Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Dupont, J.
Right arrow Articles by Siegenthaler, P.-A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Dupont, J.
Right arrow Articles by Siegenthaler, P.-A.
Agricola
Right arrow Articles by Dupont, J.
Right arrow Articles by Siegenthaler, P.-A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Plant and Cell Physiology, 1986, Vol. 27, No. 3 473-484
© 1986

Article

A Parallel Study of Pigment Bleaching and Cytochrome Breakdown during Aging of Thylakoid Membranes

Jacques Dupont1 and Paul-André Siegenthaler2

1Laboratoire de Biologic Végétale IV, CNRS (UA 1180), Université Pierre et Marie Curie 12 rue Cuvier, 75005 Paris, France
2Laboratoire de Physiologic Végétale, Université de Neuchâtel chemin de Chantemerle 20, CH-2000 Neuchâtel, Suisse

Aging of freshly isolated thylakoid membranes from spinach leaves (Spinacia oleracea L.) leads to dramatic alterations in both the cytochrome (b559 (HP) and f) composition and pigment (chlorophylls a and b and ß-carotene) content. These changes occur at a faster rate under anaerobic conditions or after heating thylakoid membranes, and in light as well as in darkness. In addition, when thylakoid membranes are heated at 78°C for 8 min, or incubated in the presence of an emulsion of linoleic acid, a huge decrease in both cytochrome (particularly cyt. b559 (HP)) and pigment contents occur. Whatever the experimental conditions, cytochrome b559 (HP) destruction occurs as soon the aging process starts. Conversely, pigment bleaching is detectable after an initial lag phase of about 60–70 min. Then, the two processes (cytochrome breakdown and bleaching of pigments) appear to take place in parallel. The addition of salicylhydroxamic acid or 8-hydroxy-quinoline, two radical scavenger components, to the aging medium strongly reduces the rate and extent of cytochrome breakdown and pigment bleaching.

On the basis of these results, a tentative scheme accounting for the bleaching of pigments and the breakdown of cytochromes during aging in vitro of thylakoid membranes is proposed. It is suggested that these changes are mediated via a non-enzymatic mechanism in which free radicals could be implicated. The possible role of free radicals inducing ultrastructural changes at the level of chloroplast membranes in senescent leaves is also considered.

(Received October 11, 1985; Accepted January 24, 1986)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.