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BioMed Research International
Volume 2013 (2013), Article ID 256549, 9 pages
http://dx.doi.org/10.1155/2013/256549
Research Article

Photosystem II Photochemistry and Phycobiliprotein of the Red Algae Kappaphycus alvarezii and Their Implications for Light Adaptation

1School of Ocean Sciences, China University of Geosciences, Beijing 100083, China
2Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
3Department of Biology, Changshu Institute of Technology, Changshu 215500, China
4Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China

Received 1 September 2013; Accepted 19 October 2013

Academic Editor: Hanzhi Lin

Copyright © 2013 Xiangyu Guan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Photosystem II photochemistry and phycobiliprotein (PBP) genes of red algae Kappaphycus alvarezii, raw material of κ-carrageenan used in food and pharmaceutical industries, were analyzed in this study. Minimum saturating irradiance ( ) of this algal species was less than 115 μmol m−2 s−1. Its actual PSII efficiency (yield II) increased when light intensity enhanced and decreased when light intensity reached 200 μmol m−2 s−1. Under dim light, yield II declined at first and then increased on the fourth day. Under high light, yield II retained a stable value. These results indicate that K. alvarezii is a low-light-adapted species but possesses regulative mechanisms in response to both excessive and deficient light. Based on the PBP gene sequences, K. alvarezii, together with other red algae, assembled faster and showed a closer relationship with LL-Prochlorococcus compared to HL-Prochlorococcus. Many amino acid loci in PBP sequences of K. alvarezii were conserved with those of LL-Prochlorococcus. However, loci conserved with HL-Prochlorococcus but divergent with LL-Prochlorococcus were also found. The diversities of PE and PC are proposed to have played some roles during the algal evolution and divergence of light adaption.