obtained, and 599 differentially expressed genes (120 upregulated and 479 downregulated) were identified. Using the Kyoto Encyclopedia of Genes and Genomes pathway analysis, candidate genes involved in the anthocyanin biosynthetic pathway (five unigenes) and the chlorophyll metabolic pathway (two unigenes) were identified. Meanwhile, the low expression of the chlorophyll and anthocyanin biosynthetic genes resulted in the absence of chlorophylls and anthocyanins in the yellow mutant. This study provides a basis for similar research in other closely related species. [ABSTRACT FROM AUTHOR] more...

In this study, the performance of waste seashells (SS) in adsorbing color and oxidation parameters during the bleaching process of sunflower oil was evaluated and compared with that of commercial clay. Seashell activation methods included microwave treatment (900 W for 30 min), acid treatment (7 N H2SO4), and a combination of both. Interestingly, the unactivated SS demonstrated superior adsorption performance compared with the activated SS. SS, which have the ability to eliminate color pigments like chlorophyll and carotenoid, were found to be effective in this regard. However, their effectiveness in reducing the peroxide and p-anisidine value was not as successful as that of commercial clay. Free acidity content remained constant across all treatments. SS emerged as a cost-effective alternative adsorbent, promising in preventing environmental pollution. Their use signifies a valuable contribution to sustainability. This study sheds light on SS potential as an eco-friendly solution in industrial processes, warranting further exploration and application. Practical applications Biowaste valorization is a process that involves converting organic waste materials into valuable products, energy, or resources, instead of simply disposing of them in landfills or incinerating them. This approach has gained significance owing to its potential to address environmental, economic, and social challenges. In this respect, this study presents that bioadsorbent obtained from waste SS can be utilized for bleaching of sunflower oil. [ABSTRACT FROM AUTHOR] more...

During the ripening process of grapes, the grapevine leaves are the most active green organs that are important for photosynthesis, which is closely linked to the development and metabolism of the plant. The detection of plant pigments and phenolic compounds in grapevine leaves can be a good indicator of the ageing process, vine vigor and the plant's ability to respond to fungal attack. In a one-year study, the development of leaf chlorophylls, carotenoids and phenolic compounds during the ripening of six indigenous Croatian grape cultivars and the international cultivars Merlot and Chardonnay was investigated. The chlorophyll a/b ratio and total chlorophyll and total carotenoid concentrations were also investigated. PCA was used to highlight relevant information from the data with the aim of distinguishing individual compounds based on the cultivar and phenological stage. The leaf total hydroxycinnamic acid and flavan-3-ol concentrations decreased slowly during grape development, with the highest concentration immediately after flowering and the lowest during grape ripening. The concentrations of β-carotene, lutein and xanthophylls tended to decrease during bunch closure or veraison, while the concentration of chlorophylls a and b peaked during veraison and then decreased during grape ripening. This research will provide an opportunity to select cultivars with the physiological adaptation to synthesize secondary metabolites that are important for managing stress conditions. [ABSTRACT FROM AUTHOR] more...

This study aimed to evaluate different L. corniculatus L. ecotypes under water-deficit conditions to identify changes in relative water content and photosynthetic pigments as indicators of physiological responses during different years' seasons. The experiment was conducted in a randomized block design with three replicates. Ten treatments were performed as a factorial of 2 × 5, where the first variation factor was the soil water content—no water deficit (NDW) with 100% field capacity (FC), and water deficit (DW) corresponding to 85.4% of the FC—and the second variation factor comprised four ecotypes and one variety of L. corniculatus. A significant effect was identified on the concentration of photosynthetic pigments, mainly total chlorophyll, with chlorophyll a in the 255301 ecotype with records of 187.8, 167.5, and 194.6 mg g−1 FW in WD, corresponding to an increase of 86.0%, 172.6%, and 16.6%, respectively, in relation the lower values obtained in the ecotype 202700 under NWD. In carotenoids, higher concentrations were observed in the 255301 and 202700 ecotypes and the Estanzuela Ganador variety under WD in most seasonal periods, except summer; a similar response was found in the 202700 ecotype and the Estanzuela Ganador variety during the winter season, also in WD. The results showed that the first two principal components accounted for 71.8% of the total variation, with PC1 representing chlorophyll a, chlorophyll b, and total chlorophyll, and PC2 representing carotenoids, temperature, relative chlorophyll index, and relative water content. The observations were grouped based on soil moisture content, with the optimal moisture group exhibiting higher chlorophyll and carotenoid concentrations. The findings suggest that soil moisture content significantly affects the performance of L. corniculatus ecotypes, and the plant shows seasonal variations in response to water-deficit conditions. This research contributes to understanding the physiological responses of L. corniculatus and its potential as a water-efficient forage crop for promoting sustainable agriculture and enhancing food security. [ABSTRACT FROM AUTHOR] more...

In recent years, there has been a growing interest in plant pigments as readily available nutraceuticals. Photosynthetic pigments, specifically chlorophylls and carotenoids, renowned for their non-toxic antioxidant properties, are increasingly finding applications beyond their health-promoting attributes. Consequently, there is an ongoing need for cost-effective methods of isolation. This study employs a co-precipitation method to synthesize magnetic iron oxide nanoparticles. Scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) confirms that an aqueous environment and oxidizing conditions yield nanosized iron oxide with particle sizes ranging from 80 to 140 nm. X-ray photoelectron spectroscopy (XPS) spectra indicate the presence of hydrous iron oxide FeO(OH) on the surface of the nanosized iron oxide. The Brunauer–Emmett–Teller (BET) surface area of obtained nanomaterial was 151.4 m2 g−1, with total pore volumes of pores 0.25 cm3 g−1 STP. The material, designated as iron oxide nanoparticles (IONPs), serves as an adsorbent for magnetic solid phase extraction (MSPE) and isolation of photosynthetic pigments (chlorophyll a, lutein) from extracts of higher green plants (Mentha piperita L., Urtica dioica L.). Sorption of chlorophyll a onto the nanoparticles is confirmed using UV–vis spectroscopy, Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS), and high-performance liquid chromatography (HPLC). Selective sorption of chlorophyll a requires a minimum of 3 g of IONPs per 12 mg of chlorophyll a, with acetone as the solvent, and is dependent on a storage time of 48 h. Extended contact time of IONPs with the acetone extract, i.e., 72 h, ensures the elimination of remaining components except lutein, with a spectral purity of 98%, recovered with over 90% efficiency. The mechanism of chlorophyll removal using IONPs relies on the interaction of the pigment's carbonyl (C=O) groups with the adsorbent surface hydroxyl (–OH) groups. Based on molecular dynamics (MD) simulations, it has been proven that the selective adsorption of pigments is also influenced by more favorable dispersion interactions between acetone and chlorophyll in comparison with other solutes. An aqueous environment significantly promotes the removal of pigments; however, it results in a complete loss of selectivity. [ABSTRACT FROM AUTHOR] more...

Celery (Apium graveolens L.) is a kind of green leaf vegetable with a large consumption demand in the food industry. It is a commonly used material in quick-frozen food stuffing such as dumplings and steamed stuffed. Fresh celery leaf blades and petioles are rich in photosynthetic pigments including chlorophyll and carotenoid, their contents are closely related to the quality of celery and its products. In order to explore the effects of freezing and thawing temperature and thawing time on the degradation of photosynthetic pigments in celery leaf blades and petioles, the changes in photosynthetic pigments during thawing storage were measured under different freezing and thawing temperatures. The results showed that lower freezing and thawing temperatures were beneficial to the preservation of photosynthetic pigments in celery leaf blades and petioles, and the loss of photosynthetic pigments enhanced with the increase in thawing temperature and thawing time. Under the cold storage condition of −80 °C, the loss rate of pigment substances can be reduced by nearly 20% compared with that of −18 °C, and −80 °C and 4 °C could be the best temperature combination of freezing and thawing. The content and degradation rate of photosynthetic pigments in celery leaf blades were higher than that in petioles during thawing, with a total chlorophyll loss rate reaching 35% during 6 to 12 h after thawing. The increase in temperature difference between freezing and thawing could aggravate the damage to the cell structure and the degradation of the pigment, as chlorophyll is more sensitive to temperature changes, and the degradation rate is significantly higher than that of carotenoids. From the perspective of delaying the degradation of photosynthetic pigments, the results of this study will provide potential references for the reasonable configuration of freezing and thawing temperatures in the process of storage and transportation of celery products. [ABSTRACT FROM AUTHOR] more...

Owing to the uniqueness of quantum dots (QDs) as a potential nanomaterial for agricultural application, hence in the present study, titanium dioxide quantum dots (TiO2 QDs) were successfully synthesized via sol-gel technique and the physico-chemical properties of the prepared TiO2 QDs were analyzed. Based on the results, the TiO2 QDs showed the presence of anatase phase of TiO2. TEM examination revealed spherical QDs morphology with an average size of 7.69 ± 1.22 nm. The large zeta potential value (-20.9 ± 2.3 mV) indicate greater stability of the prepared TiO2 QDs in aqueous solutions. Moreover, in this work, the application of TiO2 QDs on Hibiscus sabdariffa plants was conducted, where H. sabdariffa plants were foliar sprayed twice a week in the early morning with different concentrations of TiO2 QDs (0, 2, 5, 10, 15 and 30 ppm) to evaluate their influence on these plants in terms of morphological indexes and biochemical parameters. The results exhibited an increasing impact of the different used concentrations of TiO2 QDs on morphological indexes, such as fresh weight, dry weight, shoot length, root length, and leaf number, and physio-biochemical parameters like chlorophyll a, chlorophyll b, carotenoid contents, total pigments and total phenolic contents. Remarkably, the most prominent result was recorded at 15 ppm TiO2 QDs where plant height, total protein and enzymatic antioxidants like catalase and peroxidase were noted to increase by 47.6, 20.5, 29.5 and 38.3%, respectively compared to control. Therefore, foliar spraying with TiO2 QDs positively serves as an effective strategy for inducing optimistic effects in H. sabdariffa plants. [ABSTRACT FROM AUTHOR] more...

Chlorophyll is the major light‐absorbing pigment for plant photosynthesis. While evolution has been selected for high chlorophyll content in leaves, previous work suggests that domesticated crops grown in modern high‐density agricultural environments overinvest in chlorophyll production, thereby lowering light use and nitrogen use efficiency. To investigate the potential benefits of reducing chlorophyll levels, we created ethanol‐inducible RNAi tobacco mutants that suppress Mg‐chelatase subunit I (CHLI) with small RNA within 3 h of induction and reduce chlorophyll within 5 days in field conditions. We initiated chlorophyll reduction later in plant development to avoid the highly sensitive seedling stage and to allow young plants to have full green leaves to maximise light interception before canopy formation. This study demonstrated that leaf chlorophyll reduction >60% during seed‐filling stages increased tobacco seed nitrogen concentration by as much as 17% while canopy photosynthesis, biomass and seed yields were maintained. These results indicate that time‐specific reduction of chlorophyll could be a novel strategy that decouples the inverse relationship between yield and seed nitrogen by utilising saved nitrogen from the reduction of chlorophyll while maintaining full carbon assimilation capacity. Summary statement: Reducing chlorophyll levels in tobacco plants during seed filling stages, without compromising canopy carbon assimilation, increased seed nitrogen concentration by up to 17%, suggesting a potential strategy to improve yield and seed nitrogen content simultaneously. [ABSTRACT FROM AUTHOR] more...

Leaf color is a key ornamental characteristic of cultivated caladium (Caladium × hortulanum Birdsey), a plant with diverse leaf colors. However, the genetic improvement of leaf color in cultivated caladium is hindered by the limited understanding of leaf color diversity and regulation. In this study, the chlorophyll and anthocyanin content of 137 germplasm resources were measured to explore the diversity and mechanism of leaf color formation in cultivated caladium. Association analysis of EST-SSR markers and pigment traits was performed, as well as metabolomics and transcriptomics analysis of a red leaf variety and its white leaf mutant. We found significant differences in chlorophyll and anthocyanin content among different color groups of cultivated caladium, and identified three, eight, three, and seven EST-SSR loci significantly associated with chlorophyll-a, chlorophyll-b, total chlorophyll and total anthocyanins content, respectively. The results further revealed that the white leaf mutation was caused by the down-regulation of various anthocyanins (such as cyanidin-3-O-rutinoside, quercetin-3-O-glucoside, and others). This change in concentration is likely due to the down-regulation of key genes (four PAL, four CHS, six CHI, eight F3H, one F3′H, one FLS, one LAR, four DFR, one ANS and two UFGT) involved in anthocyanin biosynthesis. Concurrently, the up-regulation of certain genes (one FLS and one LAR) that divert the anthocyanin precursors to other pathways was noted. Additionally, a significant change in the expression of numerous transcription factors (12 NAC, 12 bZIP, 23 ERF, 23 bHLH, 19 MYB_related, etc.) was observed. These results revealed the genetic and metabolic basis of leaf color diversity and change in cultivated caladium, and provided valuable information for molecular marker-assisted selection and breeding of leaf color in this ornamental plant. [ABSTRACT FROM AUTHOR] more...

Under controlled environmental conditions, the authors studied the effect of extended light/dark cycles of 24/12, 48/24, 96/48, and 120/60 h and continuous lighting on the content and ratio of photosynthetic and nonphotosynthetic pigments in a number of Solanaceae (eggplant (Solanum melongena L.), sweet pepper (Capsicum annuum L.), tobacco (Nicotiana tabacum L.), and tomato (Solanum lycopersicum L.)) and Brassicaceae (broccoli (Brassica oleracea var. italica Plenck), mizuna (Brassica rapa ssp nipposinica (L.H. Bailey) Hanelt), arugula (Eruca vesicaria sp. sativa Mill.), and cauliflower (Brassica oleracea L. var. botrytis L.)) plants. Plants were grown in controlled-climate chambers at 23°С and light intencity of 270 µmol/(m2 s) PAR. Control plants were grown under photoperiod of 16/8 h. Continuous lighting decreased the content of chlorophyll, its share in light-harvesting complex and chlorophyll to carotenoids ratio, but increased chlorophyll a/b ratio and the content of anthocyanins and flavonoids; these effects were differently manifested depending on plant species. At all other examined light/dark cycles (24/12, 48/24, 96/48, and 120/60 h) where average daily light integral did not differ from such under common photoperiod (16/8 h), changes in pigment complex were often observed similar to photoprotective reactions occurring upon exposure of plants to excess illumination (a decrease in the content of photosynthetic pigments, modification of their ratios, and accumulation of protective, nonphotosynthetic pigments). At the same time, plant responses were species-specific. On the whole, the obtained results have shown that changes within the plant pigment complex may be induced not only by excessive light energy coming to plants, but also by distribution of daily light integral in time as it occurs in response to abnormal light/dark cycles that, in the authors' opinion, cause a circadian asynchrony. [ABSTRACT FROM AUTHOR] more...

Zinc-oxide nanoparticles (ZnO-NP) effect on crop physiology and zinc recovery remains poorly studied for acidic-sandy soils. To address this, greenhouse pot (plastic-pots, 6 kg soil, maize) experiments with ZnO-NP (50, 100, 150, 200 mg kg−1) applied via different methods (soil-drench, seed-coating and foliar-spray) was conducted in a 60 days study. Results revealed that ZnO-NP via seed-coating (100 mg kg−1) and soil-drench (150 mg kg−1) enhanced shoot and total P uptake, while ZnO-NPs (foliar) (50 mg kg−1) enhanced maize growth (6–11%), with agronomic and physiological improvements ultimately resulted in greater biomass (16–20%), Zn agronomic efficiency and uptake. Compared to ZnSO4 treatment and the control, seed-coating with 100 mg kg−1 ZnO-NP increased leaf chlorophyll and pigment content by 12–127%. Principal component analysis revealed a close association among growth traits, plant pigments, fluorescence parameters, total Zn and P concentration, and uptake with total biomass as influenced by ZnO-NPs. Thus, compared to conventional ZnSO4 and higher dosages of ZnO-NPs, foliar-spray of ZnO-NP at 50 mg kg−1, seed-coating at 100 mg kg−1, or soil-drench at 150 mg kg−1 increased maize biochemical characteristics, growth, biomass, and Zn agronomic efficiency. These elucidate important implications of ZnO-NP application for increasing plant development and Zn biofortification in acidic-sandy soils. [ABSTRACT FROM AUTHOR] more...

Photosynthesis is the most important biochemical process that takes place in plants and chlorophyll is the main pigment involved in it. Current destructive methods for determining chlorophyll content are accurate, but time-consuming and relatively expensive. The SPAD (Soil Plant Analysis Development) is a portable chlorophyll meter that provides an instant and nondestructive reading of the green color of leaves. As an important source of vitamins and antioxidants such as vitamins C, carotenoids and fiber content, lettuce (Lactucasativa L.) plays a crucial role in human nutrition, being one of the most popular staple plant foods among the population. Considering the possibility of management based on the characteristics of photosynthetic pigments, the study aimed to relate the SPAD index values with the content of leaf pigments in lettuce. The study was conducted in the Northwest region of Paraná, Brazil. The experiment was carried out in a completely randomized design with 48 leaf samples being determined the SPAD index and the content of leaf pigments. The determination of the SPAD index was performed with the SPAD-502 equipment (Minota®) with three readings per sample. For the extraction of leaf pigments, chlorophyll (a; b), total chlorophyll (a + b) and carotenoids, acetone was used as an extractor and the reading was performed in a spectrophotometer. The SPAD index was correlated with the levels of chlorophyll a (0.93), chlorophyll b (0.89), total chlorophyll (0.93) and carotenoids (0.95) in lettuce leaves. Through the SPAD, the chlorophyll content in lettuce leaves can be determined in a representative way. [ABSTRACT FROM AUTHOR] more...

Abstract—The association of degradation of membrane-bound chlorophyll with changes in the dark respiration rates and photosynthesis in Festuca arundinacea Schreb. leaves under the influence of various concentrations of limited and aromatic hydrocarbons present in technogenic emissions was studied. One day after intoxication, a negative correlation between the content of non-phytol forms of pigments and the rate of photosynthesis was found. A positive correlation was found between the content of (1) phytol forms and the rate of photosynthesis and (2) non-phytol forms and the respiration rate. The relationships between the processes changed three days after characterizing the detoxifying and adaptive abilities of plants. [ABSTRACT FROM AUTHOR] more...

As a principal pigment in plants, chlorophyll a (Chl a) is widely used to evaluate quality changes and senescence process during storage of leafy vegetables. The determination of Chl a in plant extracts by spectrophotometric methods using various empirical equations is often unreliable. Considering the sensitivity of fluorescence detection, we report here a simple, inexpensive spectrofluorimetric method that can detect and quantify Chl a in plant extracts. The fluorescence standard used for the quantitative determination of Chl a was isolated in our laboratory from the extract of Anthrospira platensis (Spirulina). The method proved to be reliable, fast, and low cost in a study of the influence of the most commonly used domestic storage conditions on Chl a degradation in fresh-cut arugula. [ABSTRACT FROM AUTHOR] more...

Introduction: Plant growth and greening in response to light require the synthesis of photosynthetic pigments such as chlorophylls and carotenoids, which are derived from isoprenoid precursors. In Arabidopsis, the pseudo-etiolated-in-light phenotype is caused by the overexpression of repressor of photosynthetic genes 2 (RPGE2), which regulates chlorophyll synthesis and photosynthetic genes. Methods: We investigated a homologous protein in the Russian dandelion (Taraxacum koksaghyz) to determine its influence on the rich isoprenoid network in this species, using a combination of in silico analysis, gene overexpression, transcriptomics and metabolic profiling. Results: Homology-based screening revealed a gene designated pseudo- etiolated-in-light-like (TkPEL-like), and in silico analysis identified a light-responsive G-box element in its promoter. TkPEL-like overexpression in dandelion plants and other systems reduced the levels of chlorophylls and carotenoids, but this was ameliorated by the mutation of one or both conserved cysteine residues. Comparative transcriptomics in dandelions overexpressing TkPEL-like showed that genes responsible for the synthesis of isoprenoid precursors and chlorophyll were downregulated, probably explaining the observed pale green leaf phenotype. In contrast, genes responsible for carotenoid synthesis were upregulated, possibly in response to feedback signaling. The evaluation of additional differentially expressed genes revealed interactions between pathways. Discussion: We propose that TkPEL-like negatively regulates chlorophyll- and photosynthesis-related genes in a light-dependent manner, which appears to be conserved across species. Our data will inform future studies addressing the regulation of leaf isoprenoid biosynthesis and photomorphogenesis and could be used in future breeding strategies to optimize selected plant isoprenoid profiles and generate suitable plant-based production platforms. [ABSTRACT FROM AUTHOR] more...

The use of microalgae cultures to process effluents from industries, leachates, and tanneries, among others, quantified by the reduction of metallic materials in the medium and the reduction of chemical oxygen demand (COD), helps reduce the environmental impact caused by human development. In addition, with the growth of the culture, it is possible to produce a significant amount of chlorophyll, a carotenoid of high value in the cosmetics and food industries that are used as a natural pigment. In this context, this work presents a study conducted to verify the bioremediation and chlorophyll production potential of the cultivation of the microalgae Chlorella minutíssima, using the Taguchi method. The microalgae Chlorella minutissima has given good results in the bioremediation of leachate, as a mean reduction of 33% in COD was obtained, as well as a 92% reduction in the toxic components. In addition, statistical analysis revealed that the four process factors were significant factors for chlorophyll a, chlorophyll b and carotenoid productivity (p < 0.05). Finally, it was observed that the maximum chlorophyll a (111.9 ± 0.8 mg·L-1·d-1), chlorophyll b (66.1 ± 1.7 mg·L-1·d-1), and carotenoid (31.9 ± 0.03 mg·L-1·d-1) values obtained occurred in Experiment 8, which is closer to the ideal conditions identified by statistical analysis, revealing the effectiveness of the use of the Taguchi method for the design of experiments. [ABSTRACT FROM AUTHOR] more...

The incorporation of bioactive additives such as natural pigments in food products offers many nutritional advantages, associated with functional properties in particular antioxidant effects. The aim of this work was to study the effect of adding natural pigments extracted from the brown seaweed Phyllaria reniformis on the oxidative stability of commercially available soybean and sunflower oils. Phyllaria reniformis pigment extract (200 and 1000 ppm) was dissolved in the two edible oils, and in comparison, a synthetic antioxidant butylated hydroxyanisole (BHA) was added. Experimental results showed that the addition of pigment extract had no significant effect on the quality parameters of vegetable oils: Free acidity (FA) and peroxide value (PV). Carotenoids were improved 2 and 1.5 times when adding 200 ppm of pigment extract to soybean and sunflower oils, respectively. While, when adding 1000 ppm, carotenoids were improved 3 times in comparison to the virgin oils. Similarly, chlorophylls contents in enriched sunflower oil with 200 or 1000 ppm of pigment extract increased 2 and 3 times in comparison to the control sample, however, in enriched soybean oil, this increase was interestedly higher achieving 10 and 33 times. Moreover, colour coordinates (a*, b* and L*) in enriched oils changed to become greener and yellower. Antioxidant activities were improved compared to the control oils. The addition of pigment extract or BHA to soybean oil increased significantly (p≤0.05) its oxidative stability. Thus, these pigment extracts could be recommended as a potent source of natural antioxidants replacing synthetic ones for the protection of edible oils against oxidation. [ABSTRACT FROM AUTHOR] more...

Flavonoids are antioxidant phytochemicals that confer a beneficial effect on human health. We have previously developed and characterized eight lettuce (Latuca sativa L.) lines that accumulated high levels of diverse flavonoids and their precursors in controlled environment conditions. Three Rutgers Scarlet lettuce (RSL) lines selected in tissue culture for deep-red color (RSL-NAR, RSL-NBR, RSL-NFR) accumulate anthocyanins and quercetin, three lines identified in a chemically mutagenized red lettuce population accumulate kaempferol (KfoA and KfoB) or naringenin chalcone (Nco), and two lines that were spontaneous green mutants derived from the red line RSL-NAR (GSL, GSL-DG) accumulate quercetin. These eight lines were field-grown in the Salinas Valley of California for four years together with seven control accessions of varying colors (light green, dark green, red, and dark red). At market maturity, a substantial variation in plant composition was observed, but the three RSL lines consistently accumulated high levels of cyanidin, GSL and GSL-DG accumulated the highest levels of quercetin, KfoA and KfoB accumulated kaempferol, and Nco amassed naringenin chalcone, confirming that these mutant lines produce high levels of beneficial phytochemicals under field conditions. Mutant lines and control accessions were also assessed for their biomass production (plant weight, height, and width), overall content of pigments (leaf chlorophyll and anthocyanins), resistance to diseases (downy mildew, lettuce drop, and Impatiens necrotic spot virus), postharvest quality of processed tissue (deterioration and enzymatic discoloration), and composition of 23 mineral elements. All but one mutant line had a fresh plant weight at harvest comparable to commercial leaf cultivars; only Nco plants were significantly (p < 0.05) smaller. Therefore, except for Nco, the new, flavonoid hyperaccumulating lines can be considered for field cultivation. [ABSTRACT FROM AUTHOR] more...

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Additive‐assisted donor and acceptor domain regulation is regarded as an effective strategy to further release the potential photovoltaic performance of the existing organic solar cells (OSCs). Meanwhile, it is also critical to find high‐efficient, stable, non‐toxic, and low‐cost biological materials as bio‐additives to replace the traditional toxic halogen‐based additives. In this study, bio‐additives derived from a natural chlorophyll pigment named as ZnChl and H2Chl are employed to optimize the morphology and molecular stack of the PM6:Y6 active layer. The eutectic molecular stack of the blends is more ordered and tighter after introducing the bio‐additive chlorophyll derivatives to the system compared to the pristine PM6:Y6 blends. Owing to such a fine‐tuned donor‐acceptor microstructure network, the photovoltaic performance of the H2Chl bio‐additive‐based OSC achieves a 17.30% PCE and ZnChl‐based device obtains an efficiency of 16.61%, which is much higher than that of the control device with a 15.97% PCE. The result proves the feasibility of introducing environmental‐ and eco‐friendly chlorophyll derivatives as bio‐additives to further improve the photovoltaic performance of the OSCs. [ABSTRACT FROM AUTHOR] more...

Light is one the most important factors affecting growth and development of microorganisms with high photosynthesis performance such as Chlorella vulgaris. Due to its simple life cycle Chlorella used as model organism to study, the photosynthesis mechanisms and the cell metabolism control. The aim of presented research was to determine the effect of different light intensity on Chlorella vulgaris growth rate, the amount of chlorophyll a and b, composition and formation of pigment complex. In the basis of results, it has been found that when the light intensity increases to 500-μmol m-2 s-1, the absorption spectrum peak of chlorophyll a shifted to a short wave for 4-5 nm. Research showed that there are 5 forms of chlorophyll a and 2 forms of chlorophyll b aggregates at the pigment complex of Chlorella vulgaris. [ABSTRACT FROM AUTHOR] more...

Summary: In natural ecosystems, plants compete for space, nutrients and light. The optically dense canopies limit the penetration of photosynthetically active radiation and light often becomes a growth‐limiting factor for the understory. The reduced availability of photons in the lower leaf layers is also a major constraint for yield potential in canopies of crop monocultures. Traditionally, crop breeding has selected traits related to plant architecture and nutrient assimilation rather than light use efficiency. Leaf optical density is primarily determined by tissue morphology and by the foliar concentration of photosynthetic pigments (chlorophylls and carotenoids). Most pigment molecules are bound to light‐harvesting antenna proteins in the chloroplast thylakoid membranes, where they serve photon capture and excitation energy transfer toward reaction centers of photosystems. Engineering the abundance and composition of antenna proteins has been suggested as a strategy to improve light distribution within canopies and reduce the gap between theoretical and field productivity. Since the assembly of the photosynthetic antennas relies on several coordinated biological processes, many genetic targets are available for modulating cellular chlorophyll levels. In this review, we outline the rationale behind the advantages of developing pale green phenotypes and describe possible approaches toward engineering light‐harvesting systems. [ABSTRACT FROM AUTHOR] more...

ONE of the major factors significantly modifying plant physiology and ultimately causing a loss in crop productivity is water deficiency stress. Plant-based pigments are highly effective in enhancing growth and reducing the consequences of water stress. The present study aimed to identify the effects of copper chlorophyllin (Cu-Chl) at rates of 0, 1, and 2% on the growth, yield, and physiological traits of spinach plants of the variety Viroflay grown under three irrigation levels of 100%, 75%, and 50% crop evapotranspiration rates (ETc) in the 2020 and 2021 growing seasons. In comparison with full irrigation (100% ETc), deficit irrigation with 50% ETc drastically reduced plant growth parameters (height, leaf number, leaf area, and fresh and dry weight), yield, relative water content (RWC), leaf membrane stability index (MSI), electrolyte leakage (EL), chlorophyll a, chlorophyll b, carotenoids, Fe, and Cu content. However, the nitrate and oxalate content increased in the plants. All studied values were significantly higher except nitrate and oxalate content which were lower with Cu-Chl application, in comparison with those without Cu-Chl application. The present work demonstrated that the adverse effects of water deficit on growth, yield, plant water status, and photosynthetic pigments of spinach plants could be alleviated when using Cu-Chl application. [ABSTRACT FROM AUTHOR] more...

This study pursued tests on 17 local and exotic soybean (Glycine max L. Merr.) cultivars with two different water regimes. In the optimal irrigated condition (control), the soybean plants gained five times irrigation in the scheme of 1:3:1 during the vegetation period, with the total volume of water used for that irrigation being 5000-5500 m3/ha. For the water deficit condition, irrigation was only three times on the scheme 1:1:1, using a total volume of water at 3000-3500 m3/ha. In the optimal irrigated condition, water provision was only once during the formation of soybean leaves, three times during the budding period, and once again at the beginning of the blooming period. In that condition, the provision of an artificially created water deficit condition and drought with one irrigation ensued at the beginning of the blossoming period. According to the results, chlorophyll "b" pigment was more sensitive to water deficit conditions than chlorophyll "a." The increase in chlorophyll "b" under drought conditions increased chlorophyll's protection function, the primary photosynthetic pigment, with its reception of photons from sunlight. Stress enzyme activity increased to different extents compared with optimal water supply conditions in the soybean cultivars under water deficit conditions. The number of chloroplast pigments in plant leaves and the activity of peroxidase, catalase, and superoxide dismutase enzymes in leaves strongly influenced local and exotic soybean genotypes during the blooming-harvest period under drought conditions. With water deficit conditions, the number of pods per plant and 1000-grain weight reduced from 8.6% to 63.7% and 1.7% to 12.8% in the local and 3.8% to 28.3% and 5.6% to 58.8% in exotic soybean cultivars compared with water optimal conditions. [ABSTRACT FROM AUTHOR] more...

Bamboo is nutritionally significant across the world because the shoots are high in calories and nutritional fiber but low in cholesterol. However, recent research has shown that bamboo shoots also contain a substantial quantity of heavy metals, including arsenic (As). Therefore, we explored whether the co-application of iron oxide nanoparticles (IONPs) and selenium nanoparticles (Se-NPs) would attenuate As toxicity in bamboo plants (Pleioblastus pygmaeus). A greenhouse experiment was performed to investigate plant responses to arsenic toxicity. Bamboo plants exposed to four levels of As (0, 10, 20, and 40 mg L−1) were foliar-sprayed with 60 mg L−1 of Se-NPs and 60 mg L−1 of IONPs alone and in combination. The data indicated that different As concentrations (10, 20, and 40 mg L−1) caused membrane damage and reactive oxide species (ROS) production in bamboo cells, characterized by H2O2, O2•−, MDA, and EL increasing by up to 47%, 54%, 57%, and 65%, respectively, in comparison with a control. The co-application of 60 mg L−1 of Se-NPs + IONP markedly improved the antioxidant enzyme activities (by 75% in SOD, 27% in POD, 52% in CAT, 37% in GR, and 38% in PAL), total flavonoid content (42%), phenolic content (36%), proline (44%), nitric oxide (59%), putrescine (Put) (85%), spermidine (Spd) (53%), relative water content (RWC) (36%), photosynthetic characteristics (27%) in net photosynthesis (Pn) (24% in the intercellular CO2 concentration (Ci), 39% in stomatal conductance (Gs), and 31% in chlorophyll pigments), and ultimately biomass indices and growth. The co-application of Se-NPs + IONPs with 10 and 20 mg L−1 of As raised the TI by 14% and 9% in the shoot and by 18% and 14% in the root, respectively. IONPs and Se-NPs reduced ROS, cell membrane lipoperoxidation, and electrolyte leakage, all contributing to the decrease in oxidative stress by limiting As uptake and translocation. In sum, Se-NPs and IONPs improved bamboo endurance, yet the most effective approach for increasing bamboo's ability to recover from As toxicity was the concurrent use of 60 mg L−1 of Se-NPs and 60 mg L−1 of IONPs. Our IONP and Se-NP data from single and combined applications offer novel knowledge in improving the tolerance mechanism against As exposure in Pleioblastus pygmaeus. [ABSTRACT FROM AUTHOR] more...

High volumes of wastewater from aquaculture operations are produced and this wastewater contains very high organic compounds as well as nutrients like nitrogen and phosphorus. The possibility of utilizing aquaculture wastewater as a cultivation medium for microalgae is intriguing. The objective of this research was to utilize aquaculture wastewater as a cultivation, biomass production as well as yield of pigments from a commercially significant species Spirulina (Arthrospira) platensis. Aquaculture wastewater obtained from ornamental fish culture tanks of ICAR-CIFE was used for the experiments after certain amendments. The relative performance of the amended aquaculture wastewaters supplemented with NaHCO3 (8 g l-1) and NaNO3 (2.5 g l-1) was determined through the biomass production, pigment quantity (carotenoid and chlorophyll-a) and compared with the prescribed medium (CIFE medium). The dry weight (DW) was almost comparable with the control showing a negligible decrease of 1.14%. In the case of carotenoid, cells grown in amended aquaculture wastewater expressed only 22.40 % reduction from that of control. The value of chlorophyll-a content 49.7±1.56 mg g-1 DW was recorded for amended aquaculture wastewaters. The present study shows the potential of S. platensis cultivation using aquaculture wastewater to make it costeffective by reducing the cost of biomass production through the reuse of the aquaculture wastewater. The quality of biomass and pigment properties in amended aquaculture wastewater grown cultures were not altered to the extent which affects the quality and purity of the value added pigments such as carotenoid and chlorophyll-a. [ABSTRACT FROM AUTHOR] more...

Many studies have investigated the photoprotective and photosynthetic capacity of plant leaves, but few have simultaneously evaluated the dynamic changes of photoprotective capacity and photosynthetic maturation of leaves at different developmental stages. As a result, the process between the decline of photoprotective substances and the onset of photosynthetic maturation during plant leaf development are still poorly understood, and the relationship between them has not been quantitatively described. In this study, the contents of photoprotective substances, photosynthetic pigment content and photosynthetic capacity of leaves at different developmental stages from young leaves to mature leaves were determined by spatio-temporal replacement in eight dominant tree species in subtropical evergreen broadleaved forests. The correlation analysis found that the data sets of anthocyanins, flavonoids, total phenolics and total antioxidant capacity were mainly distributed on one side of the symmetry axis (y  =  x), while the data sets of flavonoids, total phenolics and total antioxidant capacity were mainly distributed on both sides of the symmetry axis (y  =  x). In addition, the content of photoprotective substances in plant leaves was significantly negatively correlated with photosynthetic pigment content and photosynthetic capacity but was significantly positively correlated with dark respiration rate (Rd). When chlorophyll accumulated to ~50% of the final value, the photoprotective substance content and Rd of plant leaves reached the lowest level, and anthocyanins disappeared completely; in contrast, the photosynthetic capacity reached the highest level. Our results suggest that anthocyanins mainly play a light-shielding role in the young leaves of most plants in subtropical forests. In addition, 50% chlorophyll accumulation in most plant leaves was the basis for judging leaf photosynthetic maturity. We also believe that 50% chlorophyll accumulation is a critical period in the transition of plant leaves from high photoprotective capacity (high metabolic capacity, low photosynthetic capacity) to low photoprotective capacity (low metabolic capacity, high photosynthetic capacity). [ABSTRACT FROM AUTHOR] more...

【Objective】 The present paper aimed to explore the physiological and biochemical response of Nymphaea minuta to low light environment, and to provide theoretical basis for seedling breeding and potted flower production management of micro-tropical water lily represented by N.minuta. 【Method】 A completely random experimental design was conducted. The shading treatments were set to 0(total illumination control, CK), 30% (light shading), 50% (medium shading), 70% (heavy shading) respectively by constructing shading nets with different layers. The number of leaves, leaf dry weight, leaf area and other growth indicators were measured by shading treatment for 120 days. The content and composition of photosynthetic pigments, soluble sugar, soluble protein and starch contents were measured by shading treatment for 30, 60, 90 and 120 days respectively. The effects of different shading conditions on leaf growth, photosynthetic pigment content and primary metabolites content of N.minuta were analyzed. 【Result】 During the shading period of 30-120 days, there were no significant differences between the average leaf area, photosynthetic pigment content, and soluble protein content of N.minuta treated with shading rate of 30%, 50% and CK (P＞0.05). After shading treatment for 120 days, the leaf number, average leaf dry weight, specific leaf weight, soluble sugar content, soluble protein content and starch content of N.minuta decreased with increasing shading rate, while total chlorophyll content, chlorophyll a content, chlorophyll b content, chlorophyll a/b content and carotenoid content all increased with increasing shading rate. Comparing with CK, the shading rate of 70% at 120 days treatments, the leaf number, average leaf dry weight and specific leaf weight of N.minuta were significantly decreased by 52.9%, 81.3% and 57.8%, respectively (P＜0.05, the same as below), total chlorophyll content, chlorophyll a content, chlorophyll b content and carotenoid content were significantly increased by 108.7%, 81.6%, 237.5% and 88.2% respectively, chlorophyll a/b content was significantly decreased by 39.1%, soluble sugar content, soluble protein content and starch content were significantly decreased by 43.4%, 56.2% and 53.2% respectively. The results of correlation analysis showed that the leaf number and average leaf dry weight were extremely positively correlated with soluble protein content (P＜0.01, the same as below), and the average leaf dry weight was negatively correlated with total chlorophyll content, chlorophyll a content, chlorophyll b content and carotenoid content. 【Conclusion】 N.minuta grew well in light and medium shading environments with shading rates of 30% and 50%, showing good light adaptive response and regulation ability. These two shading methods can be used for reference in the breeding of micro-tropical waterlily seedlings and potted flower production management. [ABSTRACT FROM AUTHOR] more...

For many years, there has been a growing trend toward producing plants using tissue culture, the most efficient method at present. Every year, more and more protocols for micropropagation of economically valuable species are appearing. Many factors influence the regenerating explants under sterile laboratory conditions. One of the most important is light. The aim of the present study was to increase the efficiency of micropropagation of hellebore 'Molly's White' using energy-efficient light-emitting diodes (LEDs), which were compared to traditionally used fluorescent lamps (FLs). To choose the best light and reduce production costs, white, blue or red LEDs with two levels of photosynthetic photon flux density (PPFD), 40 and 70 μmol/m2/s, were used at the multiplication and rooting stages. LED light color has been shown to affect regeneration rate and plant growth in length during micropropagation, while both light parameters (color as well as intensity) affect the length of regenerating shoots and the content of assimilation pigments in plants. The use of white LED light, which gives the highest multiplication rate, at an intensity of 70 μmol/m2/s saves more than 57 kWh during an 8-week micropropagation cycle compared to conventional fluorescent lamps with the same parameters. [ABSTRACT FROM AUTHOR] more...

Hydrocarbon stress is among significant environmental stresses limiting crop growth and production. Allicin is an organosulfur compound with the potential to detoxify radicals, abate oxidative injury, and safeguard mitochondrial function. However, allicin role in mediating plant defense responses under abiotic stresses is not established. Therefore, the impact of varying levels of allicin (0, 50, 100, and 200 mg L−1) on growth, photoysnthesis, osmolyte accumulation, and antioxidant defense system of wheat plants under petroleum hydrocarbon (0, 5 and 10%) was evaluated. Hydrocarbon stress (10%) significantly inhibited growth characteristics, relative water contents, chlorophyll, antioxidant pigments, DPPH radical scavenging potential, reducing sugars, free amino acids, as well as soluble proteins in wheat plants. Hydrocarbon stress (10%) augmented the secondary metabolites accumulation like anthocyanins, phenolics, flavonoids, and ascorbic acid in wheat plants. Plants accumulated more total soluble sugars, non-reducing sugars and proline concentrations after exposure to 10% hydrocarbon stress. Hydrocarbon stress enhanced the activities of antioxidant enzymes (SOD, POD, CAT, and APX). Plants exposed to hydrocarbon stress displayed a significant accretion in oxidative damage, mirrored as enhanced electrolyte leakage, ROS generation (H2O2 and O2.−), lipoxygenase activity, and lipid peroxidation estimated as MDA and methylglyoxal levels. Besides, exogenous allicin (100, 200 mg L−1) improved plant growth, chlorophyll contents, and osmolytes accumulation under hydrocarbon stress. Furthermore, allicin (100 mg L−1) effectively increased plants' non-enzymatic antioxidant levels and enzymatic antioxidant activities under hydrocarbon stress. Allicin diminished oxidative stress by lowering electrolyte leakage (39.4%), H2O2 (20.9%), O2.− (37.7%), lipoxygenase activity (23.1%), MDA (25.2%), and MG (32.4%) levels under hydrocarbon stress. This is the first report describing the involvement of allicin, notably higher doses (100 and 200 mg L−1), in alleviating the phytotoxic impacts of hydrocarbon stress by modulating growth, osmolyte accumulation, oxidative defense, and ROS metabolism. [ABSTRACT FROM AUTHOR] more...

When obtaining new cultivars or monitoring the nutritional composition of lettuce, new techniques are necessary given the high cost and time required to conduct laboratory analyses of plant composition by conventional methods. The objective of this study was to evaluate different vegetation indices for the estimation of anthocyanin, chlorophyll, and carotenoids in mini-lettuce genotypes with different leaf colors and different typologies from red, green, and blue (RGB) images. The contents of pigments were evaluated in 15 lettuce genotypes, in addition to the soil plant analysis development (SPAD) index and vegetation indices in the visible range. The variability among genotypes was confirmed by the Scott-Knott test (p < 0.05) and multivariate analysis. Linear regressions were obtained between the green leaf index (GLI) and leaf pigments. GLI was a good predictor for estimating the contents of anthocyanin (r = −0.83; r2 = 0.75), carotenoid (r = −0.59; r2 = 0.43), chlorophyll a (r = −0.69; r2 = 0.48), chlorophyll b (r = −0.62; r2 = 0.39), and total chlorophyll (r = −0.77; r2 = 0.65) in red and green mini-lettuce. The high-performance phenotyping technique can be used to evaluate leaf pigments in breeding programs, as well as in crops for monitoring biofortification levels in lettuce. [ABSTRACT FROM AUTHOR] more...