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2020年9月21日，中国科学院分子植物科学卓越创新中心/上海植物逆境生物学研究中心何跃辉课题组在Nature Plants发表了题为“Maternal transmission of the epigenetic ‘memory of winter cold’ in Arabidopsis”的研究论文，揭示了长期低温（寒冬）诱导的“春化”状态（或“冬季低温记忆”）通过卵细胞传递给合子和早期胚胎的母系遗传机制。 一些植物可以“记住”过去的环境经验，以适应给定的环境。例如，在经历了冬季(冬季寒冷)的长期低温暴露后，春化反应植物记住了过去春季气温上升时的寒冷经历，以获得在有利于种子生产的较晚季节开花的能力。.在拟南芥中，长期的寒冷通过聚梳组(PcG)染色质修饰剂诱导有效的花抑制因子开花位点C(FLC)的沉默。(2)在拟南芥中，长时间的低温诱导有效的花抑制因子开花位点C(FLC)被聚梳组(PcG)染色质修饰剂沉默。这种多梳抑制的染色质状态在表观遗传上被保持，因此在随后的生长和发育中在返回温暖时被“记忆”。“冬季寒冷的记忆”一直被认为是有丝分裂稳定的，但减数分裂不稳定的是，因此不会在世代之间传递。一般来说，染色质介导的环境记忆是否以及如何在植物中跨代传递尚不清楚。在这里，我们证明了卵细胞在FLC或对冬季寒冷的记忆中保持着冷诱导的多梳抑制染色质状态，这在雌配子形成过程中是减数分裂稳定的，并为这种多梳介导的记忆在精子细胞中不被维持提供了证据。此外，我们还表明，这种冷记忆是母系遗传的，而不是父系遗传给受精卵和早期胚胎的。我们的研究证明并进一步提供了对染色质状态介导的环境记忆在植物中代际传递的机制见解。“环境经历记忆”母系遗传机制的解析对认识植物如何适应环境具有重要的科学意义。 何跃辉课题组的副研究员罗晓、在读博士生藕洋和李人杰为共同第一作者。何跃辉研究员为该论文的通讯作者。该研究得到了国家自然科学基金委和中国科学院相关经费的资助。 图1：染色质状态介导的植物“冬季低温记忆”母系遗传机制 Some plants can ‘remember’ past environmental experience to become adapted to a given environment. For instance, after experiencing prolonged low-temperature exposure in winter (winter cold), vernalization-responsive plants remember past cold experience when temperature rises in spring, to acquire competence to flower at a later season favourable for seed production1,2. In Arabidopsis thaliana, prolonged cold induces silencing of the potent floral repressor FLOWERING LOCUS C (FLC) by Polycomb group (PcG) chromatin modifiers. This Polycomb-repressed chromatin state is epigenetically maintained and thus ‘memorized’ in subsequent growth and development upon return to warmth1,3. ‘Memory of winter cold’ has been viewed as being mitotically stable but meiotically unstable3,4,5, and thus not to be transmitted intergenerationally. In general, whether and how chromatin-mediated environmental memories are transmitted across generations are unknown in plants. Here, we show that the cold-induced Polycomb-repressed chromatin state at FLC or memory of winter cold is maintained in the egg cell, that is meiotically stable in the process of female gamete formation, and provide evidence that this Polycomb-mediated memory is not maintained in the sperm cell. Moreover, we show that this cold memory is inherited maternally but not paternally to the zygote and early embryos. Our study demonstrates and further provides mechanistic insights into intergenerational transmission of chromatin state-mediated environmental memories in plants 来源： Luo, X., Ou, Y., Li, R. et al. Maternal transmission of the epigenetic ‘memory of winter cold’ in Arabidopsis. Nat. Plants (2020). https:///10.1038/s41477-020-00774-0  版权作品，未经PaperRSS书面授权，严禁转载，违者将被追究法律责任。 PaperRSS，关注生命科学，高校院所科研进展。 |
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