AGL23, a type I MADS-box gene that controls female gametophyte and embryo development in Arabidopsis
AGL23, a type I MADS-box gene that controls female gametophyte and embryo development in Arabidopsis
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DOI：
10.1111/j.1365-313x.2008.03485.x
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发表时间：
2008-06-01
期刊：
影响因子：
7.2
通讯作者：
Colombo, Lucia
中科院分区：
文献类型：
--
作者：
Colombo, Monica;Masiero, Simona;Colombo, Lucia
MADS-box转录因子是植物发育过程中的关键调控因子。虽然MIKC(类型II)MADS-box基因的功能已经得到了深入的研究，但关于其他新发现的MADS-box基因类别的数据有限，尽管后者占拟南芥MADS-box基因家族的60%以上。在这里，我们描述了AGL23的功能，这是一个属于Mα亚家族的拟南芥I型MADS-box基因。我们发现AGL23在雌配子体和胚胎的发育过程中起着重要的作用。Agl23-1突变体形成一个功能性大孢子。然而，在这个阶段，雌配子体发育停止，大孢子在胚珠发育的后续阶段持续存在。尽管雌配子体缺陷的外显性不完全，但agl23-1突变的纯合植物从未被鉴定出来。对发育中的种子的分析表明，agl23-1等位基因纯合的胚胎是白化的，不能产生可存活的植株。电子显微镜分析表明，这种表型是由于缺乏叶绿体所致，这有力地表明AGL23参与了胚胎发育过程中细胞器的生物发生。
MADS-box transcription factors are key regulators of plant developmental processes. While the function of MIKC (type II) MADS-box genes has been intensively studied, only limited data are available for the other more recently identified classes of MADS-box genes, despite these latter comprising more than 60% of the Arabidopsis MADS-box gene family. Here we describe the function of AGL23, an Arabidopsis type I MADS-box gene belonging to the M alpha subfamily. We show that AGL23 plays an important role during development of the female gametophyte and embryo. The agl23-1 mutant forms a functional megaspore. However, at this stage female gametophyte development is arrested and the megaspore persists during subsequent phases of ovule development. Despite the incomplete penetrance of the female gametophyte defect, plants homozygous for the agl23-1 mutation were never identified. Analysis of developing seeds showed that embryos homozygous for the agl23-1 allele are albino and unable to give rise to viable plants. Electron microscopy analysis revealed that this phenotype is due to the absence of chloroplasts, strongly suggesting that AGL23 is involved in controlling the biogenesis of organelles during embryo development.