Abstract
Background: Members of AP1/FUL subfamily genes play an essential role in the regulation of floral meristem transition, floral organ identity, and fruit ripping. At present, there have been insufficient studies to explain the function of the AP1/FUL-like subfamily genes in Asteraceae. Results: Here, we cloned two euAP1 clade genes TeAP1-1 and TeAP1-2, and three euFUL clade genes TeFUL1, TeFUL2, and TeFUL3 from marigold (Tagetes erecta). Expression profile analysis demonstrated that TeAP1-1 and TeAP1-2 were mainly expressed in receptacles, sepals, petals, and ovules. TeFUL1 and TeFUL3 were expressed in floral buds, stems and leaves as well as in productive tissues, while TeFUL2 was mainly expressed in floral buds and vegetative tissues. Transgenic Arabidopsis lines showed that overexpression TeAP1-2 or TeFUL2 resulted in early flowering, implying that these two genes might regulate the floral transition. Yeast two-hybrid analysis indicated that TeAP1/FUL proteins only interacted with TeSEP proteins to form heterodimers, and that TeFUL2 could also form a homodimer.Conclusion: In general, TeAP1-1 and TeAP1-2 might play a conserved role in regulating sepal and petal identity, just like the role of MADS-box class A genes, while TeFUL genes might display divergent functions. This study provides an insight into molecular mechanism of AP1/FUL-like genes in Asteraceae species.