相對(duì)于動(dòng)物干細(xì)胞,，植物有其自身干細(xì)胞版本,。植物干細(xì)胞，或分裂組織,，可以發(fā)育成幾乎所有細(xì)胞類型,。植物的地上部分，例如花,、葉和種子是由枝條頂端分生組織（SAM）產(chǎn)生的,，SAM是位于莖的頂端的特種分生組織。與動(dòng)物干細(xì)胞不同,，只要植物在生長,，枝條頂端分生組織就能分化成任何種類細(xì)胞。盡管干細(xì)胞非常重要,，但他們的分子構(gòu)成卻一直是科學(xué)家的難題,。
加洲大學(xué)河濱分校的G.V. Reddy及其同事通過研究模式植物擬南芥，鑒定了所有在植物干細(xì)胞表達(dá)的基因,。他們同時(shí)精確指出了在分生細(xì)胞和調(diào)控植物分生細(xì)胞死亡的壁龕細(xì)胞中表達(dá)的基因,。此結(jié)果將有助于科學(xué)家更好地理解干細(xì)胞主導(dǎo)的分子路徑，并為培育更好的作物和植物品種開創(chuàng)道路,。研究也將幫助科學(xué)家深刻理解一些基礎(chǔ)問題,，例如什么決定干細(xì)胞身份，為什么植物和動(dòng)物的干細(xì)胞都能轉(zhuǎn)變?yōu)樘囟?xì)胞,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS March 3, 2009, doi: 10.1073/pnas.0900843106
Gene expression map of the Arabidopsis shoot apical meristem stem cell niche
Ram Kishor Yadav, Thomas Girke, Sumana Pasala, Mingtang Xie and G. Venugopala Reddy,1
1 Center for Plant Cell Biology and Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California, Riverside, CA 92521.
Despite the central importance of stem cells in plant growth and development, the molecular signatures associated with them have not been revealed. Shoot apical meristems (SAMs) harbor a small set of stem cells located at the tip of each plant and they are surrounded by several million differentiating cells. This imposes a major limitation in isolating pure populations of stem cells for genomic analyses. We have developed a system to isolate pure populations of distinct cell types of the SAMs, including stem cells. We have used this system to profile gene expression from 4 different cell samples of SAMs. The cell sample-specific gene expression profiling has resulted in a high-resolution gene expression map to reveal gene expression networks specific to individual spatial domains of SAMs. We demonstrate that the cell sample-specific expression profiling is sensitive in identifying rare transcripts expressed in a few specific subsets of cells of SAMs. Our extensive RNA in situ analysis reveals that the expression map can be used as a predictive tool in analyzing the spatial expression patterns of genes and it has led to the identification of unique gene expression patterns within the SAMs. Furthermore, our work reveals an enrichment of DNA repair and chromatin modification pathways in stem cells suggesting that maintenance of genome stability and flexible chromatin may be crucial for stem cell function. The gene expression map should guide future reverse genetics experiments, high-resolution analyses of cell–cell communication networks and epigenetic modifications.
