Morphogenesis of maize embryos requires ZmPRPL35-1 encoding a plastid ribosomal protein
Morphogenesis of maize embryos requires ZmPRPL35-1 encoding a plastid ribosomal protein
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DOI：
10.1104/pp.103.030767
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发表时间：
2004-02-01
期刊：
影响因子：
7.4
通讯作者：
Rogowsky, PM
中科院分区：
文献类型：
--
作者：
Magnard, JL;Heckel, T;Rogowsky, PM
在玉米（Zea mays）的胚特异性突变体中，两种受精产物具有相反的命运：尽管胚乳发育正常，但胚在其发育中表现出或多或少的严重畸变，导致不能存活的种子。我们在这里表明，在突变体emb 8516，突变胚胎的发展偏离尽快从野生型兄弟姐妹的过渡阶段。模式形成的基本事件发生，因为突变胚显示顶基极性和分化的原胚层。然而，形态发生是强烈异常的。年轻的突变体胚胎的特点是在他们的悬浮体状末端突起，最终导致不规则形状和可变大小的结构。缺乏一个盾或胚芽鞘证明在胚胎适当的极端形态发生的虚拟缺乏。基于突变表型和MuDR元件插入之间的共分离实现突变的分子克隆。Mu插入位于基因ZmPRPL 35 -1中，可能编码质体核糖体大亚基的蛋白质L35。第二等位基因g2422的分离和突变体emb 8516与ZmPRPL 35 -1的基因组克隆的互补证实了ZmPRPL 35 -1中的损伤引起emb表型。ZmPRPL 35 -1是存在于染色体臂61和9 L上的两个基因座上的低拷贝基因。该基因在野生型玉米植物的所有主要组织中组成型表达。在emb/emb胚乳中缺乏表达表明胚乳发育不需要ZmPRPL 35 -1的功能性拷贝，并表明质体和胚胎特异性信号事件之间的联系。
In emb (embryo specific) mutants of maize (Zea mays), the two fertilization products have opposite fates: Although the endosperm develops normally, the embryo shows more or less severe aberrations in its development, resulting in nonviable seed. We show here that in mutant emb8516, the development of mutant embryos deviates as soon as the transition stage from that of wild-type siblings. The basic events of pattern formation take place because mutant embryos display an apical-basal polarity and differentiate a protoderm. However, morphogenesis is strongly aberrant. Young mutant embryos are characterized by protuberances at their suspensor-like extremity, leading eventually to structures of irregular shape and variable size. The lack of a scutellum or coleoptile attest to the virtual absence of morphogenesis at the embryo proper-like extremity. Molecular cloning of the mutation was achieved based on cosegregation between the mutant phenotype and the insertion of a MuDR element. The Mu insertion is located in gene ZmPRPL35-1, likely coding for protein L35 of the large subunit of plastid ribosomes. The isolation of a second allele g2422 and the complementation of mutant emb8516 with a genomic clone of ZmPRPL35-1 confirm that a lesion in ZmPRPL35-1 causes the emb phenotype. ZmPRPL35-1 is a low-copy gene present at two loci on chromosome arms 61, and 9L. The gene is constitutively expressed in all major tissues of wild-type maize plants. Lack of expression in emb/emb endosperm shows that endosperm development does not require a functional copy of ZmPRPL35-1 and suggests a link between plastids and embryo-specific signaling events.