Changing plastid dynamics within early root and shoot apical meristem-derived tissue of A. thaliana

Bramham, Lawrence; Pyke, Kevin

Abstract

Whilst plastids are fundamental to many aspects of plant biology and the production of enhanced crop cultivars, research into the dynamics of non-green plastids has remained somewhat disregarded by the scientific community compared to chloroplasts. They are equally pivotal to normal plant development however, and are now increasingly becoming the focus of research made possible by genetic manipulation and reporter gene constructs.

The total plastid content of all plant cells originates from small, undifferentiated plastids termed proplastids found within the meristematic regions of both root and shoot tissue. The cellular regulatory mechanisms controlling the development of plastids in young tissues are poorly understood, especially in the case of non-green plastids in roots. This investigation consequently aimed to elucidate the differences in plastid content, morphology and subcellular localization within epidermal cells derived from the root and shoot apical meristems (RAM and SAM respectively) of Arabidopsis thaliana.

Quantification of non-green plastids was facilitated via the use of confocal laser scanning microscopy in conjunction with the expression of plastid-targeted green fluorescent protein driven by a constitutive promoter. Characterization of early seedling development and tissue diversification was also achieved by assessing epidermal cell size relative to developmental progression, ultimately facilitating comparative analyses of plastid dynamics on both a temporal and tissue-varietal basis.

The number of plastids in epidermal cells within RAM-derived tissue was shown to increase across regions of cell division before being regulated throughout subsequent zones of elongation and maturing root tissue. In contrast, epidermal cells of the hypocotyl exhibit a more generalized increase in plastid number and less strict maintenance of cell plan area coverage during tissue expansion.

The findings presented here suggest the functioning of distinct mechanisms regulating plastid division and growth in relation to cell size within shoot and root apical meristem-derived tissues.

Citation

Bramham, L., & Pyke, K. (2017). Changing plastid dynamics within early root and shoot apical meristem-derived tissue of A. thaliana. Bioscience Horizons, 10(2017), https://doi.org/10.1093/biohorizons/hzx001

• Journal Article Type: Article
• Acceptance Date: Jan 6, 2017
• Publication Date: Feb 18, 2017
• Deposit Date: Apr 26, 2017
• Publicly Available Date: Apr 26, 2017
• Journal: Bioscience Horizons
• Electronic ISSN: 1754-7431
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 2017
• DOI: https://doi.org/10.1093/biohorizons/hzx001
• Keywords: Plastids, GFP, Epidermal Cells, Root, Hypocotyl, Arabidopsis thaliana
• Public URL: https://nottingham-repository.worktribe.com/output/845273
• Publisher URL: https://academic.oup.com/biohorizons/article/doi/10.1093/biohorizons/hzx001/3003274/Changing-Plastid-Dynamics-within-Early-Root-and
• Contract Date: Apr 26, 2017