Induction of leaves directly from leaves in the maize mutant Lax midrib1-O.
Induction of leaves directly from leaves in the maize mutant Lax midrib1-O.
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直接从玉米突变体 Lax midrib1-O 的叶子诱导叶子。
DOI：
10.1006/dbio.1997.8579
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Freeling,M
中科院分区：
文献类型：
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作者：
Schichnes,D;Schneeberger,R;Freeling,M
玉米显性突变Lax midrib1-O （3L上的Lxm1-O）所指定的几个表型之一是叶片“瓣”的增殖，通常在叶片背面的叶脉周围配对。通过组织学和扫描电镜，我们发现这些皮瓣是真实的叶片结构；在罕见的情况下，发现完整的异位叶。叶瓣出现前的第一次分裂发生在质体期4和质体期7之间，此时叶片分化过程正在进行中。在皮瓣起始部位未见分生组织或任何小的、致密的细胞质原基样细胞的迹象。此外，异位叶起始位点不表达KNOX （knotting -like homeobox）蛋白，这是茎尖分生组织细胞身份的分子标记。因此，增殖成异位叶的细胞不是由分生组织或原基产生的。类似的现象在几个单子叶中有描述，但在其他单子叶中没有。皮瓣形态的细节与叶体形态的比较表明，叶体区域的细胞维持了它们在分生组织中获得的能力。然后，这些细胞以一种被调节的方式，对从静脉发出的延迟信号做出适当的反应，该信号表示“制造你有能力制造的器官”。
One of the several phenes specified by the maize dominant mutation Lax midrib1-O (Lxm1-O on 3L) is the proliferation of leaf “flaps” usually paired around veins on the abaxial leaf surface. Using histology and scanning electron microscopy, we show these flaps to be authentic leaf structures; in rare instances, complete ectopic leaves are found. The first divisions preceding flap emergence occur between plastochrons 4 and 7, stages when the course of leaf differentiation is well under way. No sign of meristem or any small, densely cytoplasmic primordium-like cells were seen at the sites of flap initiation. In addition, the sites of ectopic leaf initiation do not express KNOX (Knotted-like homeobox) proteins, a molecular marker for shoot apical meristem cell identity. Thus, the cells that proliferate into ectopic leaves do not arise from a meristem or a primordium. A similar phenomenon has been described in several dicots, but in no other monocots. The details of flap morphology compared to the morphology of the leaf proper suggest a model whereby cells in regions of the leaf proper maintain the competence they acquired in the meristem. These cells then respond properly, in a regulated manner, to a delayed signal emanating from veins denoting “make the organ you are competent to make.”