Root Type-specific Establishment of Postembryonic Stem Cell Niches during Maize Lateral Root Formation

玉米侧根形成过程中胚胎后干细胞生态位的根型特异性建立

• 批准号: 467842672
• 负责人: Professor Dr. Frank Hochholdinger
• 金额: --
• 依托单位: Lehrstuhl für Crop Functional Genomics
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/467842672?language=en
• 关键词: Root; Type; specific; Establishment; Postembryonic

Lateral roots are established from pericycle stem cell niches of other roots. In maize, phloem pole pericycle cells give rise to lateral roots, while in Arabidopsis lateral roots emerge from xylem pole pericycle cells. Maize forms different root types at different stages of development. Root type-specific developmental control of lateral root formation in maize is demonstrated, for example, by the mutant rootless with undetectable meristem 1 (rum1), which does not form lateral roots in the primary root, while lateral root formation in the shoot-borne root-system is not affected.The overreaching hypothesis of this project is that the establishment of lateral root stem cell niches involves conserved and distinct players in the different root types of maize. In this project, we will (i) study the cellular organization of lateral root stem cell niches in the different main root types of maize during early development. Moreover, we will (ii) elucidate the plasticity of gene expression networks in phloem and xylem pole pericycle cells during early stem cell niche establishment in the main maize root types of wild-type and the mutant rum1. This will be achieved by a combination of laser capture microdissection (LCM) of these cells in combination with RNA-seq. Subsequently, we will analyze the regulation of the transcriptomic landscape of these cell types with respect to developmental stage, genotype and root type. Finally, we aim to (iii) identify and characterize novel root type-specific genetic regulators of lateral root stem cell niche establishment. To this end we will characterize mutants of candidate genes identified in the RNAseq experiment via our reverse genetic mutant repository which covers ca. 60% of all maize genes. Novel lateral root mutants identified in our collection will be further characterized to better understand the molecular framework underlying root type-specific regulation of lateral root stem cell niche establishment.

侧根由其他根的中柱鞘干细胞龛建立。在玉米中，韧皮部极周壁细胞产生侧根，而在拟南芥中侧根从木质部极周壁细胞出现。玉米在不同发育阶段形成不同的根型。玉米中侧根形成的根类型特异性发育控制例如通过具有不可检测分生组织的无根突变体1（rum 1）证明，其在主根中不形成侧根，而侧根的形成主要发生在茎生根-该项目的过度假设是，侧根干细胞小生境的建立涉及保守和独特的参与者，玉米的不同根系类型。在本项目中，我们将（i）研究玉米不同主根类型发育早期侧根干细胞微位的细胞组织。此外，我们将（ii）阐明基因表达网络的可塑性在韧皮部和木质部极周细胞在早期干细胞生态位建立在主要玉米根类型的野生型和突变体rum 1。这将通过这些细胞的激光捕获显微切割（LCM）与RNA-seq的组合来实现。随后，我们将分析这些细胞类型的转录组景观与发育阶段，基因型和根类型的调节。最后，我们的目标是（iii）确定和表征新的根类型特异性侧根干细胞生态位建立的遗传调节因子。为此，我们将通过我们的反向遗传突变库来表征在RNAseq实验中鉴定的候选基因的突变体，该库涵盖了约100个基因。60%的玉米基因。在我们的集合中确定的新的侧根突变体将被进一步表征，以更好地理解侧根干细胞生态位建立的根类型特异性调节的分子框架。