Coalescence and directed anisotropic growth of starch granule initials in subdomains of Arabidopsis thaliana chloroplasts
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Living cells orchestrate enzyme activities to produce myriads of biopolymers but cell-biological understanding of such processes is scarce. Starch, a plant biopolymer forming discrete, semi-crystalline granules within plastids, plays a central role in glucose storage, which is fundamental to life. Combining complementary imaging techniques and Arabidopsis genetics we reveal that, in chloroplasts, multiple starch granules initiate in stromal pockets between thylakoid membranes. These initials coalesce, then grow anisotropically to form lenticular granules. The major starch polymer, amylopectin, is synthesized at the granule surface, while the minor amylose component is deposited internally. The non-enzymatic domain of STARCH SYNTHASE 4, which controls the protein’s localization, is required for anisotropic growth. These results present us with a conceptual framework for understanding the biosynthesis of this key nutrient. Show more
Journal / seriesNature Communications
Pages / Article No.
Subject3-D reconstruction; Chloroplasts; Plant physiology; Polysaccharides
Organisational unit03707 - Zeeman, Samuel C. / Zeeman, Samuel C.
166487 - Multi-dimensional imaging to visualize starch biosynthesis in plants. (SNF)
182570 - Understanding the Cell Biology of Starch Metabolism in Plants (SNF)
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Is supplemented by: https://doi.org/10.3929/ethz-b-000508434
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