Activation of Tomato Growth Under Photoconversion Coatings with Nanoluminophor Sr0.76Ba0.20Yb0.02Er0.02F2.04

The effect of coatings containing upconversion luminescent nanoparticles on the cultivation of Solanum lycopersicum has been studied. Sr0.76Ba0.20Yb0.02Er0.02F2.04 particles capable of converting infrared radiation into visible light (λem = 660 nm, 545 nm, and 525 nm) were used as the phosphor. It was shown that the cultivation of tomatoes under photoconversion coatings accelerated the adaptation of plants to ultraviolet radiation. A more efficient distribution of the energy of absorbed light between the processes of photosynthesis and thermal dissipation under upconversion coatings was revealed. As a result, plants grown under photoconversion coatings increased the number and total leaf area, stem length, and leaf chlorophyll content

Carotenoid-dependent singlet oxygen photogeneration in light-harvesting complex 2 of Ectothiorhodospira haloalkaliphila leads to the formation of organic hydroperoxides and damage to both pigments and protein matrix

Earlier, it was suggested that carotenoids in light-harvesting complexes 2 (LH2) can generate singlet oxygen, further oxidizing bacteriochlorophyll to 3-acetyl-chlorophyll. In the present work, it was found that illumination of isolated LH2 preparations of purple sulfur bacterium Ectothiorhodospira haloalkaliphila with light in the carotenoid absorption region leads to the photoconsumption of molecular oxygen, which is accompanied by the formation of hydroperoxides of organic molecules in the complexes. Photoformation of two types of organic hydroperoxides were revealed: highly lipophilic (12 molecules per one LH2) and relatively hydrophobic (68 per one LH2). It has been shown that illumination leads to damage to light-harvesting complexes. On the one hand, photobleaching of bacteriochlorophyll and a decrease in its fluorescence intensity are observed. On the other hand, the photoinduced increase in the hydrodynamic radius of the complexes, the reduction in their thermal stability, and the change in fluorescence intensity indicate conformational changes occurring in the protein molecules of the LH2 preparations. Inhibition of the processes described above upon the addition of singlet oxygen quenchers (L-histidine, Trolox, sodium L-ascorbate) may support the hypothesis that carotenoids in LH2 preparations are capable of generating singlet oxygen, which, in turn, damage to protein molecules

Current Approaches to Light Conversion for Controlled Environment Agricultural Applications: A Review

Modern agriculture cannot be imagined without the introduction of smart and efficient technologies. These, undoubtedly, include technologies for directed regulation of the illumination of agricultural plants. Depending on the climatic conditions of cultivation, farmers shade or additionally illuminate the plants, and also change the spectrum of the light reaching the plants. The aim of this review is to provide an overview of solar light conversion methods and approaches for agricultural applications and discuss their advantages and limitations

Changes in transpiration data in plants of the genus Solanum

A study was carried out of the physiological parameters of the tomato variety “Barberry F1”, under the influence of an external factor, at night in the conditions of the Moscow region. Parameters such as transpiration were observed. According to the results of the experiment, there are significant differences between the two variants of the experiment (control and experiment). Under the influence of the limiting factor, there is a general increase in the efficiency of transpiration; in addition to the general increase, changes occur in the studied parameters under the conditions of dividing the plant into tiers. Thus, in the control plant, the middle leaves show significant differences from the upper and lower tier, whereas in the experiment this difference is significant only in some cases

The Influence of Composite Luminescent Materials Based on Graphene Oxide on the Growth and Development of <i>Solanum lycopersicum</i> in Greenhouses

The effect of graphene oxide-based photoconversion covers on the growth and photosynthesis of tomatoes (Solanum lycopersicum) was investigated. Two types of photoconversion composite for covers were produced. In the first, only graphene oxide nanoparticles were used as a phosphor, and in the second, the graphene oxide nanoparticles were used jointly with europium oxide nanoparticles. The freshly prepared composites for covers had almost identical photoluminescence spectra: an intense peak in the red region and a minor peak in the blue region. It was revealed that during operation, luminescence in the red region decreased, while in the blue region it increased, probably due to the photothermal reduction of graphene oxide. It was shown that the photoconversion covers increased productivity (25%) and intensified photosynthesis (30–35%) in the tomato plants. It is suggested that the stimulation of plant growth is caused by changes in the light spectrum induced by the photoconversion covers

Additive Production of a Material Based on an Acrylic Polymer with a Nanoscale Layer of Zno Nanorods Deposited Using a Direct Current Magnetron Discharge: Morphology, Photoconversion Properties, and Biosafety

On the basis of a direct current magnetron, a technology has been developed for producing nanoscale-oriented nanorods from zinc oxide on an acrylic polymer. The technology makes it possible to achieve different filling of the surface with zinc oxide nanorods. The nanorods is partially fused into the polymer; the cross section of the nanorods is rather close to an elongated ellipse. It is shown that, with intense abrasion, no delamination of the nanorods from the acrylic polymer is observed. The zinc oxide nanorods abrades together with the acrylic polymer. Zinc oxide nanorods luminesces with the wavelength most preferable for the process of photosynthesis in higher plants. It was shown that plants grown under the obtained material grow faster and gain biomass faster than the control group. In addition, it was found that on surfaces containing zinc oxide nanorods, a more intense formation of such reactive oxygen species as hydrogen peroxide and hydroxyl radical is observed. Intensive formation of long-lived, active forms of the protein is observed on the zinc oxide coating. The formation of 8-oxoguanine in DNA in vitro on a zinc oxide coating was shown using ELISA method. It was found that the multiplication of microorganisms on the developed material is significantly hampered. At the same time, eukaryotic cells of animals grow and develop without hindrance. Thus, the material we have obtained can be used in photonics (photoconversion material for greenhouses, housings for LEDs), and it is also an affordable and non-toxic nanomaterial for creating antibacterial coatings

Cultivation of Solanum lycopersicum under Glass Coated with Nanosized Upconversion Luminophore

The effect of upconverting luminescent nanoparticles coated on glass on the productivity of Solanum lycopersicum was studied. The cultivation of tomatoes under photoconversion glass led to an increase in plant productivity and an acceleration of plant adaptation to ultraviolet radiation. An increase in the total leaf area and chlorophyll content in the leaves was revealed in plants growing under the photoconversion glass. Plants growing under the photoconversion glass were able to more effectively utilize the absorbed light energy. The results of this study suggest that the spectral changes induced by photoconversion glass can accelerate the adaptation of plants to the appearance of ultraviolet radiation

Research on nature-like and high-tech means to enhance winter wheat growth and development

The search and creation of agrochemicals of a new generation, similar to bioprotectors, for agriculture is an urgent task of today scientific findings. The applied high-tech agrochemicals, in addition to their protective properties, have positive effect on the growth and development of cereals. The initial stages of growth and development (stress phases) are passing better with the introduction of effective fertilizers, agrochemicals and growth regulators. However, the use of their concentrated solutions is ineffective due to losses or transitions to an inaccessible state. Prolonged gradual release of Fe (II) will provide the concentration required for plants in the soil

Plant Photochemistry under Glass Coated with Upconversion Luminescent Film

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions

Plant Photochemistry under Glass Coated with Upconversion Luminescent Film

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions