Genome-wide identification, characterization, and expression analysis of the gibberellin-20-oxidase gene family in Artemisia annua L.

The gibberellin-20-oxidase (GA20ox) gene family plays an important role in plant growth and development by modulating the activity of gibberellins (GAs). In this study, transcriptomic sequencing of two Artemisia annua L. strains with different morphological features and active components revealed 11,449 differentially expressed genes, which included 2 GA20ox genes. Subsequently, genome-wide analysis of the GA20ox gene family of A. annua was performed using bioinformatics tools. A total of 8 GA20ox genes were identified, named the AaGA20ox family, with different molecular weights, isoelectric points, and amino acid numbers were identified, which were located in the cytoplasm. The secondary structures of AaGA20ox proteins primarily consisted of an alpha helix and random coils, whereas the tertiary structures within the same subfamily exhibited a high degree of similarity. Analysis of upstream promoter regions revealed the presence of cis-acting elements closely associated with plant growth and development, response to light, hormone regulation, and various stress responses. Analysis of transcriptomic data of various tissues indicated differential expression of AaGA20ox genes among the roots, stems, leaves, and flowers of two A. annua strains, HAN1 and LQ9. These findings improve the understanding of the AaGA20ox gene family, provide a valuable reference for further investigation into the function of AaGA20ox genes in A. annua, and reveal some factors responsible for phenotypic differences between HAN1 and LQ9.