The partial sequence of the rbcL from Bryopsis hypnoides, including the sequences of the upstream, extron and partial intron, was amplified by PCR and their sequences were determined. With Spinacia oleracea as the out...The partial sequence of the rbcL from Bryopsis hypnoides, including the sequences of the upstream, extron and partial intron, was amplified by PCR and their sequences were determined. With Spinacia oleracea as the outgroup, neighbor-joining method and maximum parsimony method were used respectively to build phylogenetic trees according to the rbcL exon sequence among 13 species that were the typical species of six phyla. Two kinds of trees showed clearly that there were two groups among those species, the green lineage and the non-green lineage. And the relationships of algae in the green lineage were similar in the two trees but those in the non-green lineage were not consistent. Analysis of codon preference indicated that the codon preference of the rbcL exon of Bryopsis hypnoides distinctly differed from that of the relevant sequence of photosynthetic bacteria.展开更多
An increase in the level of atmospheric carbon dioxide （CO2） and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower p...An increase in the level of atmospheric carbon dioxide （CO2） and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower pH in seawater and may affect the physiology of seaweed species. Accordingly, the main goal of the current study was to determine the physiological responses of Bryopsis plumosa to elevated-CO2. The results indicated that photosynthesis of B. plumosa was insignificantly affected to elevated-CO2, but photosynthetic pigment contents and phenolics were significantly decreased. The results obtained from the research reveal that B. plumosa may become physiologically advanced when exposed to CO2-induced ocean acidification. In particular, B. plumosa may be more able to compete with calcifying algae when it will become future predicted CO2 scenario.展开更多
Abstract: Tissue culture, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and spectra analysis were used for studying the aggregation mechanism of protoplasts from Bryopsis hypnoides Lamouroux and the discrepancy be...Abstract: Tissue culture, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and spectra analysis were used for studying the aggregation mechanism of protoplasts from Bryopsis hypnoides Lamouroux and the discrepancy between the protoplast-regenerated plants and the wild type. The aggregation of protoplasts from B. hypnoides was observed in natural seawater and artificial seawater with different pH values, and the location and mechanism of the materials causing the aggregation were also studied. Results showed that the protoplasts could aggregate into some viable spheres in natural seawater and subsequently grow into mature individuals. Aggregation of the protoplasts depended exclusively upon the pH value (6–11), and the protoplasts aggregated best at pH 8–9. Some of the extruded protoplasts were separated into two parts by centrifugation: the pellet (PO) and the supernatant (PL). The PO could aggregate in artificial seawater (pH 8.3) but not in PL. No aggregation was found in PO cultured in natural seawater containing nigericin, which can dissipate the proton gradients across the membrane. These experiments suggest that the aggregation of protoplasts is proton-gradient dependent and the materials causing the aggregation were not in the vacuolar sap, but located on the surface or inside the organelles. Furthermore, the transfer of the materials across the membrane was similar to z\pH-based translocation (δpH/TAT) pathway that occurs in the chloroplasts of higher plants and bacteria. Obvious discrepancies in both the total soluble proteins and the ratio of chlorophyll a to chlorophyll b between the regenerated B. hypnoides and the wild type were found, which may be related to the exchange of genetic material during aggregation of the organelles. In the process of development, diatom Amphora coffeaeformis Agardh attached to the protoplast aggregations, retarding their further development, and once they were removed, the aggregations immediately germinated, which showed that diatoms can affect the development of other algae.展开更多
Bryopsis hypnoides Lamouroux was regenerated In vitro from the protoplasm squeezed out from wild algae and the regenerated Individuals had an advantage over Indlvlduala from the wild In terms of growth. Culturing of s...Bryopsis hypnoides Lamouroux was regenerated In vitro from the protoplasm squeezed out from wild algae and the regenerated Individuals had an advantage over Indlvlduala from the wild In terms of growth. Culturing of segments of thalll also showed that segments from the regenerated algae grew better than those from individuals from the wild. The segment that corresponds to a part of a cell, at least a part of the protoplasm, can develop Into a mature Individual, Including rhlzold and thallus, suggesting that a multlnucleate alga, such as B. hypnoides, Is different from higher plants, whose totlpotancy Is based on an Intact cell （or protoplasm）. Further cultivation of mature Individuals from segments Indicated that the organelles In the thallus had two ways In which they could survive when the alga was on the decline： （Ⅰ） the organelles were transferred Into a ball with a gelatinous envelope through a formed pipe and the ball seemed to be capable of being propagated; and （Ⅱ） the organelles were aggregated In the thallus and then moved to the outside. An Interesting result Is that one organelle aggregation located outside the thallus germinated and developed Into a mature alga, although most organelle aggregations gradually lost vitality and died. The results of the present study reveal that the aggregation of organelles can regenerate a stronger organism than Individuals from the wild owing to the complete exchange of genetic material and may possibly enable organelles to survive in unfavorable surroundings.展开更多
Newly regenerated thalli were used to study the phototropism of Bryopsis hypnoides Lamouroux under different qualities of light. Positive phototropism in the thalli and negative phototropiam In the rhizoida of B. hypn...Newly regenerated thalli were used to study the phototropism of Bryopsis hypnoides Lamouroux under different qualities of light. Positive phototropism in the thalli and negative phototropiam In the rhizoida of B. hypnoides were investigated and analyzed in terms of bending. Both thaiii and rhlzoids developed from thallus segments exhibited typical tip growth, and their photoreceptive sites for phototroplam were also restricted to the apical hemisphere. The bending curvature of rhizoids and thalli were determined with unilateral lights at various wavelengths and different fluence rates after a fixed duration of Illumination. The trends of bending from the rhizoid and thallus were coincident, which showed that the action spectrum had a large range, from ultraviolet radiation （366.5 nm） to green light （524 nm）. Based on the bending curvatures, blue light had the highest efficiency, while the efficiency of longer wavelengths （〉500 nm） was significantly lower. External Ca^2＋ had no effect on the bending curvature of thalli and rhlzolda. Blue light （440 nm） induced thallus branching from rhizoids, while red light （650 nm） had no such effect. Fast-occurring chloroplast accumulation In the outermost cytoplasmic layer of the blue light （440 nm）-Irradiated region In the rhizoid was observed, from which protrusions （new thalli） arose after 4 h of the onset of illumination, and this action was thought to be driven by the dynamics of actin microfilamenta.展开更多
By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa （Hudson） C. Agardh. In this study, we focus...By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa （Hudson） C. Agardh. In this study, we focused on the primary and secondary sex ratios （i.e. at inception and maturity） using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli＇s enriched seawater （PES） medium under a 14：10 h light： dark cycle at 14 ℃. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PES medium under a 14：10 h light ： nbsp;dark cycle at 18℃. Then they were transferred into Schreiber medium and cultured under a 10：14 h light： dark cycle at 22℃. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1：1. Synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature.展开更多
基金This study was supported by the National Natural Science Foundation of China under contract Nos 39890390,30170499,40476059 and 30250003the Project of Scientific Innovation of Chinese Academy of Sciences under contract No.KZCX2-211+1 种基金the Project of Scientific Innovation of Institute of Oceanology,Chinese Academy of Sciences under contract No.2002-2005the“863”Project of China under contract No.2004AA603220.
文摘The partial sequence of the rbcL from Bryopsis hypnoides, including the sequences of the upstream, extron and partial intron, was amplified by PCR and their sequences were determined. With Spinacia oleracea as the outgroup, neighbor-joining method and maximum parsimony method were used respectively to build phylogenetic trees according to the rbcL exon sequence among 13 species that were the typical species of six phyla. Two kinds of trees showed clearly that there were two groups among those species, the green lineage and the non-green lineage. And the relationships of algae in the green lineage were similar in the two trees but those in the non-green lineage were not consistent. Analysis of codon preference indicated that the codon preference of the rbcL exon of Bryopsis hypnoides distinctly differed from that of the relevant sequence of photosynthetic bacteria.
基金The Uludag University Scientific Research Project Unit through the research project of UAP(F)2011/79
文摘An increase in the level of atmospheric carbon dioxide （CO2） and the resultant rise in CO2 in seawater alter the inorganic carbon concentrations of seawater. This change, known as ocean acidification, causes lower pH in seawater and may affect the physiology of seaweed species. Accordingly, the main goal of the current study was to determine the physiological responses of Bryopsis plumosa to elevated-CO2. The results indicated that photosynthesis of B. plumosa was insignificantly affected to elevated-CO2, but photosynthetic pigment contents and phenolics were significantly decreased. The results obtained from the research reveal that B. plumosa may become physiologically advanced when exposed to CO2-induced ocean acidification. In particular, B. plumosa may be more able to compete with calcifying algae when it will become future predicted CO2 scenario.
文摘Abstract: Tissue culture, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and spectra analysis were used for studying the aggregation mechanism of protoplasts from Bryopsis hypnoides Lamouroux and the discrepancy between the protoplast-regenerated plants and the wild type. The aggregation of protoplasts from B. hypnoides was observed in natural seawater and artificial seawater with different pH values, and the location and mechanism of the materials causing the aggregation were also studied. Results showed that the protoplasts could aggregate into some viable spheres in natural seawater and subsequently grow into mature individuals. Aggregation of the protoplasts depended exclusively upon the pH value (6–11), and the protoplasts aggregated best at pH 8–9. Some of the extruded protoplasts were separated into two parts by centrifugation: the pellet (PO) and the supernatant (PL). The PO could aggregate in artificial seawater (pH 8.3) but not in PL. No aggregation was found in PO cultured in natural seawater containing nigericin, which can dissipate the proton gradients across the membrane. These experiments suggest that the aggregation of protoplasts is proton-gradient dependent and the materials causing the aggregation were not in the vacuolar sap, but located on the surface or inside the organelles. Furthermore, the transfer of the materials across the membrane was similar to z\pH-based translocation (δpH/TAT) pathway that occurs in the chloroplasts of higher plants and bacteria. Obvious discrepancies in both the total soluble proteins and the ratio of chlorophyll a to chlorophyll b between the regenerated B. hypnoides and the wild type were found, which may be related to the exchange of genetic material during aggregation of the organelles. In the process of development, diatom Amphora coffeaeformis Agardh attached to the protoplast aggregations, retarding their further development, and once they were removed, the aggregations immediately germinated, which showed that diatoms can affect the development of other algae.
基金Supported by the National Natural Science Foundation of China （40476059, 30170499, 30250003 and 39890390）, the Knowledge Innovation Program of the Chinese Academy of Sciences （KZCX2-211） and the Hi-Tech Research and Development （863） Program of China （2004AA603220）.
文摘Bryopsis hypnoides Lamouroux was regenerated In vitro from the protoplasm squeezed out from wild algae and the regenerated Individuals had an advantage over Indlvlduala from the wild In terms of growth. Culturing of segments of thalll also showed that segments from the regenerated algae grew better than those from individuals from the wild. The segment that corresponds to a part of a cell, at least a part of the protoplasm, can develop Into a mature Individual, Including rhlzold and thallus, suggesting that a multlnucleate alga, such as B. hypnoides, Is different from higher plants, whose totlpotancy Is based on an Intact cell （or protoplasm）. Further cultivation of mature Individuals from segments Indicated that the organelles In the thallus had two ways In which they could survive when the alga was on the decline： （Ⅰ） the organelles were transferred Into a ball with a gelatinous envelope through a formed pipe and the ball seemed to be capable of being propagated; and （Ⅱ） the organelles were aggregated In the thallus and then moved to the outside. An Interesting result Is that one organelle aggregation located outside the thallus germinated and developed Into a mature alga, although most organelle aggregations gradually lost vitality and died. The results of the present study reveal that the aggregation of organelles can regenerate a stronger organism than Individuals from the wild owing to the complete exchange of genetic material and may possibly enable organelles to survive in unfavorable surroundings.
基金Supported by the National Natural Science Foundation of China(30170499, 40476059,and 39890390)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-211)the Hi-Tech Research and Development(863) Program of China(2004AA603220)
文摘Newly regenerated thalli were used to study the phototropism of Bryopsis hypnoides Lamouroux under different qualities of light. Positive phototropism in the thalli and negative phototropiam In the rhizoida of B. hypnoides were investigated and analyzed in terms of bending. Both thaiii and rhlzoids developed from thallus segments exhibited typical tip growth, and their photoreceptive sites for phototroplam were also restricted to the apical hemisphere. The bending curvature of rhizoids and thalli were determined with unilateral lights at various wavelengths and different fluence rates after a fixed duration of Illumination. The trends of bending from the rhizoid and thallus were coincident, which showed that the action spectrum had a large range, from ultraviolet radiation （366.5 nm） to green light （524 nm）. Based on the bending curvatures, blue light had the highest efficiency, while the efficiency of longer wavelengths （〉500 nm） was significantly lower. External Ca^2＋ had no effect on the bending curvature of thalli and rhlzolda. Blue light （440 nm） induced thallus branching from rhizoids, while red light （650 nm） had no such effect. Fast-occurring chloroplast accumulation In the outermost cytoplasmic layer of the blue light （440 nm）-Irradiated region In the rhizoid was observed, from which protrusions （new thalli） arose after 4 h of the onset of illumination, and this action was thought to be driven by the dynamics of actin microfilamenta.
基金a grant-in-aid from the Ministry of Education, Culture and Science of Japan.
文摘By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa （Hudson） C. Agardh. In this study, we focused on the primary and secondary sex ratios （i.e. at inception and maturity） using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli＇s enriched seawater （PES） medium under a 14：10 h light： dark cycle at 14 ℃. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PES medium under a 14：10 h light ： nbsp;dark cycle at 18℃. Then they were transferred into Schreiber medium and cultured under a 10：14 h light： dark cycle at 22℃. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1：1. Synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature.
