Cloning and functional analysis of <italic>ScGA20ox1</italic> gibberellin oxidase gene in sugarcane

Abstract

<p id="C3">GA20-oxidase (GA20ox) is a key rate-limiting enzyme in the synthesis of gibberellic acid (GA), but the biological function and expression pattern of gene <italic>GA20ox1 </italic>in sugarcane remain unknown. In this study, we cloned GA20-oxidase gene (<italic>ScGA20ox1</italic>) from the sugarcane variety ROC22 sequence by RT-PCR and RACE, which had a total length of 1574 bp and a complete open reading frame (ORF) of 1125 bp that encoded 375 amino acids. The ScGA20ox1 protein is a hydrophilic protein with a molecular weight of 42.3 kD, an iscelectric point (pI) of 5.95, and no transmembrane structure or signal peptide. Real-time fluorescence quantitative analysis revealed that <italic>ScGA20ox1</italic> had the highest expression levels in stems, medium in the leaves, and the lowest in roots of sugarcane seedlings. Drought stress, low temperature stress, and GA₃ treatment change the expression patterns of <italic>ScGA20ox1</italic> in different tissues. <italic>ScGA20ox1</italic> was transformed into Arabidopsis via Agrobacterium-mediated transformation. Transgenic <italic>Arabidopsis thaliana</italic> plants with overexpressed <italic>ScGA20ox1</italic> were obtained from the transformed <italic>Arabidopsis thaliana via</italic> Agrobacterium-mediated transformation, which showed a phenotypic variation of plant height and internode length increase. In conclusion, <italic>ScGA20ox1</italic> was involved in sugarcane’s growth as a crucial regulator in response to abiotic stress and the phenotypic variation of overexpressed transgenic <italic>Arabidopsis thaliana</italic> changed, which would lay a theoretical basis for future in-depth studies on <italic>ScGA20ox1</italic>’s biological function and analysis of the molecular mechanism of sugarcane plant shape regulation.