Research Advances on Tobacco Florigen Gene FT and Its Regulatory Mechanisms

Tobacco (Nicotiana tabacum L.) is an economic crop in which mature leaves are harvested. Early flowering has serious influence on quality and yield of tobacco. Moreover, long growth cycle is also a major factor limiting the progress of tobacco breeding. Initiation of floral development is regulated through the integration of photoperiod, vernalization, gibberellin and/or autonomous signaling pathways. FT is a key regulatory protein at the intersection of these pathways. Four FT-like genes were isolated from tobacco. Only NtFT4 is a floral inducer and others are floral inhibitors. Tobacco CET, CO, FPF1, LFY, NFL, MADS box and other genes also play very important roles in tobacco flowering. In this article, we summarize the research progress on characteristics, function and regulatory mechanisms of tobacco FT gene. It provided useful information for preventing early flowering and accelerating breeding progress in tobacco.