The onset of embryo maturation in Arabidopsis is determined by its developmental stage and does not depend on endosperm cellularization
The onset of embryo maturation in Arabidopsis is determined by its developmental stage and does not depend on endosperm cellularization
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DOI：
10.1111/tpj.14324
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发表时间：
2019-07-01
期刊：
影响因子：
7.2
通讯作者：
Jenik, Pablo D.
中科院分区：
文献类型：
--
作者：
O'Neill, John P.;Colon, Kristen T.;Jenik, Pablo D.
种子是休眠和干燥的结构，充满了发芽后使用的存储产品。这些特性是由成熟程序决定的，在拟南芥中，成熟程序开始于胚胎发生中期，在果实中所有种子的大约相同的时间和发育阶段。这两个因素，时间顺序和发育时间，在种子发育过程中密切相关，所以他们的相对贡献的过渡到成熟还没有得到很好的理解。目前还不清楚这种转变是由每颗种子自主决定的，还是取决于果实发出的信号。胚乳细胞化后开始成熟，有人提出这两个过程之间存在因果关系。我们通过分析拟南芥突变种子中的成熟标记来探索所有这些问题，这些突变种子以较慢的速度发育，或者胚乳细胞化发生得太早，太迟或根本没有。我们的数据表明，胚胎的发育阶段是成熟开始的关键决定因素，并且每个种子自主地进行过渡。我们还发现，与以前的模型相比，胚乳细胞化是不需要的成熟的开始，这表明这种过渡是独立的己糖/蔗糖在种子中的比例。我们的观察表明，控制胚乳细胞化，胚生长和胚成熟的机制相互独立地起作用。重要性声明发育过程可以受到时间（实足年龄）或阶段顺序的影响。它们也可以由非自主信令触发。我们证明，在拟南芥种子成熟的发病是由胚胎发育阶段，自主地由每个种子，这是独立的胚乳细胞化。
Seeds are dormant and desiccated structures, filled with storage products to be used after germination. These properties are determined by the maturation program, which starts, in Arabidopsis thaliana, mid-embryogenesis, at about the same time and developmental stage in all the seeds in a fruit. The two factors, chronological and developmental time, are closely entangled during seed development, so their relative contribution to the transition to maturation is not well understood. It is also unclear whether that transition is determined autonomously by each seed or whether it depends on signals from the fruit. The onset of maturation follows the cellularization of the endosperm, and it has been proposed that there exists a causal relationship between both processes. We explored all these issues by analyzing markers for maturation in Arabidopsis mutant seeds that develop at a slower pace, or where endosperm cellularization happens too early, too late, or not at all. Our data show that the developmental stage of the embryo is the key determinant of the initiation of maturation, and that each seed makes that transition autonomously. We also found that, in contrast with previous models, endosperm cellularization is not required for the onset of maturation, suggesting that this transition is independent of the hexose/sucrose ratio in the seed. Our observations indicate that the mechanisms that control endosperm cellularization, embryo growth, and embryo maturation act independently of each other.Significance Statement Developmental processes can be influenced by the passage of time (chronological age) or by the sequence of stages. They can also be triggered by non-autonomous signaling. We demonstrate that the onset of seed maturation in Arabidopsis is determined by the embryo developmental stage, autonomously by each seed, and that is independent from the cellularization of the endosperm.