The GURKE gene encoding an acetyl-CoA carboxylase is required for partitioning the embryo apex into three subregions in Arabidopsis
The GURKE gene encoding an acetyl-CoA carboxylase is required for partitioning the embryo apex into three subregions in Arabidopsis
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DOI：
10.1093/pcp/pch148
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发表时间：
2004-09-01
影响因子：
4.9
通讯作者：
Tasaka, M
中科院分区：
文献类型：
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作者：
Kajiwara, T;Furutani, M;Tasaka, M
在拟南芥中，球形胚的顶端形成了三个主要区域，即子叶边界和茎顶端分生组织（SAM），它们最终发育成两片子叶。为了揭示这种模式形成的分子机制，我们从EMS诱变株系中分离出一个子叶缺陷突变体。这种突变体在最严重的情况下完全缺乏子叶，并且与先前报道的胚胎顶端图案缺陷的突变体gurke（gk）等位。为了评估GK基因突变的形态学效应，我们研究了分别作为SAM、子叶和子叶边界的标记物的芽无分生组织（STM）、AINTEGUMENTA（ANT）和杯形子叶1（CUC1）的GK胚胎中的表达模式。所有这些基因的表达在gk中大部分重叠，表明未能将胚胎的顶端划分为三个亚区。还观察到CUC1表达结构域的封闭，并可以解释gk中子叶发育的抑制。此外，我们克隆了GK基因，并证实它编码ACC1，一种催化丙二酰辅酶A合成的乙酰辅酶A羧化酶。我们的研究结果表明，衍生自丙二酰辅酶A的代谢产物是必需的胚胎的顶端部分的分区。
In Arabidopsis, three major regions, which ultimately develop into the two cotyledons, the cotyledon boundaries and the shoot apical meristem (SAM), are formed at the apex of the globular stage embryo. To reveal the molecular mechanism underlying this pattern formation, we isolated a cotyledon-defective mutant from EMS mutagenized lines. This mutant completely lacks cotyledons in the most severe cases, and is allelic to gurke (gk), which was previously reported as a mutant defective in apical patterning of the embryo. To evaluate the morphological effects of the mutation in the GK gene, we investigated the expression patterns in gk embryos of SHOOT MERISTEMLESS (STM), AINTEGUMENTA (ANT) and CUP-SHAPED COTYLEDON1 (CUC1), which are markers of the SAM, cotyledons and cotyledon boundaries, respectively. Expression of all these genes largely overlapped in gk, suggesting a failure to partition the apex of the embryo into the three subregions. Enlargement of the CUC1 expression domain was also observed and may explain the inhibition of cotyledon development in gk. Moreover, we cloned the GK gene, and confirmed that it encodes ACC1, an acetyl-CoA carboxylase which catalyzes malonyl-CoA synthesis. Our results suggest that metabolites derived from malonyl-CoA are required for partitioning of the apical part of the embryo.