Summary Arabidopsis lamin analogs CROWDED NUCLEIs (CRWNs) are necessary to maintain nuclear structure, genome function, and proper plant growth. However, whether and how CRWNs impact reproduction and genome‐wide epigenetic modifications is unknown. Here, we investigate the role of CRWNs during the development of gametophytes, seeds, and endosperm, using genomic and epigenomic profiling methods. We observed defects in crwn mutant seeds including seed abortion and reduced germination rate. Quadruple crwn null genotypes were rarely transmitted through gametophytes. Because defects in seeds often stem from abnormal endosperm development, we focused on crwn1 crwn2 (crwn1/2) endosperm. These mutant seeds exhibited enlarged chalazal endosperm cysts and increased expression of stress‐related genes and the MADS‐box transcription factor PHERES1 and its targets. Previously, it was shown that PHERES1 expression is regulated by H3K27me3 and that CRWN1 interacts with the PRC2 interactor PWO1. Thus, we tested whether crwn1/2 alters H3K27me3 patterns. We observed a mild loss of H3K27me3 at several hundred loci, which differed between endosperm and leaves. These data indicate that CRWNs are necessary to maintain the H3K27me3 landscape, with tissue‐specific chromatin and transcriptional consequences.

中文翻译：

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CRWN 核纤层组件维持 H3K27me3 景观并促进拟南芥成功繁殖

概括 拟南芥核纤层蛋白类似物 CROWDED NUCLEI (CRWN) 对于维持核结构、基因组功能和正常植物生长是必需的。然而，CRWN 是否以及如何影响生殖和全基因组表观遗传修饰尚不清楚。在这里，我们使用基因组和表观基因组分析方法研究了 CRWN 在配子体、种子和胚乳发育过程中的作用。 我们观察到缺陷皇冠突变种子包括种子败育和发芽率降低。四人间皇冠无效基因型很少通过配子体传播。由于种子缺陷通常源于胚乳发育异常，因此我们重点关注crwn1 crwn2（皇冠1/2）胚乳。这些突变种子表现出合点胚乳囊肿增大以及胁迫相关基因和 MADS-box 转录因子表达增加菲勒斯1及其目标。 此前，已经表明菲勒斯1表达受 H3K27me3 调节，CRWN1 与 PRC2 相互作用子 PWO1 相互作用。因此，我们测试了是否皇冠1/2改变 H3K27me3 模式。我们在数百个位点观察到 H3K27me3 的轻度丢失，这在胚乳和叶子之间有所不同。 这些数据表明，CRWN 对于维持 H3K27me3 景观是必要的，具有组织特异性染色质和转录后果。