Identification and Expression Analysis of the Populus trichocarpa GASA -Gene Family

The gibberellic acid-stimulated ( ) gene family plays an important regulatory role in the growth and development of plants. In this study, we identified 19 genes using bioinformatics-based methods in , and these genes could be divided into three categories based on their phylogenetic relationships. Based on an analysis of the structure and motifs of these genes, it was concluded that class II members are more conserved than class I and class III members are, and the results of collinearity analysis showed that members of class II are collinearly related in poplar. Expression analysis of roots, stems, and leaves showed that most of the genes are expressed at higher levels in the stems or roots than in the leaves; a similar expression pattern was found in , indicating that the -family members mainly play a role in the morphogenesis of poplar. Considering the phenomenon of gene amplification, we found that the higher the similarity of homologous genes was, the more similar the expression patterns. This study represents the first whole-genome identification and expression-profile analysis of the -gene family in poplar, a model species, laying a foundation for functional studies of poplar genes and serving as a reference for related research on other woody plant species.