Arabidopsis MSI1 is a component of the MEA/FIE Polycomb group complex and required for seed development
Arabidopsis MSI1 is a component of the MEA/FIE Polycomb group complex and required for seed development
复制标题
DOI：
10.1093/emboj/cdg444
复制
发表时间：
2003-09-15
期刊：
影响因子：
11.4
通讯作者：
Gruissem, W
中科院分区：
文献类型：
--
作者：
Köhler, C;Hennig, L;Gruissem, W
被子植物的种子发育始于双受精，导致二倍体胚和三倍体胚乳的形成。在没有受精的情况下，对种子发育的某些方面的早熟起始的主动抑制需要Polycomb组蛋白MEDEA（MEA）、非受精性胚乳（FIE）和非受精性种子2。在这里，我们表明，拟南芥WD-40域蛋白MSI1是目前一起与MEA和FIE在一个600 kDa的复合物，并直接与FIE相互作用。msi1杂合突变体植物显示种子败育率为50%，当突变等位基因是母系遗传时，种子败育，而不管父系野生型或突变型MSI1等位基因。此外，msi1突变体配子体在不受精的情况下以较高的启动率启动胚乳发育。授粉后，只有卵细胞受精，中央细胞在受精前开始分裂，导致形成含有胚的种子，胚被二倍体胚乳包围。我们的研究结果表明，MSI1在种子发育的正确启动和进行中具有重要的功能。
Seed development in angiosperms initiates after double fertilization, leading to the formation of a diploid embryo and a triploid endosperm. The active repression of precocious initiation of certain aspects of seed development in the absence of fertilization requires the Polycomb group proteins MEDEA (MEA), FERTILIZATION-INDEPENDENT ENDOSPERM (FIE) and FERTILIZATION-INDEPENDENT SEED2. Here we show that the Arabidopsis WD-40 domain protein MSI1 is present together with MEA and FIE in a 600 kDa complex and interacts directly with FIE. Mutant plants heterozygous for msi1 show a seed abortion ratio of 50% with seeds aborting when the mutant allele is maternally inherited, irrespective of a paternal wild-type or mutant MSI1 allele. Further more, msi1 mutant gametophytes initiate endosperm development in the absence of fertilization at a high penetrance. After pollination, only the egg cell becomes fertilized, the central cell starts dividing prior to fertilization, resulting in the formation of seeds containing embryos surrounded by diploid endosperm. Our results establish that MSI1 has an essential function in the correct initiation and progression of seed development.