Media composition affects seed dormancy, apical dominance and phenolic profile of Knautia sarajevensis (Dipsacaceae), Bosnian endemic

Knautia sarajevensis is an endemic plant of the Dinaric Alps and is mainly distributed on Bosnian Mountains. Due to the quite large flower heads and easy maintenance, this plant has a potential use as a substitute ornamental plant for K. arvensis in perennial beds. The current study evaluated the germination process in different treatments in an attempt to suppress dormancy and increase germination rate, and to develop a successful protocol for micropropagation. An over 60% germination rate was achieved through cultivation of seeds on MS basal medium with reduced mineral nutrient composition and the absence of sucrose. On the other hand, a below 10% germination rate was achieved with untreated seeds. Suppression of apical dominance was achieved through application of high concentrations of kinetin, apical shoot decapitation or cultivation of shoots in liquid media. Overall, liquid cultures were more successful as a micropropagation system for this plant. Shoots spontaneously developed roots on multiplication treatments and were successfully acclimatized. Moreover, phenolic compound profile was analysed in the light of the possible medicinal potential of this plant. Variable amounts of total phenolic compounds as well as individual phenolics were recorded, according to treatment and solidification of media. An increase in rosmarinic acid content was reported for kinetin treatments and acclimatized plants comparing to mother plants in natural habitat. The present study shows that choice of cytokinin concentration, explant type as well as culture type influences not only shoot proliferation and apical dominance suppression but also in vitro production of phenolics

Preharvest Abiotic Stress Affects the Nutritional Value of Lettuce

Lettuce (Lactuca sativa L.) is one of the most consumed leafy green vegetables in the world, and is a good source of important bioactive compounds. However, environmental stress factors, such as salinity or drought, cause physiological and biochemical changes in plants and influence the yields and levels of both primary and secondary metabolites, which drastically changes the nutritional value and quality of the crop. In the present work, six typical Czech cultivars/landraces of various lettuce morphotypes (Altenbursky, Dubacek, Kamenac, Jupiter, Prazan, and Robin) were grown under driven conditions and then analyzed for the content of sugars, fatty acids, amino acids, phenolics, and vitamins. Obtained data were subjected to compositional tables statistical analysis, which provided not only information on general trends in the changes in their nutritional value but also how these changes affected each particular variety. Overall, drought caused the largest relative increase in phenolic compounds and some amino acids. Conversely, drought caused overall the largest relative decrease in vitamin C, but also in fatty acids. In addition, salt stress caused a larger decrease in many metabolites, especially the amino acid arginine, while fatty acids were only slightly increased, together with vitamin E. In addition, the interpretation of data from statistical analysis showed that varieties Prazan and Altenbursky had the least changes in their chemical composition when subjected to drought stress. Again, var. Altenbursky showed the least variability in comparison to other varieties when subjected to salt stress. These findings confirm the fact that landraces and old cultivars do not change their chemical profiles significantly, as is the case for improved cultivars, and they emphasize the need for their cultivation when raising the productivity of staple food crops

Preharvest Abiotic Stress Affects the Nutritional Value of Lettuce

Lettuce (Lactuca sativa L.) is one of the most consumed leafy green vegetables in the world, and is a good source of important bioactive compounds. However, environmental stress factors, such as salinity or drought, cause physiological and biochemical changes in plants and influence the yields and levels of both primary and secondary metabolites, which drastically changes the nutritional value and quality of the crop. In the present work, six typical Czech cultivars/landraces of various lettuce morphotypes (Altenbursky, Dubacek, Kamenac, Jupiter, Prazan, and Robin) were grown under driven conditions and then analyzed for the content of sugars, fatty acids, amino acids, phenolics, and vitamins. Obtained data were subjected to compositional tables statistical analysis, which provided not only information on general trends in the changes in their nutritional value but also how these changes affected each particular variety. Overall, drought caused the largest relative increase in phenolic compounds and some amino acids. Conversely, drought caused overall the largest relative decrease in vitamin C, but also in fatty acids. In addition, salt stress caused a larger decrease in many metabolites, especially the amino acid arginine, while fatty acids were only slightly increased, together with vitamin E. In addition, the interpretation of data from statistical analysis showed that varieties Prazan and Altenbursky had the least changes in their chemical composition when subjected to drought stress. Again, var. Altenbursky showed the least variability in comparison to other varieties when subjected to salt stress. These findings confirm the fact that landraces and old cultivars do not change their chemical profiles significantly, as is the case for improved cultivars, and they emphasize the need for their cultivation when raising the productivity of staple food crops

Volatiles of <i>Helichrysum italicum</i> (Roth) G. Don from Croatia

<div><p><i>Helichrysum italicum</i> (Roth) G. Don is a flowering plant of the family Asteraceae. It is rich in oil that is used for different medicinal purposes and in fragrance industry. Volatile profile of four populations of <i>H. italicum,</i> collected from natural habitat in Dalmatia (Croatia), was analysed by capillary GC–MS. Sample from BraČ Island had α-<i>trans</i>-bergamotene (10.2%) and β-acoradiene (10.1%) as the majors, whereas sample collected on Biokovo Mt. was rich in neryl acetate (8.1%). β-Acoradiene was also the main constituent of sample collected near Tijarica, whereas rosifoliol (8.5%) was the most abundant constituent in sample collected near Makarska. Presented results show the influence of environmental conditions on chemical differentiation of the volatiles of <i>H. italicum</i> from Croatia.</p></div

Phenolics of Aerial Parts of Gentiana lutea L. and Their Biological Activity

Gentiana lutea L. is a medicinal plant the roots of which are primarily used in treatments of various human digestive disorders, but also the production of alcoholic liquors. The roots (radix) of G. lutea are described in the European Pharmacopeia, but knowledge about the chemical composition and biological activities of its aerial parts is still limited. Thus, until today aerial parts of this species have not been used in medical treatments or consumed. Therefore, flowers, leaves, and stems extracts of G. lutea obtained by using four different extraction solvents (petrol ether, chloroform, ethanol, and water) were examined for their chemical composition and biological activities. High concentrations of salicylic acid, apigenin, and naringenin were recorded for ethanol stem extracts, while significant amounts of kaempferol were detected in leaves and flowers in chloroform and water extracts, respectively. The highest antioxidant potential was recorded for flower and stem petrol ether extracts with the lowest IC50 values, ranging from 94.46 ± 9.45 to 105.38 ± 10.54 μg/mL. Ethanol extracts of flowers and stems showed moderate antioxidant activity (IC50 143.15 ± 14.32 and 146.90 ± 14.69 μg/mL) as well as strong antimicrobial activity against Candida albicans (21.00 ± 1.00 and 27.50 ± 1.78 mm inhibition zones, respectively). In addition, ethanol extracts had higher antimycotic activity compared to naturally occurring phenolic compounds that are used as positive controls. Moreover, statistical analysis of the activities of plant extracts and single compounds showed that levels of chlorogenic and caffeic acids strongly correlate with the biological activities of the extracts, i.e., they are the main carriers of these biological activities. The presented results indicate the possible use of aerial parts of G. lutea as a natural preservative, as well as a antimicrobial agent, which significantly amplifies the benefits of this medicinal crop and greatly affects the sustainability of cultivated Gentiana plantation

Which Seed Properties Determine the Preferences of Carabid Beetle Seed Predators?

Ground beetles are important invertebrate seed predators in temperate agro-ecosystems. However, there is a lack of information regarding which seed properties are important to carabids when they select seeds for consumption. Therefore, seed properties, such as size, shape, morphological defence, and chemical composition, were measured, and in addition to seed taxonomy and ecology, these data were used to explain carabid preferences. Carabid preferences were assessed using a multi-choice experiment with 28 species of weed seeds presented to 37 species of Carabidae. Multiple regression on distance matrices (MRM) was used to determine the importance of particular sets of seed properties for carabids. The analysis was conducted for the full set of carabids (37 species) as well as for subsets of species belonging to the tribes of Harpalini or Zabrini. For the complete set of species, seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties significantly explained carabid preferences (proportion of explained variance, R2 = 0.465). The model for Harpalini fit the data comparably well (R2 = 0.477), and seed dimensions, seed mass and seed coat properties were significant. In comparison to that for Harpalini, the model for Zabrini had much lower explanatory power (R2 = 0.248), and the properties that significantly affected the preferences were seed dimensions, seed mass, taxonomy, plant strategy, and seed coat properties. This result suggests that the seed traits that carabids respond to may be specific to taxonomic and likely relate to the degree of specialisation for seeds. This study contributes to understanding the mechanisms that determine the preferences of carabid beetles for seeds

Exploring New Sources of Bioactive Phenolic Compounds from Western Balkan Mountains

This study presents the first report on phenolic composition and bioactivity of ethanolic extracts of three plant species that grow in the western Balkan mountains and are used in traditional folk medicine: Valeriana montana, Salix retusa, and Campanula hercegovina. Phenolics were extracted from different aerial plant parts using 80% ethanol to assess the possibility of sustainable use of these plants as a source of bioactive compounds without disruption to the roots (for V. montana) or destruction of whole habitats (for S. retusa and C. hercegovina). The ethanolic extract of V. montana flower contained noticeable levels of apigenin and quercetin. The branches and bark of S. retusa were significantly rich in catechin, while rutin was the major phenolic found in the leaf extract of C. hercegovina. Furthermore, the flower extract of V. montana revealed the best antioxidant activity, which was comparable to 4-hydroxybenzoic acid and quercetin. Considering antimicrobial activity, the leaf extracts of V. montana and C. hercegovina demonstrated potent activity against all microbes tested, while the extracts of S. retusa were moderately effective. The presented results emphasize the potential of these plants as novel sources of bioactive compounds

Polyamine uptake transporter 2 (put2) and decaying seeds enhance phyA-mediated germination by overcoming PIF1 repression of germination

Red light promotes germination after activating phytochrome phyB, which destabilizes the germination repressor PIF1. Early upon seed imbibition, canopy light, unfavorable for photosynthesis, represses germination by stabilizing PIF1 after inactivating phyB. Paradoxically, later upon imbibition, canopy light stimulates germination after activating phytochrome phyA. phyA-mediated germination is poorly understood and, intriguingly, is inefficient, compared to phyB-mediated germination, raising the question of its physiological significance. A genetic screen identified polyamine uptake transporter 2 (put2) mutants that overaccumulate polyamines, a class of antioxidant polycations implicated in numerous cellular functions, which we found promote phyA-mediated germination. In WT seeds, our data suggest that canopy light represses polyamines accumulation through PIF1 while red light promotes polyamines accumulation. We show that canopy light also downregulates PIF1 levels, through phyA; however, PIF1 reaccumulates rapidly, which limits phyA-mediated germination. High polyamines levels in decaying seeds bypass PIF1 repression of germination and stimulate phyA-mediated germination, suggesting an adaptive mechanism promoting survival when viability is compromised

Influence of Extraction Solvent on the Phenolic Profile and Bioactivity of Two Achillea Species

The phenolic composition, as well as the antioxidant and antimicrobial activities of two poorly investigated Achillea species, Achillea lingulata Waldst. and the endemic Achillea abrotanoides Vis., were studied. To obtain a more detailed phytochemical profile, four solvents with different polarities were used for the preparation of the plant extracts whose phenolic composition was analyzed using UHPLC-MS/MS (ultra-high performance liquid chromatography-tandem mass spectrometry). The results indicate that both of the investigated Achillea species are very rich in both phenolic acids and flavonoids, but that their profiles differ significantly. Chloroform extracts from both species had the highest yields and were the most chemically versatile. The majority of the examined extracts showed antimicrobial activity, while ethanolic extracts from both species were potent against all tested microorganisms. Furthermore, the antioxidant activity of the extracts was evaluated. It was found that the ethanolic extracts possessed the strongest antioxidant activities, although these extracts did not contain the highest amounts of detected phenolic compounds. In addition, several representatives of phenolic compounds were also assayed for these biological activities. Results suggest that ethanol is a sufficient solvent for the isolation of biologically active compounds from both Achillea species. Moreover, it was shown that the flavonoids naringenin and morin are mainly responsible for these antimicrobial activities, while caffeic, salicylic, chlorogenic, p-coumaric, p-hydroxybenzoic, and rosmarinic acid are responsible for the antioxidant activities of the Achillea extracts