Analysis of codon use features of plant disease resistance gene | 植物抗病基因密码子使用特性分析

صينى. 植物抗病基因（R基因）相对植物整个基因组进化较快，且作用机制复杂，抗病基因一直是遗传及病理学研究的热点问题。本研究运用CodonW等软件对多种植物的42个不同抗病基因进行密码子偏好性及聚类分析，初步探究了植物抗病基因密码子使用模式。结果表明水稻Xal3、Xa21以及Xa27基因和玉米Hml基因明显区别于大部分R基因，除了这4个基因外之外，大部分R基因偏好于使用以A或T结尾的密码子，碱基组成AT含量大于GC。TTG、CTT、TAT等28个密码子为R基因的偏爱密码子，其中24个以A或T结尾。聚类结果在一定程度上反映了不同抗病功能基因的相似性及相同抗病基因的差异性。本研究为新的R基因的预测及R基因相关基因工程操作提供了一定参考。

إنجليزي. Compared to the whole genome, plant disease resistance genes (R genes) are highly diverse and evolved rapidly, and their mechanism of action is complex. The study of Resistance genes has been a hot spot area in Genetics and pathology. In this study, CodonW was used to analyze codon usages of 42 R genes from different plants. The results showed that the codons ending with A/T, especially T, were frequently used and GC content was lower than AT content in most of R genes. Relative synonymous codon usage (RSCU) analyses showed that 28codons were preferable in the codons of coding DNA sequences (CDS) of R genes. Both cluster trees based on the relative RSCU and CDS of R gene could not reveal the evolutional relations of plant species. However, they could indicate the similarity of genes with different functions and the differences between genes having same disease to some extent. Xa13,Xa21, Xa27 and Hml were significantly from most of R gene. For example, they use the codons ending with G/T more frequently than that ending with A/T. This study provided certain reference for the prediction of new R genes and the operation of gene engineering R genes.