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Wang J.,CAS Qingdao Institute of Oceanology | Wang J.,University of Chinese Academy of Sciences | Jiang P.,CAS Qingdao Institute of Oceanology | Zhou W.,Marine Fisheries Institute of Jiangsu | And 3 more authors.
Botanica Marina | Year: 2010

The genome DNA required for molecular studies of Porphyra has generally been extracted from either blades or free-living "Conchocelis". However, the main disadvantages are complicated procedures, high cost, and DNA contamination. In this study, we developed a strategy for pure DNA extraction from shell-boring "Conchocelis" and a single-step technique to prepare PCR templates. The results show that contamination of free-living "Conchocelis" with microalgae was eliminated after the filaments had bored into shells. The electrophoretic banding patterns and intensities were similar between materials obtained from free-living "Conchocelis" and shell-boring "Conchocelis", suggesting that total DNA extraction from the latter was efficient. Molecular evidence demonstrated additional bands in PCR products of internal transcribed spacer (ITS) amplifications prepared from cultures of free-living "Conchocelis" contaminated with microalgae. The additional bands appeared in all three Porphyra yezoensis replicates and one out of three Porphyra haitanensis replicates, but were not detectable in preparations from shell-boring "Conchocelis". The DNA extracted from shell-boring "Conchocelis" reduced the risk of microalgal contamination and the single-step technique reduced the time required for the preparation of DNA for molecular studies of Porphyra. The single-step method should be useful for PCR amplification of small amounts of materials, large sample sizes, or samples contaminated with microalgae. The technique may also be suitable for other genera of Bangiaceae, providing that shell-boring "Conchocelis" stages are present in their life cycles. © 2010 by Walter de Gruyter Berlin New York.

Yang R.-L.,Tianjin University of Science and Technology | Zhou W.,CAS Qingdao Institute of Oceanology | Zhou W.,University of Chinese Academy of Sciences | Zhou W.,Marine Fisheries Institute of Jiangsu | And 5 more authors.
Planta | Year: 2012

Porphyra yezoensis has a macroscopic foliage gametophyte phase with only a single cell layer, and is ideally suited for the study of the sexual differentiation process, from the vegetative cell to the spermatia. Firstly, we compared variations in the responses of the vegetative and male sectors to desiccation. Later, cell tracking experiments were carried out during the formation of spermatia from vegetative cells. The two sectors showed similar tolerance to desiccation, and the formation of spermatia from vegetative cells was independent of the degree of desiccation. Both light and scanning electron microscopy (SEM) observations of the differentiation process showed that the formation of spermatia could be divided into six phases: the one-cell, two-cell, four-cell, eight-cell, pre-release and spermatia phases. Photomicrographs of Fluorescent Brightener staining showed that the released spermatia had no cell walls. Photosynthetic data showed that there was a significant rise in Y(II) in the four-cell phase, indicating an increase in photosynthetic efficiency of PSII during this phase. We propose that this photosynthetic rise may be substantial and provide the increased energy needed for the formation and release of spermatia in P. yezoensis. © 2011 Springer-Verlag.

Wang J.,CAS Qingdao Institute of Oceanology | Wang J.,University of Chinese Academy of Sciences | Zhu J.,Changshu Institute of Technology | Zhou W.,Marine Fisheries Institute of Jiangsu | And 3 more authors.
Journal of Applied Phycology | Year: 2010

Pigment mutants were used as genetic markers to study the early development and morphogenesis of blades in four species of Porphyra. In Porphyra haitanensis, P. yezoensis, and P. oligospermatangia, the first two divisions are transverse during conchospore germination, yielding four cells arranged in a line. These species are representative of linear development pattern in Porphyra. Resulting in blades with color sectors vertically arranged. In P. katadai var. hemiphylla, the first division is transverse and the upper cell divides vertically forming two side-by-side cells, and its blades are derived mostly from the upper cell showing a bilateral development pattern with two lateral parts of different colors. In this type of germination, most or the entire blade is derived from the upper cells. Some fronds of P. katadai var. hemiphylla developed in linear pattern. In addition, 9.3% of the conchospore germlings of linear development were produced at 10°C, 15.3% at 15°C, and 38.0% at 20°C for conchospore germlings of P. katadai var. hemiphylla. More linear development occurred at higher temperatures. The results revealed general trends of early developmental patterns and morphogenesis of blades within the genus of Porphyra. Developmental patterns and morphogenesis of blades are under the influence of temperatures. © Springer Science+Business Media B.V. 2009.

Gu W.,CAS Qingdao Institute of Oceanology | Gu W.,University of Chinese Academy of Sciences | Xie X.,Tianjin University of Science and Technology | Gao S.,CAS Qingdao Institute of Oceanology | And 4 more authors.
PLoS ONE | Year: 2013

Both biomass dominated green vegetative cells (GV) and astaxanthin-dominated orange resting cells (OR) affect the final astaxanthin yield in industry. Examination of Haematococcus pluvialis revealed that the OR cells greatly varied from the GV cells at both cellular and subcellular levels. In particular, the thylakoid membranes in the OR were disassembled and fragmented. Furthermore, the OR conserved most of the photosynthetic pigments, with elevated concentrations of violaxanthin, antheraxanthin, and neoxanthin. Notably, moderate photosynthesis was detected in OR, even though most of the thylakoid membranes were disassembled, when compared with those in the GV. However, the energy distribution pattern between photosystem I and II (PSI and PSII) in the OR favored PSI, which was also confirmed by 77-K fluorescence. As zeaxanthin was not detected in the OR, we attribute the acclimation role to astaxanthin, instead of xanthophyll cycle. Additionally, proteomic-scale comparison analysis of thylakoids of the OR and GV indicated no photosynthetically remarkable variations. However, an extensive acclimation mechanism of H. pluvialis was proposed, in which proteins in thylakoid of GV were noted to be involved in biomass accumulation and those in OR were involved in stress response. Conclusions of the comparative analysis might provide some physiological background of OR for astaxanthin production by using H. pluvialis. © 2013 Gu et al.

Zhou W.,CAS Qingdao Institute of Oceanology | Zhou W.,University of Chinese Academy of Sciences | Zhou W.,Marine Fisheries Institute of Jiangsu | He L.,CAS Qingdao Institute of Oceanology | And 5 more authors.
Chinese Journal of Oceanology and Limnology | Year: 2014

Pyropia yezoensis, an intertidal seaweed, experiences regular dehydration and rehydration with the tides. In this study, the responses of P. yezoensis to dehydration and rehydration under high and low CO2 concentrations ((600-700)×10-6 and (40-80)×10-6, named Group I and Group II respectively) were investigated. The thalli of Group I had a significantly higher effective photosystem II quantum yield than the thalli of Group II at 71% absolute water content (AWC). There was little difference between thalli morphology, total Rubisco activity and total protein content at 100% and 71% AWC, which might be the basis for the normal performance of photosynthesis during moderate dehydration. A higher effective photosystem I quantum yield was observed in the thalli subjected to a low CO2 concentration during moderate dehydration, which might be caused by the enhancement of cyclic electron flow. These results suggested that P. yezoensis can directly utilize CO2 in ambient air during moderate dehydration. © 2014 Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag Berlin Heidelberg.

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