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Co‐immunolocalization of topoisomerase II and chloroplast DNA in developing, dividing and mature wheat chloroplasts
Author(s) -
Marrison Joanne L.,
Leech Rachel M.
Publication year - 1992
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.1992.tb00147.x
Subject(s) - topoisomerase , chloroplast , chloroplast dna , biology , dapi , plastid , dna , dna replication , microbiology and biotechnology , biochemistry , genetics , staining , gene
This paper describes the first localization of immunofluorescence of topoisomerase II in developing chloroplasts. In order to investigate the relationship between topoisomerase II and chloroplast DNA (ctDNA) replication during chloroplast development the 7‐day‐old wheat leaf was used. Topoisomerase II was immunolabelled and fluorescein tagged and the ctDNA simultaneously stained with 4,6‐diamidino‐2‐phenylindole (DAPI) in the same sections. Topoisomerase II was detected at every stage of chloroplast development and maximal levels of topoisomerase II were found in chloroplasts at the time of ctDNA replication. Topoisomerase II was localized around the plastid periphery, exactly mirroring the position of the ctDNA. After chloroplast division both topoisomerase II and ctDNA are seen to be restricted to small discrete areas within the plastid, but at different sites. These findings strongly suggest a role for topoisomerase II in ctDNA decatenation prior to chloroplast division.