Plant Physiol.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on March 28, 2008; 10.1104/pp.108.117598

OPEN ACCESS ARTICLE
This Article
Free via Open Access: OA
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrowOA All Versions of this Article:
147/1/402    most recent
pp.108.117598v1
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 Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Busch, F.
Right arrow Articles by Ensminger, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Busch, F.
Right arrow Articles by Ensminger, I.
Agricola
Right arrow Articles by Busch, F.
Right arrow Articles by Ensminger, I.

Received February 9, 2008
Accepted March 18, 2008

Increased Air Temperature during Simulated Autumn Conditions Impairs Photosynthetic Electron Transport Between PSII and PSI

Florian Busch , Norman P.A. Huner , and Ingo Ensminger *

Department of Biology and The BIOTRON, The University of Western Ontario, London, Ontario, Canada, N6A 5B7; Institute of Chemistry and Dynamics of the Geosphere ICG-III: Phytosphere, Research Centre Julich, 52425 Julich, Germany; Department of Forest Ecology, Forest Research Institute Baden-Wuerttemberg, 79100 Freiburg, Germany

* Corresponding author; email: ingo.ensminger{at}forst.bwl.de.

Changes in temperature and daylength trigger physiological and seasonal developmental processes that enable evergreen trees of the boreal forest to withstand severe winter conditions. Climate change is expected to increase the autumn air temperature in the northern latitudes while the natural decreasing photoperiod remains unaffected. As previously shown (Busch et al., 2007), an increase in autumn air temperature inhibits CO2 assimilation with a concomitant increased capacity for zeaxanthin-independent dissipation of energy exceeding the photochemical capacity in Pinus banksiana. In this study we tested our previous model of antenna quenching and tested a limitation in intersystem electron transport in plants exposed to elevated autumn air temperatures. Using a factorial design, we dissected the effects of temperature and photoperiod on the function as well as the stoichiometry of the major components of the photosynthetic electron transport chain in P. banksiana. Natural summer conditions (LD/HT: 16h photoperiod/22°C) and late autumn conditions (SD/LT: 8h/7°C) were compared to a treatment of autumn photoperiod with increased air temperature (SD/HT: 8h/22°C) and a treatment with summer photoperiod and autumn temperature (LD/LT: 16h/7°C). Exposure to SD/HT resulted in an inhibition of the effective quantum yield associated with a decreased PSII/PSI stoichiometry coupled with decreased levels of Rubisco. Our data indicate that a greater capacity to keep P700 oxidized in plants exposed to SD/HT compared to the summer control may be attributed to a reduced rate of electron transport from the cytochrome b6f complex to PSI. Photoprotection under increased autumn air temperature conditions appears to be consistent with zeaxanthin-independent antenna quenching through LHCII aggregation and a decreased efficiency in energy transfer from the antenna to the PSII core. We suggest that models that predict the effect of climate change on the productivity of boreal forests must take into account the interactive effects of photoperiod and elevated temperatures.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 2008 by the American Society of Plant Biologists