Ectopic expression of AtSOC1 gene driven by the inducible promoter rd29A, causes early flowering in Chrysanthemum

Suppressor of Overexpression of Constans1 of Arabidopsis (AtSOC1) plays an important role in floral induction and development as one of the flowering pathway integrators. rd29A is a stress inducible promoter. To obtain a new chrysanthemum germplasm with an inducible flowering time, we succeeded in making transgenic chrysanthemum plants carrying AtSOC1 genes driven by the rd29A promoter via Agrobacterium-mediated transformation. Molecular characterization confirmed the stable integration of the introduced gene cassette in the transformants. The result showed that AtSOC1 expression was elevated to varying extents in different transgenic lines. One of the lines showed an obvious phenotype of early flowering, which was induced by drought stress. These results indicated that AtSOC1, driven by the rd29A promoter, can regulate the flowering time when drought stress treatments are applied to chrysanthemum.