Kleinmanns Julia A, Schatlowski Nicole, Heckmann David, Schubert Daniel
Plant Developmental Epigenetics, Heinrich Heine Universität DüsseldorfDüsseldorf, Germany.
Computational Cell Biology, Heinrich Heine Universität DüsseldorfDüsseldorf, Germany.
Front Plant Sci. 2017 Sep 11;8:1530. doi: 10.3389/fpls.2017.01530. eCollection 2017.
The PRC2 interacting protein BLISTER likely acts downstream of PRC2 to silence Polycomb target genes and is a key regulator of specific stress responses in . Polycomb group (PcG) proteins are key epigenetic regulators of development. The highly conserved Polycomb repressive complex 2 (PRC2) represses thousands of target genes by trimethylating H3K27 (H3K27me3). Plant specific PcG components and functions are largely unknown, however, we previously identified the plant-specific protein BLISTER (BLI) as a PRC2 interactor. BLI regulates PcG target genes and promotes cold stress resistance. To further understand the function of , we analyzed the transcriptional profile of mutants. Approximately 40% of the up-regulated genes in are PcG target genes, however, mutants did not show changes in H3K27me3 levels at all tested genes, indicating that BLI regulates PcG target genes downstream of or in parallel to PRC2. Interestingly, a significant number of BLI regulated H3K27me3 target genes is regulated by the stress hormone absciscic acid (ABA). We further reveal an overrepresentation of genes responding to abiotic stresses such as drought, high salinity, or heat stress among the up-regulated genes in mutants. Consistently, mutants showed reduced desiccation stress tolerance. We conclude that the PRC2 associated protein BLI is a key regulator of stress-responsive genes in : it represses ABA-responsive PcG target genes, likely downstream of PRC2, and promotes resistance to several stresses such as cold and drought.
与PRC2相互作用的蛋白BLISTER可能在PRC2下游发挥作用，使多梳靶基因沉默，并且是植物中特定应激反应的关键调节因子。多梳蛋白组（PcG）蛋白是发育过程中的关键表观遗传调节因子。高度保守的多梳抑制复合物2（PRC2）通过对H3K27进行三甲基化（H3K27me3）来抑制数千个靶基因。然而，植物特有的PcG组分和功能在很大程度上尚不清楚，我们之前鉴定出植物特有的蛋白BLISTER（BLI）是一种PRC2相互作用蛋白。BLI调节PcG靶基因并促进抗寒能力。为了进一步了解BLI的功能，我们分析了BLI突变体的转录谱。在BLI突变体中，约40%上调的基因是PcG靶基因，然而，在所有测试基因中，BLI突变体的H3K27me3水平并未显示出变化，这表明BLI在PRC2的下游或与其平行调节PcG靶基因。有趣的是，大量受BLI调节的H3K27me3靶基因受应激激素脱落酸（ABA）调节。我们进一步揭示，在BLI突变体上调的基因中，对干旱、高盐或热应激等非生物胁迫作出反应的基因明显富集。一致地，BLI突变体表现出脱水胁迫耐受性降低。我们得出结论，与PRC2相关的蛋白BLI是植物中应激反应基因的关键调节因子：它可能在PRC2下游抑制ABA响应的PcG靶基因，并促进对寒冷和干旱等多种胁迫的抗性。
