Genome-Wide Analysis of the Gibberellin-Oxidases Family Members in Four Species and a Functional Analysis of in Plant Height.

Gibberellins (GAs), enzymes that play a significant role in plant growth and development, and their levels in plants could be regulated by gibberellin-oxidases (GAoxs). As important fruit trees and ornamental plants, the study of the mechanism of plant architecture formation of the genus is crucial. Here, 85 genes were identified from , , , and , and they were classified into six subgroups. Conserved motif and gene structure analysis showed that GAoxs were conserved in the four species. Collinearity analysis revealed two fragment replication events of s in the genome. Promoter cis-elements analysis revealed 24 s contained hormone-responsive elements and development regulatory elements. The expression profile indicated that s have tissue expression specificity, and GA levels during the dormancy stage of flower buds were controlled by certain s. After being treated with IAA or GA, the transcription level of in stems was significantly increased and showed a differential expression level between upright and weeping stems. GUS activity driven by promoter was detected in roots, stems, leaves, and flower organs of . overexpression in leads to dwarfing phenotype, increased number of rosette leaves but decreased leaf area, and delayed flowering. Our results showed that GAoxs were conserved in species, and played an essential role in regulating plant height.