Napsucialy-Mendivil Selene, Dubrovsky Joseph G
Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico.
Methods Mol Biol. 2018;1761:47-75. doi: 10.1007/978-1-4939-7747-5_4.
Root system formation to a great extent depends on lateral root (LR) formation. In Arabidopsis thaliana, LRs are initiated within a parent root in pericycle that is an external tissue of the stele. LR initiation takes place in a strictly acropetal pattern, whereas posterior lateral root primordium (LRP) formation is asynchronous. In this chapter, we focus on methods of genetic and phenotypic analysis of LR initiation, LRP morphogenesis, and LR emergence in Arabidopsis. We provide details on how to make cleared root preparations and how to identify the LRP stages. We also pay attention to the categorization of the LRP developmental stages and their variations and to the normalization of the number of LRs and LRPs formed, per length of the primary root, and per number of cells produced within a root. Hormonal misbalances and mutations affect LRP morphogenesis significantly, and the evaluation of LRP abnormalities is addressed as well. Finally, we deal with various molecular markers that can be used for genetic and phenotypic analyses of LR development.
根系形成在很大程度上取决于侧根（LR）的形成。在拟南芥中，侧根在中柱外部组织——中柱鞘的母根内起始。侧根起始以严格的向顶模式发生，而后侧根原基（LRP）的形成是异步的。在本章中，我们重点介绍拟南芥中侧根起始、侧根原基形态发生和侧根出现的遗传和表型分析方法。我们详细介绍了如何制作透明根标本以及如何识别侧根原基阶段。我们还关注侧根原基发育阶段的分类及其变化，以及每单位主根长度、每单位根内产生的细胞数所形成的侧根和侧根原基数量的标准化。激素失衡和突变会显著影响侧根原基的形态发生，同时也涉及对侧根原基异常的评估。最后，我们讨论了可用于侧根发育遗传和表型分析的各种分子标记。
