Department of Botany, Section Molecular Developmental Biology, University of Nijmegen, Toernooiveld, Nijmegen, The Netherlands.
Planta. 1978 Jan;140(3):283-8. doi: 10.1007/BF00390261.
Acute irradiation of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) pollen by X-rays enhances pollen tube elongation. To determine whether this effect was due to physical damage of the pollen membranes or to metabolic processes, irradiated and control pollen were grown under conditions of anoxia. Thus, it was determined that physical damage only could be of minor importance. As parameters for metabolic processes RNA- and protein synthesis were studied. The only difference between irradiated and control pollen with respect to RNA synthesis was the time at which it started. Protein synthesis in vitro revealed that polyribosomes from irradiated pollen were more active than those from control pollen at lower concentrations. These results were confirmed by in ovo experiments with both polysomal preparations. The results indicate that X-ray irradiation is interfering with the main regulatory mechanism of pollen tube growth, which is de- and re-masking of, mainly, presynthesized mRNA.
X 射线急性辐照花旗松（Pseudotsuga menziesii [Mirb.] Franco）花粉可促进花粉管伸长。为了确定这种效应是由于花粉膜的物理损伤还是代谢过程所致，将辐照和对照花粉在缺氧条件下进行培养。因此，确定物理损伤的重要性较小。作为代谢过程的参数，研究了 RNA 和蛋白质的合成。辐照花粉与对照花粉在 RNA 合成方面的唯一区别在于开始的时间。体外蛋白质合成表明，在较低浓度下，来自辐照花粉的多核糖体比来自对照花粉的多核糖体更活跃。这一结果通过用两种多核糖体制剂进行的胚胎内实验得到了证实。结果表明，X 射线辐照干扰了花粉管生长的主要调节机制，主要是预先合成的 mRNA 的去掩蔽和再掩蔽。
