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Chlorophylls (Chls) are the most abundant plant pigments on Earth. Chls are located in the membrane of thylakoids where they constitute the two photosystems (PSII and PSI) of terrestrial plants, responsible for both light absorption and transduction of chemical energy via photosynthesis. The high efficiency of photosystems in terms of light absorpt...
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... harvesting complexes have evolved many adaptive mechanisms that permit photosynthetic organisms to thrive in different environments. The spectral distribution of sunlight that reaches our planet largely covers the absorption spectra of photosynthetic pigments utilized in light harvesting antennas (Figure 2). In a general way, light harvesting antennas have developed the ability to optimize light capture under both low-and high-intensity light conditions [1]. ...
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... Regarding the yield of the extraction, in Figure 3A, the percentages for each solvent were shown; low yields are observed for the extracts of the apolar solvents (hexane and dichloromethane), which were mainly extracted metabolites that absorb in the visible region, as can be seen in the color of the extracts ( Figure S1), with minimal absorption in the UVA-UVB region; these are not of interest to our research. Additionally, the maximum absorbance of these two extracts were presented in characteristic spectral regions (640-700 nm) for compounds of the type of chlorophylls a and b and carotenoids [23]. Therefore, the use of these solvents facilitated the removal of interfering compounds such as lipids and pigments. ...
Overexposure to solar radiation has become an increasingly worrying problem due to the damage to the skin caused by ultraviolet radiation (UVR). In previous studies, the potential of an extract enriched with glycosylated flavonoids from the endemic Colombian high-mountain plant Baccharis antioquensis as a photoprotector and antioxidant was demonstrated. Therefore, in this work we sought to develop a dermocosmetic formulation with broad-spectrum photoprotection from the hydrolysates and purified polyphenols obtained from this species. Hence, the extraction of its polyphenols with different solvents was evaluated, followed by hydrolysis and purification, in addition to the characterization of its main compounds by HPLC–DAD and HPLC–MS, and evaluation of its photoprotective capacity through the measurement of the Sun Protection Factor (SPF), UVA Protection Factor (UVAPF), other Biological Effective Protection Factors (BEPFs), and its safety through the cytotoxicity. In the dry methanolic extract (DME) and purified methanolic extract (PME), flavonoids such as quercetin and kaempferol were found, which demonstrated antiradical capacity, as well as UVA–UVB photoprotection and prevention of harmful biological effects, such as elastosis, photoaging, immunosuppression, DNA damage, among others, which demonstrates the potential of the ingredients in this type of extract to be applied in photoprotection dermocosmetics.
... [99]. The formation of some SMs helps plants cope with stressors, since they act as scavengers of free radicals and protect plant cells from oxidative damage [100]. Furthermore, the SMs pathway is supported by the derivation of photosynthetic products with a variety of intermediates, increasing the photosynthetic rate through a positive-feedback mechanism, so that the soluble sugars, which are the primary products of photosynthesis, increase. ...
The conservation of medicinal plants, particularly endangered or endemic species, is of the utmost importance, especially in light of inevitable climate change and its consequences. Species inhabiting high altitudes adopt exceptional defense mechanisms in response to abiotic stresses as a survival strategy. The objective of the current study was to investigate the effects of altitudinal variations on secondary metabolite accumulation and antioxidant enzyme capacity in four plants (Cotoneaster orbicularis, Crataegus x sinaica, Echinops spinosissimus subsp. Spinosissimus, and Tanacetum sinaicum) growing naturally on the Sinai Peninsula’s high mountains. Plant leaves and soil samples were collected from three altitudes between 1500 and 2250 m a.s.l. to evaluate the adaptive responses of these species in relation to high-altitude oxidative stresses. The results showed that at higher altitudes, the electrical conductivity and the micronutrient contents of the soil decreased, which may be due to the prevalence of silt and clay decreasing at higher altitudes. Chlorophyll a, chlorophyll b, ascorbic acid, and total soluble protein showed similar results in relation to higher altitudes for all species. On the other hand, proline, total soluble sugars, carotenoids, phenols, tannins, and flavonoids increased in response to high altitudes. The activity levels of catalase and ascorbic acid peroxidase showed a significant increase aligned with higher altitudes, while a significant decrease in activity levels was obtained for polyphenol oxidase. In conclusion, the present findings showed that Cotoneaster orbicularis exhibited the maximum response for coping with high-altitude stresses, followed by the remaining three species regarding the level of biochemical and physiological responses. The present work will help formulate conservation plans for important medicinal species.
... With increasing biofouling accumulations, we see a similar curve but a diminished RGB signal of up to 50% from no biofouling to high biofouling accumulations. This corresponds partially with the absorption features of chlorophyll [45], which is consistent with the fact that the biofouling is mostly composed of green turf algae. On the other hand, we see practically no difference in the spectral response of the HDPE mesh in the 10 m NIR band between the different stages of biofouling accumulation, which is also consistent with chlorophyll absorbance features, since chlorophyll does not absorb above the 750 nm range. ...
Large-area, artificial floating marine litter (FML) targets were deployed during a controlled field experiment and data acquisition campaign: the Plastic Litter Project 2021. A set of 22 Sentinel-2 images, along with UAS data and ancillary measurements were acquired. Spectral analysis of the FML and natural debris (wooden planks) targets was performed, along with spectral comparison and separability analysis between FML and other floating materials such as marine mucilage and pollen. The effects of biofouling and submersion on the spectral signal of FML were also investigated under realistic field conditions. Detection of FML is performed through a partial unmixing methodology. Floating substances such as pollen exhibit similar spectral characteristics to FML, and are difficult to differentiate. Biofouling is shown to affect the magnitude and shape of the FML signal mainly in the RGB bands, with less significant effect on the infrared part of the spectrum. Submersion affects the FML signal throughout the range of the Sentinel-2 satellite, with the most significant effect in the NIR part of the spectrum. Sentinel-2 detection of FML can be successfully performed through a partial unmixing methodology for FML concentrations with abundance fractions of 20%, under reasonable conditions.
... Unlike the case with chlorophyll which is widely found in leaves, the absorption range is 460-650 nm [16]. The working principle of solar cells with this pigment is similar to photosynthesis in plants [17]. ...
The need for energy that continues to increase has led to research processes to create renewable technologies. One of them is the manufacture of Dye-Sensitized Solar Cell with a photosensitizer derived from abundant natural ingredients, easy to extract and environmentally friendly. Although the resulting efficiency is not as great as that of synthetic materials, combining these natural pigments can expand the absorption area. This can be seen from the efficiency produced, which is greater than a single dye. This review analyses the synthesis process and characterization of the dye combination as a DSSC photosensitizer starting from dye extraction, TiO2 deposition to characterization using various tools. In addition, there are results of research with dye combinations that can be prospects for further research.
... The absorption spectra of chlorophyll a, b, and carotenoids peak in the blue and red regions of PAR. Among the three light sources, RGB LED best matched the combined absorption spectra of chlorophyll a, b, and β-carotene [44]. Nevertheless, no difference in growth, maximum cell size, cell number, or photosynthetic pigment composition was observed among the three light sources. ...
Light is the essential energy source for autotrophically growing organisms, including microalgae. Both light intensity and light quality affect cell growth and biomass composition. Here we used three green algae—Chlamydomonas reinhardtii, Desmodesmus quadricauda, and Parachlorella kessleri—to study the effects of different light intensities and light spectra on their growth. Cultures were grown at three different light intensities (100, 250, and 500 µmol m−2 s−1) and three different light sources: fluorescent lamps, RGB LEDs, and white LEDs. Cultures of Desmodesmus quadricauda and Parachlorella kessleri were saturated at 250 µmol m−2 s−1, and further increasing the light intensity did not improve their growth. Chlamydomonas reinhardtii cultures did not reach saturation under the conditions used. All species usually divide into more than two daughter cells by a mechanism called multiple fission. Increasing light intensity resulted in an increase in maximum cell size and division into more daughter cells. In Parachlorella kessleri cells, the concentration of photosynthetic pigments decreased with light intensity. Different light sources had no effect on algal growth or photosynthetic pigments. The results show a species-specific response of algae to light intensity and support the use of any white light source for their cultivation without negative effects on growth.
... the use of plant species that are able to grow, develop, and produce well in low light intensity environments is very important to be able to take advantage of the land between the stands A photosystem (PS) consists of an antenna which is a collection of pigments and accessory pigments that capture and transfer photon energy to the reaction center, and a reaction center (composed of chlorophyll a) which transfers electrons out of the reaction center (Belgio et al., 2012). That is, chlorophyll a is not the only photosynthetically important pigment in chloroplasts but there are other pigments in the thylakoid membrane that can absorb light and transfer its energy to chlorophyll a (Sulistyowati et al., 2016;Guidi et al., 2017). ...
Introduction: Plants that grow and develop in a shaded environment are difficult to produce optimally. Therefore, the use of plant species that are able to produce optimally in a shaded environment is very important to be used as an agroforestry area. The research purposes was to observe morpho-physiological characters that can be used as characters to determine chilli plants that can produced in low light intensity area. Methods: A field experiment was conducted at farmer field in Pekuncen, Banyumas, Indonesia from May to October 2020. The research was arranged in randomized complete block design (RCBD) with three replications. The first plot was shading intensity (0% (control) and 50%) and the second plot consisted of nine chilli varieties, V1 (Segana), V2 (Lada Hijau), V3 (Bara), V4 (Catas),V5 (Kerinci), V6 (Raya), V7 (Genie), V8 (Sonar), and V9 (Rajo). Results: The results of this research showed that shade affected on leaves number and leaves area, but not affected on plant height and stem diameter. Shading net was affected on chlorophyll a and b, but not affected on chlorophyll content. Decreasing of total chlorophyll on 50% shade net occurring in shade sensitive varieties was significantly different than shade-tolerant varieties. Tolerant varieties based on the observation criteria were Bara (V3), Genie (V7), and Sonar (V8). Conclusion: Leaf area and leaf pigment character can be used as a reference for determining the resistance of varieties to low light.
... Absorbance spectra of chlorophyll and carotenoids in healthy plants. Source:[38]. ...
Health monitoring in plants is vital for agricultural sustainability. Currently, the number of techniques able to detect plant stress and disease at an early stage is limited. Prevention of diseases and stress, while the plants are still in an asymptomatic stage could lead to better crop management in agricultural industries. This review focuses on the applications of visible and near-infrared (Vis-NIR) spectroscopy in disease detection and the implications of stress in various species of plants. It is a rapid and non-destructive technique that doesn’t require or requires only minimal sample processing before measurements and data analysis. The visible and near-infrared region can detect almost all functional groups and compounds making it a promising tool for data analysis. A brief overview of the methods used and the absorption bands in the Vis-NIR range related to plant disease and stress will be discussed. The comprehensive review of the application of the visible and near-infrared range regions according to different types of disease and stress including the methods used for the data analysis is being addressed.
... Chlorophyll is the basic pigment that performs photosynthesis by absorbing light and converting it into chemical energy, so life on Earth depends largely on chlorophyll [16]. ...
... The optimal absorption wavelength range for LHCs is in the red region (680-690 nm), where the energy is utilized by chlorophyll to split water and reduce ferredoxin (Fd). Different LHC complexes differ in the number of pigments and their composition and structure in a way that they are an optimized energy collector system (Guidi et al., 2017). Increased contents of carotenoids could be a way to improve light capture and energy transfer to chlorophylls. ...
Cyanobacterial Lifestyle and its Applications in Biotechnology discusses the different aspects of cyanobacteria, with an aim of helping readers better understand advanced cyanobacterial molecular biology aspects that will allow us to uncover the potential of cyanobacteria in the tailoring of stress smart crops for sustainable agriculture. Chapters deal with the different aspects of cyanobacteria and discuss diverse cyanobacterial communities that have the ability to fix atmospheric nitrogen with their photosynthetic properties and applications in field conditions. The book discusses several cyanobacterial species that have been exploited to enhance soil fertility, mitigate biotic and abiotic stress, and provide contamination management.
This book tackles the urgent need to explore cyanobacterial metabolism under stress as well as their regulatory pathways for sustainable agriculture. In recent decades, the application of cyanobacteria has attracted the scientists because of uniqueness, better adaptability, and synthetic products, hence this book provides a timely resource on the topic.
Key Features
Presents molecular approaches on the identification of cyanobacteria and their evolution
Expands our horizon on the topics of cyanobacterial lifestyle and stress management
Includes cyanobacterial photosynthesis research
Discusses metabolic engineering in cyanobacteria
... Th phycobilisome (PBS) is a large umbrella-like structure that can absorb light from the blue-green to the red region of the visible light spectrum (500-700 nm) [53]. This feature is very unique for cyanobacteria, red algae and glaucophytes since other green organisms (green algae, higher plants) absorb light mainly in the blue (430-480nm) and red (680-700 nm) regions and not in the green, yellow and orange regions [54]. The uniqueness of the PBS light absorption capacity is enabled by the pigments known as phycobilins. ...
Photosynthesis is the major natural process that can harvest and harness solar energy into chemical energy. Photosynthesis is performed by a vast number of organisms from single cellular bacteria to higher plants and to make the process efficient, all photosynthetic organisms possess a special type of pigment protein complex(es) that is (are) capable of trapping light energy, known as photosynthetic light-harvesting antennae. From an evolutionary point of view, simpler (unicellular) organisms typically have a simple antenna, whereas higher plants possess complex antenna systems. The higher complexity of the antenna systems provides efficient fine tuning of photosynthesis. This relationship between the complexity of the antenna and the increasing complexity of the organism is mainly related to the remarkable acclimation capability of complex organisms under fluctuating environmental conditions. These antenna complexes not only harvest light, but also provide photo-protection under fluctuating light conditions. In this review, the evolution, structure, and function of different antenna complexes, from single cellular organisms to higher plants, are discussed in the context of the ability to acclimate and adapt to cope under fluctuating environmental conditions.
