title: Osmotic stress inhibits thymidine incorporation into soybean protoplast DNA.
abstract: DNA synthesis in protoplasts isolated from soybean cell suspension cultures has been investigated by [(3)H] thymidine uptake and incorporation kinetics. Initial rates of incorporation in exponential and 5-fluorodeoxyuridine synchronized protoplasts are inhibited by increased osmolarities of the medium. The inhibition was not readily reversible during 3 h culture in low osmotic medium. Velocity sedimentation analyses of replicating DNA from such protoplasts shows a complex pattern of inhibition. The inhibition probably effects replicon initiation as well as strand elongation and ligation of replication intermediates.
authors.affiliation: Cell Culture and Nitrogen Fixation Laboratory, Plant Physiology Institute, Agricultural Research Service, U.S. Department of Agriculture, 20705, Beltsville, Maryland, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Cress