叶片衰老由复杂的调节网络控制,其中通过转录因子和表观遗传调节因子的活性确保鲁棒性。然而,这些如何协调叶片衰老的过程仍然知之甚少。我们发现WHIRLY1与组蛋白去乙酰化酶(HDA)15相互作用,一种减少钾依赖3(RPD3)/HDA1型HDA,通过使用绿色荧光蛋白-纳米RAP-质谱测定。WHIRLY1和HDA15之间的发育依赖性相互作用通过拟南芥中的双分子荧光互补测定和共免疫沉淀测定得到进一步证实。多组学全基因组转录组和H3K9乙酰基组富集分析表明,HDA15通过抑制叶片衰老和开花正调控因子的表达,延缓叶片衰老和开花,如LOX2和LARP1C,并降低这些基因座处的H3K9ac水平;WHIRLY1和HDA15共同靶向营养循环相关基因子集的转录起始位点附近的区域(例如,谷胱甘肽S-转移酶10,非编码RNA,和光系统II蛋白D1合成衰减器PDIL1-2),以及WRKY53和ELF4,并通过去除H3K9乙酰化共同抑制其表达。我们的研究揭示了通过单链DNA/RNA结合蛋白WHIRLY1募集HDA15,参与叶片衰老和开花的营养循环和衰老相关基因的关键转录调控节点。
Leaf senescence is controlled by a complex regulatory network in which robustness is ensured by the activity of transcription factors and epigenetic regulators. However, how these coordinate the process of leaf senescence remains poorly understood. We found that WHIRLY1 interacts with Histone Deacetylase (HDA)15, a Reduced Potassium Dependence3 (RPD3)/HDA1-type HDA, by using green fluorescent protein-nanotrap-mass spectrum assays. The development-dependent interaction between WHIRLY1 and
HDA15 was further confirmed by bimolecular fluorescence complementation assays and co-immunoprecipitation assays in Arabidopsis. Multi-omics genome-wide transcriptome and H3K9 acetylome enrichment analysis showed that
HDA15 delays leaf senescence and flowering by repressing the expression of the positive regulators of leaf senescence and flowering, such as LOX2 and LARP1C, and reducing H3K9ac levels at these loci; WHIRLY1 and
HDA15 co-target to the region near the transcription start site of a subset of nutrient recycling-related genes (e.g., Glutathione S-transferases 10, non-coding RNA, and photosystem II protein D1 synthesizer attenuator PDIL1-2), as well as WRKY53 and ELF4, and co-repress their expression by removing H3K9 acetylation. Our study revealed a key transcription regulatory node of nutrient recycling and senescence-associated genes involved in leaf senescence and flowering via the recruitment of
HDA15 by the single-stranded DNA/RNA-binding protein WHIRLY1.