Stromules are stroma-containing tubules which can grow from the surface of plastids, most commonly leucoplasts and chromoplasts, but also chloroplasts in some tissues. Their functions are obscure. Stills from video rate movies are presented here. They illustrate interaction of stromules with cytoskeletal strands and the anchoring of stromules to unidentified components at the cell surface. Anchoring leads to stretching and relaxation of stromules when forces arising from cytoplasmic streaming act on the attached, freely suspended plastid bodies. Data on stromule growth, retraction, and regrowth rates are provided. Formation and movement of stromular branches and bridges between plastids are described. The shedding of a tip region into the streaming cytoplasm is recorded in frame-by-frame detail, in accord with early observations.
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http://dx.doi.org/10.1007/s00709-004-0073-3 | DOI Listing |
New Phytol
December 2024
Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA.
Chloroplast Unusual Positioning 1 (CHUP1) plays an important role in the chloroplast avoidance and accumulation responses in mesophyll cells. In epidermal cells, prior research showed silencing CHUP1-induced chloroplast stromules and amplified effector-triggered immunity (ETI); however, the underlying mechanisms remain largely unknown. CHUP1 has a dual function in anchoring chloroplasts and recruiting chloroplast-associated actin (cp-actin) filaments for blue light-induced movement.
View Article and Find Full Text PDFJ Exp Bot
October 2024
Laboratory of Plant Development & Interactions, Department of Molecular & Cellular Biology, University of Guelph, 50 Stone Road, Guelph, ON N1G2W1, Canada.
Peri-nuclear clustering (PNC) of chloroplasts has largely been described in senescent and pathogen- or reactive oxygen species-stressed cells. Stromules, tubular plastid extensions, are also observed under similar conditions. Coincident observations of PNC and stromules associate the two phenomena in facilitating retrograde signaling between chloroplasts and the nucleus.
View Article and Find Full Text PDFPlant Physiol Biochem
August 2024
Department of Environmental Biology, Sapienza University of Rome, Italy.
In land plants plastid type differentiation occurs concomitantly with cellular differentiation and the transition from one type to another is under developmental and environmental control. Plastid dynamism is based on a bilateral communication between plastids and nucleus through anterograde and retrograde signaling. Signaling occurs through the interaction with specific phytohormones (abscisic acid, strigolactones, jasmonates, gibberellins, brassinosteroids, ethylene, salicylic acid, cytokinin and auxin).
View Article and Find Full Text PDFPlant Physiol
September 2024
Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
Plastids in vascular plants have various differentiated forms, among which amyloplasts are crucial for starch storage and plant productivity. Despite the vast knowledge of the binary-fission mode of chloroplast division, our understanding of the replication of non-photosynthetic plastids, including amyloplasts, remains limited. Recent studies have suggested the involvement of stromules (stroma-filled tubules) in plastid replication when the division apparatus is faulty.
View Article and Find Full Text PDFCurr Opin Plant Biol
June 2024
Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA. Electronic address:
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