Baranova E.N.,All Russia Science Research Institute of Agricultural Biotechnology |
Chaban I.A.,All Russia Science Research Institute of Agricultural Biotechnology |
Kononenko N.V.,All Russia Science Research Institute of Agricultural Biotechnology |
Shupletsova O.N.,Rudnitskii Zonal Northeast Agricultural Research Institute |
And 2 more authors.
Biologicheskie Membrany | Year: 2015
Using the methods of light microscopy and DNA cytophotometry, structural organization of the calli of the barley hybrid line Duet x Bios grown in the absence and in the presence of aluminum ions (20 and 40 mg/L) was studied. In the morphogenic calli grown in the standard conditions without aluminum, three main cell types were identified: meristematic, differentiated, and dying. Meristematic cells form a morphogenic zone. A characteristic feature of differentiated cells is a progressive accumulation of vacuoles with storage substances. Structurally separated zones of meristematic cells were not found the calli surviving in the presence of aluminum. Besides, the number of differentiated cells with storage substances is dramatically reduced and the number of dying cells is increased in such calli. According to the cytophotometry data, morphological changes in the aluminum-tolerant calli are accompanied by partial suppression of proliferation, accumulation of cells in postsynthetic phase of the cell cycle, and polyploidization, presumably caused by the DNA endoredu-plication. It is noteworthy that the aluminum-tolerant calli exhibit a high regenerative capacity: the proportion of morphogenic calli surviving in the presence of 40 mg/L aluminum is about 5 times greater than that in the calli grown in the control medium. To identify cellular targets of the aluminum effect in differentiated tissues, the roots of rhizogenic calli were studied. For this purpose, the calli derived from aluminum-tolerant plants (cultivar Kupetz), from aluminum-sensitive line 999-93, and from aluminum-tolerant line 917-1 obtained by the method of cell selection were used. It was found that aluminum induces the death of differentiated cells of epidermis and vascular system in growing roots of calli derived from non-tolerant lines, whereas undifferentiated cells of meristem remain undamaged. In contrast, rhizogenic calli derived from tolerant forms produce normal roots. This observation has an important prognostic value because it makes it possible to select aluminum-tolerant regenerants at the early stages of cell selection. The data suggest that most likely cause of the emergence of resistant lines is somaclonal variation induced by high concentrations of the selecting agent. Under stressful conditions such variability may result in the in vitro system from the activation of epigenetic factors, such as, for example, methylation of DNA or modification of the chromatin proteins. Source
Shirokikh I.G.,Russian Academy of Sciences |
Nasarova Y.I.,Rudnitskii Zonal Northeast Agricultural Research Institute |
Shirokikh A.A.,Rudnitskii Zonal Northeast Agricultural Research Institute |
Ogorodnikova S.Y.,Russian Academy of Sciences |
And 2 more authors.
Contemporary Problems of Ecology | Year: 2015
Tobacco (Nicotiana tabacum L.) plants with the gene of Fe-superoxide dismutase (Fe SOD1) from Arabidopsis thaliana L., which confers resistance to plants against the damaging effects of oxidative stress, have been used in the work. The abundances and structures of complexes of actinomycetes of the genus Streptomyces in the rhizosphere and rhizoplane of the original variety Samsun and independent transgenic lines Trtf 3 and Trtf 13 have been compared. The plants have been grown under optimum conditions (control) and on a native acidic soddy–podzolic soil under aluminum stress. The results show that the heterologous sequence inserted into the tobacco genome has a significant impact on the abundance, species diversity, and functional activity of streptomycetes in the rhizosphere of transformant plants. © 2015, Pleiades Publishing, Ltd. Source