title: Photosystem II photochemistry and phycobiliprotein of the red algae Kappaphycus alvarezii and their implications for light adaptation.
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 (I k) 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.
authors.affiliation: School of Ocean Sciences, China University of Geosciences, Beijing 100083, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Guan
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Jianyi
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Yao
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Liu
authors.affiliation: Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Song
authors.initials: S
authors.lastname: Qin
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
mesh_terms: D000221:Adaptation, Ocular / Q000235:genetics* / Q000502:physiology; D005075:Biological Evolution; D014644:Genetic Variation; D010777:Photochemistry; D045332:Photosystem II Protein Complex / Q000235:genetics* / Q000502:physiology; D052979:Phycobiliproteins / Q000235:genetics* / Q000502:physiology; D000461:Rhodophyta / Q000235:genetics* / Q000502:physiology
chemical_list: D045332:Photosystem II Protein Complex; D052979:Phycobiliproteins