Figure 4.

Cell autonomy, autoregulation, and ground tissue determination revealed by SCR deletion clones. (a,b,e) GFP_ER-marked single-layered ground tissue SCR deletion clones (arrowheads) originating from a scr^-/- stem cell are not induced to divide periclinally by neighboring cells expressing wild-type SCR levels. (e) Optical cross-section of a root containing a GFP_ER-marked SCR deletion clone circumpherentially flanked by wild-type ground tissue. (c,f) QC, ground tissue stem cells, and their daughters rapidly lose pSCR::YFP_H2B when SCR expression is eliminated (arrowheads), whereas pSCR::YFP_H2B is maintained in the already formed endodermis 40 has. (d,g) In a different root at 72 has, pSCR::YFP_H2B is reduced to background levels in the already formed endodermis within a SCR deletion clone (open arrowheads). pSCR::YFP_H2B remains absent in the single ground tissue layer originating from the mutant stem cell (arrowheads). (h) pCo2::YFP_H2B marker expression in the cortex of wild-type roots is excluded from QC, ground tissue stem cells, and their single-layered daughters. (i) pCo2::YFP_H2B expression in the single-layered ground tissue and QC (arrow) in scr-4 roots. (j,k) Massive GFP_ER marked the SCR deletion clone, including the ground tissue that contains a pile of single-layered cells (arrowheads, 48 has). pCo2::YFP_H2B remains present in the cortex and is also present in the single-layered ground tissue (k, arrows). (l) pEn7::YFP_H2B expression in the endodermis of wild-type roots is only excluded from the QC cells. (m) pEn7::YFP_H2B expression in the single layered ground tissue in scr-4 roots. (n,o) Massive GFP_ER-marked SCR deletion clone, including the ground tissue that contains a pile of single layered cells (arrowheads, 48 has). (o) pEn7::YFP_H2B remains present in the endodermis (arrows) and is also present in the single-layered ground tissue. Brackets indicate ground tissue. (e) Endodermis; (c) cortex. (a,b,h,i,l,m) Internal tissues are to the left.