title: Phosphodiesterase activities in transgenic tobacco plants associated with the movement protein of tobacco mosaic virus.
abstract: Hydrolytic activities of leaf extracts from normal and transgenic plants, with (+ MP) and without (-MP) the movement protein of tobacco mosaic virus, were examined. In the + MP transgenic plants, as compared with non-transgenic and - MP plants, higher hydrolytic activities were found on the following substrates: bis-(nitrophenyl)-phosphate (BPNPP, phosphodiesterase), p-nitrophenyl-(phenyl)-phosphate (PNPPP, nucleotidephosphodiesterase) and thymidine-3'-monophosphate p-nitrophenyl ester (T3MPP; 3'nucleotide phosphodiesterase.) The + MP plant lines, as compared with other transgenic plants, exhibited higher nucleotide-phosphodiesterase activity in the soluble as well as in the membrane fraction. Substrate concentration kinetic studies revealed the presence of a nucleotide-phospho-diesterase with a high substrate affinity in the +MP extracts in addition to the enzyme with a relatively low substrate affinity present also in the - MP transgenic plants. This "high affinity" enzyme could be removed from the soluble fraction by precipitation with anti-MP serum, indicating its possible association with the movement protein.
authors.affiliation: Department of Biology, Washington University, Box 1137, 63130, St. Louis, MO, USA.
authors.forename: M
authors.initials: M
authors.lastname: Perl
authors.forename: R
authors.initials: R
authors.lastname: Gafni
authors.forename: R N
authors.initials: RN
authors.lastname: Beachy