PNAS| DME 去甲基化酶调节孢子体基因表达、细胞增殖、分化和分生组织复苏
开花植物的生命周期由单倍体(配子体)和二倍体(孢子体)交替世代组成，其中孢子体世代始于单倍体配子受精。在拟南芥中，雄性和雌性配子体的配子体伴生细胞中的DEMETER (DME) DNA去甲基化酶催化了全基因组的DNA去甲基化，这是正常发育所必需的。在孢子体中，胚胎后期的生长和发育在很大程度上依赖于大量干细胞龛或分生组织的活动。通过分析纯合子拟南芥中缺失的DME -2等位基因，我们发现DME影响孢子体生长发育的许多方面。dme-2突变体表现为种子萌发延迟，根毛生长变化，细胞增殖和分化异常，新生芽形成增强，根系静默和气孔前体细胞失调，花序分生组织(IM)复活。我们还发现，孢子体的DME活性对发育中的拟南芥的转录组产生了深远的影响，包括在DME -2突变体组织中被错误调控的离散调控基因组，这使得我们能够潜在地将表型与特定基因表达途径的变化联系起来。这些结果表明，DME在拟南芥孢子体发育过程中发挥了关键作用，并提示DME介导的活性DNA去甲基化可能参与了拟南芥孢子体生命周期中干细胞活性的维持。
The flowering plant life cycle consists of alternating haploid (gametophyte) and diploid (sporophyte) generations, where the sporophytic generation begins with fertilization of haploid gametes. In Arabidopsis, genome-wide DNA demethylation is required for normal development, catalyzed by the DEMETER (DME) DNA demethylase in the gamete companion cells of male and female gametophytes. In the sporophyte, postembryonic growth and development are largely dependent on the activity of numerous stem cell niches, or meristems. Analyzing Arabidopsis plants homozygous for a loss-of-function dme-2 allele, we show that DME influences many aspects of sporophytic growth and development. dme-2 mutants exhibited delayed seed germination, variable root hair growth, aberrant cellular proliferation and differentiation followed by enhanced de novo shoot formation, dysregulation of root quiescence and stomatal precursor cells, and inflorescence meristem (IM) resurrection. We also show that sporophytic DME activity exerts a profound effect on the transcriptome of developing Arabidopsis plants, including discrete groups of regulatory genes that are misregulated in dme-2 mutant tissues, allowing us to potentially link phenotypes to changes in specific gene expression pathways. These results show that DME plays a key role in sporophytic development and suggest that DME-mediated active DNA demethylation may be involved in the maintenance of stem cell activities during the sporophytic life cycle in Arabidopsis.
文章来源网络整理；如有侵权请及时联系PaperRSS小编删除，转载请注明来源。
温馨提示：
为方便PaperRSS粉丝们科研、就业等话题交流。我们根据10多个专业方向（植物、医学、药学、人工智能、化学、物理、财经管理、体育等），特建立了30个国内外博士交流群。群成员来源欧美、日韩、新加坡、清华北大、中科院等全球名校。