Hormonal control of cell identity and growth in the shoot apical meristem

2022 ◽  
Vol 65 ◽  
pp. 102111
Author(s):  
Bihai Shi ◽  
Teva Vernoux
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Hormonal Control ◽  
Cell Identity

scholarly journals Plastid Osmotic Stress influences cell differentiation at the Plant Shoot Apex

2016 ◽  
Author(s):  
Margaret E. Wilson ◽  
Matthew Mixdorf ◽  
R. Howard Berg ◽  
Elizabeth S. Haswell
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Osmotic Stress ◽  
Shoot Apex ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Retrograde Signaling ◽  
Cell Identity ◽  
Callus Production ◽  
Stress Influences

ABSTRACTThe balance between proliferation and differentiation in the plant shoot apical meristem is controlled by regulatory loops involving the phytohormone cytokinin and stem cell identity genes. Concurrently, cellular differentiation in the developing shoot is coordinated with the environmental and developmental status of plastids within those cells. Here we employ an Arabidopsis thaliana mutant exhibiting constitutive plastid osmotic stress to investigate the molecular and genetic pathways connecting plastid osmotic stress with cell differentiation at the shoot apex. msl2 msl3 mutants exhibit dramatically enlarged and deformed plastids in the shoot apical meristem, and develop a mass of callus tissue at the shoot apex. Callus production in this mutant requires the cytokinin receptor AHK2 and is characterized by increased cytokinin levels, down-regulation of cytokinin signaling inhibitors ARR7 and ARR15, and induction of the stem cell identity gene WUSCHEL. Furthermore, plastid stress-induced apical callus production requires elevated plastidic ROS, ABA biosynthesis, the retrograde signaling protein GUN1, and ABI4. These results are consistent with a model wherein the cytokinin/WUS pathway and retrograde signaling control cell differentiation at the shoot apex.SUMMARY STATEMENTPlastid osmotic stress influences differentiation at the plant shoot apex. Two established mechanisms that control proliferation, the cytokinin/WUSCHEL stem cell identity loop and a plastid-to-nucleus signaling pathway, are implicated.

scholarly journals Mechanical stress contributes to the expression of the STM homeobox gene in Arabidopsis shoot meristems

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Benoît Landrein ◽  
Annamaria Kiss ◽  
Massimiliano Sassi ◽  
Aurélie Chauvet ◽  
Pradeep Das ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Homeobox Gene ◽  
Master Regulator ◽  
Cell Identity ◽  
Auxin Distribution ◽  
Mechanical Signals ◽  
Shoot Meristems

The role of mechanical signals in cell identity determination remains poorly explored in tissues. Furthermore, because mechanical stress is widespread, mechanical signals are difficult to uncouple from biochemical-based transduction pathways. Here we focus on the homeobox gene SHOOT MERISTEMLESS (STM), a master regulator and marker of meristematic identity in Arabidopsis. We found that STM expression is quantitatively correlated to curvature in the saddle-shaped boundary domain of the shoot apical meristem. As tissue folding reflects the presence of mechanical stress, we test and demonstrate that STM expression is induced after micromechanical perturbations. We also show that STM expression in the boundary domain is required for organ separation. While STM expression correlates with auxin depletion in this domain, auxin distribution and STM expression can also be uncoupled. STM expression and boundary identity are thus strengthened through a synergy between auxin depletion and an auxin-independent mechanotransduction pathway at the shoot apical meristem.

scholarly journals Sample preparation for laser-microdissection of soybean shoot apical meristem

2012 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Chui E. Wong ◽  
Mohan B. Singh ◽  
Prem L. Bhalla
Keyword(s):  
Sample Preparation ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Laser Microdissection ◽  
Specific Cell ◽  
Legume Crop ◽  
Continuous Formation ◽  
Molecular Events ◽  
Depth Analysis ◽  
Specialized Equipment

The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissection. Here, we optimized the sample preparation for a major legume crop, soybean. We used Farmer’s solution as a fixative and paraffin as the embedding medium for soybean shoot apical meristem tissue without the use of any specialized equipment. Shorter time for tissue fixation (two days) was found to be critical for the preservation of RNA in soybean shoot apical meristem. We further demonstrated the utility of this method for different tissues derived from soybean and rice. The method outlined here shall facilitate studies on crop plants involving laser-microdissection.

Somatic embryogenesis from Arabidopsis shoot apical meristem mutants

Planta ◽  
2002 ◽  
Vol 214 (6) ◽  
pp. 829-836 ◽  
Author(s):  
Andreas Mordhorst ◽  
Marijke Hartog ◽  
Mazen El Tamer ◽  
Thomas Laux ◽  
Sacco de Vries
Keyword(s):  
Somatic Embryogenesis ◽  
Shoot Apical Meristem ◽  
Apical Meristem

scholarly journals Arabidopsis Argonaute10 Specifically Sequesters miR166/165 to Regulate Shoot Apical Meristem Development

Cell ◽  
2011 ◽  
Vol 145 (2) ◽  
pp. 242-256 ◽  
Author(s):  
Hongliang Zhu ◽  
Fuqu Hu ◽  
Ronghui Wang ◽  
Xin Zhou ◽  
Sing-Hoi Sze ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Meristem Development

scholarly journals Spatiotemporal Sequestration of miR165/166 by Arabidopsis Argonaute10 Promotes Shoot Apical Meristem Maintenance

Cell Reports ◽  
2015 ◽  
Vol 10 (11) ◽  
pp. 1819-1827 ◽  
Author(s):  
Yuyi Zhou ◽  
Minami Honda ◽  
Hongliang Zhu ◽  
Zhonghui Zhang ◽  
Xinwei Guo ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Meristem Maintenance

Phyllotaxis of the palm Euterpe oleracea Mart. at the level of the shoot apical meristem

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 528-536 ◽  
Author(s):  
Denis Barabé ◽  
Laura Bourque ◽  
Xiaofeng Yin ◽  
Christian Lacroix
Keyword(s):  
Shoot Apical Meristem ◽  
Fundamental Theorem ◽  
Apical Meristem ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Divergence Angle ◽  
Euterpe Oleracea ◽  
The Mean ◽  
The Relationship ◽  
Euterpe Oleracea Mart

Previous studies on palm phyllotaxis deal mainly with the mature trunk. The goals of this study are (i) to determine the relationship between the number of parastichies, the divergence angle, and the plastochrone ratio at the level of the shoot apical meristem; (ii) to examine whether there are fluctuations in the divergence angle; (iii) to interpret the significance of phyllotactic parameters with respect to the mode of growth of the apex. The tubular base of the leaf primordium is more or less asymmetrical, and completely surrounds the shoot apical meristem. The phyllotactic system corresponds to a (2, 3) conspicuous parastichy pair. The mean divergence angle per apex varies between 126.9° ± 9.3° (mean ± SD) and 135. 8° ± 8.0°. Divergence angles for all apices fluctuate within a range of 115.89° to 157.33°. The mean plastochrone ratios between apices varies from 1.35 ± 0.18 to 1.58 ± 0.12. The plastochrone ratio at each plastochrone for all apices ranges from 1.09 to 2.00. There is no correlation between the angle of divergence and the plastochrone ratio. There is a fluctuation in the value of the divergence angle that falls within the range predicted by the fundamental theorem of phyllotaxis. The high value of the ratio of the diameter of leaf primordia over the diameter of the apex, and the long plastochrone might explain the lack of correlation between certain phyllotactic parameters.

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