Endemic species analysis: Foliar epidermal anatomical characters of Aster glehnii F. Schmidt (Asteraceae).

The classification and identification of Aster glehnii F. Schmidt are determined from its foliar epidermal anatomical features. Scanning electronic microscopy has been used to determine the foliar epidermal anatomical characteristics of the species in detail. This study compared the qualitative and quantitative characteristics of the leaf epidermis of A. glehnii for taxonomic identification to be used as a reference for future studies on the species. A. glehnii has smooth, thin cuticles, depressed anomocytic stomata dispersed randomly throughout the leaf surface, polygonal epidermal cells with straight to slightly curved anticlinal walls, and no trichomes. There are obvious veins containing thick-walled bundle sheath cells. The stomatal density is between 100 and 150 stomata per millimeter. The vein density ranges from five to 10 veins per millimeter, and the epidermal cells are 10 to 20 µm long and 5 to 10 µm in width. Understanding the connections between the different A. glehnii species and categorizing and identifying them depend heavily on these foliar epidermal structural features. Taxonomy and conservation are closely intertwined because the former serves as the basis for comprehending and safeguarding biodiversity. RESEARCH HIGHLIGHTS: Optical microscopy of the A. glehnii leaf epidermis for taxonomic identification SEM was used to identify and authenticate endemic species Microscopic identification of endemic species can assist in the conservation.

Identification of lupeol produced by Vernonanthura patens (Kunth) H. Rob. leaf callus culture.

The lupeol detection in callus of Vernonanthura patens (Kunth) H. Rob. leaves is discussed. Leaf segments previously treated with sodium hypochlorite, ethanol, and distilled water were placed in MS basal medium (Murashige and Skoog) for 7 days. Next, callus induction were done in two complemented MS medium for 6 weeks. Then, callus propagation were performed in MS medium supplemented with 1.0 mg/L of benzylaminopurine (BAP) and 0.5 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) for 50 days. Fresh callus were extracted every 10 days in an ultrasonic bath using ethyl acetate (1.0 g/10 mL). The identification was carried out by Gas Chromatography-Mass Spectrometry (GC-MS) using selected ion monitoring (SIM) acquisition mode with characteristic ions of lupeol. The results obtained indicate the occurrence of lupeol in callus extract after twenty days of proliferation. These findings could be use in subsequent scale-up studies for biomass production containing this active compound in order to replace conventional methods.

Palynological investigation of selected species of family asteraceae using light and scanning electron microscopic techniques.

Palynological study on 11 species of family asteraceae, that is, Sonchus asper L., Gazania rigens L., Helianthus annus L., Dahlia pinnata Cav., Zinnia peruviana L., Tagetes erectus L., Glebionis coronaria L., Calendula officinale L., Osteospermum ecklonis L., Centaurea cyanus L. and Cosmos sulphureus Cav. was carried out in Islamia College University Campus. The light microscopy showed that pollens were oblate-sheroidal (C. cyanus), oblate (Z. peruviana), prolate-spheroidal (H. annuus, T. erectus, G. coronaria, C. officinale, O. ecklonis, C. sulphureus) and spheroidal (S. asper, G. rigens, D. pinnata) in shape. The pollen was trizonocolporate, tricolporate and echinolophate type, all pollens had echinate ornamentation except G. regins which had reticulate ornamentation under SEM. Maximum Pollens were isopolar and asymmetrical while some were apolar and radially symmetric. The P/E ratio was larger in G. rigens (45/47 µm), T. erectus (45/40 µm) and C. officinale (40/45 µm) while others had smaller P/E diameter. C. sulphureus had 6 µm thick exine when compared to other taxa. The larger number of spines/echini were found on the exine surface of H. annuus and S. asper and the distance between adjacent echini were 4-5 µm in C. cyanus and G. rigens than others which had distance equal to 1-3 µm, while pores were visible on pollen surface of C. cyanus, O. ecklonis, Z. peruviana, H. annuus and G. rigens under light microscope and were invisible on other pollen surfaces. The pollen of family asteraceae members was of stenopalynous type.

In vitro cytotoxic and genotoxic effects of Cissus verticillata and Sphagneticola trilobata used for treatment of Diabetes Mellitus in Brazilian folk medicine

Cissus verticillata and Sphagneticola trilobata have been used in Brazilian folk medicine for Diabetes Mellitus treatment, although their pharmacological and toxicological profile has not been clearly established. Thus, the aim of this study was to evaluate the preclinical toxicity of the aqueous extracts of C. verticillata and S. trilobata. The main groups of secondary metabolites were investigated, and the species differed by the presence of coumarins in C. verticillata and by tannins in S. trilobata extracts. The highest contents of phenolic compounds and flavonoids were quantified in C. verticillata infusion with 2.594 ± 0.04 mg equivalents of gallic acid g-1 of extract and 1.301 ± 0.015 mg equivalents of catechin g-1 of extract, respectively. While the extract of S. trilobata showed minimum values of these compounds, with 0.002 ± 0.001 mg equivalents of gallic acid g-1 extract and 0.005 ± 0.0004 mg equivalents of catechin g-1 of extract, respectively. These differences implied the results of in vitro antioxidant activity evaluated using ferric reducing antioxidant power (FRAP), in which the sample of C. verticillata at 5 mg mL-1 showed a value of 122 µM ferrous sulfate equivalents (FSE), while S. trilobata showed 0.93 µM FSE at the same concentration. With respect to cytotoxic assay with murine fibroblast cell line (3T3) only S. trilobata exhibited cytotoxic effects measured by MTT and Sulforhodamine B assays, evidenced by the cell viability value of approximately 16%, in both tests after 24 and 72 hours of exposure of the cells to 5 mg mL-1 of the extract. Comparatively, at 5 mg mL-1 the C. verticillata extract showed cell viability of 142% and 95%, respectively, after 24 hours of cell exposure. On the other hand, both species showed genotoxic profiles evidenced by chromosomal aberrations by Allium cepa bioassay, observed by the higher percentage values of chromosome bridges, chromosome loss, and disturbed anaphase for all concentrations of both extracts than those of the negative control. The results support the characterization of the toxicological profile for both species and create an alert regarding the use of S. trilobata, which should be avoided.

Plant Tissue Cultures.

Plant tissue cultures are an efficient system to study cell wall biosynthesis in living cells in vivo. Tissue cultures also provide cells and culture medium from which enzymes and cell wall polymers can easily be separated for further studies. Tissue cultures with tracheary element differentiation or extracellular lignin formation have provided useful information related to several aspects of xylem and lignin formation. In this chapter, methods for nutrient medium preparation and callus culture initiation and its maintenance as well as those for protoplast isolation and viability observation are described. As a case study, we describe the establishment of a xylogenic culture of Zinnia elegans mesophyll cells.

Glandular trichomes of the leaves in three Doronicum species (Senecioneae, Asteraceae): morphology, histochemistry, and ultrastructure.

Two types of glandular tichomes (GTs) develop on the leaves in three Doronicum species. The purpose of the work was to establish common and distinctive morphological, anatomical, histochemical, and ultrustructural features of the trichomes. It turned out that differences between types of trichomes are more significant than interspecific ones. For each Doronicum species, differences between GTs of two types include the dimensions, intensity of coloration by histochemical dyes, as well as ultrastructural features of the cells. The GTs of the first type are higher than GTs of the second type. Two to three upper cell layers of the first trichomes develop histochemical staining, whereas in the second ones, only apical cells give a positive histochemical reaction. In all trichomes, polysaccharides, polyphenols, and terpenoids are detected. In the GTs of the first type, polysaccharides are synthesized in larger quantity; in the GTs of the second type, synthesis of the secondary metabolites predominates. Main ultrastructural features of the GTs of the first type include proliferation of RER and an activity of Golgi apparatus denoting the synthesis of enzymes and pectin; however, development of SER, diversiform leucoplasts with reticular sheaths, and chloroplasts with peripheral plastid reticulum also demonstrate the synthesis of lipid substances. The ultrastructural characteristics of the second type GTs indicate the primary synthesis of lipid components. Secretion is localized in a periplasmic space of the upper cell layers. The secretory products pass through the cell wall, accumulate in the subcuticular cavity, and rupture it.

The Impact of Different Cultivation Systems on the Content of Selected Secondary Metabolites and Antioxidant Activity of Carlina acaulis Plant Material.

Roots and leaves of Carlina acaulis L. are still used in ethnomedicine in many European countries; however, the limited occurrence of the plants and protection of this species necessitate a search for alternative ways for obtaining this plant material. In this study, in vitro cultures, hydroponic cultures, and field cultivation were applied to obtain the C. acaulis plant material. Its quality was evaluated using antioxidant activity tests and high performance liquid chromatography analysis. Our study showed that the antioxidant activity and the content of chlorogenic and 3,5-di-caffeoylquinic acid in roots of plants cultivated in hydroponics and field conditions were comparable. However, the amount of carlina oxide was significantly higher in plants from the field. The flavonoid content in leaves obtained from both cultivation systems was at the same level; however, the antioxidant activity and the content of the investigated metabolites were higher in the soil cultivation system. The callus line exhibited high differentiation in phytochemical compositions depending on the treatments and medium compositions.

GhWIP2, a WIP zinc finger protein, suppresses cell expansion in Gerbera hybrida by mediating crosstalk between gibberellin, abscisic acid, and auxin.

Cell expansion is a key determinant for the final size and shape of plant organ, and is regulated by various phytohormones. Zinc finger proteins (ZFPs) consist of a superfamily involved in multiple aspects of organ morphogenesis. However, little is known about WIP-type ZFP function in phytohormone-mediated organ growth. Using reverse genetics, RNA-seq and phytohormone quantification, we elucidated the role of a new WIP-type ZFP from Gerbera hybrida, GhWIP2, in controlling organ growth via regulation of cell expansion. GhWIP2 localizes to the nucleus and acts as a transcriptional repressor. Constitutive overexpression of GhWIP2 (GhWIP2OE) in both Gerbera and Arabidopsis thaliana caused major developmental defects associated with cell expansion, including dwarfism, short petals, scapes, and petioles. Furthermore, GhWIP2OE plants were hypersensitive to GA, but not to ABA, and showed a reduction in endogenous GA and auxin, but not ABA concentrations. Consistent with these observations, RNA-seq analysis revealed that genes involved in GA and auxin signaling were down-regulated, while those involved in ABA signaling were up-regulated in GhWIP2OE plants. Our findings suggest that GhWIP2 acts as a transcriptional repressor, suppressing cell expansion during organ growth by modulating crosstalk between GA, ABA, and auxin.

Pattern of callose deposition during the course of meiotic diplospory in Chondrilla juncea (Asteraceae, Cichorioideae).

Total absence of callose in the ovules of diplosporous species has been previously suggested. This paper is the first description of callose events in the ovules of Chondrilla juncea, which exhibits meiotic diplospory of the Taraxacum type. We found the presence of callose in the megasporocyte wall and stated that the pattern of callose deposition is dynamically changing during megasporogenesis. At the premeiotic stage, no callose was observed in the ovules. Callose appeared at the micropylar pole of the cell entering prophase of the first meioticdivision restitution but did not surround the megasporocyte. After the formation of a restitution nucleus, a conspicuous callose micropylar cap and dispersed deposits of callose were detected in the megasporocyte wall. During the formation of a diplodyad, the micropylar callose cap decreased and the walls of a newly formed megaspores showed scattered distribution of callose. Within the older diplodyad, callose was mainly accumulated in the wall between megaspores, as well as in the wall of the micropylar cell; however, a dotted fluorescence of callose was also visible in the wall of the chalazal megaspore. Gradual degradation of callose in the wall of the chalazal cell and intense callose accumulation in the wall of the micropylar cell were related to the selection of the functional megaspore. Thus, our findings may suggest that callose fulfills a similar role both during megasporogenesis in sexual angiosperms and in the course of meiotic diplospory in apomicts and seems to form a regulatory interface between reproductive and somatic cells.

Trichomes and chemical composition of the volatile oil of Trichogonia cinerea (Gardner) R. M. King & H. Rob. (Eupatorieae, Asteraceae).

Trichogonia cinerea is endemic to Brazil and occurs in areas of cerrado and campo rupestre. In this study, we characterized the glandular and non-glandular trichomes on the aerial parts of this species, determined the principal events in the development of the former, and identified the main constituents of the volatile oil produced in its aerial organs. Fully expanded leaves, internodes, florets, involucral bracts, and stem apices were used for the characterization of trichomes. Leaves, internodes, florets, and involucral bracts were examined by light microscopy and scanning electron microscopy, whereas stem apices were examined only by light microscopy. Branches in the reproductive phase were used for the extraction and determination of the composition of the volatile oil. The species has three types of glandular trichomes, biseriate vesicular, biseriate pedunculate, and multicellular uniseriate, which secrete volatile oils and phenolic compounds. The major components identified in the volatile oil were 3,5-muuroladiene (39.56%) and butylated hydroxytoluene (13.07%).