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Arthospira platensis and Spirulina platensis microalgae are a rich source of pro-health metabolites (% d.m.): proteins (50.0–71.3/46.0–63.0), carbohydrates (16.0–20.0/12.0–17.0), fats (0.9–14.2/6.4–14.3), polyphenolic compounds and phenols (7.3–33.2/7.8–44.5 and 4.2/0.3 mg GAE/g), and flavonoids (1.9/0.2 QUE/g) used in pharmaceutical and cosmetic formulations. This review summarises the research on the chemical profile, therapeutic effects in dermatological problems, application of Arthrospira and Spirulina microalgae, and contraindications to their use. The pro-health properties of these microalgae were analysed based on the relevant literature from 2019 to 2024. The antiviral mechanism of microalgal activity involves the inhibition of viral replication and enhancement of immunity. The anti-acne activity is attributed to alkaloids, alkanes, phenols, alkenes, phycocyanins, phthalates, tannins, carboxylic and phthalic acids, saponins, and steroids. The antibacterial activity generally depends on the components and structure of the bacterial cell wall. Their healing effect results from the inhibition of inflammatory and apoptotic processes, reduction of pro-inflammatory cytokines, stimulation of angiogenesis, and proliferation of fibroblasts and keratinocytes. The photoprotective action is regulated by amino acids, phlorotannins, carotenoids, mycosporins, and polyphenols inhibiting the production of tyrosinase, pro-inflammatory cytokines, and free oxygen radicals in fibroblasts and the stimulation of collagen production. Microalgae are promising molecular ingredients in innovative formulations of parapharmaceuticals and cosmetics used in the prophylaxis and therapy of dermatological problems. This review shows the application of spirulina-based commercial skin-care products as well as the safety and contraindications of spirulina use. Furthermore, the main directions for future studies of the pro-health suitability of microalgae exerting multidirectional effects on human skin are presented. [ABSTRACT FROM AUTHOR]

Raspberry fruits are an important source of many biologically active chemical compounds exerting nutritional and pro-health effects. The study presents a comparative analysis of nutritionally important bioactive chemical compounds—polyphenols; flavonoids, including anthocyanins; vitamin C; amino acids; fatty acids; and primary metabolites—contained in the fruits of three biennial fruiting cultivars, R. idaeus 'Glen Ample', 'Laszka', and 'Radziejowa', i.e., common cultivars in Poland and Europe. The antioxidant activity of fresh fruits and juice was determined with five methods. The analyses revealed the strong free radical scavenging potential of the fruits and juice, confirmed by the high concentration of nutrients, e.g., polyphenols, anthocyanins, vitamin C, amino acids, and fatty acids. The antioxidant activity of the juice determined with the ferric reducing antioxidant power (FRAP) and OH radical methods was from 2.5 to 4.0 times higher than that of the fruits. The following orders of total polyphenol contents were established in the analyzed cultivars: 'Glen Ample' < 'Laszka' < 'Radziejowa' in the fruits and 'Glen Ample' < 'Radziejowa' < 'Laszka' in the juice. The highest antioxidant activity was exhibited by the 'Radziejowa' fruits. Given their high content of dietary fiber, the fruits of the analyzed raspberry cultivars can be consumed by dieting subjects. The concentrations of vitamin C (28–34 mg/100 g) and anthocyanins (20–34 mg/100 g) indicate the biological and pharmacological activity of these fruits. The main unsaturated fatty acids in the fruits were gamma-linoleic acid (C18:2n6c) and alpha-linolenic acid (C18:3n3), which neutralize excess free radicals. The amino acids nutritionally essential to humans were dominated by leucine, arginine, and phenylalanine. This is the first comparative analysis of the antioxidant activity of fruits and juice and the contents of selected active compounds in the fruits of biennial fruiting cultivars of R. idaeus, i.e., a highly commercialized crop in Europe. [ABSTRACT FROM AUTHOR]

Psychotropic effect of Crocus sativus L. (family Iridaceae) biologically active chemical compounds are quite well documented and they can therefore be used in addition to the conventional pharmacological treatment of depression. This systematic review on antidepressant compounds in saffron crocus and their mechanisms of action and side effects is based on publications released between 1995–2022 and data indexed in 15 databases under the following search terms: antidepressant effect, central nervous system, Crocus sativus, cognitive impairement, crocin, crocetin, depression, dopamine, dopaminergic and serotonergic systems, picrocrocin, phytotherapy, neurotransmitters, safranal, saffron, serotonin, and biologically active compounds. The comparative analysis of the publications was based on 414 original research papers. The investigated literature indicates the effectiveness and safety of aqueous and alcoholic extracts and biologically active chemical compounds (alkaloids, anthocyanins, carotenoids, flavonoid, phenolic, saponins, and terpenoids) isolated from various organs (corms, leaves, flower petal, and stigmas) in adjuvant treatment of depression and anxiety. Monoamine reuptake inhibition, N-methyl-d-aspartate (NMDA) receptor antagonism, and gamma-aminobutyric acid (GABA)-α agonism are the main proposed mechanism of the antidepressant action. The antidepressant and neuroprotective effect of extract components is associated with their anti-inflammatory and antioxidant activity. The mechanism of their action, interactions with conventional drugs and other herbal preparations and the safety of use are not fully understood; therefore, further detailed research in this field is necessary. The presented results regarding the application of C. sativus in phytotherapy are promising in terms of the use of herbal preparations to support the treatment of depression. This is particularly important given the steady increase in the incidence of this disease worldwide and social effects. [ABSTRACT FROM AUTHOR]

Leaves of Rubus idaeus are a raw material, ingredients of herbal blend, and a source of antioxidants. There are no data concerning histochemistry of trichomes, and little is known about the leaf structure of this species. The aim of this study was to determine the histochemistry of active compounds and the structure of glandular trichomes, micromorphology, anatomy, and ultrastructure of leaves as well as content of elements. To determine the histochemistry of glandular trichomes, different chemical compounds were used. The leaf structure was analysed using light, scanning, and transmission electron microscopes. The content of elements was determined with atomic absorption spectrometry, and the microanalysis of the epidermis ultrastructure was carried out with a transmission electron microscope equipped with a digital X-ray analyser. In glandular trichomes, polyphenols, terpenes, lipids, proteins, and carbohydrates were identified. The main elements in the ultrastructure of the epidermis were Na, Mo, Se, Ca, and Mg. In dry matter of leaves, K, Mg, Ca, P, and Fe were dominant. Infusions from leaves are safe for health in terms of the Cd and Pb concentrations. Leaves can be a valuable raw material. Non-glandular trichomes prevent clumping of mixed raw materials in herbal mixtures. [ABSTRACT FROM AUTHOR]

There is very scanty information concerning the floral nectary structure and nectar secretion in Prunus laurocerasus L. Therefore, the aim of the study was to determine the micromorphology, anatomy and ultrastructure of nectaries; the abundance of nectar production; and the quantitative and qualitative composition of sugars contained in the nectar of two P. laurocerasus cultivars: 'Schipkaensis' and 'Zabeliana'. The nectary structure was studied using light, fluorescence, scanning and transmission electron microscopy techniques. The nectar sugars were analysed with HPLC. The 'Schipkaensis' had longer inflorescences with a larger number of flowers and a longer perianth than 'Zabeliana'. The micromorphological structure of the nectaries in 'Schipkaensis' exhibited denser (approx. 39%) and larger (approx. 50%) stomata and thicker (approx. 13%) cuticular striae forming wider bands (approx. 26%) than in 'Zabeliana'. The results provide new data on the micromorphology, anatomy and ultrastructure of these floral nectaries. Nectary cuticle ornamentation as well as the size, type and density of stomata and stomatal complex topography can have a diagnostic value in Prunus. The nectar sugar weight indicates a significant apicultural value of the cherry laurel, especially in the case of 'Schipkaensis'. Cherry laurel is an entomophilous species recommended for cultivation in nectariferous zones and insect pollinator refuges; however, climatic conditions eliminating the invasiveness of these plants should be considered. [ABSTRACT FROM AUTHOR]

Heracleum sosnowskyi Manden. was introduced in Poland as a fodder plant. Currently, it is regarded as an invasive plant posing a health hazard to humans and animals and a threat to native flora. The aim of the study was to localise furanocoumarins in the stem and leaf tissues. The investigations were carried out using light, fluorescence, and scanning electron microscopy as well as histochemical assays. The epidermis of the analysed organs bears live, non-capitate hairs with variable length, which contain lipids, essential oils, polysaccharides, tannins, and furanocoumarins. The observations performed with scanning electron microscopy revealed the presence of a foamy substance and furanocoumarin crystals on the surface of the trichomes and other epidermal cells, as well as in the parenchyma cells. Characteristic furanocoumarin autofluorescence was present in the epidermis and on its surface, as well as in the subepidermal parenchyma. Secondary fluorescence was emitted by furanocoumarins in different leaf petiole tissues: psoralen, bergapten, and xanthotoxin. We have detected for the first time the presence of furanocoumarins in different tissues of leaves in H. sosnowskyi. Furanocoumarins were also abundantly present on the epidermal surface of cells. This explains why the contact with the plant is dangerous to humans and results in development of photodermatoses. [ABSTRACT FROM AUTHOR]

Representatives of the family Sapindaceae exhibit high morphological diversity of the nectary structure. The present paper shows for the first time the results of micromorphological, anatomical, and ultrastructural analyses of floral nectaries in Aesculus hippocastanum. We have also described the forage and signal attractants of these flowers, which are important for the ecology of pollination. Using light, fluorescence, and electron microscopy, we demonstrated that the A. hippocastanum nectary forming a lobed disc is histologically differentiated into the epidermis with stomata, nectariferous parenchyma, subglandular parenchyma, and vascular bundles reaching the basal part of the nectariferous parenchyma. The use of histochemical assays revealed the presence of insoluble polysaccharides, lipids, terpenoids, and polyphenols including coumarins in the nectary tissues. Nectar is exuded onto the nectary surface via stomata and the permeable cuticle. As indicated by the observation of the ultrastructure of the nectary cells, transport of pre-nectar into parenchymal cells may proceed via the symplast and apoplast. We have also demonstrated that nectar transfer outside the protoplasts of parenchymal cells has a character of granulocrine secretion. A. hippocastanum flowers produce nectar abundantly; one flower secreted on average 2.64 mg of nectar and the concentration of sugars in the nectar was 33%. [ABSTRACT FROM AUTHOR]

In Poland Galanthus nivalis L. is partially protected. The flowers of this species are one of the first sources of nectar and pollen for insects from February to April. The aim of this study was to present the flowering biology as well as the topography, anatomical, and ultrastructural features of the floral nectary. The flower lifespan, the breeding system, and the mass of pollen and nectar produced by the flowers were determined. Examination of the nectary structure was performed using light, fluorescence, scanning and transmission electron microscopy. The flower of G. nivalis lives for about 30 days. The stamens and pistils mature simultaneously and during this time nectar is secreted. The anthers of one flower produced the large amount of pollen (4 mg). The breeding system of G. nivalis was found to be characterized by partial self-compatibility, outcrossing, and xenogamy. The nectary is located at the top of the inferior ovary. The nectary epidermal cells are characterized by striated cuticular ornamentation. Initially, the secreted nectar formed vesicle-like protuberances under the cuticle. The epidermal and parenchymal cells contain numerous plastids, mitochondria, dictyosomes, ER cisterns, and vesicles fused with the plasmalemma, which indicates granulocrine nectar secretion. [ABSTRACT FROM AUTHOR]

In Poland Scorzonera hispanica L. is rare in the wild. This species is used as a vegetable and medicinal plant. Currently, attempts are being made to introduce this plant into cultivation in Poland. In this study, comparative analyses were conducted of the epidermis surface micromorphology and anatomical structure of the leaves of S. hispanica 'Maxima' and 'Meres'. The investigations were performed using fluorescence, light and scanning electron microscopy. The cuticle on the surface of epidermal cells is smooth or striated. In the epidermis, there are anomocytic stomata. The stomatal index in the epidermis of the studied cultivars is 9.3-11%. In the midrib of the leaf, there is an aerial cavity which occupies a substantial area. In this place, cracking and breaking of the leaf blade were observed. Over the aerial cavity under the adaxial epidermis, there is a single layer of collenchyma cells and 1-2 rows of parenchyma cells. Tangential collenchyma is also present between the abaxial epidermis and large vascular bundles located in the midrib and on both sides of the large vascular bundles in the lamina. This tissue strengthens the leaf margin. The mesophyll cells located in the abaxial epidermis of the midrib form protrusions surrounding the large vascular bundles. The leaves of S. hispanica represent the equifacial type. [ABSTRACT FROM AUTHOR]

In its stems and leaves, Heracleum sosnovskii Manden. contains furanocoumarins, which exert a phototoxic effect on humans. The aim of the investigations was to describe the external secretory structures of the epidermis and internal secretory tissues in organs responsible for emission of secretion that is toxic to human skin. The study was conducted using light and fluorescence microscopy. On the stems and leaves, various types of secretory trichomes with dispersed or deposited secretion were found. The trichomes were most abundant on the abaxial leaf surface. Epidermal cells and the secretion present on the trichomes exhibited intense fluorescence, which may indicate the presence of furanocoumarins in the tissue and trichome secretions. [ABSTRACT FROM AUTHOR]

Aesculus hippocastanum L. is an ornamental tree appreciated for its beautiful flowers and leaves. The flowers of this species contain secondary metabolites exhibiting pharmacological activity. They also produce essential oils and coloured "nectar guides", which enable insects to reach nectar and pollen. The aim of the study was to investigate the types and characteristics of chestnut flower trichomes, which may contain biologically active substances. The analyses were performed using light, fluorescence, and scanning electron microscopy. Three types of trichomes were found on the sepals and the surface of the ovary, whereas the corolla petals exhibited two types of hairs and papillae. The hairs differ in terms of their length and number of cells. The perianth and pistil had no capitate hairs, whereas the ovary exhibited the presence of colleters. Histochemical assays revealed that all the types of trichomes and papillae contained lipids or essential oils; hence, they can be classified as glandular structures. The "nectar guides" were characterised by higher density of secretory hairs than that on the rest of the petal surface, which implies that these petal fragments may emit stronger fragrance. [ABSTRACT FROM AUTHOR]

The Polemoniaceae family forms flowers diverse in the terms of pollination methods and nectar types. The micromorphology of the nectary surface and the tissue structures as well as the ultrastructure of the cells of the floral nectaries in Polemonium caeruleum L. were examined using light, scanning and transmission electron microscopy. A bowl-shaped nectary, detached from the ovary, grows at its base. Its contour shows folds with depressions in the places where the stamens grow, forming five-lobed disc (synapomorphic character). Nectar is secreted through modified anomocytic stomata, which are formed in the epidermis covering the tip and the lateral wall of the projection located between the staminal filaments. The undulate nectary consists of a single-layered epidermis and three to nine layers of parenchymal cells. The cells of the nectary contain a dense cytoplasm, numerous plastids with an osmophilic stroma and starch grains, well-developed endoplasmic reticulum, as well as a large number of mitochondria interacting with the Golgi bodies. The ultrastructure of nectary cells indicates the granulocrine secretion mechanism and diversified transport of nectar. [ABSTRACT FROM AUTHOR]

Despite the close and clinically confirmed association between depression and overactive bladder, it remains unclear whether this affective disorder is a factor causing overactive bladder or whether overactive bladder is a specific symptom of psychosomatic disorders. This study examined the effects of repeated corticosterone administration on the occurrence of symptoms associated with depression and overactive bladder. Additionally, we examined whether administering TC-G 1008, an antidepressant that selectively activates the GPR39 receptor, could alleviate corticosterone-induced depression-like behavior and detrusor overactivity-related changes in cystometric measurements. We also explored its potential to reverse alterations in various biomarkers associated with both conditions in the serum, urinary bladder, and brain of female rats. The administration of corticosterone (20 mg/kg/day for 14 days) yielded anticipated results, including an increase in the duration of immobility during the forced swim test, alterations in parameters specific to bladder overactivity, a decrease in neurotrophins, and an elevation in pro-inflammatory cytokine levels. Treatment with TC-G 1008 (15 mg/kg/day) alleviated symptoms of both detrusor overactivity and depression, while also restoring the levels of biochemical and cystometric markers to normal ranges. Additionally, antidepressants based on GPR39 agonists could enhance the levels of kynurenic acid in the neuroprotective pathway. These results indicate that the GPR39 agonist receptor might be a promising future therapeutic approach for treating overactive bladder that occurs alongside depression. [ABSTRACT FROM AUTHOR]

Increasing demand for sustainable vegetable production is leading to low- and zero-pesticide farming practices. This review examines many strategies intended to lower pesticide use without impacting crop quality and production. The use of biopesticides, biological control, integrated pest management (IPM), and organic farming are some of the important techniques that are examined. This investigation also covers cutting-edge technology that improves the efficacy and efficiency of various techniques, such as robots, artificial intelligence (AI), and precision agriculture. A rigorous evaluation of the effects of pesticide residues on the environment and human health emphasises how crucial it is to use fewer pesticides. Market trends and customer preferences are considered, as well as the social and economic effects of implementing these strategies. The paper's conclusion identifies obstacles to the general adoption of low- and zero-pesticide approaches and makes recommendations for future research topics to overcome these obstacles. [ABSTRACT FROM AUTHOR]

Poland is the largest European Union producer of Rubus idaeus. This species provides insects with nectar and pollen from June to September. The rationale behind the present research is the increasing commercial production and the use of food attractants for pollinators increasing fruit yields. The intensive search for phytochemicals applicable in industry and phytotherapy together with the unavailability of data on anther epidermis and endothecium structure justify undertaking these investigations. The pollen mass, the content of elements, protein, and fat, as well as the composition of amino acids and fatty acids in the pollen of six R. idaeus cultivars were compared. In terms of pollen production, the cultivars ranked as follows: 'Pokusa' < 'Polana' < 'Glen Ample' < 'Polka' < 'Radziejowa' < 'Laszka'. The protein content (26–31%) in the pollen indicates its good quality and high attractiveness. Exogenous amino acids, including those with dietary importance, constituted a substantial proportion (33–39%). The content of MUFAs and PUFAs was 32–47% and 3.7–9.1%, respectively. The presence of elements that determine the nutritional value and proper development of pollen was detected in the mineral composition of the exine. The data on the epidermis and endothecium structure provide new information about the micromorphology, anatomy, ultrastructure of and generative organs and auxiliary criteria in the taxonomy of related species. [ABSTRACT FROM AUTHOR]

Herbal therapy is a potential alternative applied to pharmacological alleviation of depression symptoms and treatment of this disorder, which is predicted by the World Health Organization (WHO) to be the most serious health problem worldwide over the next several years. It has been well documented that many herbs with psychotropic effects have far fewer side effects than a variety of pharmaceutical agents used by psychiatrists for the treatment of depression. This systematic review presents literature data on the antidepressant activity of representatives of the genera Hemerocallis (H. fulva and H. citrina Baroni, family Xanthorrhoeaceae) and Gladiolus (G. dalenii, family Iridaceae) and on biologically active compounds and their mechanisms of action to consider the application of herbal preparations supporting the treatment of depression. [ABSTRACT FROM AUTHOR]

The article focuses on a research conducted to examine the nectar production and location and structure of the floral nectaries in the melliferous plant Daphne mezereum (D. mezereum) flowers. Topics discussed include high content of daphnin and coumarins in the D. mezereum's bark and Daphne odora's leaf buds, secretion of nectar onto the nectary surface of the stomata, and role of corolla filled with nectar in attracting bees and butterflies to the flower.

The article focuses on a research conducted to examine the micromorphology of pollen grains of three apricot species Prunus armeniaca cultivars including Early Orange, Harcot, and Wczesna z Morden using scanning electron microscopy and light microscopy. Topics discussed include study's aim to determine shape, size, and exine ornamentation of the species, large distance in the striae observed in Harcot pollen grains, and perforation in tectum of Prunus armeniaca's pollen grains.

The aim of the present study was to evaluate the possibility of using a protein hydrolysate, Hemozym N-K 4.5-6, as a component of salinized soil in the cultivation of flossflower (Ageratum houstonianum Mill., Asteraceae). The experiment was focused on the yield and decorative value of A. houstonianum, grown under different concentrations of NaCl and/or Hemozym. Ageratum houstonianum plants were grown in the soil under different NaCl salinity (EC: 0.28 -- as control or 3.25 dS m-1 -- salt stress) or/and Hemozym dose (0, 0.07 or 0.14 ml kg-1). The results of the experiment imply that A. houstonianum is sensitive to salinity. The application of Hemozym to both unsalinized and salinized soils caused an increase in the yield of the plant organs (roots, stems, leaves, and inflorescence), the number of leaves, and the chlorophyll content without significant changes in the carotenoids. Moreover, an increase in the number and size of first-order inflorescences (heads) as well as more intensive flower color were observed. Thus, it can be stated that the protein hydrolysate studied can be a beneficial component of both salinized and unsalinized soils in the cultivation of A. houstonianum. [ABSTRACT FROM AUTHOR]

The intensely fragrant flowers of the Rosa rugosa Thunb. have been applied in medicine, and food and cosmetic industries. The species is cultivated for production of rose essential oil (Oleum Rosae) from its flowers. R. rugosa petals secrete the largest quantities of essential oil. The aim of the study was to identify the characteristics of the epidermis of both sides of the petal and to observe whether adaxial and abaxial epidermal cells can secrete essential oil. The investigations were conducted using light and scanning electron microscopy. The analyses were focused on petal thickness and characteristics of the mesophyll. The study has demonstrated that only adaxial epidermal cells form conical papillae covered by massive cuticular striae. The surface of the papillae displayed remnants of a secretory substance. In turn, the inner walls of the abaxial epidermal cells were flat and covered by a striated cuticle, which exhibited various striation patterns. Fragrant substances stored under the cuticle caused local stretching thereof and disappearance of striation. The results of our observations allow a statement that the cells of the adaxial and abaxial epidermis of R. rugosa petals differ in terms of the structure and they secrete fragrant substances. [ABSTRACT FROM AUTHOR]

Lettuce ( Lactuca sativa L.) is moderately sensitive to cadmium (Cd) and shows high accumulation of this metal. Thus, this species is considered to be a good model for both identifying determinants controlling Cd accumulation in plant tissues and for developing breeding strategies aimed at limiting the accumulation of this metal in edible tissues. Simultaneously, lettuce is characterised by medium requirements for sulphur (S) – a macronutrient whose role is associated not only with proper growth and development, but also with stress tolerance. The common use of NPK fertilizers without sulphates (S-SO 4 ) together with the progressive process of reducing emissions of S compounds to the natural environment may lead to deficiency of this element in plants. The present study evaluated the changes in macronutrient content and accumulation in Cd-stressed lettuce ‘Justyna’ supplied with different S doses. Four concentrations of Cd (0, 0.0002, 0.02 or 0.04 mM) and three levels of S applied in the form of S-SO 4 (2, 6 or 9 mM S) were used. Cd exposure impaired the macronutrient balance and accumulation in lettuce. Intensive S nutrition to some extent alleviated Cd-induced toxicity. High S doses, especially 6 mM S, partially improved macronutrient status and restored the macronutrient balance. In Cd-stressed plants supplemented with additional S, an increase in root and shoot biomass and in the content of N, K and Mg was found, without significant changes in the Ca content. Simultaneously, the P and S contents in the biomass of both above- and underground organs remained unchanged. In the leaves, as opposite to the roots, intensive S nutrition reduced the accumulation of Cd. However, the foliar Cd concentration still exceeded the acceptable limits established for consumption. All the obtained results concerning the content of macronutrients and their ratios were referred, inter alia , to the standards i.e. the Diagnosis and Recommendation Integrated System (DRIS) norms. [ABSTRACT FROM AUTHOR]

Kynurenic acid (KYNA) is a metabolite of tryptophan exerting a number of positive actions in rodents, including anti-inflammatory and antioxidative activity. In this study, an analysis of KYNA concentration in a number of honeys, including chestnut honey, as well as chestnut tree parts and products made from chestnuts, was performed. It was found that the content of KYNA in chestnut honey is exceptionally high, in comparison both with other types of honey investigated and with selected chestnut products, such as peeled fruit, crème, puree and flour. It was also detected that the content of KYNA in chestnut tree male flower is several times higher than in female flower. Our results indicate that chestnut honey, which is predominantly produced in Mediterranean countries, contains very high amounts of KYNA and can be an important source of dietary KYNA. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the usefulness of protein hydrolysate (Hemozym) for fertilization purposes used in unpolluted and cadmium-polluted soil. Three levels of Hemozym (0, 0.1, and 0.2 cm3 kg−1dry weight [DW] soil) and cadmium (Cd) rate 5 mg kg−1DW soil were used. The fertilizer value of Hemozym was evaluated based on characteristics of the sorptive complex and soil respiratory activity as well as based on the soil and plant heavy-metal content. Increased soil fertility due to the beneficial effect of Hemozym on the improvement in the physicochemical properties of the soil and its microbial activity. However, they do not allow us to determine unambiguously the effect of this fertilizer on solubility vs. binding of heavy metals that occur naturally in the soil (zinc [Zn], copper [Cu], and lead [Pb]) and of intentionally introduced Cd, in spite of an indicative tendency towards the conversion of metals into poorly soluble forms. [ABSTRACT FROM AUTHOR]

Calcium is one of the most poorly reutilized nutrients. Its deficiencies cause various physiological disturbances and, consequently, reduce the quantity and quality of yields. Reduced content of Ca2+ ions in cells leads to development of, e.g., bitter pit in apples. Efficient and instantaneous mitigation of Ca2+ deficiencies is provided by foliar feeding. There are no detailed data on the effect of foliar feeding with various calcium forms on the cell structure or on the microanalysis and mapping of this element in apple fruit cells. Therefore, we carried out comparative studies of the ultrastructure of epidermis and hypodermis cells, to assess the content and distribution of calcium in the cell wall, cytoplasmic membrane, cytoplasm, and precipitates of Malus domestica Borkh. 'Szampion' fruit exposed to four Ca treatments, including the control with no additional Ca supplementation (I) and foliar applications of Ca(NO3)2 (II), CaCl2 (III), and Ca chelated with EDTA (IV). Light and transmission electron microscopy and an X-ray microanalyzer were used and showed a beneficial effect of calcium preparations on the ultrastructure of fruit epidermis and hypodermis cells, manifested in the presence of a normally developed cell wall with a regular middle lamella, preserved continuity of cytoplasmic membranes, and stabilized cell structure. In the selected elements of apical epidermis cells, the highest level of Ca2+ ions was detected in the middle lamella, cell wall, plasmalemma, and cytoplasm. The highest increase in the Ca2+ content in these cell constituents was recorded in treatment IV, whereas the lowest value of the parameters was noted in variant III. [ABSTRACT FROM AUTHOR]