scholarly journals Spatial specificity of auxin responses coordinates wood formation

2017 ◽  
Author(s):  
Klaus Brackmann ◽  
Virginie Jouannet ◽  
Jiyan Qi ◽  
Theresa Schlamp ◽  
Karin Grünwald ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Spatial Organization ◽  
Wood Formation ◽  
Auxin Signaling ◽  
Cambium Activity ◽  
Plant Stem ◽  
Cell Niche ◽  
Spatial Specificity ◽  
Signaling Components

AbstractSpatial organization of signaling events of the phytohormone auxin is fundamental for maintaining a dynamic transition from plant stem cells to differentiated descendants. The cambium, the stem cell niche mediating wood formation, fundamentally depends on auxin signaling but its exact role and spatial organization is obscure. Here, we show that, while auxin signaling levels increase in differentiating cambium descendants, a moderate level of signaling in cambial stem cells is essential for cambium activity. We identify the auxin-dependent transcription factor ARF5/MONOPTEROS to cell-autonomously restrict the number of stem cells by attenuating the activity of the stem cell promoting WOX4 gene. In contrast, ARF3 and ARF4 function as cambium activators in a redundant fashion from outside of WOX4-expressing cells. Our results reveal an influence of auxin signaling on distinct cambium features by specific signaling components and allow the conceptual integration of plant stem cell systems with distinct anatomies.

scholarly journals WUSCHEL acts as an auxin response rheostat to maintain apical stem cells in Arabidopsis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanfei Ma ◽  
Andrej Miotk ◽  
Zoran Šutiković ◽  
Olga Ermakova ◽  
Christian Wenzl ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell System ◽  
Auxin Signaling ◽  
Stable Gene ◽  
Stem Cell System ◽  
Plant Stem ◽  
Low Levels ◽  
Stable Gene Expression

Abstract To maintain the balance between long-term stem cell self-renewal and differentiation, dynamic signals need to be translated into spatially precise and temporally stable gene expression states. In the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers differentiation while at the same time, pluripotent stem cells are maintained throughout the entire life-cycle. We find that stem cells are resistant to auxin mediated differentiation, but require low levels of signaling for their maintenance. We demonstrate that the WUSCHEL transcription factor confers this behavior by rheostatically controlling the auxin signaling and response pathway. Finally, we show that WUSCHEL acts via regulation of histone acetylation at target loci, including those with functions in the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly dynamic developmental signal into stable cell behavior with high spatial precision and temporal robustness.

scholarly journals Plant stem cell organization and differentiation at single-cell resolution

2020 ◽  
Author(s):  
James W. Satterlee ◽  
Josh Strable ◽  
Michael J. Scanlon
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Cell Fates ◽  
Organizing Center ◽  
Cell Organization ◽  
Plant Stem ◽  
Cell Niche ◽  
Transcriptional Landscape

Plants maintain populations of pluripotent stem cells in shoot apical meristems (SAMs), which continuously produce new aboveground organs. We used single-cell RNA sequencing to achieve an unbiased characterization of the transcriptional landscape of the maize shoot stem-cell niche and its differentiating cellular descendants. Stem cells housed in the SAM tip are engaged in genome integrity maintenance and exhibit a low rate of cell division, consistent with their contributions to germline and somatic cell fates. Surprisingly, we find no evidence for a canonical stem cell organizing center subtending these cells. In addition, we use trajectory inference to trace the gene expression changes that accompany cell differentiation. These data provide a valuable scaffold on which to better dissect the genetic control of plant shoot morphogenesis.

scholarly journals A model of protein interactions for regulating plant stem cells

2017 ◽  
Author(s):  
Jérémy Gruel ◽  
Julia Deichmann ◽  
Benoit Landrein ◽  
Thomas Hitchcock ◽  
Henrik Jönsson
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Protein Interactions ◽  
Stem Cell Niche ◽  
Apical Meristem ◽  
Stem Cell Marker ◽  
Tissue Size ◽  
Plant Stem ◽  
Cell Niche ◽  
Plant Stem Cells

AbstractThe plant shoot apical meristem holds a stem cell niche from which all aerial organs originate. Using a computational approach we show that a mixture of monomers and heterodimers of the transcription factors WUSCHEL and HAIRY MERISTEM is sufficient to pattern the stem cell niche, and predict that immobile heterodimers form a regulatory ‘pocket’ surrounding the stem cells. The model achieves to reproduce an array of perturbations, including mutants and tissue size modifications. We also show its ability to reproduce the recently observed dynamical shift of the stem cell niche during the development of an axillary meristem. The work integrates recent experimental results to answer the longstanding question of how the asymmetry of expression between the stem cell marker CLAVATA3 and its activator WUSCHEL is achieved, and recent findings of plasticity in the system.

scholarly journals WUSCHEL acts as a rheostat on the auxin pathway to maintain apical stem cells in Arabidopsis

2018 ◽  
Author(s):  
Yanfei Ma ◽  
Andrej Miotk ◽  
Zoran Šutiković ◽  
Anna Medzihradszky ◽  
Christian Wenzl ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell System ◽  
Auxin Signaling ◽  
Stable Gene ◽  
Stem Cell System ◽  
Plant Stem ◽  
Low Levels ◽  
Stable Gene Expression

ABSTRACTTo maintain the balance between long-term stem cell self-renewal and differentiation, dynamic signals need to be translated into spatially precise and temporally stable gene expression states. In the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers differentiation while at the same time, pluripotent stem cells are maintained throughout the entire life-cycle. We find that stem cells are resistant to auxin mediated differentiation, but require low levels of signaling for their maintenance. We demonstrate that the WUSCHEL transcription factor confers this behavior by rheostatically controlling the auxin signaling and response pathway. Finally, we show that WUSCHEL acts via regulation of histone acetylation at target loci, including those with functions in the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly dynamic developmental signal into stable cell behavior with high spatial precision and temporal robustness.

Tissue Stem Cells and Stem Cell Niche of the Human Vocal Fold

2020 ◽  
Vol 71 (2) ◽  
pp. 211-213
Author(s):  
K. Sato ◽  
S. Chitose ◽  
K. Sato ◽  
F. Sato ◽  
T. Kurita ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Niche ◽  
Vocal Fold ◽  
Cell Niche

scholarly journals Immunostaining of Lgr5, an Intestinal Stem Cell Marker, in Normal and Premalignant Human Gastrointestinal Tissue

2008 ◽  
Vol 8 ◽  
pp. 1168-1176 ◽  
Author(s):  
Laren Becker ◽  
Qin Huang ◽  
Hiroshi Mashimo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Niche ◽  
Intestinal Stem Cells ◽  
Stem Cell Marker ◽  
Tumor Initiating Cells ◽  
Colonic Adenomas ◽  
Potential Marker ◽  
Cell Niche ◽  
Crypt Base

Lgr5 has recently been identified as a murine marker of intestinal stem cells. Its expression has not been well characterized in human gastrointestinal tissues, but has been reported in certain cancers. With the increasing appreciation for the role of cancer stem cells or tumor-initiating cells in certain tumors, we sought to explore the expression of Lgr5 in normal and premalignant human gastrointestinal tissues. Using standard immunostaining, we compared expression of Lgr5 in normal colon and small intestine vs. small intestinal and colonic adenomas and Barrett's esophagus. In the normal tissue, Lgr5 was expressed in the expected stem cell niche, at the base of crypts, as seen in mice. However, in premalignant lesions, Lgr5+cells were not restricted to the crypt base. Additionally, their overall numbers were increased. In colonic adenomas, Lgr5+cells were commonly found clustered at the luminal surface and rarely at the crypt base. Finally, we compared immunostaining of Lgr5 with that of CD133, a previously characterized marker for tumor-initiating cells in colon cancer, and found that they identified distinct subpopulations of cells that were in close proximity, but did not costain. Our findings suggest that (1) Lgr5 is a potential marker of intestinal stem cells in humans and (2) loss of restriction to the stem cell niche is an early event in the premalignant transformation of stem cells and may play a role in carcinogenesis.

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