Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot.
Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot.
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发表时间：
2000-02
期刊：
影响因子：
4.6
通讯作者：
J. Wysocka-Diller;Y. Helariutta;H. Fukaki;J. Malamy;P. Benfey
中科院分区：
文献类型：
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作者：
J. Wysocka-Diller;Y. Helariutta;H. Fukaki;J. Malamy;P. Benfey
SCARECROW (SCR) 基因的突变会导致根部出现放射状图案缺陷，即地面组织层的损失。对 scr 突变体芽表型的分析表明，下胚轴和芽花序也具有放射状图案缺陷，失去正常的淀粉鞘层，因此无法感知芽中的重力。与其在根内皮层中的表达类似，SCR 在下胚轴和花序茎的淀粉鞘中表达。叶束鞘细胞和根静止中心细胞中的 SCR 表达模式导致这些组织中其他表型缺陷的鉴定。针状突变体背景中的 SCR 表达表明芽花序中淀粉鞘的可能起源。对胚胎发生最早阶段的 SCR 表达和突变表型的分析揭示了细胞分裂缺陷和细胞中 SCR 表达之间的密切相关性，这些细胞有助于胚胎根和芽中的基础组织放射状图案。我们的数据提供的证据表明，在胚胎发生期间以及胚胎后，相同的分子机制调节根和芽中地面组织的径向图案。
Mutation of the SCARECROW (SCR) gene results in a radial pattern defect, loss of a ground tissue layer, in the root. Analysis of the shoot phenotype of scr mutants revealed that both hypocotyl and shoot inflorescence also have a radial pattern defect, loss of a normal starch sheath layer, and consequently are unable to sense gravity in the shoot. Analogous to its expression in the endodermis of the root, SCR is expressed in the starch sheath of the hypocotyl and inflorescence stem. The SCR expression pattern in leaf bundle sheath cells and root quiescent center cells led to the identification of additional phenotypic defects in these tissues. SCR expression in a pin-formed mutant background suggested the possible origins of the starch sheath in the shoot inflorescence. Analysis of SCR expression and the mutant phenotype from the earliest stages of embryogenesis revealed a tight correlation between defective cell divisions and SCR expression in cells that contribute to ground tissue radial patterning in both embryonic root and shoot. Our data provides evidence that the same molecular mechanism regulates the radial patterning of ground tissue in both root and shoot during embryogenesis as well as postembryonically.