Photosynthetic Apparatus Of Plants Research Articles

Electron transport in chloroplasts: regulation and alternative pathways of electron transfer

This work represents an overview of electron transport regulation in chloroplasts as considered in the context of structure-function organization of photosynthetic apparatus in plants. A basic focus of the article is concentrated on a bifurcated oxidation of plastoquinol by the cytochrome b6f complex, which represents the rate-limiting step of electron transfer between photosystems 2 and 1. Electron transport along the chains of the noncyclic, cyclic and pseudocyclic electron flow, their relationships to generation of the trans-thylakoid difference in electrochemical potentials of protons in chloroplasts, and the pH-dependent mechanisms of regulation of the cytochrome b6f complex, are considered. Redox reactions with the participation of molecular oxygen and ascorbate, the alternative mediators of electron transport in chloroplasts, have also been discussed.

Electron Transport in Chloroplasts: Regulation and Alternative Pathways of Electron Transfer.

This work represents an overview of electron transport regulation in chloroplasts as considered in the context of structure-function organization of photosynthetic apparatus in plants. Main focus of the article is on bifurcated oxidation of plastoquinol by the cytochrome b6f complex, which represents the rate-limiting step of electron transfer between photosystems II and I. Electron transport along the chains of non-cyclic, cyclic, and pseudocyclic electron flow, their relationships to generation of the trans-thylakoid difference in electrochemical potentials of protons in chloroplasts, and pH-dependent mechanisms of regulation of the cytochrome b6f complex are considered. Redox reactions with participation of molecular oxygen and ascorbate, alternative mediators of electron transport in chloroplasts, have also been discussed.

Insect Frass as a Novel Organic Soil Fertilizer for the Cultivation of Spinach (Spinacia oleracea): Effects on Soil Properties, Plant Physiological Parameters, and Nutrient Status

Soils naturally low in organic matter need to be amended with recycled organic materials that would boost soil health. In this work, we tested insect frass, the excrements of the yellow mealworm, Tenebrio molitor, as a novel organic soil amendment in a spinach cultivation. In a 60-day pot experiment with spinach (Spinacia oleracea), we added frass at rates of 0, 0.25, 0.5, and 1%, as well as an inorganic nitrogen-phosphorus-potassium (NPK) fertilizer as a positive control. We found that organic matter increased significantly from 2.7% in the unamended control to 3.2% in the treatment of 1% frass, showing that frass has a valuable role in boosting soil carbon (C). Also with increasing frass rates, N uptake by plant was enhanced, due to the fact that nitrogen use efficiency (NUE) remained unchanged. These findings exhibit the fact that added N was utilized satisfactorily. However, frass effectiveness was not successful in the case of added P and K: the likely reason is the already very high P and K available contents in the unamended soil. Spinach growth was significantly favored by the amendment of frass in a rate-dependent manner: the higher biomass accumulation was found under 1% frass—six-fold higher than NC, while even at 0.25% the yield was significantly higher. Plants at this treatment had the highest chlorophyll a + b content throughout the course of the experiment and also exhibited the highest photosynthetic efficiency and performance of the plant photosynthetic apparatus under frass treatments. The index of total photosynthetic efficiency (PItotal) also fared better in the frass-added treatments upwards from 0.25%. We conclude that frass is a highly valuable soil conditioner, given the amble organic C and N that adds to soil, resulting in boosted growth of spinach. As this report is a preliminary study, we suggest that future works should expand frass testing to (a) more plants, where a series of important plant physiology features must be evaluated, and (b) the role of frass in trace element availability.

Impact of technological practices on the photosynthetic productivity of spring barley in Northern Forest-Steppe conditions

Aim. To determine the features of the formation of the photosynthetic apparatus in spring barley plants depending on the influence of individual elements of cultivation technology and to identify the most effective combinations for maximizing the genetic potential of the crop under the conditions of the northern part of the Right-Bank Forest-Steppe of Ukraine. Methods. During the research, a field study method, visual observation, weighing, the «cutting» method, calculations, and statistical analysis were applied. Results. The research conducted during 2018–2020 has shown that the fertilization system, the use of growth stimulants, and the preceding crop significantly influence the photosynthetic activity of spring barley plants at different stages of organogenesis. The leaf surface index values increased and reached their maximum at the VII and IX stages of organogenesis, after which they gradually decreased. The maximum leaf surface area of 5.03 to 5.24 m2/m2 was achieved in crops with the application of N60P80K80+N60(IV) in the presence of the preceding crop’s by-product. The photosynthetic potential of crops during the period from the II to XI stages of organogenesis was at the level of 1.02–2.42 million m2/ha·day when grown after soybeans and 0.92–2.39 million m2/ha·day when grown after corn for grain. The period from the IV to VIІІ stages of plant organogenesis was characterized by the most active accumulation of dry matter and the most significant influence of all studied agronomic practices on the formation of this indicator. Conclusions. Optimal indicators of photosynthetic activity of spring barley crops (leaf area index of 4.65 m²/m² at the VIII stage of organogenesis, net photosynthesis productivity of 6.71 g/m² per day, dry matter accumulation of 9.51 t/ha at the XI stage of organogenesis) are ensured by the cultivation technology that involves the application of mineral fertilizers at a rate of N45P90K90+N45(IV) against the background of the predecessor’s (corn for grain) byproduct and the use of growth stimulants for pre-sowing seed treatment and foliar application at the IV stage of organogenesis. Such parameters of plant photosynthetic apparatus operation contribute to obtaining a barley grain yield at the level of 4.88–5.27 t/ha.

Daily Short-Term Temperature Drops Can Alleviate the Negative Effect of Continuous Lighting on the Photosynthetic Apparatus in Plants

Several crops (tomato, eggplant, sweet pepper, and cucumber) were used to examine the impact of continuous (24 h a day) lighting on photosynthetic characteristics of plants grown permanently at 26°C and those exposed daily to short-term (2 h) cooling at 10°C (temperature-drop treatments). The plant response was assessed by indices characterizing the pigment complex and the photosynthetic activity of leaves. Growing plans under continuous light at a constant temperature resulted in leaf photodamage and photoinhibition in all four species, although to varying degrees. The temperature-drop treatments prevented the photodamage of leaves under continuous light in all species and enabled high sustainable levels of photosynthetic activity in tomato, pepper, and cucumber. The results suggest that temperature-drop treatments can be regarded as an agricultural technique that exploits the benefits of continuous lighting while mitigating the negative effects of constant light. However, the effectiveness of this technique would depend on the choice of optimal intensities and durations of the drop treatment since these parameters may vary depending on plant species.

Daily Short-Term Temperature Drops Can Alleviate the Negative Effect of Continuous Lighting on the Photosynthetic Apparatus in Plants

Daily Short-Term Temperature Drops Can Alleviate the Negative Effect of Continuous Lighting on the Photosynthetic Apparatus in Plants

Leaf chlorophyll fluorescence and reflectance of oakleaf lettuce exposed to metal and metal(oid) oxide nanoparticles

BackgroundMost nanoparticles (NPs) have a significant impact on the structure and function of the plant photosynthetic apparatus. However, their spectrum of action varies significantly, from beneficial stimulation to toxicity, depending on the type of NPs, the concentration used and plant genotypic diversity. Photosynthetic performance can be assessed through chlorophyll a fluorescence (ChlF) measurements. These data allow to indirectly obtain detailed information about primary light reactions, thylakoid electron transport reactions, dark enzymatic stroma reactions, slow regulatory processes, processes at the pigment level. It makes possible, together with leaf reflectance performance, to evaluate photosynthesis sensitivity to stress stimuli. ResultsWe investigated effects of different metal and metal(oid) oxide nanoparticles on photosynthesis of oakleaf lettuce seedlings by monitoring the chlorophyll a fluorescence light radiation and reflectance from the leaves. Observations of ChlF parameters and changes in leaf morphology were carried out for 9 days in two-day intervals. Spectrophotometric studies were performed at 9th day. Suspensions of NPs with the following concentrations were used: 6% TiO2, SiO2; 3% CeO2, SnO2, Fe2O3; 0.004% (40 ppm) Ag; 0.002% (20 ppm) Au. Nanoparticles were applied directly on the leaves which caused small symptoms of chlorosis, necrosis and leaf veins deformation, but the plants fully recovered to the initial morphological state at 9th day. Leaf reflectance analysis showed an increase in FRI for SiO2-NPs and CeO2-NPs treatments and ARI2 for Fe2O3, however, WBI and PRI coefficients for the latter nanoparticle were lower than in control. Chlorophyll a fluorescence parameters have changed due to NPs treatment. Fe2O3-NPs caused an increase in Fv/F0, PIABS, ET0/RC, DI0/RC, ABS/RC in different time points in comparison to control, also Ag, Au and SnO2 treatment caused an increase in Fv/F0, PIABS or ET0/RC, respectively. On the other hand, TiO2-NPs caused a decrease in Fv/Fm and Fv/F0 parameters, but an increase in DI0/RC value was observed. SnO2-NPs decreased PIABS, but increased ET0/RC than compared to control. Nanoparticles affected the shape of the O-J-I-P curve in slight manner, however, further analyses showed unfavourable changes within the PSII antenna, manifested by a slowdown in the transport of electrons between the Chl molecules of the light-harvesting complex II and the active center of PSII due to NPs application.ConclusionChanges in ChlF parameters and leaf reflectance values clearly proved the significant influence of NPs on the functioning of the photosynthetic apparatus, especially right after NPs application. The nature of these changes was strictly depended on the type of nanoparticles and sometimes underwent very significant changes over time. The greatest changes in ChlF parameters were caused by Fe2O3 nanoparticles, followed by TiO2-NPs. After slight response of O-J-I-P curves to treatment of the plants with NPs the course of the light phase of photosynthesis stabilized and at 9th day were comparable to the control curve.

Formally Exact Simulations of Mesoscale Exciton Diffusion in a Light-Harvesting 2 Antenna Nanoarray.

The photosynthetic apparatus of plants and bacteria combine atomically precise pigment-protein complexes with dynamic membrane architectures to control energy transfer on the 10-100 nm length scales. Recently, synthetic materials have integrated photosynthetic antenna proteins to enhance exciton transport, though the influence of artificial packing on the excited-state dynamics in these biohybrid materials is not fully understood. Here, we use the adaptive hierarchy of pure states (adHOPS) to perform a formally exact simulation of excitation energy transfer within artificial aggregates of light-harvesting complex 2 (LH2) with a range of packing densities. We find that LH2 aggregates support a remarkable exciton diffusion length ranging from 100 nm at a biological packing density to 300 nm at the densest packing previously suggested in an artificial aggregate. The unprecedented scale of these formally exact calculations also underscores the efficiency with which adHOPS simulates excited-state processes in molecular materials.

Non-Photochemical Quenching of Chlorophyll a Fluorescence as an Indicator of the State of a Plant Photosynthetic Apparatus Under Abiotic Stress

Non-Photochemical Quenching of Chlorophyll a Fluorescence as an Indicator of the State of a Plant Photosynthetic Apparatus Under Abiotic Stress

Adjustments in photosynthetic pigments, PS II photochemistry and photoprotection in a tropical C4 forage plant exposed to warming and elevated [CO2

Global climate change will impact crops and grasslands, affecting growth and yield. However, is not clear how the combination of warming and increased atmospheric carbon dioxide concentrations ([CO2]) will affect the photosystem II (PSII) photochemistry and the photosynthetic tissue photoinhibition and photoprotection on tropical forages. Here, we evaluated the effects of elevated [CO2] (∼600 μmol mol−1) and warming (+2 °C increase temperature) on the photochemistry of photosystem II and the photoprotection strategies of a tropical C4 forage Panicum maximum Jacq. grown in a Trop-T-FACE facility under well-watered conditions without nutrient limitation. Analysis of the maximum photochemical efficiency of PSII (Fv/Fm), the effective PSII quantum yield Y(II), the quantum yield of regulated energy dissipation Y(NPQ), the quantum yield of non-regulated energy dissipation Y(NO), and the malondialdehyde (MDA) contents in leaves revealed that the photosynthetic apparatus of plants did not suffer photoinhibitory damage, and plants did not increase lipid peroxidation in response to warming and [CO2] enrichment. Plants under warming treatment showed a 12% higher chlorophyll contents and a 58% decrease in α-tocopherol contents. In contrast, carotenoid composition (zeaxanthin and β-carotene) and ascorbate levels were not altered by elevated [CO2] and warming. The elevated temperature increased both net photosynthesis rate and aboveground biomass but elevated [CO2] increased only net photosynthesis. Adjustments in chlorophyll, de-epoxidation state of the xanthophylls cycle, and tocopherol contents suggest leaves of P. maximum can acclimate to 2 °C warmer temperature and elevated [CO2] when plants are grown with enough water and nutrients during tropical autumn-winter season.

Chlorophyll fluorescence changes, as plant early state indicator under different water salinity regimes on the invasive macrophyte Elodea canadensis (Michx., 1803)

Analysis of the photosynthetic apparatus provides information on the physiological state of plants. The changes of metabolites in plant cells analysed with the pulsed chlorophyll fluorometer make it possible to determine these changes in plant cells even in the presence of insignificant cell damage. The possible effects of different salinity levels, 0.584, 1.461, 2.922 and 5.844 PSU (denoting Practical Salinity Unit) on the fluorescence properties of the pigment complexes of the aquatic invasive E. canadensis photosynthetic apparatus were investigated. Information about E. canadensis macrophyte photosynthetic systems (PSI and PSII) was obtained. After a prolonged impact, the results indicate that high salinity levels in substrates 2.922 and 5.844 PSU seriously affect plant photosynthetic apparatus inhibition. The decrease in ∆Fv/Fm΄ values at 2.922 and 5.844 PSU indicates general deterioration in macrophytes' physiological state. In the post-stress period, photosynthesis intensified. An interesting feature was noted: a low water salinity level (0.584) stimulates chlorophyll formation and increases the FvFm parameter. The research revealed the influence of salinity levels in the substrate on the photosynthesis processes in plants. The PSII system of submerged macrophytes responds rapidly to high salinity levels, probably due to the inhibition of protein synthesis. These data provide information for further bio-diagnosis of overall plant health and prediction of exposure levels, as well as the ability to make predictions of invasive plant growth and spread. The invasion of this plant macrophyte causes the most serious concern in Europe nowadays.

Physiological Performance of Mimosa pudica L. under Different Light Quality and Photoperiods

In the present study, we examined the light quality and photoperiod-dependent physiological performance of Mimosa pudica. Plants were grown in pots under white, blue, green and red-light compositions under 12 h per day (12/12 h) and 24 h per day (24/0 h) for 12 days. After 12 days, the physiological parameters’ morphology, fresh weight, chlorophyll fluorescence and biochemical analyses, which include antioxidants, lipid peroxidation, pigment content and carbohydrate content were also measured. Necrosis was found in red, blue and green light and the plant was senesced at the end of the experiment. The blue 24-h light period showed the highest pigment and antioxidant content, whereas the lowest was observed in green light conditions. The OJIP curve was complete in white light, hence it was not completely formed in red, blue and green light. The phenomenological parameters also fluctuated in different light conditions. Photosynthesis ultimately results in starch content, which was highest in blue light and lowest in red light. Different monochromatic light qualities inhibited plant growth by reducing the activity of photosynthetic apparatus in plants. White light was more effective in driving photosynthesis and promoting the plant growth, while green and red light showed a suppressive effect on plants’ growth. The 24 h photoperiod was also accompanied by various spectra to reduce the plants’ growth. The results clearly indicate that the photoperiod and light spectrum must be considered before growing plants in a greenhouse.

Ultrastructure, adaptability, and alleviation mechanisms of photosynthetic apparatus in plants under waterlogging: A review

Photosynthesis is a process highly sensitive to various abiotic and biotic stresses in plants. Among them, the major abiotic stress, waterlogging, affects the crop's growth and productivity. Under waterlogging, the photosynthetic apparatus of plants was destroyed. Waterlogging reduced chlorophyll content and the net photosynthetic rate. Therefore, this updated review summarized the effect of waterlogging on chloroplast ultrastructure, photosynthetic characteristics, and chlorophyll fluorescence attributes of plant species. By studying various research papers, we found that intercellular concentration of available carbon dioxide in mesophyll cells, assimilation of carbon, and the net photosynthetic ratio declined under waterlogging. The chlorophyll fluorescence efficiency of plants decreased under waterlogging. Thus, the study of photosynthesis in plants under waterlogging should be done with respect to changing climate. Moreover, the recognition of photosynthetic characteristics present in tolerant species will be beneficial for designing the waterlogging-tolerant crop plant in changing environments.

The effect of supplementary light on the photosynthetic apparatus of strawberry plants under salinity and alkalinity stress

Considering the destructive effect of stresses on the photosynthetic apparatus of plants and the important role of light in photosynthesis, we investigated the effect of complementary light on the photosynthetic apparatus under salinity and alkalinity stress conditions. Light-emitting diodes (LEDs) in monochromatic blue (460 nm), monochromatic red (660 nm), dichromatic blue/red (1:3), white/yellow (400–700 nm) at 200 μmol m−2 S−1, and without LED treatment were used. The stress treatments were in three stages: Control (no stress), Alkalinity (40 mM NaHCO3), and Salinity (80 mM NaCl). Our results showed that salinity and alkaline stress reduced CO2 assimilation by 62.64% and 40.81%, respectively, compared to the control treatment. The blue light spectrum had the highest increase in water use efficiency (54%) compared to the treatment without supplementary light. Under salinity and alkalinity stress, L, K, and H bands increased and G bands decreased compared to the control treatment, with blue/red light causing the highest increase in L and K bands under both stress conditions. In salinity and alkalinity stress, white/yellow and blue/red spectra caused the highest increase in H bands. Complementary light spectra increased the G band compared to the treatment without complementary light. There was a significant decrease in power indices and quantum power parameters due to salt and alkalinity stress. The use of light spectra, especially blue, red, and blue/red light, increased these parameters compared with treatment without complementary light. Different light spectra have different effects on the photosynthetic apparatus of plants. It can be concluded that using red, blue spectra and their combination can increase the resistance of plants to stress conditions and be adopted as a strategy in planting plants under stress conditions.

Spectral characterization of the main pigments in the plant photosynthetic apparatus by theory and experiment

Comprehensive experimental spectroscopic and TD-CAM-B3LYP/6-31G*, DFT/MRCI libraries of the most relevant plant light harnessing pigments are presented. Included are β-carotene, zeaxanthin, violaxanthin, lutein, neoxanthin, chlorophyll a and chlorophyll b . We employ vibrational broadening with various approximations to enable direct comparison of computational to experimental data. Spectroscopic shifts based on continuum solvents and protein matrices were computed as well, employing CPCM or (for chlorophylls) QM/MM models. We also provide insight into the transient behavior after photoexcitation through optimization of the corresponding excited states. It is found, that the investigated carotenoids only differ in their excitation energies but display analogous subsequent photophysics. Vibrational broadening of the carotenoid spectra compares well to experimental data regardless of the actual approach chosen. This appears to be a result of a strong gradient at the Franck-Condon point. Thus, it is not trivial to assess which computational method is actually suited for these purposes. Further, Q and Soret band reorganization energies are very similar in both, chlorophylls a and b . Both, TD-DFT, as well as DFT/MRCI predict the existence of an intramolecular charge transfer state in the Soret region of chlorophylls. The existence/absence of this state has previously not been experimentally corroborated. However, measurements of chlorophyll a absorption spectra in different solvents support this assumption. The results suggest, that the relaxation of the chlorophyll Soret bands might be affected by the presence of such an intramolecular charge transfer state.

The thermodynamics of light absorption for a two-level system

The thermodynamics of light absorption is analysed using, as model system, a two-level molecular system characterised by mirror symmetry between its absorption and emission spectra. This means that the structure of the HOMO-1 and HOMO (highest occupied molecular orbital) ground state and the LUMO, LUMO + 1 (lowest unoccupied molecular orbital) excited states are nearly identical in their vibronic structures. This is a good model for many dyes and, in particular, for chlorophyll molecules, the main chromophore presents in the photosynthetic apparatus of plants. When a photon is absorbed by this two-level system, a transition from the HOMO ground state to the LUMO excited state occurs. Then, the system rapidly relaxes to an equilibrium distribution over the excited state sublevels and this equilibrium distribution is defined by the temperature of the bath that contains the molecule. In the described scenario, taking into account the changes in internal energy and the partition function before and after the photon absorption event, it is demonstrated that no entropy change occurs upon electronic transition from the ground state to the excited state, upon photon absorption. Furthermore, the idea that the photon-induced electronic transition can be described in terms of system heating is considered. We conclude that photon energy cannot be considered as heat. Instead, when thermal excitation is taken into account, the increased system temperature leads inexorably to entropy changes.

Physiological and biochemical characteristic of Miscanthus × giganteus grown in heavy metal – oil sludge co-contaminated soil

The effect of oil sludge and zinc, present in soil both separately and as a mixture on the physiological and biochemical parameters of Miscanthus × giganteus plant was examined in a pot experiment. The opposite effect of pollutants on the accumulation of plant biomass was established: in comparison with uncontaminated control the oil sludge increased, and Zn reduced the root and shoot biomass. Oil sludge had an inhibitory effect on the plant photosynthetic apparatus, which intensified in the presence of Zn. The specific antioxidant response of M. × giganteus to the presence of both pollutants was a marked increase in the activity of superoxide dismutase (mostly owing to oil sludge) and glutathione-S-transferase (mostly owing to zinc) in the shoots. The participation of glutathione-S-transferase in the detoxification of both the organic and the inorganic pollutants was assumed. Zn inhibited the activity of laccase-like oxidase, whereas oil sludge promoted laccase and ascorbate oxidase activities. This finding suggests that these enzymes play a part in the oxidative detoxification of the organic pollutаnt. With both pollutants used jointly, Zn accumulation in the roots increased 6-fold, leading to increase in the efficiency of soil clean-up from the metal. In turn, Zn did not significantly affect the soil clean-up from oil sludge. This study shows for the first time the effect of co-contamination of soil with oil sludge and Zn on the physiological and biochemical characteristics of the bioenergetic plant M. × giganteus. The data obtained are important for understanding the mechanisms of phytoremediation with this plant.

The role of <i>Arabidopsis thaliana</i> photoreceptors in regulating the process of state transitions

The initial formation of the photosynthetic apparatus in plants occurs during photomorphogenesis. The red/far-red (phytochromes) and blue (cryptochrome) light protein-photoreceptors play the most important role in photomorphogenesis initiation and regulation. The exited phytochrome and cryptochrome molecules can interact with transcription factors, changing the expression of nuclear genes, which encode the proteins of the plant photosynthetic apparatus. Since light is a variable factor, plants have developed appropriate adaptation mechanisms, including their photosynthetic apparatus protection. The mechanism of state transitions ensures a rapid adaptation of the photosynthetic apparatus. This adaptation mechanism increases the adsorption efficiency under current light conditions and prevents intensive generation of active forms of oxygen in chloroplasts, which leads to photo-oxidation and even cell death. This work aims to determine the role of photoreceptors - phytochromes A and B, as well as cryptochrome 1 and 2 - in regulating the process of state transitions in the Arabidopsis thaliana model plant. Arabidopsis mutants with the defects on A and B phytochromes and cryptochrome 1 and 2 genes were used as the research objects. The blue native electrophoresis in polyacrylamide gel was used to visualise state transitions. It was found that these photoreceptors had no direct effect on the redox-regulation of the state transitions mechanism in Arabidopsis. Presumably, these photoreceptors protect the photosynthetic apparatus from excessive light not by regulating the state transitions but indirectly, through regulating the chlorophyll, carotenoid and antioxidant components content.

Mechanisms shaping the synergism of zeaxanthin and PsbS in photoprotective energy dissipation in the photosynthetic apparatus of plants.

Safe operation of photosynthesis is vital to plants and is ensured by the activity of processes protecting chloroplasts against photo-damage. The harmless dissipation of excess excitation energy is considered to be the primary photoprotective mechanism and is most effective in the combined presence of PsbS protein and zeaxanthin, a xanthophyll accumulated in strong light as a result of the xanthophyll cycle. Here we address the problem of specific molecular mechanisms underlying the synergistic effect of zeaxanthin and PsbS. The experiments were conducted with Arabidopsis thaliana, using wild-type plants, mutants lacking PsbS (npq4), and mutants affected in the xanthophyll cycle (npq1), with the application of molecular spectroscopy and imaging techniques. The results lead to the conclusion that PsbS interferes with the formation of densely packed aggregates of thylakoid membrane proteins, thus allowing easy exchange and incorporation of xanthophyll cycle pigments into such structures. It was found that xanthophylls trapped within supramolecular structures, most likely in the interfacial protein region, determine their photophysical properties. The structures formed in the presence of violaxanthin are characterized by minimized dissipation of excitation energy. In contrast, the structures formed in the presence of zeaxanthin show enhanced excitation quenching, thus protecting the system against photo-damage.

Influence of Nanoparticles of Metals and Their Oxides on the Photosynthetic Apparatus of Plants

A comparative survey of the published data concerning the effects of the most frequently used metal nanoparticles and their oxides on the main parameters of the photosynthetic apparatus activity and the chloroplast ultrastructure of higher plants is presented. It is demonstrated that metal nanoparticles are capable of both stimulating and suppressing activities towards the photosynthetic apparatus. Possible mechanisms of the effects of metal nanoparticles on the plant organism are discussed.