This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Barr, R. Articles by Giaquinta, R. T. Search for Related Content PubMed PubMed Citation Articles by Barr, R. Articles by Giaquinta, R. T. Agricola Articles by Barr, R. Articles by Giaquinta, R. T.

Articles

Dichlorophenylurea-insensitive Reduction of Silicomolybdic Acid by Chloroplast Photosystem II

^a Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907

The photoreduction of silicomolybdate and other heteropoly ions by chloroplasts is insensitive to 3-(3, 4-dichlorophenyl)-1, 1-dimethylurea (DCMU). Both water and diphenylcarbazide can be used as electron source for the reduction. Three different assays for silicomolybdate reduction are described including oxygen evolution, formation of a reduced heteropoly blue silicomolybdate, or an indirect assay for reduced silicomolybdate by redox indicators, such as ferricyanide or cytochrome c. The effects of detergents and tris washing are consistent with silicomolybdate reduction through photosystem II before the DCMU site. The effects of orthophenanthroline and bathophenanthroline indicate chelator-sensitive sites in photosystem II before the site of DCMU action.