Maternal Control of Nutrient Allocation in Plant Seeds by Genomic Imprinting
Maternal Control of Nutrient Allocation in Plant Seeds by Genomic Imprinting
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DOI：
10.1016/j.cub.2012.10.012
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发表时间：
2012-10
期刊：
影响因子：
9.2
通讯作者：
Liliana M. Costa;Jing Yuan;J. Rouster;W. Paul;H. Dickinson;J. Gutierrez-Marcos
中科院分区：
文献类型：
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作者：
Liliana M. Costa;Jing Yuan;J. Rouster;W. Paul;H. Dickinson;J. Gutierrez-Marcos
印记基因通常在哺乳动物胎盘和植物种子胚乳中表达，在那里它们表现出偏好的单亲等位基因表达。在哺乳动物中，印记基因直接调节胎盘功能和从母亲到胎儿的营养分配[1-4];然而，迄今为止在植物中报道的超过60个印记基因中没有一个被证明在调节资源流向胚胎方面发挥同等作用[5-7]。在这里，我们证明了玉米中的imprintedMaternally expressed gene 1（Meg 1）[8]对于位于母体：种子界面的胚乳营养传递细胞的建立和分化是必要的和充分的。与这些研究结果一致，Meg 1也调节母体营养吸收，蔗糖分配和种子生物量产量。此外，我们生成了一个印记和非印记合成Meg 1（synMeg 1）剂量系列，其中剂量的增加和印记的缺乏都导致母体资源对胚乳的不平等投资。这些研究结果强调剂量调控基因组印记是至关重要的保持平衡分配的母体营养物质的子代组织在植物中，在哺乳动物。然而，与哺乳动物不同的是，Meg 1是一种母系表达的印记基因，它令人惊讶地促进而不是限制后代的营养分配。
Imprinted genes are commonly expressed in mammalian placentas and in plant seed endosperms, where they exhibit preferential uniparental allelic expression. In mammals, imprinted genes directly regulate placental function and nutrient distribution from mother to fetus [1–4]; however, none of the >60 imprinted genes thus far reported in plants have been demonstrated to play an equivalent role in regulating the flow of resources to the embryo [5–7]. Here we show that imprintedMaternally expressed gene1(Meg1) in maize [8] is both necessary and sufficient for the establishment and differentiation of the endosperm nutrient transfer cells located at the mother:seed interface. Consistent with these findings,Meg1also regulates maternal nutrient uptake, sucrose partitioning, and seed biomass yield. In addition, we generated an imprinted and nonimprinted syntheticMeg1(synMeg1) dosage series whereby increased dosage and absence of imprinting both resulted in an unequal investment of maternal resources into the endosperm. These findings highlight dosage regulation by genomic imprinting as being critical for maintaining a balanced distribution of maternal nutrients to filial tissues in plants, as in mammals. However, unlike in mammals,Meg1is a maternally expressed imprinted gene that surprisingly acts to promote rather than restrict nutrient allocation to the offspring.