The 30th International Conference on Arabidopsis Research (ICAR 2019)

651 / 2019-04-29 19:14:12

SIN3 LIKE genes mediate long-day induction of flowering but inhibit the floral transition in short days through histone deacetylation in Arabidopsis

Histone deacetylation, Sin3 Like, HDAC, Photoperiod pathway, AP2 gene family, Flowering locus T, Arabidopsis thaliana

Growth and Development > Growth and Development

Seasonal cues such as photoperiod changes are crucial for plants to align the timing of the floral transition. And plants evolved an exquisite mechanism named photoperiod pathway to monitor day length change. FT is the major regulate integrator and output of photoperiod pathway. However, beside the classical CO-FT regulatory module, other mechanisms upstream of FT is still obscure.
Here we show that the homologous of widely conserved histone deacetylation complex (HDAC) component SWI-INDEPENDENT3 (Sin3) are also involved in photoperiod regulation of flowering. There are six homologous of Sin3 (SNL1 to 6), and mutation of SNLs result in late flowering under long day(LD) condition but early flowering under short day(SD) condition. Further, we found that at LD, SNLs promote flowering through directly bind and repress AP2 gene family members, Toe1, Toe2 and SMZ. And interestingly, at SD, SNLs suppress flowering through directly associate and down-regulate AGL19.
Function as a scaffold in HDAC, SNLs mediate site specific histone deacetylation by associate with transcription factors to drive histone deacetylase to target loci. In the snl1/2/3/4/5 quintuple mutant, the general histone acetylation level was obviously decreased, which confirmed the functionally necessity of SNLs in the HDAC of plants.
Taken together, our work further filled the gaps of functional research of Sin3-HDAC in plants and firstly characterized the role of SNLs in plants flowering.