Function of cohesin ring complexes in the control of phytohormone-mediated stress response andchromatin structuring in Arabidopsis

三维基因组结构对基因表达的调控具有决定性作用。细胞学和生物化学研究，结合全基因组分析，已经确定了多种分子因素，如染色质绝缘体、多梳基团复合体(PcG)和蛋白质环复合体，以构建染色质结构和调节真核生物中的基因转录-对生物体的发育和生理产生各种影响。对于植物来说，与酵母和人类等其他真核生物相比，我们对基因组结构形成的知识仍然很初级，有很多迹象表明，植物在进化过程中已经发展出了独特的/额外的3D基因组包装的分子机制。染色质结构是非常动态的，随着细胞类型和细胞发育阶段的不同而变化。特别强烈的是由于外部刺激而产生的变化。在植物中，染色质被重组以响应非生物和生物胁迫，这对基因表达的适应起着重要作用。然而，染色质的三维结构是如何变化的，特别是染色质环的景观是如何变化的，以及形成环的粘附素环复合体起到什么作用还不清楚。基因敲除突变体的早期实验表明，在拟南芥中，某些粘附素确实在对外部刺激的反应中发挥着令人惊讶的强大作用。我打算研究三方粘附素环复合体在营养植物细胞染色质环的形成和调节中的作用。在这里，我提出了一个假设，即通过控制染色质环的形成，粘附素环复合体是基因组可塑性和适应性的关键因素。它们可能负责基因簇的形成和分离，基因的沉默或增强子元件激活转录，这对调节各种细胞过程非常重要，我对拟南芥中发生的响应非生物和生物胁迫的事件感兴趣。

The three-dimensional genome architecture is decisive for the regulation of gene expression. Cytological and biochemical studies, together with genome-wide analyses, have identified multiple molecular factors, such as chromatin insulators, Polycomb group complexes (PcG), and protein ring complexes to structure chromatin and regulate gene transcription in eukaryotes – with a variety of effects on the development and physiology of the organisms. For plants, compared to other eukaryotes such as yeasts and humans, our knowledge of the formation of genome structures is still rudimentary and there is much to suggest that plants, during evolution, have developed unique / additional molecular mechanisms of 3D genome packaging. The chromatin structure is very dynamic and changes according to cell types and cell developmental stages. Particularly strong is the change due to external stimuli. In plants, chromatin is reorganized in response to abiotic and biotic stress, which significantly contributes to the adaptation of gene expression. However, how the three-dimensional chromatin structure changes, especially the landscape of chromatin loops, and what role the loop-forming cohesin ring complexes play is not known yet. Early experiments with knockout mutants suggest that certain cohesins do indeed play a surprisingly strong role in responding to external stimuli in Arabidopsis. I intend to investigate the role of tripartite cohesin ring complexes in the formation and regulation of chromatin loops in vegetative plant cells. Here I put forward the hypothesis that cohesin ring complexes are a crucial factor for the plasticity and adaptability of the genome by controlling chromatin loop formation. They may be responsible for the formation and separation of gene clusters, the silencing of genes or the activation of transcription by enhancer elements, which is important to regulate all kinds of cellular processes, of which I am interested in the events that occur in response to abiotic and biotic stress in Arabidopsis.