Volume 60 (2014): Issue 4 (December 2014)

Southern sweet-grass (Hierochloë australis /Schrad./ Roem. & Schult.) is a perennial, wild growing tuft grass occurring in North-East Poland, Belarus and Finland. In Poland the species is under the partial legal protection. The raw material harvested from this plant are leaves rich in coumarins, mainly in coumarin responsible for specific sweet aroma of leaves. They are used mostly for the aromatization of alcohol and tobacco products. Due to high demand for the raw material and decrease in the natural resources of the species, it is advisable to introduce the plant into cultivation. In the presented study vegetative planting stock (1-, 2-, and 4-stem cuttings) were used to set the plantation of southern sweet-grass. The influence of the planting stock type on the mass of leaves and their quality in the first and second year of plant vegetation as well as the mass of seeds from two-year-old plants were investigated. The highest number of well rooted plants was obtained from 4-stem cuttings (74.07%) and the least - from 1-stem cuttings (47.53%). Both, on one- and two-year-old plantations the plants from 4-stem cuttings were characterized by the highest mass of leaves (7.73 and 24.65 g ˟ plant-1, respectively). The plants were also characterized by the highest number of generative shoots (40.71 pcs. ˟ plant-1) and mass of seeds (4.62 g ˟ plant-1). The total contents of coumarins and phenolic acids did not depend on the type of planting stock. The contents of these compounds was higher in two-year-old plants than in one-year-old ones, whereas the content of flavonoids was higher in one-year-old plants.

Endophytic fungi were isolated from different parts of the plants Corylus avellana (Corylaceae) and Ocimum basilicum (Lamiaceae) and then identified to the genus level based on the morphology of the fungal culture and the characteristics of the spores. The fungicidal and antitumor activity of isolates and extracts obtained from them was determined. We found that a few isolates from Corylus avellana and Ocimum basilicum produced metabolites that inhibited the growth of Oomycetes fungi to a highly significant extent. In the potato disc bioassay only an extract from the isolate C-9 showed an inhibitory action in tumor development. Paclitaxel presence in extract from the isolate C-9 was confirmed using the thin layer chromatography method (TLC) and UV-VIS spectroscopic analysis. The above results indicated that the tested samples revealed an antitumor activity. The detection of paclitaxel in the isolate C-9 suggests that the antitumor activity resulted probably from the presence of this taxane in the tested material.

Nyctanthes arbor tristis (NATE) ethanol extract (150 mg/kg, orally) was evaluated for its protective effect against scopolamine-induced (1 mg/kg i.p.) cognitive impairments in rats using behavioral models like radial arm maze test, Morris water maze test and active avoidance test. NATE effect was evaluated and compared with the standard piracetam (200mg/kg i.p.). NATE (p<0.005) significantly reversed the impairment produced by the scopolamine in radial arm maze test. In addition, NATE also decreased the time period taken to find the hidden platform in Morris water maze test and increased number of avoidances in active avoidance paradigm. Acetylcholinesterase activity and thiobarbituric acid levels were significantly (p<0.005) decreased along with the rise in activities of superoxide dismutase and catalase. This might suggest that the NATE has protective effect against scopolamine-induced cognitive impairment in rats through acetylcholine muscarinic receptor pathway and also antioxidant activity. No significant changes were found in histopathological studies of brain.

In the research on induced androgenesis, eight groups of plants, the progeny of interspecific hybrid of Capsicum frutescens L. x C. annuum L., were used. Half of them were standard hard-flesh forms, while the others have represented SS or Ss genotype conditioning the soft flesh of ripe fruit. Anthers from the plants of six groups produced mixoploid callus and the DNA content ranged from 1C to 16C. Three groups formed embryos which converted into plants. The total number of regenerants was 19, included both androgenic haploids (13) and diploids (6). The results did not allow to present the simple relationship between the physiological feature of soft-flesh and the effectiveness of androgenesis. Pungent, soft-flesh genotypes appeared as a poor responsive in anther culture. The R2 and R3 generation of two soft-flesh diploids, evaluated in two-year experiments, showed full phenotypic uniformity, proofing the androgenic origin of diploids. These DH lines were different with regard to capsaicinoid profiles. The content of capsaicinoids ranged from 0.056 to 2.170 and from 0.019 to 1.610 g*kg-1 for capsaicin and dihydrocapsaicin, respectively. The highest concentration of the compounds was observed in the placenta. Although the androgenic effectiveness was not fully satisfactory, the doubled haploid technology can be used for the rapid genetic stabilization of soft-flesh Capsicum spp. recombinants and the special attention should be paid to the spontaneous androdiploids.

Plants have developed intricate defense mechanisms against pathogen infections. Immune system of medicinal plants is well developed. The molecular mechanisms of their ability to protect themselves are not fully understood. Little is known about RNA-binding proteins (RBPs) present in medicinal plants. However, CmGRP1 is an RBP found in the milky sap of medicinal plant Chelidonium majus L. what implies possible importance of RBPs in plant immunity. In this review recent insights into the role of plant RBPs in antiviral and antibacterial defense responses are discussed.