Jarillo José A, Piñeiro Manuel, Cubas Pilar, Martínez-Zapater José M
Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)- Centro de Biotecnologíay Genómica de Plantas (UPM-INIA), Spain.
Int J Dev Biol. 2009;53(8-10):1581-96. doi: 10.1387/ijdb.072460jj.
Plant development results from specific patterns of gene expression that are tightly regulated in a spatio-temporal manner. Chromatin remodeling plays a central role in establishing these expression patterns and maintaining epigenetic transcriptional states through successive rounds of mitosis that take place within a cell lineage. Plant epigenetic switches occur not only at the embryo stage, but also during postembryonic developmental transitions, suggesting that chromatin remodeling activities in plants can provide a higher degree of regulatory flexibility which probably underlies their developmental plasticity. Here, we highlight recent progress in the understanding of plant chromatin dynamic organization, facilitating the activation or repression of specific sets of genes involved in different developmental programs and integrating them with the response to environmental signals. Chromatin conformation controls gene expression both in actively dividing undifferentiated cells and in those already fate-determined. In this context, we first describe chromatin reorganization activities required to maintain meristem function stable through DNA replication and cell division. Organ initiation at the apex, with emphasis on reproductive development, is next discussed to uncover the chromatin events involved in the establishment and maintenance of expression patterns associated with differentiating cells; this is illustrated with the complex epigenetic regulation of the Arabidopsis floral repressor FLOWERING LOCUS C (FLC). Finally, we discuss the involvement of chromatin remodeling in plant responses to environmental cues and to different types of stress conditions.
植物发育源于基因表达的特定模式，这些模式在时空上受到严格调控。染色质重塑在建立这些表达模式以及通过细胞谱系中连续的有丝分裂轮次维持表观遗传转录状态方面发挥着核心作用。植物表观遗传开关不仅发生在胚胎阶段，也发生在胚胎后发育转变过程中，这表明植物中的染色质重塑活动可以提供更高程度的调控灵活性，这可能是其发育可塑性的基础。在这里，我们重点介绍了在理解植物染色质动态组织方面的最新进展，这有助于激活或抑制参与不同发育程序的特定基因集，并将它们与对环境信号的响应整合起来。染色质构象在活跃分裂的未分化细胞和那些已经确定命运的细胞中都控制着基因表达。在这种背景下，我们首先描述了通过DNA复制和细胞分裂维持分生组织功能稳定所需的染色质重组活动。接下来讨论顶端器官的起始，重点是生殖发育，以揭示参与分化细胞相关表达模式建立和维持的染色质事件；这以拟南芥花抑制因子开花位点C（FLC）的复杂表观遗传调控为例进行说明。最后，我们讨论染色质重塑在植物对环境线索和不同类型胁迫条件的响应中的作用。
