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 Redlinger, T. E. Articles by McDaniel, R. G. Search for Related Content PubMed PubMed Citation Articles by Redlinger, T. E. Articles by McDaniel, R. G. Agricola Articles by Redlinger, T. E. Articles by McDaniel, R. G.

Articles

Comparison of Light-dependent Oxygen Uptake, Protochlorophyll(ide)-650 Photoconversion, and Chlorophyll Disappearance in Wheat Etioplasts ¹

Department of Plant Sciences, University of Arizona, Tucson, Arizona 85721

Red light exposures given to dark-grown wheat seedlings (Triticum aestivum L.) prior to etioplast isolation reduced the ability of these organelles to consume O₂. The same preharvest red light exposures also decreased protochlorophyll(ide) content of etioplasts. In addition, regeneration of both O₂ uptake rates as well as protochlorophyll(ide) levels followed a parallel time course. These similarities suggested that photoconversion of protochlorophyll(ide)-650 to chlorophyll(ide) may mediate some process with O₂ as the electron acceptor. This process appears to involve photooxidation of nonphotoconvertible protochlorophyll(ide) as well as of newly formed chlorophyll(ide). This hypothesis is further supported by the observations that: (a) the in vitro light induced O₂ uptake phenomenon was observed in solubilized protochlorophyll(ide) holochrome preparations; and (b) photoinduced O₂ uptake was reduced to zero rate by light exposure time equivalent to that required for chlorophyll(ide) and nonphotoconvertible protochlorophyll(ide) destruction.

¹ Journal article No. 2769 of the Arizona Agricultural Experiment Station.