Department of Plant Biology, Cornell University, Ithaca, New York 14853, USA.
Nat Commun. 2014 Nov 28;5:5628. doi: 10.1038/ncomms6628.
The spindle assembly checkpoint complex (SAC) is essential for quality control during mitosis in yeast and animals. However, its function in plants is not well understood. Here we show that MAD1, an Arabidopsis SAC component, is involved in endopolyploidization and flowering time via genetic interaction with MOS1, a negative regulator of plant immunity. MOS1 is found to interact with MAD2, another SAC component, and promote flowering and inhibit endopolyploidization, but this function is antagonized by MAD1. Furthermore, MAD1 and MOS1 both interact with SUF4, a transcription factor regulating the expression of the flowering time gene FLC. These findings reveal MOS1, MAD1 and SUF4 as regulators of endopolyploidization and flowering time and suggest an involvement of cell cycle control in the timing of reproductive transition.
纺锤体组装检查点复合物（SAC）对于酵母和动物有丝分裂过程中的质量控制至关重要。然而，其在植物中的功能尚不清楚。在这里，我们表明，拟南芥 SAC 成分 MAD1 通过与 MOS1 的遗传相互作用参与了内多倍体化和开花时间，MOS1 是植物免疫的负调节剂。发现 MOS1 与另一个 SAC 成分 MAD2 相互作用，促进开花并抑制内多倍体化，但 MAD1 拮抗了这一功能。此外，MAD1 和 MOS1 都与 SUF4 相互作用，SUF4 是一个转录因子，调节开花时间基因 FLC 的表达。这些发现揭示了 MOS1、MAD1 和 SUF4 作为内多倍体化和开花时间的调节剂，并表明细胞周期控制参与了生殖转变的时间。
