RUSSIAN AGRICULTURAL SCIENCES (см -2011 - №6, 453-461)
Effect of Weak Magnetic Field and Low Positive Temperature on Chromatin and Nucleolus Ultrastructure of Rye and Barley1
E. N. Baranova, G. B. Baranova, and P. N. Kharchenko
AllRussian Research Institute of Agricultural Biotechnology, Russian Academy of Agricultural Sciences,
Timiryazevskaya 42, Moscow, 127550 Russia
Abstract—Using two crops (rye, barley) we have demonstrated a fundamental difference in the structural organization of condensed chromatin, nucleolus and chromatinRNP complexes in the experiments with the weakening (spherical ferromagnetic shield) and the enhancing (constant magnet) of magnetic field at low positive (–3–+1°C) and room temperatures (+24°C). As a model we used the spring and winter varieties of cereals placed after imbibition in the experimental conditions. We used the classic regime of seed vernaliza tion (12 and 42 days at temperatures ranging from 0 to +4°C) for winter cereals and temperate climate zones of germination at room temperature in the control and experimental conditions. After experimental exposure the plants visually were observed during the growth until the transition to gener ative development. It is shown that the effect of a weak constant magnetic field (shielding) leads to a change in the ultrastructural organization of the nuclei that has been manifested in chromatin decondensation and formation of complicated chromatinRNP complexes. There were three types of previously not described structures: 1 (A)—alternate, parallel stretches of condensed chromatin associated with the RNP and fully consisted with the peripheral component of the nucleolus, and then divided between a bright area, which can be traced thin threadlike formation, indicating a relationship with RNP condensed chromatin, 2 (B)—sin gle strands of condensed chromatin in conjunction with the RNP and the characteristic separation, and 3 (C)—some parallel RNP complexes of chromatin extending from the nucleolus in the form of “pseudo pods of amoeba”. The plating of imbibed seeds into a spherical shield conditions, and also under influence of enhanced magnetic field caused by constant magnet at room temperature and at low positive temperatures led to changes of chromatin compartmentalization, and of the nucleolus and chromatinRNP complexes structure. Decondensation of chromatin and the appearance of RNPchromatin complexes under shielding of magnetic field are reversible. Keywords: rue, barley, root meristem, geomagnetic field, weak magnetic fields, nucleus, nucleolus, chromatin decondensation, cell ultrastructure.
ПОДРОБНЕЕ В ЖУРНАЛЕ И ПО ЗАПРОСУ (статья полностью)
Рис.1. Longitudional section of meristematic zone of barley (A)–(C) and rye (D)–(F) root in normal
conditions and in condi tions of enhancing or slackening of static magnetic field. Normal conditions (A, D);
influence of constant magnet (B, E); influ ence of ferromagnetic shield (C, F).
Oval—meristem, circle—enlargement fragment.
Fig. 3. Fragments of nucleus and nucleolus of barley root meristematic cells. Normal conditions (A)–(C), constant magnet (D)–(F), ferromagnetic shield (C)–(I). Black asterisk—decondensed chromatin and karyoplasms, white asterisk—“clods” of condensed chromatin, black arrow – interchromatin granules, white arrow—“stretches” of RNP (nucleoluslike material) in codensed chromatin encirclement.
Fig. 5. Fragments of nucleus and nucleolus in rye root meristematic cells. Control (A)–(C), constant magnet (D)–(F), ferromagnetic shield (C)–(I). Black asterisk—decondensed chromatin and karyoplasms, white asterisk—“clods” of condensed chromatin, black arrow – interchromatin granules, white arrow—“stretches” of RNP (nucleoluslike material) in encirclement of condensed chromatin.
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