title: Reversible swelling and contraction of isolated spinach chloroplasts.
abstract: By use of a micro technique for producing extracts of spinach mesophyll cells, chloroplasts were isolated in a state wherein they displayed microscopically visible, reversible osmotic properties. Swollen spherical chloroplasts treated with hypertonic sucrose or mannitol media, but not NaCl, could be shrunken to a state resembling their disk appearance in living cells. Reversible osmotic behavior was more easily demonstrated when the chloroplasts were initially isolated from cells in a relatively low osmolar concentration in contrast to using 0.25 m sucrose or more concentrated media. Individual chloroplasts could be swollen and contracted repeatedly through as many as 4 cycles. The relationship between the capacity for osmotic behavior and chloroplast appearance in cell extracts is discussed.
authors.affiliation: Department of Botanical Sciences, University of California, Los Angeles, California 90024.
authors.forename: T
authors.initials: T
authors.lastname: Hongladarom
authors.forename: S I
authors.initials: SI
authors.lastname: Honda