Genome-Wide Analysis of the Rice Gibberellin Dioxygenases Family Genes

Gibberellins (GAs), a pivotal plant hormone, play fundamental roles in plant development, growth, and stress response. In rice, gibberellin-dioxygenases (GAoxes) are involved in the biosynthesis and deactivation of gibberellins. However, a comprehensive genome-wide analysis of GA oxidases in rice was not uncovered. Here, a total of 80 candidate OsGAox genes were identified and 19 OsGAox genes were further analyzed. Studies on those 19 OsGAox genes, including phylogenetic tree construction, analysis of gene structure, exploration of conserved motifs and expression patterns, were conducted. Results showed that the GAox genes in Arabidopsis and rice were divided into four subgroups and shared some common features. Analysis of gene structure and conserved motifs revealed that splicing phase and motifs were well conserved during the evolution of GAox genes in Arabidopsis and rice, but some special conserved motifs possessed unknown functions need to be further studied. Exploration of expression profiles from RNA-seq data indicated that each GAox gene had tissue-specific expression patterns, although they varied greatly. The expression patterns of these genes under GA(3) treatment revealed that some genes, such as OsGA2ox1, OsGA2ox3, OsGA2ox4, OsGA2ox7, OsGA20ox1, and OsGA20ox4, may play a major role in regulating the level of bioactive GA. Taken together, our study provides a comprehensive analysis of the GAox gene family and will facilitate further studies on their roles in rice growth and development so that these genes can be better exploited.