Editing Meristem (section)

===Root apical meristem===
{{Multiple image
| direction         = vertical
| image1            = Light microscopy of root apical meristem.png
| image2 = Root-tip-tag.png
| caption2 = 10× microscope image of root tip with meristem{{ordered list|quiescent center|calyptrogen (live rootcap cells)|rootcap|sloughed off dead rootcap cells|procambium}}
}}
Unlike the shoot apical meristem, the root apical meristem produces cells in two dimensions. It harbors two pools of [[stem cells]] around an organizing center called the quiescent center (QC) cells and together produces most of the cells in an adult root.<ref name=" Jose Sebastian 2013">{{cite journal | doi = 10.1002/9780470015902.a0020121.pub2 | title=Root Apical Meristems | journal=eLS | last1 = Sebastian | first1 = Jose | last2 = Lee | first2 = Ji-Young| year=2013 | isbn=978-0470016176 }}</ref><ref name="Bennett, T">{{cite journal | last1 = Bennett | first1 = Tom | last2 = Scheres | first2 = Ben | year = 2010 | title = Root development-two meristems for the price of one? | journal = Current Topics in Developmental Biology | volume =  91| pages =  67–102| doi = 10.1016/S0070-2153(10)91003-X | pmid = 20705179 | isbn = 9780123809100 }}</ref> At its apex, the root meristem is covered by the root cap, which protects and guides its growth trajectory. Cells are continuously sloughed off the outer surface of the [[root cap]]. The QC cells are characterized by their low mitotic activity. Evidence suggests that the QC maintains the surrounding stem cells by preventing their differentiation, via signal(s) that are yet to be discovered. This allows a constant supply of new cells in the meristem required for continuous root growth. Recent findings indicate that QC can also act as a reservoir of stem cells to replenish whatever is lost or damaged.<ref name=" Heidstra, R">{{cite journal | last1 = Heidstra | first1 = Renze | last2 = Sabatini | first2 = Sabrina | year = 2014 | title = Plant and animal stem cells: similar yet different | journal = Nature Reviews Molecular Cell Biology | volume = 15 | issue = 5| pages = 301–12 | doi = 10.1038/nrm3790 | pmid = 24755933 | s2cid = 34386672 }}</ref> Root apical meristem and tissue patterns become established in the embryo in the case of the primary root, and in the new lateral root primordium in the case of secondary roots.