Overexpression of CONSTANS from Arabidopsis thaliana did not cause early flowering in the short-day tobacco plant, Nicotiana tabacum cv. Hicks Maryland Mammoth, under a long-day condition

摘要

Transgenic short-day tobacco plants, Nicotiana tabacum cv. Hicks Maryland Mammoth, were generated in which Arabidopsis thaliana CONSTANS cDNA with the Omega translational enhancer was expressed under the control of the constitutive cauliflower mosaicvirus 35S promoter. In a long-day condition, 16 h light/8 h dark, the transgenic plants did not flower over 210 days of experimental period after they had been transferred to pots while control transgenic plants possessing an empty T-DNA flowered around121 days after the transfer. This result suggests that Arabidopsis CONSTANS does not act as a positive regulator for flowering in short-day plants under long-day conditions, and supports the idea that CO orthologs in short-day plants act as a repressor for flowering under long-day conditions, similar to Hdl in rice.