Magnesium and manganese induced changes on chemical, nutritional, antioxidant and antimicrobial properties of the pansy and Viola edible flowers

Pansy and viola edible flowers were grown hydroponically with different levels of Mg and Mn. The nutritional composition was determined using standard methods. Free sugars, fatty acids, organic acids, tocopherols, and phenolic compounds were analyzed using various HPLC and GC devises. The extract's antimicrobial, antioxidant, cytotoxicity, and anti-inflammatory activity were assessed. The results indicated that Mg enrichment negatively affected plant growth and mineral accumulation but improved photosynthetic performance. The edible flowers contained significant amounts of protein, low levels of fat, and varying sugar contents, such as glucose and fructose. Various fatty acids and phenolic compounds were identified, with different concentrations depending on the treatment. The flowers exhibited antioxidant potential, antimicrobial activity, cytotoxic effects, and anti-inflammatory properties. The correlations between the investigated parameters not only expand knowledge on Mg and Mn interaction but also catalyze significant advancements in sustainable agriculture and food health, fostering a healthier and more conscious future.

Phytochemical Profiles and Biological Activities of Plant Extracts from Aromatic Plants Cultivated in Cyprus

Medicinal and aromatic plants' properties, still an interesting research area, are attributed to the presence of various specialized products that possess important pharmacological activities. In the present study, six medicinal/aromatic plants (Sideritis cypria, Origanum dubium, Melissa officinalis, Mentha piperita, Thymus capitatus, and Salvia fruticosa) were evaluated for their phytochemical and nutritive composition, as well as their biological activities, including antioxidant, antimicrobial, and cytotoxic properties. The results obtained indicate that M. piperita was rich in proteins and minerals such as N and Mg, while S. cypria accumulated more K, Na, P, and Ca. The highest content of phenols and flavonoids was observed in M. piperita, followed by O. dubium and T. capitatus, which eventually influenced their high antioxidant capacity. NMR screening revealed the presence of (i) triterpenoids and hydroxycinnamic acid derivatives in M. officinalis; (ii) terpenoids, flavonoids, and phenolic acid derivatives in S. fruticosa; (iii) flavonoids and phenolic acid derivatives in M. piperita; (iv) phenolic monoterpenes in O. dubium and T. capitatus; and (v) terpenoids, flavones, and phenylethanoid glycosides in S. cypria. The results of the antimicrobial activity showed that the tested samples overall had quite good antimicrobial potential. High antibacterial activity was found in O. dubium and T. capitatus, while O. dubium and S. cypria exhibited great antifungal activities. The studied species also had an important effect on the viability of female-derived and colon cancer cells. In particular, in colon cancer cells, the extracts from T. capitatus, M. officinalis, M. piperita, and S. fruticosa exhibited a stronger effect on cell viability in the more metastatic cell line at significantly lower concentrations, indicating an important therapeutic potential in targeting highly metastatic tumors. This finding is worth further investigation. The present study unveiled interesting phytochemical profiles and biological properties of the six medicinal/aromatic plants, which should be further explored, contributing to green chemistry and the possible creation of natural health products for humans' health/nutrition and additives in cosmetics.

Ammonium to total nitrogen ratio affects the purslane (Portulaca oleracea L.) growth, nutritional, and antioxidant status

Purslane (Portulaca oleracea L.) is a widespread weed, which is greatly appreciated for its high nutritional value. The present work evaluated the effect of different ammonium/total nitrogen ratios (NH4/Total N: Nr 0.01-0.15) on growth, physiological and biochemical parameters, and nutrient accumulation in different plant parts of hydroponically grown purslane, under two growing seasons, spring and autumn. Young seedlings of purslane were transferred to a Nutrient Film Technique (NFT) system and they were exposed to different Nr levels. The pH and the electrical conductivity of the nutrient solution were kept constant at 5.8 and 2.3 mS cm-1, respectively. After the end of the cultivation periods (19 days for spring and 22 days for autumn), a series of assessments (growth parameters, mineral content in different plant organs, antioxidant status of the plant, etc.) were done. Plant height, leaf number, root fresh weight and plant biomass revealed decreased trends at the higher NH4/total N ratios, especially during the autumn growing season. Total phenols, flavonoids and antioxidant capacity appeared increased at Nr ≤ 0.10 during both seasons (autumn and spring), revealing higher nitrogen accumulation rates and increased water and nutrient use efficiency. Purslane plants grown in Nr 0.05-0.10 revealed a less intense oxidative stress, with decreased lipid peroxidation levels that was the result of the activation of both enzymatic (superoxide dismutase, catalase and peroxidase) and non-enzymatic (ascorbic acid) antioxidant capacity of the plant. Increased Nr resulted in the accumulation of potassium, while calcium and magnesium levels in leaves were decreased. Additionally, the greater water use efficiency was measured for plants grown under Nr 0.01-0.05. Therefore, the recommended ammonium/total nitrogen ratio for purslane production of increased yield, improved nutritional value and efficient use of water and nitrogen sources is to employ Nr of 0.05, while additional care should be addressed during autumn periods as plants are subjected to greater impacts of the Nr ratio.

Effects of the extraction techniques on the chemical composition and bioactive properties of lemon balm (Melissa officinalis L.) plants grown under different cropping and irrigation regimes

The present study aims to determine the combined effect of cropping system and irrigation regime on the chemical composition and bioactive properties of lemon balm aerial parts. For this purpose, lemon balm plants were grown under two farming systems (conventional farming vs organic farming) and two irrigation levels (full irrigation vs deficit irrigation) and harvested twice throughout the growing period. The collected aerial parts were subjected to three different methods of extractions, namely infusion, maceration and ultrasound-assisted extraction and the obtained extracts were evaluated in terms of chemical profile and bioactivities. Five organic acids with varied composition among the tested treatments were identified in all the tested samples for both harvests, namely, citric, malic, oxalic, shikimic and quinic acid. Regarding phenolic compounds composition, the most abundant ones were rosmarinic acid, lithospermic acid A isomer I and hydroxylsalvianolic E, especially for the maceration and infusion extraction methods. Full irrigation resulted in lower EC₅₀ values than deficit irrigation only in the treatments of the second harvest, while variable cytotoxic and anti-inflammatory effects were recorded in both harvests. Finally, in most cases the lemon balm extracts has similar or better activity than the positive controls, while the antifungal activity of lemon balm extracts was stronger than the antibacterial effects. In conclusion, the results of the present study showed that the implemented agronomic practices, as well as the extraction protocol may significantly affect the chemical profile and bioactivities of lemon balm extracts, suggesting that both the farming system and the irrigation schedule may improve the quality of the extracts depending on the implemented extraction protocol.

Sideritis L. essential oils: A systematic review

Essential oils are extensively used in the food, cosmetic, perfume, pharmaceutical, and agrochemical industries due to their aroma and pharmacological properties. The Lamiaceae family is mainly represented by widely well-known medicinal and aromatic plants that produce essential oil. Over the years, Sideritis L. essential oils have attracted great interest due to their chemical variability among the different taxa and their pharmacological activities. In-depth research of previously published literature was performed on electronic databases with several key search words for the collection of the available data and a total of 128 scientific studies were used since 1983. To date, 155 accepted Sideritis samples have been studied originating from 15 countries and more than 250 compounds have been reported in 87 Sideritis taxa overall. Furthermore, antimicrobial and antioxidant effects have been the most studied pharmacological activities. This review summarizes and critically discusses the research work on the chemical composition and pharmacological activities of essential oil of the genus Sideritis based on the currently valid taxonomy. Additionally, statistical analysis is encompassed to provide a deeper comprehensive understanding of the high chemical polymorphism of Sideritis essential oils. We expect that this review will encourage researchers to investigate unexplored Sideritis taxa and will contribute to revealing uncharted scientific territory and future perspectives on these plants.

Origanum dubium (Cypriot Oregano) as a Promising Sanitizing Agent against Salmonella enterica and Listeria monocytogenes on Tomato and Cucumber Fruits

In recent years, the use of natural products such as essential oils (EOs) and other plant extracts for the preservation of fresh produce has attracted much interest from the food industry. Many endemic medicinal and aromatic plants, such as Cypriot oregano (Origanum dubium), present a plethora of properties that can be utilized by the fruit and vegetable sectors of the food industry. The purpose of the present study was to assess the effects of O. dubium EO and hydrosol (at different concentrations and durations of dipping application) for the preservation of tomato and cucumber fruit quality, and their effectiveness as sanitizing agents against two foodborne pathogens (Listeria monocytogenes and Salmonella enterica). The results of this study indicated that increased concentrations of EO, combined with a longer duration of application, resulted in less marketable fruit compared to hydrosol application. Interestingly, EO application at lower concentrations and shorter durations of application (i.e., 0.01% for 5 min) increased fruit antioxidant, ascorbic acid and carotenoid levels (for tomato fruit), suggesting an increase in the nutritional value of the treated fruit, compared to the control. EO and hydrosol were able to decrease the bacterial populations (both bacteria) on fruits. Both products were especially effective against L. monocytogenes, even seven days after their application and storage at 11 °C (up to an approx. 3 log reduction with the EO application). Overall, the results of this study suggest that the use of O. dubium EO and hydrosol could be considered as alternative sanitation means for tomatoes and cucumbers.

Physiological and biochemical responses of Tanacetum balsamita L. to the foliar application of Dobogen biostimulant, glucose and KNO3 under salinity stress

Salinity is one of the predominant abiotic stress factors that influence the growth and productivity of plants. Salinity adversely impacts the growth responses via ionic toxicity, osmotic stress, impaired nutrients uptake, hormonal disparity, and the over-production of reactive oxygen species. To study the effects of salinity stress (0, 50, 100, and 150 mM) and foliar treatments (dH₂O, 2 g L⁻¹ Dobogen biostimulant, 2 g L⁻¹ KNO_3, and 2 g L⁻¹d-glucose) on the growth and physiological responses of Tanacetum balsamita, a factorial experiment was conducted based on the completely randomized design at the research greenhouse of Azarbaijan Shahid Madani University, Iran. The results showed the significant interaction effects of salinity and foliar sprays on chlorophyll a, K⁺, Na⁺, Mg²⁺, Fe²⁺, Zn²⁺, Mn²⁺, and Si content, K/Na ratio, and total phenolics and flavonoids content. The highest phenolic content was acquired with 100 mM salinity and foliar spray of Dobogen and glucose, 50 mM NaCl × KNO₃ application, and 50 mM salinity × no-foliar application. The highest K/Na ratio was observed in control plants and controls × KNO₃ and/or Dobogen application. The greatest Si content was recorded with no-salinity × Dobogen and KNO₃ applications and no-saline × no-foliar (control) plants. The independent effects of treatments influenced malondialdehyde, flavonoids, proline contents, and catalase activity. Chlorophyll b and superoxide dismutase were affected by the salinity. Total soluble solids and Ca²⁺ content were responsive to the foliar applications. Malondialdehyde and proline content was the highest at 150 mM salinity. Salinity adversely affected the physiological responses of costmary. However, foliar treatments partially ameliorated the salinity effect, and the results with more detailed studies would be advisable to the extension section and pioneer farmers.

Salmonella Enteritidis survival in different temperatures and nutrient solution pH levels in hydroponically grown lettuce

Due to climate change, with contaminated and less fertile soils, and intense weather phenomena, a turn towards hydroponic vegetable production has been made. Hydroponic cultivation of vegetables is considered to be a clean, safe and environmentally friendly growing technique; however, incidence of microbial contamination i.e. foodborne pathogens, might occur, endangering human health. The aim of this study was to investigate the effects of different plant growth stages, pH (values 5, 6, 7, 8) and bacterial inoculum levels (3 and 6 log cfu/mL) on hydroponically cultivated lettuce spiked with Salmonella Enteritidis. The results revealed that the pH and inoculum levels affected the internalization and survival of the pathogen in the hydroponic environment and plant tissue. Younger plants were found to be more susceptible to pathogen internalization compared to older ones. Under the current growing conditions (hydroponics, pH and inoculum levels), no leaf internalization was observed at all lettuce growth stages, despite the bacterium presence in the hydroponic solution. Noticeably, bacteria load at the nutrient solution was lower in low pH levels. These results showed that bacterium presence initiates plant response as indicated by the increased phenols, antioxidants and damage index markers (H2O2, MDA) in order for the plant to resist contamination by the invader. Nutrient solution management can result in Taylor-made recipes for plant growth and possible controlling the survival and growth of S. Enteritidis by pH levels.

Vapour Application of Sage Essential Oil Maintain Tomato Fruit Quality in Breaker and Red Ripening Stages

Consumers seek safe, high-nutritional-value products, and therefore maintaining fresh produce quality is a fundamental goal in the food industry. In an effort to eliminate chemical-based sanitizing agents, there has been a shift in recent decades toward the usage of eco-friendly, natural solutions (e.g., essential oils-EOs). In the present study, tomato fruits (Solanum lycopersicum L. cv. Dafni) at breaker and red ripening stage were exposed to sage essential oils (EO: 50 μL L^-1 or 500 μL L^-1) for 2, 7 and 14 days, at 11 °C and 90% relative humidity (RH). Quality-related attributes were examined during (sustain effect-SE) and following (vapour-induced memory effect-ME; seven days vapours + seven days storage) vapour treatment. In breaker tomatoes, EO-enrichment (sustained effect) retained fruit firmness, respiration rates, and ethylene emission in low EO levels (50 μL L^-1). In contrast, breaker fruit metabolism sped up in high EO levels of 500 μL L^-1, with decreased firmness, increased rates of respiration and ethylene, and effects on antioxidant metabolism. The effects were more pronounced during the storage period of 14 days, comparing to the fruit exposed to common storage-transit practice. In red fruits, the EOs impacts were evidenced earlier (at two and seven days of storage) with increased rates of respiration and ethylene, increased β-carotene, and decreased lycopene content. In both breaker and red ripening fruit, EO application decreased weight losses. Considering the fruits pre-exposed to EOs, quality attributes were more affected in green fruits and affected to a lesser level in the red ones. Furthermore, based on appearance, color, and texture evaluations, organoleptic trials demonstrated an overwhelming preference for EO-treated red fruit during choice tests. EOs had lower effects on total phenolics, acidity, total soluble solids, and fruit chroma, with no specific trend for both breaker and red tomatoes. Natural volatiles may aid to retain fruit quality in parallel with their antimicrobial protection offered during storage and transportation of fresh produce. These effects may persist after the EO is removed from the storage conditions.

Polar constituents, biological effects and nutritional value of Sideritis sipylea Boiss

The present study focuses on the polar constituents and biological effects of the methanol extract and the infusion of wild Sideritis sipylea Boiss. from Samos island (Greece), as well as on the nutritional and mineral contents of this plant. The total phenolic content and antioxidant activity were examined. In addition, the anti-acetylcholinesterase property was evaluated, revealing strictly lower results than the control, galanthamine. Furthermore, the nutritional value of the plant is reported herein for the first time, revealing a promising source of protein. To the best of our knowledge, this study is the first work on the infusion of this species and the nutritional value of the plant.

Morphological Diversity, Genetic Characterization, and Phytochemical Assessment of the Cypriot Tomato Germplasm

Tomato (Solanum lycopersicum L.) is considered one of the most valuable and versatile vegetable crops globally and also serves as a significant model species for fruit developmental biology. Despite its significance, a severe genetic bottleneck and intense selection of genotypes with specific qualitative traits have resulted in the prevalence of a restricted number of (geno)types, also causing a lack of diversity across widespread cultivated types. As a result, the re-emergence of landraces as well as traditional and heirloom varieties is largely acknowledged as a countermeasure to restore phenotypic, phytochemical and genetic diversity while enriching the aroma/taste tomato palette. On those grounds, the Cypriot tomato germplasm was assessed and characterized. Ten landrace accessions were evaluated under greenhouse conditions and data were collected for 24 IPGRI discrete phenotypic traits. Grouping of accessions largely reflected the fruit shape and size; four different fruit types were recorded across accessions (flattened, heart-shaped, rounded and highly rounded). Moreover, a single run panel consisting of ten SSRs was developed and applied in order to genetically characterize 190 Cypriot genotypes and foreign heirloom varieties. Based on genetic indexes it was established that tomato landraces have a rather low level of heterogeneity and genetic variation. Finally, mineral and phytochemical analyses were conducted in order to estimate biochemical attributes (total phenolics, ascorbic acid, lycopene, β-carotene, total soluble content, titratable acidity) across genotypes; thus, ascertaining that the Cypriot panel has a high nutritional value. Due to the thermo-drought adaptation and tolerance of these genotypes, the current study serves as a roadmap for future breeding efforts in order to incorporate desirable traits or develop novel tomato lines combining resilience and alimentary value.

Copper Tolerance and Accumulation on Pelargonium graveolens L'Hér. Grown in Hydroponic Culture

Heavy metal contamination is a major health issue concerning the commercial production of medicinal and aromatic plants (MAPs) that are used for the extraction of bioactive molecules. Copper (Cu) is an anthropogenic contaminant that, at toxic levels, can accumulate in plant tissues, affecting plant growth and development. On the other hand, plant response to metal-induced stress may involve the synthesis and accumulation of beneficial secondary metabolites. In this study, hydroponically grown Pelargonium graveolens plants were exposed to different Cu concentrations in a nutrient solution (4, 25, 50, 100 μM) to evaluate the effects Cu toxicity on plant growth, mineral uptake and distribution in plants, some stress indicators, and the accumulation of bioactive secondary metabolites in leaf tissues. P. graveolens resulted in moderately tolerant Cu toxicity. At Cu concentrations up to 100 μM, biomass production was preserved and was accompanied by an increase in phenolics and antioxidant capacity. The metal contaminant was accumulated mainly in the roots. The leaf tissues of Cu-treated P. graveolens may be safely used for the extraction of bioactive molecules.

Sustainable Agriculture Systems in Vegetable Production Using Chitin and Chitosan as Plant Biostimulants

Chitin and chitosan are natural compounds that are biodegradable and nontoxic and have gained noticeable attention due to their effective contribution to increased yield and agro-environmental sustainability. Several effects have been reported for chitosan application in plants. Particularly, it can be used in plant defense systems against biological and environmental stress conditions and as a plant growth promoter—it can increase stomatal conductance and reduce transpiration or be applied as a coating material in seeds. Moreover, it can be effective in promoting chitinolytic microorganisms and prolonging storage life through post-harvest treatments, or benefit nutrient delivery to plants since it may prevent leaching and improve slow release of nutrients in fertilizers. Finally, it can remediate polluted soils through the removal of cationic and anionic heavy metals and the improvement of soil properties. On the other hand, chitin also has many beneficial effects such as plant growth promotion, improved plant nutrition and ability to modulate and improve plants’ resistance to abiotic and biotic stressors. The present review presents a literature overview regarding the effects of chitin, chitosan and derivatives on horticultural crops, highlighting their important role in modern sustainable crop production; the main limitations as well as the future prospects of applications of this particular biostimulant category are also presented.

The Combined and Single Effect of Marjoram Essential Oil, Ascorbic Acid, and Chitosan on Fresh-Cut Lettuce Preservation

Increasing demands by consumers for fresh, nutritional, and convenient food has led to the increase of fresh-cut produce market. Nowadays, there is a turn towards the investigation of natural products (i.e., essential oils, organic acids, and edible coatings) in an effort to lower the usage of chemical synthetic compounds (i.e., chlorine) as postharvest sanitizers. The aim of the present study was to assess the effectiveness of Origanum majorana essential oil (EO), ascorbic acid (AA), chitosan, and their combinations on quality attributes of fresh-cut lettuce stored for six days at 7 °C. When applied, Chitosan+AA resulted to a less acceptable product (visual quality and aroma), while the application of marjoram EO was able to preserve the visual quality of fresh-cut lettuce and at the same time resulted in a pleasant aroma. The application of EO+AA and Chitosan+AA increased total phenolics and antioxidant levels of fresh-cut lettuce on the fourth and sixth day of storage. The EO and EO+AA increased damage index (hydrogen peroxide and lipid peroxidation) of fresh-cut lettuce, while at the same time these treatments decreased the activity of enzymes related with plant tissue browning (i.e., peroxidase activity and polyphenol oxidase). Chitosan decreased total valuable counts and yeasts and molds counts on the sixth day of storage, while EO, AA, EO+Chitosan, and Chitosan+AA decreased yeasts and molds after four days of application. The findings of the present work indicating that the combination of marjoram EO, AA, and chitosan could be considered further as alternative means for fresh-cut produce preservation.

Bio-Guided Investigation of Sideritis cypria Methanol Extract Driven by in Vitro Antioxidant and Cytotoxic Assays

Sideritis cypria Post is an endemic and endangered species of Northern Cyprus. The overall aim of the present study was to evaluate the total phenolic content, the antioxidant, the cytotoxic and the antimicrobial activity of the methanol extract obtained from the aerial parts of cultivated S. cypria. A bio-guided approach led to the isolation of 27 chemical compounds by using various analytical techniques. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopy. The crude extract exerted strong antioxidant activity (DPPH and FRAP assays) which was attributed to its high total phenolic content. Furthermore, groups rich in phenolic content showed highest antioxidant property, whereas groups with phytosterols, diterpenoids and apigenin derivatives exerted cytotoxic effects in MDA-MB231 cancer cell line by the MTT method. Moreover, the cytotoxic activity of four isolated apigenin derivatives was evaluated in the same cancer cells. The antimicrobial activity of the extract and groups were measured, demonstrating lack of activity. To the best of our knowledge, this survey is the first report on the biological activities of the methanol extract of S. cypria.

A biorefinery for conversion of citrus peel waste into essential oils, pectin, fertilizer and succinic acid via different fermentation strategies

A process for the valorization of citrus peel waste (CPW) has been developed aiming to produce succinic acid and a series of added-value products through the biorefinery platform. CPW was subject to physicochemical and biological treatment to isolate essential oils (0.43%) and pectin (30.53%) as extractable products, pretreating the material for subsequent production of succinic acid that enabled application of remaining biorefinery residues (BR) as fertilizer substitute. Cellulose, hemicellulose and lignin contents of CPW accounted for 22.45%, 8.05% and 0.66% respectively, while acid hydrolysis reduced hemicellulose by 3.42% in BR. Moreover, essential oils extracted from CPW included 17 compounds, among which D-limonene reached 96.7%. The hydrolyzate generated was fermented for succinic acid production using Actinobacillus succinogenes. Different batch experiments demonstrated that the combined use of corn steep liquor (CSL) and vitamins in a lab-scale bioreactor resulted in product concentration and yield that reached 18.5 g L^-1 and 0.62 g g^-1 respectively. Although simultaneous saccharification and fermentation (SSF) could not enhance succinic acid production, a fed-batch fermentation strategy increased succinic acid concentration and yield generating 22.4 g L^-1 and 0.73 g g^-1 respectively, while the mass of the platform chemical formed was enhanced by 27% as compared to the batch process. BR was explored as fertilizer substitute aiming to close the loop in the management of CPW towards development of a zero-waste process demonstrating that although the material imposed stress on plant growth, the content of potassium, phosphorus and nitrogen in the mixture increased.

Traditionally Used Sideritis cypria Post.: Phytochemistry, Nutritional Content, Bioactive Compounds of Cultivated Populations

Sideritis species are recognized as important medicinal plants and their commercial demand is continuously on the rise both in the European and in the global market. Consequently, the cultivation of Sideritis species has been occurred to successfully meet the need for mass production of high-quality plant material. The present study was undertaken in order to investigate the chemical composition of cultivated S. cypria. Infusions of flowers and leaves were prepared separately, according to the European Medicine Agency (EMA) monograph. The infusion of the flowers revealed the presence of four flavones, isoscutellarein-7-O-[6′″-O-acetyl-β-D-allopyranosyl-(1→2)-β-D-glucopyranoside, its 4′-O-methyl-derivative, 4′-O-methyl-hypolaetin-7-O-[6′″-O-acetyl-β-D-allopyranosyl-(1→2)-β-D-glucopyranoside, and isoscutellarein-7-O-[6′″-O-acetyl-β-D-allopyranosyl-(1→2)]-6″-O-acetyl-β-D-glucopyranoside; four phenylethanoid glucosides, acteoside, leucosceptoside A, lamalboside, and leonoside A; one iridoid, melittoside, and one phenolic acid, chlorogenic acid, while the infusion of the leaves of the same population afforded the same first two flavones; five phenylethanoid glucosides, acteoside, leucosceptoside A, lavandulifolioside, leonoside A, and lamalboside; melittoside and chlorogenic acid. The structural elucidation of the isolated compounds was undertaken by high-field NMR spectroscopy. Moreover, the essential oils of the flowers and leaves were studied by GC-MS, separately. In addition, the mineral, bioactive compounds, protein and carbohydrate contents were evaluated for both plant materials.

Chemical Composition and Plant Growth of Centaurea raphanina subsp. mixta Plants Cultivated under Saline Conditions

The aim of this report was to study the effect of salinity (control: 2dS/m, S1: 4 dS/m and S2: 6 dS/m) and harvest time (first harvest on 9 May 2018 and second harvest on 19 April 2018) on the growth and the chemical composition of Centaurea raphanina subsp. mixta plants. The plants of the first harvest were used for the plant growth measurements (fresh weight and moisture content of leaves, rosette diameter, number and thickness of leaves), whereas those of the second harvest were not used for these measurements due to the flowering initiation, which made the leaves unmarketable due to their hard texture. The results of our study showed that C. raphanina subsp. mixta plants can be cultivated under mild salinity (S1 treatment) conditions without severe effects on plant growth and yield, since a more severe loss (27.5%) was observed for the S2 treatment. In addition, harvest time proved to be a cost-effective cultivation practice that allows to regulate the quality of the final product, either in edible form (first harvest) or for nutraceutical and pharmaceutical purposes as well as antimicrobial agents in food products. Therefore, the combination of these two agronomic factors showed interesting results in terms of the quality of the final product. In particular, high salinity (S2 treatment) improved the nutritional value by increasing the fat, proteins and carbohydrates contents in the first harvest, as well as the tocopherols and sugars contents (S1 and S2 treatments, respectively) in the second harvest. In addition, salinity and harvest time affected the oxalic acid content which was the lowest for the S2 treatment at the second harvest. Similarly, the richest fatty acid (α-linolenic acid) increased with increasing salinity at the first harvest. Salinity and harvest time also affected the antimicrobial properties, especially against Staphylococcus aureus, Bacillus cereus and Trichoderma viride, where the extracts from the S1 and S2 treatments showed high effectiveness. In contrast, the highest amounts of flavanones (pinocembrin derivatives) were detected in the control treatment (second harvest), which was also reflected to the highest antioxidant activity (TBARS) for the same treatment. In conclusion, C. raphanina subsp. mixta plants seem to be tolerant to medium salinity stress (S1 treatment) since plant growth was not severely impaired, while salinity and harvesting time affected the nutritional value (fat, proteins, and carbohydrates) and the chemical composition (tocopherols, sugars, oxalic acid, fatty acids), as well as the bioactive properties (cytotoxicity and antimicrobial properties) of the final product.

Wild and Cultivated Centaurea raphanina subsp. mixta: A Valuable Source of Bioactive Compounds

Centaurea raphanina subsp. mixta (DC.) Runemark is a wild edible species endemic to Greece. This study evaluated the chemical composition and bioactive properties of wild and cultivated C. raphanina subsp. mixta plants. Wild plants had higher nutritional value than cultivated ones, whereas cultivated plants contained more tocopherols. Glucose and sucrose were higher in cultivated plants and trehalose in wild ones. Oxalic and total organic acids were detected in higher amounts in cultivated samples. The main fatty acids were α-linolenic, linoleic and palmitic acid, while wild plants were richer in polyunsaturated fatty acids. Two pinocembrin derivatives were the main phenolic compounds being detected in higher amounts in wild plants. Regarding the antioxidant activity, wild and cultivated plants were more effective in the oxidative haemolysis (OxHLIA) and thiobarbituric acid reactive substances (TBARS) assays, respectively. Moreover, both extracts showed moderate cytotoxicity in non-tumor cell lines (PLP2), while cultivated plants were more effective against cervical carcinoma (HeLa), breast carcinoma (MCF-7) and non-small lung cancer (NCI-H460) cell lines. Finally, wild plants showed higher antimicrobial activity than cultivated plants against specific pathogens. In conclusion, the cultivation of C.raphanina subsp. mixta showed promising results in terms of tocopherols content and antiproliferative effects, however further research is needed to decrease oxalic acid content.

Physiological and Proteomic Approaches to Address the Active Role of Botrytis cinerea Inoculation in Tomato Postharvest Ripening

Botrytis cinerea is an unbearable postharvest threat with significant economic impacts. Necrotrophic B. cinerea can readily infect ripe fruit resulting in the rapid progression of symptoms of the disease. To unravel the mechanism by which tomato fruit opposes pathogen attack, we investigated the changes in quality-related attributes as a direct response (DR) or systemic response (SR) of infected tomatoes to the B. cinerea. Additionally, the SR of protein yield and composition were studied in fruit stored at 11 °C/90% relative humidity (RH) for one week. Fungal infection accelerated ripening with increased ethylene and respiration rates. Fruit softening, ascorbic acid and β-carotene increase were associated with DR but not with the SR of the pathogen. Pathogen infection increased lipid peroxidation, causing the production of hydrogen peroxide and oxidative stress, as fruit activated both enzymatic and non-enzymatic mechanisms to trigger stress. B. cinerea increased up to 6.6% the protein yield and downregulated at least 39 proteins. Proteins involved in fruit ripening, such as an ethylene biosynthetic enzyme, were increased in wound-inoculated fruit. Moreover, antioxidant proteins, such as ascorbate peroxidase-APX1 and superoxide dismutase-SOD, increased in infected tomatoes, as these proteins are involved in reactive oxygen species detoxification. Constitutively-expressed proteins tended to be either increased (chaperonin and malate dehydrogenase) or remained unaffected (dehydrin) by pathogen inoculation. Protein levels involved in the metabolism of carbohydrate, the pentose phosphate pathway, terpenoid and flavonoid biosynthesis were differently affected during the treatments. By enabling a better understanding of the fungal direct or systemic response on fruit quality and ripening through biochemical and proteome studies, we may improve the plant-pathogen interaction and complexity.

Sideritis Perfoliata (Subsp. Perfoliata) Nutritive Value and Its Potential Medicinal Properties

Sideritis perfoliata L. subsp. perfoliata is an endemic species of the Eastern Mediterranean region with several uses in traditional medicine. The present study aims to explore the unknown properties of S. perfoliata investigating the nutritional content as well as the antioxidant, anticancer, antituberculosis, antiwrinkle, anti-acne, hyper/hypo-pigmentation and antibacterial activities. Mineral content, nutritional value, the composition and antioxidant properties of the essential oil, the antityrosinase, the antibacterial activity and anti-elastase potential of the extract, were evaluated. The antiproliferative activity of S. perfoliata against cervical cancer (HeLa), human melanoma (UCT-Mel-1), human hepatocellular carcinoma (HepG2) and human epidermoid carcinoma (A431) was investigated. Cytotoxic effects on normal human keratinocyte (HaCat) and kidney epithelial (Vero) cell lines were also determined. Sideritis perfoliata exhibited high nutritional value of proteins and minerals (K, P, Mg, Fe, Zn, Cu). The most abundant components of the essential oil were found to be α-pinene, β-phelladrene, valeranone, β-pinene and sabinene. The ethanolic extract of S. perfoliata displayed moderate antioxidant potential and antibacterial activity against Prevotella intermedia. Noteworthy elastase and moderate anticancer potential against the human liver cancer cell line (HepG2) was observed with IC₅₀ values of 57.18 ± 3.22 μg/mL and 64.27 ± 2.04 μg/mL respectively. The noteworthy in vitro activity of S. perfoliata could be due to the presence of flavonoids and phenols in the leaves, having high nutritional value. Sideritis perfoliata could potentially be useful to reduce the appearance of wrinkles and for the treatment of liver cancer. The moderate antibacterial, antioxidant and elastase activity of the plant can be linked to the traditional use of S. perfoliata for the treatment of wounds and inflammation.

The combined and single effect of salinity and copper stress on growth and quality of Mentha spicata plants

Copper is essential for plant growth, but in excess may cause adverse effects on plant physiology. Harmful effects are also caused by plant exposure to salinity (NaCl) due to the excessive use of fertilizers, soil degradation and/or the quality of the water used for irrigation. The impact of single and combined salinity (Sal) and copper (Cu) stress on spearmint metabolism were studied in hydroponics. Spearmint plants (Mentha spicata L.) were subjected to salinity stress (150 mM NaCl) and/or excessive Cu concentration (60 μM Cu) via the nutrient solution. Not only Sal and Cu, but also their combination suppressed plant growth by decreasing plant biomass, root fresh weight and plant height. Chlorophyll content decreased mainly for the combined stress treatment (Sal + Cu). Polyphenols and antioxidants (FRAP, DPPH, ABTS) increased in single stress treatments (Sal or Cu), but decreased in the combined stress (Sal + Cu). The application of Sal or Cu stress decreased Zn, N and K (leaves), K, Ca, P and Mg (roots) content. Copper application increased Ca and Mg in leaves. In conclusion, salinity stress and Cu exposure may change the primary metabolic pathways in favor of major volatile oil components biosynthesis, resulting in significant changes of essential oil yield and composition.

Effect of phosphorus application rate on Mentha spicata L. grown in deep flow technique (DFT)

The present study evaluated the impact of phosphorus application rate on plant growth and physiological parameters, antioxidant activity, chemical composition, and essential oil yield and composition of hydroponically grown spearmint plants. Increased P levels resulted in high dry matter content of the aerial part. Antioxidant activity of spearmint leaves was significantly higher at the highest P levels. Although essential oil yield was not affected, essential oil composition varied among the studied P levels, especially carvone content. Total and individual organic acids content was higher when 50 mg/L P were added in the nutrient solution. Rosmarinic acid was the main detected phenolic compound, while the highest total phenolic compounds and rosmarinic acid content was observed at 50 and 70 mg/L of P, respectively. In conclusion, phosphorus application rate may affect spearmint growth and development, as well as chemical composition and essential oil composition.

Alternative soilless media using olive-mill and paper waste for growing ornamental plants

Peat-based growing media are not ecologically sustainable and peat extraction threatens sensitive peatland ecosystem. In this study, olive-stone waste (OSW) and paper waste (PW) were used in different ratios-as growing media-for ornamental crop production, as peat (P) substitutes. Marigold (Calendula officinalis L.), petunia (Petunia x hybrita L.) and matthiola (Matthiola incana L.) plants were grown in (1) P (100%), (2) P:OSW (90%:10%), (3) P:OSW (70%:30%), and (4) P:OSW:PW (60%:20%:20%). The physicochemical properties of these substrates and the effects on plant growth were determined. The addition of 10-30% OSW into the substrate increased marigold height compared to plants grown in 100% peat. No differences in plant size, plant biomass (leaves and flowers), and dry matter content were found. Adding PW, in combination with OSW, maintained marigold height and total number of flowers produced to similar levels as in plants grown in 100% peat. In matthiola, adding 30% OSW into the substrate reduced plant size and fresh weight, but not plant height. No differences were observed when plants grew in lower OSW (i.e., 10%) content. Petunia's height, its total number of flowers and flower earliness (flower opening) were increased in the presence of OSW compared to the plants grown in 100% peat. The addition of OSW did not affect petunia's size and fresh weight among treatments. The addition of PW suppressed several plant growth-related parameters for both matthiola and petunia. The insertion of OSW did not change leaf chlorophyll content whereas the presence of PW decreased chlorophylls for marigold, petunia, and matthiola. Both OSW and PW altered the content of total phenolics and antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) in leaves and flowers for marigold and petunia. Both 30% OSW and PW increased antioxidative enzyme metabolism due to the increased damage index and lipid peroxidation observed in plants. Leaf N and P content decreased in PW-based media, while matthiola displayed visual phytotoxicity symptoms when PW was added into the substrate. The present work indicates that up to 30% of OSW can replace peat for marigold and petunia growing and only up to 10% of OSW for matthiola, while the addition of PW on top of OSW is not recommended, so further research is needed.

Bioactive compounds content and antimicrobial activities of wild edible Asteraceae species of the Mediterranean flora under commercial cultivation conditions

Nine wild edible species belonging to Astreaceae family, native to the Mediterranean basin were tested for their chemical composition (phenolic compounds, tocopherols, and organic acids) and antimicrobial activities over two growing periods, apart from Scolymus hispanicus and Hedypnois cretica which were tested for only one growing period. Flavonoids were the most abundant phenolic compounds in all the species, except for the case of Taraxacum species where significant amounts of chicoric acid were detected, while phenolic compounds content increased in the 2nd growing period by 4.6-397.4% for the tested species. α- and β-tocopherols were the main tocopherols, apart from Taraxacum sp. where significant amounts of γ-and δ-tocopherols (18.32 and 16.31 μg/100 g fresh weight) were detected, while total tocopherols content either increased (Reicardia picroides, Picris echioides, Urospermum picroides, and Taraxacum officinale) or decreased (Hymenonema graecum, Sonchus oleraceus, Taraxacum sp.) in the 2nd growing period. Oxalic acid was the most abundant organic acid, with the highest content (972 mg/100 g fresh weight) being observed in H. graecum (L.) DC. in the 1st growing period. Moreover, with the exception of H. graecum and S. olearaceus, total organic acids content increased in the 2nd growing period. Significant antimicrobial activities were observed against Bacillus cereus, Salmonella typhimurium and Penicillium ochrochloron for all the studied species. In conclusion, the studied species showed great potential for commercial cultivation, while plant extracts could find use in the food industry as alternative food preservatives.

Nutritional Value and Bioactive Compounds Characterization of Plant Parts From Cynara cardunculus L. (Asteraceae) Cultivated in Central Greece

In the present study, the nutritional value of the edible parts (immature capitula) of cardoon plants was evaluated, while further analyses were carried out in order to assess antioxidant properties and phenolic compounds composition of the various plant parts and seed oils. Cardoon capitula (heads) were a rich source of carbohydrates, with the main detected free sugar being sucrose, as well as of macro- and micro-minerals (K, Ca, Mg, and Fe). Heads were also abundant in saturated fatty acids (palmitic, behenic, linoleic, stearic, caproic, and oleic acid), whereas seed oils in unsaturated fatty acids (linoleic, oleic, palmitic, and stearic acid). Total phenolic compounds (TPC) content and phenolics composition differed between the various plant parts, with heads and leaf blades having higher TPC than midribs and petioles. Moreover, heads and leaf midribs and petioles consisted mainly of phenolic acids (5-O-caffeoylquinic and 3,5-O-dicaffeoylquinic acid), with flavonoids being detected in lower amounts. In contrast, the composition of polyphenols in leaf blades consisted mostly of flavonoids (Luteolin-7-O-glucoside and luteolin-7-O-malonylhexoside), whereas phenolic acids were also detected in considerable amounts (5-O-feruloylquinic and 3-O-caffeoylquinic acid). Regarding antioxidant properties, leaf blades and seeds exhibited the highest potency for all the tested assays which could be partly attributed to the synergistic effects of the phenolic compounds present in each sample. In conclusion, cardoon plant parts may find various uses in the food and pharmaceutical industry, since they contain considerable amounts of bioactive molecules, while seed oils can be considered as alternative vegetable oils for human consumption.

Growth, photosynthesis and pollen performance in saline water treated olive plants under high temperature

Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl)] on physiological and reproductive functions of cultivars <em>Koroneiki</em> and <em>Amphissis</em> in a closed hydroponic system. Shoot growth was markedly reduced in high salinity dose in <em>Amphissis</em> (−81%) and <em>Koroneiki</em> (−75%). The photosynthetic rate was significantly reduced at 120 mM NaCl for both cultivars, as well as chlorophyll and carotenoids content (43% and 44%, respectively). The Na+ content in all plant parts increased in both salinity doses especially in <em>Amphissis</em> while K concentration decreased for both cultivars. Inflorescences in <em>Amphissis</em> were severely damaged due to salinity. Consequently, pollen sampling and <em>in vitro</em> germination study was only feasible for <em>Koroneiki</em>. Indeed, <em>Koroneiki</em> pollen germination was reduced at 60 mM NaCl (−42%) and at 120 mM NaCl (−88%). Pollen tube length was also reduced by 15% and 28% for the middle and high salinity dose, respectively. The results of the present study indicate that <em>Amphissis</em> is more sensitive in high salinity doses compared to <em>Koroneiki</em> and that reproductive functions are severely affected by salinity.