TY - JOUR
T1 - Measurements of the number of specified and unspecified cells in the shoot apical meristem during a plastochron in rice (Oryza sativa) reveal the robustness of cellular specification process in plant development
AU - Nosaka-Takahashi, Misuzu
AU - Kato, Makio
AU - Kumamaru, Toshihiro
AU - Sato, Yutaka
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Numbers JP17H06471 and JP20H00424 to Y.S, JP21K05521 to M.N. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Mutant strains used in this study were distributed from the National Institute of Genetics supported by the National Bioresource Project (NBRP), MEXT, Japan.
Publisher Copyright:
Copyright: © 2022 Nosaka-Takahashi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2022/6
Y1 - 2022/6
N2 - The shoot apical meristem (SAM) is composed of a population of stem cells giving rise to the aboveground parts of plants. It maintains itself by controlling the balance of cell proliferation and specification. Although knowledge of the mechanisms maintaining the SAM has been accumulating, the processes of cellular specification to form leaves and replenishment of unspecified cells in the SAM during a plastochron (the time interval between which two successive leaf primordia are formed) is still obscure. In this study, we developed a method to quantify the number of specified and unspecified cells in the SAM and used it to elucidate the dynamics of cellular specification in the SAM during a plastochron in rice. OSH1 is a KNOX (KNOTTED1-like homeobox) gene in rice that is expressed in the unspecified cells in the SAM, but not in specified cells. Thus, we could visualize and count the nuclei of unspecified cells by fluorescent immunohistochemical staining with an anti-OSH1 antibody followed by fluorescein isothiocyanate detection. By double-staining with propidium iodide (which stains all nuclei) and then overlaying the images, we could also detect and count the specified cells. By using these measurements in combination with morphological observation, we defined four developmental stages of SAM that portray cellular specification and replenishment of unspecified cells in the SAM during a plastochron. In addition, through the analysis of mutant lines with altered size and shape of the SAM, we found that the number of specified cells destined to form a leaf primordium is not affected by mild perturbations of meristem size and shape. Our study highlights the dynamism and flexibility in stem cell maintenance in the SAM during a plastochron and the robustness of plant development.
AB - The shoot apical meristem (SAM) is composed of a population of stem cells giving rise to the aboveground parts of plants. It maintains itself by controlling the balance of cell proliferation and specification. Although knowledge of the mechanisms maintaining the SAM has been accumulating, the processes of cellular specification to form leaves and replenishment of unspecified cells in the SAM during a plastochron (the time interval between which two successive leaf primordia are formed) is still obscure. In this study, we developed a method to quantify the number of specified and unspecified cells in the SAM and used it to elucidate the dynamics of cellular specification in the SAM during a plastochron in rice. OSH1 is a KNOX (KNOTTED1-like homeobox) gene in rice that is expressed in the unspecified cells in the SAM, but not in specified cells. Thus, we could visualize and count the nuclei of unspecified cells by fluorescent immunohistochemical staining with an anti-OSH1 antibody followed by fluorescein isothiocyanate detection. By double-staining with propidium iodide (which stains all nuclei) and then overlaying the images, we could also detect and count the specified cells. By using these measurements in combination with morphological observation, we defined four developmental stages of SAM that portray cellular specification and replenishment of unspecified cells in the SAM during a plastochron. In addition, through the analysis of mutant lines with altered size and shape of the SAM, we found that the number of specified cells destined to form a leaf primordium is not affected by mild perturbations of meristem size and shape. Our study highlights the dynamism and flexibility in stem cell maintenance in the SAM during a plastochron and the robustness of plant development.
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U2 - 10.1371/journal.pone.0269374
DO - 10.1371/journal.pone.0269374
M3 - Article
C2 - 35657937
AN - SCOPUS:85131702666
SN - 1932-6203
VL - 17
JO - PloS one
JF - PloS one
IS - 6 June
M1 - e0269374
ER -