HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

What's this?

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Hughes, N. M. Articles by Smith, W. K. Search for Related Content PubMed Articles by Hughes, N. M. Articles by Smith, W. K. Agricola Articles by Hughes, N. M. Articles by Smith, W. K. Social Bookmarking                            What's this?

Attenuation of incident light in Galax urceolata (Diapensiaceae): concerted influence of adaxial and abaxial anthocyanic layers on photoprotection¹

Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27106-8758 USA

ABSTRACT

Although anthocyanin coloration in lower (abaxial) leaf cells has been documented for numerous species, the functional significance of this character has not been comprehensively investigated according to habitat or leaf orientation. Here, we demonstrate that abaxial anthocyanin may function as a photoprotectant, similarly to its purported role in upper (adaxial) cells, in leaves vulnerable to high irradiance incident on abaxial surfaces. Spectral scans were derived for Galax urceolata leaves with the following phenotypes: abaxial or adaxial anthocyanin only, abaxial and adaxial anthocyanin, and no anthocyanin. To determine whether anthocyanins conferred protection from photoinhibition, maximum photosystem II efficiencies of red (anthocyanic) and green (acyanic) surfaces were compared during and after exposure to photoinhibitory conditions. Leaves were either positioned with their adaxial surfaces facing the light source or inverted to expose abaxial surfaces. Spectral scans showed increased absorptance of 500–600 nm wavelengths by red surfaces (consistent with the absorbance spectrum of anthocyanin), regardless of whether that surface was abaxial or adaxial. Leaves with anthocyanin in either illuminated surface were also photoinhibited less than leaves lacking anthocyanin in that surface. These results suggest that anthocyanic layers reduce absorbed sunlight in the mesophyll not only for adaxial surfaces, but also for the abaxial. Adaxial/abaxial anthocyanin plasticity may therefore be adaptive in high-light environments or during light-sensitive developmental stages where leaf orientation and/or substrate albedo are variable.

Key Words: abaxial • anthocyanin • Diapensiaceae • evergreen • Galax • leaf orientation • photoprotection, plasticity

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. A. Gitelson, O. B. Chivkunova, and M. N. Merzlyak Nondestructive estimation of anthocyanins and chlorophylls in anthocyanic leaves Am. J. Botany, October 1, 2009; 96(10): 1861 - 1868. [Abstract] [Full Text] [PDF]

				K. Zeliou, Y. Manetas, and Y. Petropoulou Transient winter leaf reddening in Cistus creticus characterizes weak (stress-sensitive) individuals, yet anthocyanins cannot alleviate the adverse effects on photosynthesis J. Exp. Bot., July 1, 2009; 60(11): 3031 - 3042. [Abstract] [Full Text] [PDF]

				M. N. Merzlyak, O. B. Chivkunova, A. E. Solovchenko, and K. R. Naqvi Light absorption by anthocyanins in juvenile, stressed, and senescing leaves J. Exp. Bot., October 1, 2008; 59(14): 3903 - 3911. [Abstract] [Full Text] [PDF]

				N. M. Hughes, T. C. Vogelmann, and W. K. Smith Optical effects of abaxial anthocyanin on absorption of red wavelengths by understorey species: revisiting the back-scatter hypothesis J. Exp. Bot., September 1, 2008; 59(12): 3435 - 3442. [Abstract] [Full Text] [PDF]