Figure 1.

Floral induction by NtFT4 in SD N. tabacum MM. A, Expression of NtFTs in tobacco plants grown under inductive SD conditions was analyzed by qRT-PCR. Young leaf samples were taken at 2–16 WASS. Plants grown under SD had started to bolt after 8 WASS and flower after 12 WASS. No plants bolted or flowered under noninductive LD conditions. B, Viral expression of NtFT4 by PVX/NtFT4 induced SD tobacco to flower at 9 WASS in LD, 5 weeks postinoculation. Mock-inoculated controls and plants infected with PVX/mNtFT4 remained vegetative in LD. C, RT-PCR detection and sequencing confirmation of wild-type and mutant NtFT4 transcripts expressed in tobacco. Plants were photographed as indicated WASS in A or 9 WASS in B. Bar = 4 cm.