title: VARIATIONS IN THE CELL WALLS AND PHOTOSYNTHETIC PROPERTIES OF PORPHYRA YEZOENSIS (BANGIALES, RHODOPHYTA) DURING ARCHEOSPORE FORMATION(1).
abstract: The formation of archeospores is characteristic of Porphyra yezoensis Ueda and is important for Porphyra aquaculture. Recently, it has been regarded as a valuable seed source for propagation of thalli in mariculture. Cell wall composition changes are associated with archeospore formation in P. yezoensis. Here, we report changes of cell walls of P. yezoensis during archeospore formation. The surfaces of vegetative cells that were originally smooth became rougher and more protuberant as archeosporangia were formed. Ultimately, the cell walls of archeosporangia ruptured, and archeospores were released from the torn cell walls that were left at distal margins of thalli. With changes in cell walls, both effective quantum yield and maximal quantum yield of the same regions in thalli gradually increased during the transformation of vegetative cells to archeospores, suggesting that the photosynthetic properties of the same regions in thalli gradually increased. Meanwhile, photosynthetic parameters for different sectors of thalli were determined, which included the proximal vegetative cells, archeosporangia, and newly released archeospores. The changes in photosynthetic properties of different sectors of thalli were in accordance with that of the same regions in thalli at different stages. In addition, the photosynthetic responses of archeosporangia to light showed higher saturating irradiance levels than those of vegetative cells. All these results suggest that archeosporangial cell walls were not degraded prior to release but were ruptured via bulging of the archeospore within the sporangium, and ultimately, archeospores were discharged. The accumulation of carbohydrates during archeospore formation in P. yezoensis might be required for the release of archeospores.
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Guangce
authors.initials: G
authors.lastname: Wang
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Ruiling
authors.initials: R
authors.lastname: Yang
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Xiujun
authors.initials: X
authors.lastname: Xie
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Guanghua
authors.initials: G
authors.lastname: Pan
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Xu
authors.affiliation: Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaKey Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (IOCAS), Qingdao 266071, ChinaCollege of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, ChinaDepartment of Biology, Changshu Institute of Technology, Changshu 215500, China.
authors.forename: Jianyi
authors.initials: J
authors.lastname: Zhu
keywords: Porphyra yezoensis; archeospore; cell wall; chlorophyll fluorescence; photosynthetic properties