A mutation that allows endosperm development without fertilization
A mutation that allows endosperm development without fertilization
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DOI：
10.1073/pnas.93.11.5319
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发表时间：
1996-05-28
影响因子：
11.1
通讯作者：
Fischer, RL
中科院分区：
文献类型：
--
作者：
Ohad, N;Margossian, L;Fischer, RL
受精后启动生殖发育的机制尚不清楚。高等植物的生殖是独特的，因为它是由单倍体雌配子体中的两次受精事件启动的。一个精核使卵子受精形成胚胎。第二个精核使中央细胞受精，形成胚乳，这是一种支持胚胎生长的独特组织。受精也激活母体组织分化，胚珠珠被形成种皮，子房形成果实。为了研究启动生殖发育的机制，在拟南芥中分离出了一种称为fie（不依赖受精的胚乳）的雌性配子体突变。fie突变特异性地影响中央细胞，允许中央细胞核的复制和胚乳发育而不受精。fie突变似乎不影响卵细胞，这表明控制胚胎发生和胚乳发育的起始过程是不同的。FIE/fie种皮和果实经历不依赖受精的分化，这表明fie雌配子体是激活孢子体果实和种皮发育的信号源。突变的fie等位基因不是由雌配子体传递的。雌配子体对突变体fie等位基因的遗传导致胚败育，即使花粉携带野生型FIE等位基因。因此，FIE为女性生殖发育发挥了一种新的基本功能。
The mechanisms that initiate reproductive development after fertilization are not understood. Reproduction in higher plants is unique because it is initiated by two fertilization events in the haploid female gametophyte. One sperm nucleus fertilizes the egg to form the embryo. A second sperm nucleus fertilizes the central cell to form the endosperm, a unique tissue that supports the growth of the embryo. Fertilization also activates maternal tissue differentiation, the ovule integuments form the seed coat, and the ovary forms the fruit. To investigate mechanisms that initiate reproductive development, a female-gametophytic mutation termed fie (fertilization-independent endosperm) has been isolated in Arabidopsis. The fie mutation specifically affects the central cell, allowing for replication of the central cell nucleus and endosperm development without fertilization. The fie mutation does not appear to affect the egg cell, suggesting that the processes that control the initiation of embryogenesis and endosperm development are different. FIE/fie seed coat and fruit undergo fertilization-independent differentiation, which shows that the fie female gametophyte is the source of signals that activates sporophytic fruit and seed coat development. The mutant fie allele is not transmitted by the female gametophyte. Inheritance of the mutant fie allele by the female gametophyte results in embryo abortion, even when the pollen bears the wild-type FIE allele. Thus, FIE carries out a novel, essential function for female reproductive development.