Endosperm development: dynamic processes and cellular innovations underlying sibling altruism
Endosperm development: dynamic processes and cellular innovations underlying sibling altruism
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DOI：
10.1002/wdev.31
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发表时间：
2012-07-01
影响因子：
--
通讯作者：
Gutierrez-Marcos, Jose
中科院分区：
文献类型：
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作者：
Becraft, Philip W.;Gutierrez-Marcos, Jose
胚乳是受精的产物，其进化是为了支持和滋养其遗传的双胞胎兄弟胚胎。谷类胚乳中积累了淀粉和蛋白质，这对萌发的幼苗起到了支持作用。这些营养商店促进了谷物的驯化，是目前作物改良和生物技术创新努力的重点。胚乳发育需要对基本细胞和发育过程进行几种新的修饰。谷类显示出核胚乳的发育，这一发育始于一段自由的核分裂时期，以产生核母细胞。在细胞化过程中，细胞骨架排列将细胞核分布在细胞质的周围，并指导随后细胞壁材料的沉积。位置线索和信号系统在四种主要细胞类型的指定中动态发挥作用：转移细胞、胚胎周围细胞、淀粉胚乳(SE)和糊粉。基因组平衡、表观遗传基因调控和亲本起源效应是指导这些过程的关键。转移细胞将包括糖和氨基酸在内的溶质从母体植物组织运输到发育中的谷粒中，在那里它们在胚胎和SE细胞之间分配。胚周围区域的细胞似乎协调着胚和胚乳的发育。随着种子的成熟，SE细胞吸收淀粉和蛋白质储备，经历DNA内复制，最终经历细胞程序性死亡。相反，糊粉细胞遵循与胚胎相似的成熟程序，使它们能够在干燥中存活。在萌发时，糊粉细胞分泌淀粉酶和蛋白酶，这些淀粉酶和蛋白水解酶的储存产物，以滋养萌发的幼苗。(C)2012年威利期刊公司。
The endosperm is a product of fertilization that evolved to support and nourish its genetic twin sibling embryo. Cereal endosperm accumulates starch and protein stores, which later support the germinating seedling. These nutritional stores prompted the domestication of cereals and are the focus of ongoing efforts for crop improvement and biotechnological innovations. Endosperm development entails several novel modifications to basic cellular and developmental processes. Cereals display nuclear endosperm development, which begins with a period of free nuclear division to generate a coenocyte. Cytoskeletal arrays distribute nuclei around the periphery of the cytoplasm and direct the subsequent deposition of cell wall material during cellularization. Positional cues and signaling systems function dynamically in the specification of the four major cell types: transfer cells, embryo-surrounding cells, starchy endosperm (SE), and aleurone. Genome balance, epigenetic gene regulation, and parent-of-origin effects are essential for directing these processes. Transfer cells transport solutes, including sugars and amino acids, from the maternal plant tissues into the developing grain where they are partitioned between embryo and SE cells. Cells of the embryo-surrounding region appear to coordinate development of the embryo and endosperm. As the seed matures, SE cells assimilate starch and protein stores, undergo DNA endoreduplication, and finally undergo programmed cell death. In contrast, aleurone cells follow a maturation program similar to the embryo, allowing them to survive desiccation. At germination, the aleurone cells secrete amylases and proteases that hydrolyze the storage products of the SE to nourish the germinating seedling. (C) 2012 Wiley Periodicals, Inc.