The Effects Of Enhanced Uv-b And He-ne Laser On Microfilament Cytoskeleton In Wheat

The seedlings of wheat(Jin mai 8)were exposed to He-Ne laser irradiation with 5mW·mm-2 Power density after enhanced UV-B radiated(10.08kJ·m-2·d-1). Microfilaments (MFs) were observed by confocal laser scanning microscopy (CLSM) in the wheat mesophyll protoplast and wheat root-tip cells treated with FITC- Phalloidin . The results were showed as follows:1. We can gain a large number of protoplasts using appropriate types of enzymes and low enzyme concentrations (cellulase R-10 1.5% and pectinase Y-23 0.1%), at the appropriate temperature (26℃), and digestion time (3h ).2. The actin in wheat mesophyll protoplast was studied by SDS-PAGE electrophoresis analysis .The results showed that the contents of actin were affected in a certain extent after UV-B radiation; but the He-Ne laser can reduce the UV-B radiation damage.3. Microfilaments (MFs) were observed by confocal laser scanning microscopy (CLSM) in the wheat mesophyll protoplast treated with FITC- Phalloidin .Two types of MFs bundles could be recognized(CK): those beneath the plasma membrane running parallel to each other; those surrounding the chloroplast. When the wheats were treated by enhanced ultraviolet-B radiation(B), the distribution pattern of MFs was changed into bundles or granules. Part of the actin network is disrupted treated with compound treatment (BL). The distribution of MFs have become shorter and arrange crossing networks by He-Ne laser irradiation(L).4. The distribution of microfilaments (MFs) were examined by confocal laser scanning microscopy (CLSM) in the wheat root-tip cells under the enhanced ultraviolet-B (10. 08 kJ·m - 2·d- 1 ) radiation treated with FITC- Phalloidin .The results showed that under the condition of the enhanced ultraviolet-B radiation, distribution of actin MFs were disordered in interphase cells; The arrays of MFs disintegrated into short fragments of random during prophase; Fluorescence intensity significantly decreased and bright fragments of microfilaments disappeared in Metaphase cells; MFs disappeared in the phragmoplast regions when cells were in anaphase and telophase time . And some types of chromosome aberration were induced ,including Chromosomal logging , chromosomal bridge and partition-bundle division .