Seed maturation in Arabidopsis thaliana is characterized by nuclear size reduction and increased chromatin condensation
Seed maturation in Arabidopsis thaliana is characterized by nuclear size reduction and increased chromatin condensation
复制标题
拟南芥种子成熟的特点是核尺寸减小和染色质浓缩增加
DOI：
10.1073/pnas.1117726108
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发表时间：
2011-12-13
影响因子：
11.1
通讯作者：
Soppe, Wim J. J.
中科院分区：
文献类型：
--
作者：
van Zanten, Martijn;Koini, Maria A.;Soppe, Wim J. J.
大多数植物物种依靠种子在不利的环境条件下传播和生存。种子的特点是水分含量低，代谢活动显著减少。在成熟阶段，种子积累贮藏储备，变得耐脱水和休眠。休眠解除和有利的环境条件出现后，恢复生长。在这里，我们发现拟南芥种子的胚胎子叶核的核尺寸显著减小，这是在种子成熟开始时建立的。此外，成熟种子的胚性子叶核染色质高度浓缩。在萌发过程中，细胞核恢复其大小和染色质凝聚水平。核大小的减小是由种子成熟调节因子脱落酸不敏感3控制的，而在萌发过程中的增大需要两种预测的核基质蛋白，小核1和小核2。我们的结果表明，成熟种子的核的特殊性质是对干燥的适应，与休眠无关。我们的结论是，种子中核大小和染色质凝聚的变化是独立的、发育控制的过程。
Most plant species rely on seeds for their dispersal and survival under unfavorable environmental conditions. Seeds are characterized by their low moisture content and significantly reduced metabolic activities. During the maturation phase, seeds accumulate storage reserves and become desiccation-tolerant and dormant. Growth is resumed after release of dormancy and the occurrence of favorable environmental conditions. Here we show that embryonic cotyledon nuclei of Arabidopsis thaliana seeds have a significantly reduced nuclear size, which is established at the beginning of seed maturation. In addition, the chromatin of embryonic cotyledon nuclei from mature seeds is highly condensed. Nuclei regain their size and chromatin condensation level during germination. The reduction in nuclear size is controlled by the seed maturation regulator ABSCISIC ACID-INSENSITIVE 3, and the increase during germination requires two predicted nuclear matrix proteins, LITTLE NUCLEI 1 and LITTLE NUCLEI 2. Our results suggest that the specific properties of nuclei in ripe seeds are an adaptation to desiccation, independent of dormancy. We conclude that the changes in nuclear size and chromatin condensation in seeds are independent, developmentally controlled processes.