Effects of Enhanced UV-B Radiation on the Cell Mitosis of the Callus in Wheat

Abstract

In order to study effects of enhanced Ultraviolet-B ( 280nm-320nm) radiation on the cell mitosis, mature embryos of wheat as explant were cultured in the Murashige and Skoog (MS) medium with different concentration of 2，4-D and 6-BA . The results indicated the inducing rate of the mature embryos from wheat on the MS with 2, 4-D 1.0 mg/L was higher and the callus was better than on the other Culture medium. The chromosomal mutation and mitosis of the callus in wheat were studied under the condition of the enhanced UV-B radiation. The results showed that enhanced UV-B radiation inhibited the cell division of callus in wheat, several types of chromosomal aberration such as micronucleus, multi-nucleus, nuclear aberration occurred during the interphase, which may be the results of UV-B inhabiting the DNA replication of the cell to lead to the cell DNA mutation and form the pyrimidine dimer.

The distribution of profilin in root-tip cells of wheat seedlings exposed to enhanced UV-B radiation

“…Qi et al (2002) found that the activities of superoxide dismutase, ascorbate peroxidase and CAT decreased significantly and the concentration of MDA and the rate of electrolyte leakage increased rapidly under higher UV-B radiation levels. Han et al (2002) found that 'root-bending' phenomenon would be caused under the enhanced UV-B radiation when wheat seeds germination and 'partition-bundle' division would be happened in root-tip cells of wheat seedlings. The distribution of actin filaments in wheat cells was disordered during interphase; the actin filaments disintegrated into short fragments and randomly distributed in the periplasm during prophase, and the actin fragments would disappear in metaphase (Chen et al 2011).…”

The Distribution and Morphology Alterations of Microfilaments and Microtubules in Mesophyll Cells and Root-Tip Cells of Wheat Seedlings under Enhanced Ultraviolet-B Radiation

“…R. Han et al (2002) found that the enhanced UV-B radiation would cause "root-bending" phenomenon when wheat seeds germination and "partition-bundle" division in root-tip cells of wheat seedlings [28]. Cell wall-plasma membrane-cytoskeleton have formed continuum in plant cells [29].…”

“…A large number of studies have shown that enhanced UV-B radiation could lead to some abnormal phenomenon in living organisms, such as bio-membrane damage, membrane surface charge reduction, membrane permeability enhancement, cell electrophoresis rate decline, chromosome morphology alteration and aberrant cell division [26]- [28]. R. Han et al (2002) found that the enhanced UV-B radiation would cause "root-bending" phenomenon when wheat seeds germination and "partition-bundle" division in root-tip cells of wheat seedlings [28].…”

Plant microtubules reorganization under the indirect UV-B exposure and during UV-B-induced programmed cell death

“…As cytoskeleton reorganization was revealed mainly in vitro in protoplasts and other cell cultures, [21][22][23][24] we have obtained the complementary results on cells of Nicotiana tabacum BY-2 suspension culture expressing gfp-mbd (microtubule-binding domain of MAP4) as a suitable cell model for in vivo MTs visualization. 33 Since BY-2 cells are more resistant to UV-B exposure as compared with A. thaliana seedlings, the higher doses of UV-B (34, 81 and 135 kJ/m 2 ) were used.…”

“…18,19 Cytoskeleton role in such UV-induced morphological changes as their driving force remains poorly investigated, since only a few articles are focused on the cytoskeleton reorganization in vitro as one of the events underlying UV-B-induced responses of plant cell. [21][22][23][24][25] It was shown recently that the interphase and mitotic MTs in epidermal and cortex cells of all primary root zones of Arabidopsis thaliana L. seedlings expressing gfp-map4 (microtubule-assosiated protein 4) were randomized, depolymerized and/or stabilized in dose-dependent manner after the UV-B exposure (13.6-68 kJ/m 2 ) in vivo that was accompanied by the cell swelling and excessive root hairs formation. 26 Our further experiments give additional evidences that plant MTs are involved in signal transduction under UV-B stress.…”