A series of experiments was carried out to investigate possible structural or biochemical alterations in Gossypium hirsutum plants after a long term (21 days) exposure to non ionizing radiation (1882 MHz) emitted from the base unit of a cordless DECT system. Exposed plants, compared to the negative (matched) controls, seem to be seriously affected. Notably lower biomass production for the above ground part and the root was recorded. Reduction of the photosynthetic pigments and severe damage of the chloroplast structure were also observed. It seems that non ionizing radiation can be noxious for plant life functions. © 2016 Elsevier GmbH

A series of experiments was carried out to investigate any structural or biochemical alterations on Arabidopsis thaliana (Col.) plants after a long term exposure to non ionizing radiation emitted from the base unit of a cordless DECT system. Exposed plants, compared to their control counterparts, seem to be affected concerning their biomass and leaf structure. Their leaves are thinner and possess fewer chloroplasts. SEM observations of the exposed leaves reveal that the only feature affected is the pubescence which almost disappears while TEM investigation revealed minor structural effects in the chloroplasts. The reduction in the number of chloroplasts as well as the decrease of stroma thylakoids and photosynthetic pigments are probably the main reasons for a weak photosynthetic potential and a consequent reduction of the biomass production. © 2016 Elsevier GmbH.

Kenaf (Hibiscus cannabinus L.) was experimentally cultivated with the use of digested, dried sewage sludge (130 t/ha) and water from a municipal Sewage Treatment Plant (STP) in order to assess their potential to replace conventional fertilization (100 kg N/ha, 75 kg P2O5/ha and 75 kg Κ2O/ha) and irrigation. Tap water and treated wastewater were used for irrigation in quantities corresponding to 6500 m3/ha. Four different treatment combinations were applied as follows: (a) wastewater irrigation and conventional fertilization, (b) wastewater irrigation and sewage sludge fertilization, (c) tap water irrigation and sewage sludge fertilization, and (d) tap water irrigation and conventional fertilization. The dry plant biomass collected in the final harvest (140 days after plant emergence) from the four treatment plots was 12.3 t/ha, 12.6 t/ha, 12.4 t/ha and 12.8 t/ha respectively. These differences were not statistically significant (ANOVA, P = 0.05) and, therefore, it was concluded that the use of municipal wastes had similar effects on dry biomass production with that of conventional fertilization. An earlier harvest (125 days after plant emergence) gave 11.3% lower dry biomass on average in relation to the second harvest, and this difference was statistically significant (ANOVA, P = 0.05). Premature harvest may lead to significant biomass losses, so the plant must be collected during its technological maturity stage. There was not any statistically significant difference among the four treatments and between the two harvests in fiber dimensions and derived values (suitability indices for paper manufacture). On the other hand, cellulose and lignin content in the second harvest were significantly higher compared to the first one, whereas no significant differences were detected among the four treatments. © 2016 Elsevier B.V.

Heavily "armed" with trichomes, the hypostomatic leaf of Ficus carica L. is investigated with light and scanning electron microscopy. Histochemical tests were also applied to trace the secondary matabolites produced in the leaf of this well known, Mediterranean tree with the delicious fruits. Numerous idioblasts with crystals, laticifers and sized lythocysts appear within the compact mesophyll. Protective trichomes are located on both surfaces while capitate secretive hairs and stomata appear only abaxially. Stomata, concerning their magnitude, can be assembled in three size-groups in which the arrangement of their parastomatal cells differs as well. Histochemical reactions proved positive only for alkaloids within the laticifers and phenolic compounds, especially for the condensed tannins accumulated within the vacuole of the epidermal cells of this simply constructed leaf with unique features among the Mediterranean herbs. Comparison of GC-MS and LC-HRMS spectra of different extracts of the nerves and, separately, the rest of the leaf, revealed that coumarines such as umbeliferone, psoralen, bergapten and xanthotoxol are probably biosynthetically produced within the nerve area where the highly differentiated, main secretive apparatus of the leaf (laticifers) resides. That is why, these metabolites, are absent from the extracts of the undifferentiated cells derived from in vitro cultures. © 2015 Elsevier GmbH.

Osyris alba is a dioecious shrub used in traditional medicine for its bioactive secondary metabolites. It is used for its antiparasitic, antimicrobial and anti-bleeding properties. In the present study the leaf tissue arrangement, histochemsitry and callus formation of Osyris alba L. were investigated. Leaves (fresh and fixed) were observed by light, polarized oight and electron microscopy. Fresh stem was also observed by light microscopy. The sub-cellular localization of secondary metabolites was detected. Furthermore, in vitro production of its secondary metabolite, by using cell cultures, was also preformed. The compact leaves are amphistomatic, with a single layer of epidermal cells and contain idioblasts cells with crystals. They react positively to histochemical reagents for the major groups of secondary metabolites. In the preliminary histochemical screening, in vitro cultured cells also gave positive results. In conclusion, the medicinal nature of the plant is attributed to its phytochemical profile. Plant cell culture technologies can be used for the production of its bioactive molecules. © 2016, International Journal of Pharmacognosy and Phytochemical Research. All rights reserved.

The dorsiventral, hypostomatic leaf of Euphorbia characias is investigated to disclose its structural features and the chemical nature of the secondary metabolites produced. Light and scanning electron microscopy along with histochemical tests were employed to investigate the leaf of this well known perennial dwarf Mediterranean shrub. The compact leaf is characterized by numerous, rather uniform, curly, unicellular hairs on both surfaces, vaulty protrusions of the outer periclinal walls of the epidermal cells, prominent on the lower epidermis in particular, and a network of latex producing ducts (laticifers) extending in two layers within the mesophyll. Histochemical reactions proved positive only for alkaloids within the laticifers and phenolic compounds, especially for the condensed tannins accumulated within the vacuole of the epidermal cells. GC-MS and GC-FID analyses of the latex revealed the presence of several secondary metabolites, mainly belonging to the class of triterpenes. Lanosterol, butyrospermol, cycloartenol and lupeol were the major constituents in the extract examined. © 2014 Elsevier GmbH.

The dorsiventral, amphistomatic, hairy, summer and winter leaves of Cistuscreticus had a secretory apparatus in which the secreted resinous material was not preserved in a cutinous wrap, as common during excretion in xerophytes, but was directly spread all over the protective trichomes and the leaf surface. Summer and winter leaves differed in trichome function and density, mesophyll structure, and compactness and secondary metabolite accumulation, mainly phenolics, secreted in excess in the mesophyll cells of the summer leaves. In vitro cell cultures may be used for the production of novel compounds from low-cost precursors. © 2014 Copyright Taylor & Francis Group, LLC.

The anatomy of the dorsiventral, amphistomatic leaf of Papaver rhoeas was investigated. It was a simple structure possessing large epidermal cells having their vacuole impregnated with glycoproteins which varied in texture, forming a dense, hard core in the middle of the vacuole. Slender rays of cisternae radiated from the dense central core to the cell wall. Thin-walled palisade cells presented a unique, lobed shape probably creating larger surfaces for gas exchange. Mesophyll cells secreted phenolics, condensed tannins, alkaloids, terpene containing steroids and sesquiterpenes. P. rhoeas although being a therophyte, has adopted some structural features common in mediterranean phanerophytes. © 2013 Taylor & Francis Group, LLC.

The dorsiventral, amphistomatic, hairy leaf of Pelargonium odoratissimum was lacking the variety of the anatomical features considered advantages for the Mediterranean plant life compared to the leaf of most Mediterranean xerophytes. Conversely, it had a well-equipped and intensely functioning secretory apparatus. Light, scanning, and transmission electron microscopy were employed to investigate the leaf structure while histochemical reactions traced the nature of the secreted metabolites. The numerous trichomes of the leaf were very active in producing phenolics, terpenes, and flavonoids mixed in a fragrant essential oil accumulated in an ovoid chamber at the top of each secreting hair. In-vitro cell cultures may be used for the production of novel compounds from low-cost precursors. © 2013 Taylor & Francis Group, LLC.

Light, scanning and transmission electron microscopy as well as histochemical reactions were employed to study the leaf structure and secretory activity of Ecballium elaterium, a hairy pharmaceutical perennial common in the Mediterranean region. The amphistomatic leaf has a peculiar structure due to special cells supporting the conductive bundles, a remarkable shortage of mechanical tissue, and the existence of pectin strands between mesophyll cells. The secreting activity is limited mostly to secretary hairs. These attributes of the Ecballium leaf fine structures do not resemble the common structure of leaves from Mediterranean plants and point to a peculiar strategy of this species coping with stress conditions of its habitat. © 2010 Elsevier GmbH.

Although extensively studied for its pharmaceutical properties, Teucrium polium has yet to disclose its leaf structure and the chemical nature of the accumulated or secreted products. Therefore, light, scanning, and transmission electron microscopy along with histochemical tests were employed to investigate the leaf of this perennial dwarf Mediterranean shrub. Structural characteristics include large cells with cutinized walls, creating cavities of obscured function in contact to a vessel element of the conductive tissue and different types of glandular hairs. A variety of secreted materials was identified by certain histochemical stains within the mesophyll cells and the glandular hairs. A dense indumentum of non-glandular hairs protects the secretory apparatus and the leaf surface from the stressful conditions of the Mediterranean climate.

Lippia citriodora H.B.K. is an aromatic plant indigenous to South America. It is cultivated and commercialised as an ornamental for its lemon-like scent emitted from its leaves and flowers. The present morphoanatomical and histochemical study revealed that leaves of L. citriodora possess one type of setae (non-glandular) and at least five types of glandular trichomes, with the latter differing anatomically and in the composition of their secondary metabolites. Scanning electron microscopy revealed that the same types of trichomes exist also on the calyces. Histochemical tests indicate that the glandular trichomes contain a combination of terpenoids, flavonoids, carbohydrates, phenolics and alkaloids. However, within the vacuoles of the mesophyll cells, terpenoids, phenolics, flavonoids and tannins are stored. The presence of lamellar cytoplasmic inclusions in the mesophyll cells, possibly precursors of tannins stored in the vacuoles, is reported for the first time. © 2010 CSIRO.

This study was undertaken to assess the impact of a single excessive sludge application (300 Mg ha-1) on the soil surface of an olive orchard several years after the event. Selected soil properties were compared in two soil profiles, one in the sludge-amended field and another in an adjacent unamended field of naturally growing trees. Leaf analysis included macronutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg)], trace elements [copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), nickel (Ni), boron (B)], and isotopic composition (δ 15N and δ 13C). Soil pH and other chemical properties were increased in the surface soil and the root zone of the sludge-treated profile in comparison to those of the untreated control. The multifold increase of Bray P and nitrates indicated a serious risk for dissolved phosphates in runoff and nitrate contamination of groundwater. Trace-element content also increased, but not greater than the critical soil concentration. Olive trees responded to excessive sludge application by increased N uptake as evidenced by increased leaf N content and elevated 15N signal. The increased leaf δ 13C signal of the leaves further indicated tree stress in the sludge-amended field during the summer growing season in comparison to the naturally growing control trees. Isotopic composition, leaf nutrient, and trace element concentration did not reveal the causes of leaf tip burning in half of the trees of the sludge-amended field. Copyright © Taylor & Francis Group, LLC.

Light and scanning electron microscopy as well as histochemical reactions were employed to investigate the leaf structure and secretory activity of an adventive perennial pest that is rapidly dispersing in the Mediterranean region. Interesting structural characteristics, not common among the well-adapted native Mediterranean phanerophytes, were observed. Although 'unconventional', these structural characteristics produce an ecologically equivalent, xeromorphic leaf on a plant that proves to be competitive and very efficient under the Mediterranean climatic conditions. © CSIRO 2009.

Various species of the genus Phlomis have been reported to produce metabolites demonstrating significant pharmacological efficiency. In mature summer leaves of Phlomis fruticosa several secretory cells and structures were detected. A spectrum of compounds was localized histochemically within them. Calluses produced from leaf-cell cultures were histochemically investigated as well. Callus cells, although of low-differentiation, are synthetically active and produce various compounds. Many of them could be of pharmaceutical interest. © 2007 Elsevier GmbH. All rights reserved.

Structures or cells with secreting activity were localized in the leaves of Lavandula vera. Light and electron microscopy, both TEM and SEM, were applied for the investigation of the secreting sites. A series of histochemical reactions was applied and a spectrum of metabolites produced was identified. Terpenes, flavonoids, steroids, alkaloids, and various types of phenolics were present. Leaf tissue was cultured and callus was produced. Callus cell masses were also investigated for their structure and secreting activity. Callus cells were found to be synthetically active and to produce - as leaf cells do-compounds of potential interest. © 2007 Science From Israel / LPPLtd.

Fiber dimensions and lignin and cellulose content of various highly productive, non-wood plants and agricultural residues were examined to assess their suitability for paper production. Plants like kenaf (Hibiscus cannabinus L.) and giant reed (Arundo donax L.) internodes gave very good derived values, especially slenderness ratio, which is directly comparable to some softwood and most hardwood species. Cotton (Gossypium hirsutum L.) stalks, miscanthus (Miscanthus × giganteus) and switchgrass (Panicum virgatum L.) have shorter fibers resulting to poorer flexibility and Runkel ratios, but still satisfactory slenderness ratios. Finally, fibers from olive tree (Olea europea L.) and almond tree (Prunus dulcis L.) prunings presented relatively short and thick fibers producing the poorest derived values among all the species examined. Fiber dimensions did not differ significantly within each species, when samples from different stalks/branches or different positions (base, middle top) were examined. The only exception were cotton stalks, where those differences did not have any significant effect on fiber derived values. Chemical analysis of the raw plant materials revealed satisfactory levels of α-cellulose content (close to 40%) and Klason lignin content (<30%) compared to those of hardwoods and softwoods. Relatively increased (>25%) lignin content in miscanthus, switchgrass and almond prunings may require additional pulping time and chemical charge compared to those of other non-wood raw materials. Analysis of samples at various heights/lengths of the plant materials showed that lignin and cellulose content depends on tissue maturity, but does not change significantly within each species. © 2003 Elsevier B.V. All rights reserved.

Leaves of Inula viscosa have been used in medicine from ancient times. Structures or cells with secreting activity were localized and a spectrum of products was histochemically identified within them. Leaf extracts were investigated with gas chromatography - mass spectrometry (GC-MS) and thin-layer chromatography (TLC). Calluses produced from leaf-cell cultures were also subjected to histochemical reagents and tested with GC-MS and TLC to investigate their secreting ability compared with that in leaves. Little-differentiated callus cells are synthetically active and produce, as do its leaf cells, numerous polar compounds that could be of pharmaceutical interest. © 2004 The Linnean Society of London.

Stomata of various sizes are produced on the primary root of Ceratonia siliqua L. Most are generated during embryogenesis, prior to seed desiccation. They can be detected on the dry embryo in a wide zone just above the root tip. Initially, large stomata are formed. These have the ability to induce divisions of their neighbouring cells, creating particular cell patterns around them. Later, small perigenous stomata are generated. As the root grows following seed germination, the stomatal zone overlaps with that of the root hairs. Although root stomata of C. siliqua undergo a structural differentiation that seems almost identical to that of the elliptical stomata formed on leaves, they are unable to move and remain permanently open. Polarizing microscopy of fully differentiated stomata and young stomata at the stage of stomatal pore formation revealed deposition of radial cellulose microfibril systems on their periclinal walls. However, these systems were less developed than those on leaf stomata, a feature that might he responsible for their inactivity. Besides, plastids of the root guard cells (GCs) do not differentiate into chloroplasts but function solely as amyloplasts. Root stomata have a short life span. During rapid and intense root growth, GCs cannot keep pace with the elongation of their neighbouring rhizodermal cells. They therefore split in their mid-region, transversely to the stoma axis. The two parts of the transversely torn stoma are dragged apart and a large opening is formed on the root surface, just above the substomatal cavity. The root stomata, together with these openings, may facilitate increased gaseous exchange during respiration and/or an increased transfer of some nutrients and water in the rapidly growing primary root. © 2002 Annals of Botany Company.

Four evergreen sclerophyllous species were investigated morphologically and anatomically. Buds, leaves and roots from Ceratonia siliqua, Olea europaea, Pistacia lentiscus and Quercus coccifera were studied and compared for structural diversity. Analysis of the anatomical data suggested diverging features. The ecological equivalence of these species cannot be attributed to their structure. © 1992.

Extensive investigations on the anatomy of the two leaf types in a seasonally dimorphic subshrub revealed interesting variations between summer and winter leaves. Summer leaves of Sarcopoterium spinosum possess a thick epidermis composed of tannin-containing cells and large amounts of mucilage secreted through the inner periclinal walls towards the mesophyll. A thick cuticle is also present on the surface of the leaf. In winter leaves the epidermal cells produce no mucilage while phenolics are accumulated in granular form only. Besides these, some other variations between summer and winter leaves are also discussed in respect of the ability of the plant to withstand the unfavourable Mediterranean conditions. © 1990 Annals of Botany Company.

Seasonal dimorphism is considered from the anatomical viewpoint. Significant differences can be observed between winter and summer leaves obtained from the same individuals. Winter leaves are thick, amphistomatic with a large number of chloroplasts in the cells of the loose mesophyll. The thinner summer leaves are hairier and hypostomatic, with compact mesophyll and cells that accumulate phenolics and crystals. CbJoroplasts are fewer in number and less developed, and at the ultrastructural level they present pronounced differences from those of the winter leaves. © 1989 Annals of Botany Company.

Anomocytic stomatal complexes observed with light and scanning electron microscopes on the primary roots of Ceratonia siliqua (carob tree) are described. Stomata are randomly distributed throughout the surface of the root zones which possess mature vascular tissues, i.e. from the zone of root hairs to the transition zone. Stomatal orientation does not follow that of the root epidermal cells whilst their distribution does not seem to form a regular pattern. © 1987 Annals of Botany Company.

Cambial activity of post fire resprouted stems of Quercus coccifera and Olea europaea ssp. oleaster is demonstrated.-from Authors

Cambial activity of post fire resprouted stems of Quercus coccifera and Olea europaea ssp. oleaster is demonstrated.-from Authors