Chromatin regulatory mechanisms of stress tolerance in cereals

作为固着生物的植物暴露在各种环境胁迫下，它们为了生存而对环境做出了无数的适应性反应。干旱、盐度、光照或极端温度等逆境条件一直是密集研究的主题，迅速积累的数据表明，它们调节着多个基因的表达。在过去的二十年中，基因转录受到染色质的调控，涉及DNA甲基化、组蛋白修饰和染色质重塑等调控过程。这些染色质变化的建立，贯穿于特定修饰物的作用，通过将局部染色质状态调节为“开放”(转录活性)或“关闭”(转录抑制)配置，改变了基因对转录调控蛋白的可及性。到目前为止，在植物中只发现了胁迫反应的调节和染色质动态之间的少数联系。因此，我们研究计划的长期目标是了解控制谷物非生物胁迫耐受性的染色质调节机制。为了实现这一目标，我们将：1)评估短柄短柱藻的抗寒性；2)确定短柱柄在冷锻炼过程中的表观遗传标记的景观；3)鉴定和表征调节短柱柄对低温响应的染色质修饰物。阐明像谷物这样的复杂系统中的染色质调节机制将对农业产生深远的影响。开发的知识库将使多基因性状的直接操作，如抗逆性，服从于作物和牲畜的育种计划。这些战略将为应对气候变化以及不断增长的人口对粮食和能源需求的日益增长的全球挑战提供实用工具。

Plants being sessile organisms are exposed to various environmental stresses, to which they react with a myriad of adaptive responses in order to survive. Stress conditions such as drought, salinity, light or extreme temperatures have been the subject of intense research, and rapidly accumulating data demonstrated that they regulate the expression of multiple genes. During the last two decades, it has become clear that gene transcription is under chromatin-mediated control, involving regulation processes such as DNA methylation, histone modifications, and chromatin remodeling. The establishment of these chromatin changes, throughout the action of specialized modifiers, alters the accessibility of genes to transcriptional regulatory proteins by modulating the local chromatin state to either an "open" (transcriptionally active) or "closed" (transcriptionally repressed) configuration. To date, only a few links between the regulation of stress response and chromatin dynamics have been identified in plants. Therefore, the long-term goal of our research program is to understand the chromatin regulatory mechanisms controlling abiotic stress tolerance in cereals. To achieve this goal, we will: 1) evaluate the cold hardiness of Brachypodium distachyon; 2) determine the landscape of epigenetic marks during cold hardening in Brachypodium; 3) identify and characterize chromatin modifiers modulating the response to low temperature in Brachypodium. The elucidation of chromatin-regulatory mechanisms in a complex system like cereals will have far-reaching implications for agriculture. The developed knowledge base will make the direct manipulation of multigenic traits such as stress tolerance amenable to breeding programs of crops and livestock. These strategies will provide practical tools for addressing the global challenges of changing climate and ever-increasing food and energy demands of a growing human population.