INRES, Institute of Crop Science and Resource Conservation, Crop Functional Genomics, University of Bonn, D-53113 Bonn, Germany.
Department of Statistics, Iowa State University, Ames, IA 50011-1210, USA.
J Exp Bot. 2017 Apr 1;68(9):2175-2185. doi: 10.1093/jxb/erx104.
Root hairs are tubular extensions of epidermis cells. Transcriptome profiling demonstrated that the single cell-type root hair transcriptome was less complex than the transcriptome of multiple cell-type primary roots without root hairs. In total, 831 genes were exclusively and 5585 genes were preferentially expressed in root hairs [false discovery rate (FDR) ≤1%]. Among those, the most significantly enriched Gene Ontology (GO) functional terms were related to energy metabolism, highlighting the high energy demand for the development and function of root hairs. Subsequently, the maize homologs for 138 Arabidopsis genes known to be involved in root hair development were identified and their phylogenetic relationship and expression in root hairs were determined. This study indicated that the genetic regulation of root hair development in Arabidopsis and maize is controlled by common genes, but also shows differences which need to be dissected in future genetic experiments. Finally, a maize root view of the eFP browser was implemented including the root hair transcriptome of the present study and several previously published maize root transcriptome data sets. The eFP browser provides color-coded expression levels for these root types and tissues for any gene of interest, thus providing a novel resource to study gene expression and function in maize roots.
根毛是表皮细胞的管状延伸。转录组分析表明，单细胞型根毛的转录组比没有根毛的多细胞型初生根的转录组简单。总共，831 个基因在根毛中特异性表达，5585 个基因在根毛中优先表达[错误发现率（FDR）≤1%]。其中，最显著富集的基因本体（GO）功能术语与能量代谢有关，突出了根毛发育和功能的高能量需求。随后，鉴定了 138 个已知参与拟南芥根毛发育的拟南芥基因的玉米同源基因，并确定了它们在根毛中的系统发育关系和表达。这项研究表明，拟南芥和玉米根毛发育的遗传调控受共同基因控制，但也存在需要在未来遗传实验中剖析的差异。最后，在 eFP 浏览器中实现了一个玉米根视图，其中包括本研究的根毛转录组和之前发表的几个玉米根转录组数据集。eFP 浏览器为任何感兴趣的基因提供了这些根类型和组织的彩色编码表达水平，从而为研究玉米根中的基因表达和功能提供了一个新的资源。
