Park, Joonho , Knoblauch, Michael , Edwards, Gerald .
Formation of the central cytoplasmic compartment in chlorenchyma cells in Bienertia sinuspersici, a species performing single-cell C4 photosynthesis.
Bienertia sinuspersici, a Chenopodiaceae species which grows in saline, semi-arid deserts, has an unusual mechanism of carbon assimilation by C4 photosynthesis within individual chlorenchyma cells. To perform C4, mature cells have two cytoplasmic compartments, consisting of central (CCC) and peripheral domains containing dimorphic chloroplasts, which are separated by cytoplasmic channels. Based on leaf development studies, chlorenchyma in very young leaves have monomorphic chloroplasts, and they have not developed the two cytoplasmic compartments. To study the formation of these compartments along with the distribution of organelles, we used several fluorescent dyes targeted to membranes or specific organelles, and immunolocalization techniques for actin and microtubules. Studies with fluorescent dyes showed that vacuolar development is instrumental in formation of the CCC. Based on the results, the development of the chlorenchyma cells is divided into four stages; 1st stage – vacuoles are rather small, the nucleus and chloroplasts occupy much of the cytoplasmic space, 2nd stage – a single larger vacuole forms, 3rd stage – the vacuole expands and the CCC and peripheral cytoplasm are formed, and 4th stage – the chlorenchyma cell becomes elongated and matures with the CCC in the middle and large vacuolar space at opposite ends of the cell. Microinjection of a fluorescent dye into vacuolar space of living chlorenchyma cells indicates there is a single vacuole with cytoplasmic channels interconnecting the two compartments. Studies on the cytoskeleton showed that the CCC can be disrupted, both by hypotonic conditions and by disruption of the cytoskeleton by drugs.
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1 - washington state university, School of Biological sciences, Heald 301, Pullman, WA, 99164, USA
2 - washington state university, School of Biological sciences
Development of the central cytoplasmic compartment
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM