以同步化的拟南芥(Arabidopsis thaliana)根尖细胞为材料, 研究了UV-B辐射对拟南芥细胞周期G1/S期转变的影响。细胞周期荧光显微图像分析表明, UV-B辐射延缓了拟南芥根尖细胞G1/S期的转变。基因表达的RT-PCR检测表明, 在UV-B辐射下G1/S期转变的标志基因Histone H4和E2Fa的表达受抑制, 而G1/S期转变的抑制因子KRP2基因表达则受诱导上调。单细胞凝胶电泳检测结果表明, UV-B辐射引起拟南芥根尖细胞内积累大量的环丁烷嘧啶二聚体。以上结果表明, UV-B辐射抑制植物的生长可能受细胞周期和DNA损伤调控。

Cell cycle regulation is closely linked to plant growth and development. The plant cell cycle responds rapidly to stimuli from both the internal and external environment. We present a model of partially synchronized root tips of Arabidopsis to study the effects of UV-B radiation on the G1/S transition in the cell cycle. Analysis of the fluorescence image under micros copy indicated that G1/S arrest was induc ed by UV-B radiation. The expression of two factors of G1/S transition, Histone H4 and E2Fa, was repressed under UV-B radiation, whereas the negative factor of G1/S transition, KRP2, was upregulated by UV-B radiation. UV-B radiation during the cell cycle induced accumulation of cyclobutane pyrimidine dimers. All these results suggested that UV-B induced plant growth inhibition may be mediated by cell cycle regulation and DNA damage.