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Takahashi, Shunichi Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus
Tamashiro, Ayumu Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus
Sakihama, Yasuko Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus
Yamamoto, Yasusi Department of Biology, Faculty of Science, Okayama University
Kawamitsu, Yoshinobu Laboratory of Crop Science, Faculty of Agriculture, University of the Ryukyus
Yamasaki, Hideo Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus
Background: The tropical plant Ficus microcarpa L. f. cv. Golden Leaves (GL) is a high-light sensitive tropical fig tree in which sun-leaves are yellow and shade-leaves are green. We compared the response of photosynthetic activities to strong light between GL and its wild-type (WT, Ficus microcarpa L. f.).
Results: Field measurements of maximum photosystem II (PSII) efficiency (Fv/Fm) of intact sunleaves in GL showed that photo synthetic activity was severely photoinhibited during the daytime (Fv/Fm = 0.46) and subsequently recovered in the evening (Fv/Fm = 0.76). In contrast, WT did not show any substantial changes of Fv/Fm values throughout the day (between 0.82 and 0.78). Light dependency of the CO2 assimilation rate in detached shade-leaves of GL showed a response similar
to that in WT, suggesting no substantial difference in photosynthetic performance between them.Several indicators of photoinhibition, including declines in PSII reaction center protein (D1)content, Fv/Fm value, and O2 evolution and CO2 assimilation rates, all indicated that GL is much
more susceptible to photoinhibition than WT. Kinetics of PAM chlorophyll a fluorescence revealed
that nonphotochemical quenching (NPQ) capacity of GL was lower than that of WT.
Conclusion: We conclude that the photosynthetic apparatus of GL is more highly susceptible to photoinhibition than that of WT.
Photosystem II protein complex
Digital Object Identifer:10.1186/1471-2229-2-2
Published with permission from the copyright holder. This is the institute's copy, as published in BMC Plant Biology, 2002, 2:2 (2 April 2002).
Publisher URL: http://dx.doi.org/10.1186/1471-2229-2-2
© 2002 Takahashi et al; licensee BioMed Central Ltd. Verbatim copying and redistribution of this article are permitted in any medium for any purpose, provided this notice is preserved along with the article's original URL.
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2229/2/2
BMC Plant Biology
Takahashi et al; licensee BioMed Central Ltd.