Abstract：GA20-oxidase, a key enzyme in the gibberellins (GAs) biosynthesis pathway, has been widely studied in major food crops such as rice (Oryza sativa), wheat (Triticum aestivum), and corn (Zea mays), however, research on it in sweetpotato (Ipomoea batatas) remains completely unexplored. In this study, a GA20 oxidase gene named I. batatas gibberellin 20 oxidase1 (IbGA20ox1) was identified using the full-length transcriptome and genome data of sweet potato (I. batatas), and its bioinformatics and expression pattern were analyzed, and its function was verified by overexpression in Arabidopsis thaliana. The results showed that the CDS of IbGA20ox1 gene was 1 083 bp, encoding 361 amino acids, and the molecular weight of the protein was 40.7 kD, which was an acidic hydrophile protein. Comparative analysis of protein sequences showed that GA20 oxidase in plants was highly conserved. Expression pattern analysis showed that IbGA20ox1 gene was highly expressed in sweet potato flowers, fibrous roots, leaves and buds. In leaves, this gene can be induced by gibberellin. IbGA20ox1 in A. thaliana overexpressed plants showed elongated plants, early flowering, and increased the expression of key genes of GA metabolic pathway. The results of this study provide a reference for further elucidating the functional characteristics of GA20 oxidase gene in sweet potato and revealing its molecular mechanism involved in regulating the growth and development of sweet potato.
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