Vol 51, No 1 (2017)

Development of RNAi-based therapeutics is a fast growing field of the pharmaceutical industry. Using plants for production of pharmaceutically valuable siRNAs may have significant advantages of costeffectiveness, scalability, and low risk of contamination with human pathogens. If edible plant species are genetically engineered to synthesize siRNAs, the costly stage of target product purification may be omitted. We describe the establishment of transgenic lettuce plants producing shRNA targeting delta isoform of protein kinase C (PKC-delta), an effective target for RNAi-based treatment of arterial hypertension. Transgenic lettuce plants were obtained by Agrobacterium-mediated transformation with genetic constructs harboring antiPKC and scrambled (control) shRNA genes. The presence of transgenes was proven by PCR analysis, and the accumulation of antiPKC shRNA was estimated using the RT-qPCR technique. Six transgenic lettuce lines showed varying levels of antiPKC shRNA expression with the highest value reaching 14 ± 9% of highly abundant endogenous lettuce micro RNA (miR156a), or 12.7 fmol/g dry weight. Plants carrying either antiPKC or scrambled shRNA genes flowered normally but did not produce seeds. The described transgenic lettuce plants accumulating antiPKC siRNA are the subject for animal testing and can be considered as raw material for the development of novel antihypertensive drugs.

The degree of dominance and the heritability coefficient have been investigated as the markers of allelic interactions of the loci Rht8 and Rht-B1. The interaction is characterized by partial or total dominance or even by overdominance of greater plant height and by low or medium heritability. The alleles that exert a weaker direct negative effect or no such effect predominate over the alleles that predispose to a more pronounced reduction of plant height. The impact of weather conditions on the switch of dominance is discussed. The Kooperatorka line has an additional allele (or alleles) that predisposes to greater plant height; the mode of inheritance of these alleles is partially recessive. An unidentified semidominant gene (or genes) that determines small plant height is present in the genotype of the Odes’ka 3 line. The presence of heterosis related to heterozygosity for certain genes not critically relevant for the present study makes the assessment of the allelic interaction characteristics under investigation more complicated.

The results of studied interaction of genes CTR1, ALF3 and NPH4, IAR2 at the inheritance of the root system features of Arabidopsis were presented. A recessive epistasis was found in the second generation of crossing of plant mutant lines ctr1-1 × alf3-1 (alf3-1 alf3-1 > CTR1_). Crossing plant mutant lines nph4-1 × iar2-1 resulted in a polymeric cooperation of genes NPH4 and IAR2 in F₂ generation.

The genotypic specificities of morphogenesis and regeneration have been studied in vitro in five maize inbred lines from the breeding-promising Lancaster heterotic group, compared with the representatives of other heterotic groups, that is, PLS61, A188, and Chi31. It has been shown that the ratio between the types of morphogenesis, such as organogenesis and embryoidogenesis, in a callus culture is predetermined by the explant genotype and sucrose concentrations in the medium for callusogenesis. The frequency of embryoidogenesis as the most efficient type of morphogenesis, considering further regeneration, was, on average, 40.0 ± 12.8% for maize inbreds from the Lancaster heterotic group and only 14.0 ± 4.0% from other heterotic groups. A sucrose concentration at a level of 30 g/L in the medium for callusogenesis further supported the process of regeneration through embryoidogenesis in inbreds of the Lancaster heterotic group at a level of 26.5 ± 15.4%, while the sucrose concentration of 60 g/L promoted regeneration up to a level of 57.7 ± 19.8%. Contents of sucrose in the medium for callusogenesis in the inbreds representing other heterotic groups did not affect the process of regeneration, and the level of embryoidogenesis with sucrose at the concentrations of 30 and 60 g/L was, respectively, 11.0 ± 7.0 and 15.0 ± 4.8%.

Isochromosome Y is one of the structural anomalies of the Y chromosome associated with a 45,X cell line and a broad spectrum of phenotypes. We present a case of de novo 46,X,+mar detected in a 17-yearold male patient. He had shortening of the right leg, bilateral breast enlargement, pubic, underarm and facial hair development, small penis and testicles, low serum cortisol, ACTH and total testosterone levels, normal LH value, high FSH value, normal testicles and epididymis, minimal left varicocele. The chromosome aberration was detected by cytogenetic analysis. Cytogenetic and molecular analysis was performed by conventional karyotyping and quantitative florescence PCR, respectively. The molecular analyses by PCR detected the presence of the SRY and AMXY genes, confirming the presence of the short arm of the Y chromosome. PCR demonstrated that the marker chromosome is of Y origin and corresponds to an authentic isochromosome for the short arm of the Y chromosome, i(Yp). We suggest that the structural alteration of the Y chromosome was a new mutation, which occurred in the initial mitotic division of the embryo, originally 46,XY. The result of accurate evaluation provides correct sex assignment and the prevention of the neoplastic degeneration of a dysgenetic gonad. The karyotype 46,X,i(Yp) indicates that the patient is preserving the SRY gene.

Nuruozak (Salvia leriifolia Benth), is a perennial herbaceous plant that is endemic to Iran and has recently been introduced as a medicinal plant. Artificial polyploidy is an efficient method to increase the production of secondary metabolites and can result in a whole spectrum of genetic, molecular and physiological modifications. In order to produce an autotetraploid population of nuruozak, various concentrations of colchicine (0.00, 0.05, 0.10, 0.20 or 0.50% w/v) were applied to the seeds and shoot apical meristems of young seedlings at the fourth leaf-stage. Microscopic studies, flow cytometry analysis and chromosome counting were conducted to select tetraploid nuruozak plants. Furthermore, the effects of ploidy level on the essential oil content and composition and biomass production of nuruozak plants, as well as selected structural and physiological characteristics were studied. Based on the number of the obtained tetraploids, treatment of shoot apical meristems was more efficient than seed treatment. Structural and phytochemical characteristics, chlorophyll content and photosynthetic rate were affected by the increase in ploidy level. In addition to the higher potential in biomass production, tetraploid plants produced eight new compounds which were absent in diploids.