Comparative analysis of expansin gene codon usage patterns among eight plant species.

Expansins are essential components of plant cell wall and play an important role in plant growth, development, and stress resistance via loosening function. To understand the codon usage pattern of expansin genes, we gained the sequence data of expansin genes from eight plant species. Statistics analysis showed obvious codon characteristics between monocot and dicot plants. Comparably, expansin genes in monocot plants had really higher GC content, more high-frequency codons, and more optimal codons than that in dicot plants. Several monocot plants performed somehow as dicot plants in a few characters. Codon information of expansin genes might contribute to the understanding of the relationship and evolution clues between monocot and dicot plants. It further gained insight into the improvement of the gene expression and roles.