Identification and expression of genes encoding eukaryotic initiation factor 5A in relation to environmental stress

用一种简化的差异显示方法研究了水稻抗铯突变体的突变基因。所有突变体与野生型日本晴的eIF5A基因3‘端非编码区重复序列存在差异，利用实时荧光定量聚合酶链式反应分析了eIF5A表达与Cs处理的关系。其中一个候选基因是eIF5A，编码与抗逆性有关的真核启动因子之一。Cs抵抗与eIF5A表达呈正相关。EIF5A转录本在根中的含量高于地上部。突变根中eIF5A的转录量在Cs处理后1h和24h达到最大值，且随着Cs处理时间的延长，eIF5A的转录量逐渐增加。突变体根系中的CS含量在处理开始后数小时达到平台期。这些结果表明，eIF5A在CSR突变体的Cs抗性中是有效的，但eIF5A在高等植物抗逆性中的作用还有待进一步研究。

Mutant genes in rice mutants resistant to cesium(Cs) were surveyed using a simplified differential display method. There was a difference in the number of repeated sequences of 3'-UTR of eIF5A which encodes one of eukaryotic initiation factors between all the mutants and Nipponbare (a wild type cultivar).Relationship between eIF5A expression and Cs treatment was analyzed with a real-time PCR method. One of the candidate genes was eIF5A encoding one of eukaryotic initiation factors which was involved in stress resistance. Positive relationship between Cs resistance and eIF5A expression was found. The amount of eIF5A transcripts was higher in roots than in shoots. The amount of eIF5A transcripts in the mutant roots was maximum 1 and 24 h after the beginning of Cs treatment, while the transcripts increased with prolongation of Cs treatment in Nipponbare. Cs content in the mutant roots reached to plateau several hours after the beginning of the treatment. These results indicated that eIF5A is effective in Cs resistance of CSR mutants, but further studies on the role of eIF5A in stress resistance in higher plants is necessary.