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1.
Cryopreservation of Porphyra yezoensis conchocelis was conducted with cryoprotectants and a proposed pretreatment procedure and thawing methods explored. Six cryoprotectants combined by DMSO with ethylene glycol （EG）, propylene glycol （PEG）, sorbitol and sucrose were developed. The effect of prefreezing at -40℃ or -20℃ for different time durations was compared and the thawing methods were screened. It was shown that the cryoprotectant including 10% DMSO with 0.5 molL^-1 sorbitol exhibited the optimal effect. The ideal pretreatment was that conchocelis segments were stayed for 20min at -40℃ before stored in liquid nitrogen, and 40℃ water bath was proper for quick thawing. The highest recovery rate of cryopreserved P. yezoensis conchocelis reached 89.41%. 相似文献
2.
Isolated protoplasts from thalli of Porphyra haitanensis and Porphyra yezoensis were treated with colchicine or irradiated by ultraviolet (UV). Several types of color variants were observed among the protoplast
offspring. After treatment with colchicine: (1) 0.04–0.09% of red type variants in P. haitanensis were obtained; (2) The rate of red type variants and the variegated chimeral thalli composed of red type and wild type of
sectors were 0.31–1.11% in P. yezoensis. After irradiation with UV: (1) 3.5–10.5% of red type variants in P. yezoensis were obtained: (2) 0.5–2.0% of red type variants and the variegated chimeral thalli composed of red type and wild type of
sectors were obtained in P. haitanensis. Colchicine and UV’s mutangenic effects on P. yezoensis protoplasts were stronger than those on P. haitanensis protoplasts. The most efficient concentration of colchicine was 0.05%. The optimal length of UV-radiation was 1/2 min (radiation
distance 5 cm). The red type variants induced by colchicine treatment grew faster than the wild type thalli. The clones of
vegetative propagation from protoplasts of red type variants were still red type thalli. The red type variants will be good
materials for genetic studies and improvement of Porphyra strains. 相似文献
3.
Pyropia yezoensis(formerly Porphyra yezoensis) is an economically important red alga that is cultured extensively in China. The red rot disease occurs commonly during Pyropia cultivation,causing serious economic losses. An incidence of red rot disease was found in a P. yezoensis farm from mid-November to mid-December 2015 at Lianyungang, Jiangsu Province, China. Histopathological examination revealed that the naturally infected thalli were infected apparently by a pathogen, leading to red rot symptoms. The causative agent was isolated and identified as the oomycete Pythium chondricola by morphological analysis and sequence analysis of the internal transcribed spacer and cytochrome oxidase subunit 1(cox1). In artificial infection experiments on the P. yezoensis blades, the P. chondricola isolate was able to cause the same characteristic histopathology seen in natural infections. P. chondricola grew well at a wide range of temperatures in the range 8-31℃, salinities at 0-45 and pH 5-9. In an orthogonal test used to determine the effects of environmental factors(temperature, salinity, and zoospore concentration)on infection, the data revealed that temperature was the most important factor to affect red rot disease development, with the optimal conditions for disease expansion being 20℃, 35 salinity, and a zoospore concentration of 10~6 zoospores/mL. The results obtained from the present study prompted us to set up a comprehensive epidemiological study on Pyropia, which will provide support to maintain the healthy development of the Pyropia industry in China. 相似文献
4.
The rates of photosynthesis and respiration of Porphyra, Laminaria and Undaria were determined with an oxygenmeter at different temperatures in an enclosed continuous-flow system. The temperature coefficients
of respiration and the net primary productivities for the three species were calculated. The spectacular rates of primary
production were found to be as high as 270 g C m −2 for P. yezoensis, 2200 g C m −2 for L. japonica and 160 g C m −2 for U. pinnatifida annually. The low respiratory rates of these three species as well as low light compensation points especially at low temperatures
are considered as a reason to save heat energy, resulting in a high productivity, especially in case of Laminaria.
Contribution No. 945 from the Institute of Oceanology, Academia Sinica.
The paper was presented at the International Phycological Society Meeting, 19–22 Aug. 1980, Glasgow, UK. 相似文献
5.
Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades
and conchocelis in the same culture of Porphyra. Study on samples of wild and cultivated Porphyra yezoensis and P. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade
of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown
that the single cells of Porphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing
leafy thalli.
This project was sponsored by the NSFC (No. C-0205-05-39770593) 相似文献
6.
The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor-joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences. 相似文献
7.
In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensis, cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based
on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding
for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exons and 1 intron.
The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high
as 82.23%. Four Ca 2+ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the
pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes
in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta. 相似文献
8.
According to the known sequence of iron stress-induced gene (isiAB operon), we cloned its 1.5 kb fragment by PCR, and used this fragment as integration homologous fragment. After several steps of subcloning donor DNA into theisiAB fragment, a donor plasmid pZL which could be integrated into the chromosomal DNA ofSynechococcus sp. PCC7942 was constructed. In order to express the heterologous gene at a high level through the integration platform system, we constructed the donor DNA by the following steps. We cloned the strong promoter (240 bp) of heat shock genegroESL operon fromSynechococcus sp. PCC7942 by PCR. Then subcloned the multiple cloning sites (MCS),rbcS polyA into the downstream of thegroESL promoter. The kanamycin resistance gene, as the marker gene, was also subcloned into the donor DNA. Thus, in the donor plasmid pZL, the integration homologous fragment and several expression elements, such asgroESL promoter, MCS,rbcS polyA terminator and kanamycin resistance gene, were all included. After naturally transformed and introduced the donor plasmid pZL intoSynechococcus sp. PCC7942, as in the pZL, the donor DNA sequence is flanked by two DNA fragments (0.4 kb and 0.7 kb) homologous to theisiAB fragment ofSynechococcus sp. PCC7942, the homologous DNA can recombine with the chromosomal DNA. After screening by kanamycin, the transformants which integrated the heterologous DNA were selected. The efficiency of transformation is about 1×10−6. By southern blot analysis, it was confirmed that the donor DNA had been integrated into the chromosomal DNA ofSynechococcus sp. PCC7942, located on the site of theisiAB gene, and can be replicated with the chromosomal DNA. 相似文献
9.
This paper reports results of study on the contents of proteins, amino acids, polysaccharose and uronic acids in 30 species of macroalgae from Shicao, Heishijiao, Shimiao, and Xiaofujiazhuang in the vicinity of Dalian City, N.E.China. The results showed that the protein contents of the 30 algae from highest (112.55μg/ml) to the lowest (0.24 p.g/ml) was in the descending order of Dictyopteris ndalata, Gelidium vagum,Gymnogongrus japonican, Ectocarpus confervoides, Tinocladia crassa, Sargassum thunberii. In general, the protein content in red algae was higher than that in brown algae. The content of free ami no acids showed nosignificent differences from 7.44μg/ml-4.96μg/ml in all these algae, in the descending order of Gymnogongrusrus japonican, Sargassum confusum, Undoria pinnatifida, Laminaria japonica and Ectocarpus confervoides. The content of polysaccharose varied from 168.2 gg/ml-22.15 p.g/ml in the descending order of Symphyocladiaia tiuscula, Scytosiphon lomentarius, Desmarestia viridis., Tinocladia crassa, Gracilaria asiatica and Porphyra yezoensis. The content of uronic acids is from 196.24μg/ml-20.77μg/ml in the descending order of Ulva lactuca,Symphyoclaldia latiuscula, Scytosiphon lomentarius, Ceramimum kondoi, Gracilaria vemucosa and Porphyra yezoensis. The fatty acids in 30 species of algae belong to Rhodophyta, Chlorophyta and Phaeophyta. Most phaeophytes have many (4-12) types of fatty acids. 相似文献
10.
Inorganic carbon utilization in the non-calcifying marine microalgae, Nannochloropsis oculata, Phaeodactylum tricornutum and Porphyridium purpureum was compared with high- and low-calcifying strains of Emiliania huxleyi grown in artificial seawater medium aerated with either air (0.03% V/V CO 2) or CO 2-free air. For high-calcifying strain of E. oculata and P. tricornutem, similar growth patterns were observed in air-and CO 2-free air-grown cultures. P. purpureum showed a less final cell density in CO 2-free air than in air-grown culture. However, low-calcifying strain of E. huxleyi was able to grow only in air-grown culture, but not in CO 2-free air-grown culture.
Measurements of alkalinity, pH, concentration of dissolved inorganic carbon (DIC) and free CO 2 showed different patterns of DIC utilization. With N. oculata, P. tricornutum and P. purpureum the pattern of DIC utilization was characterized by an increase of pH and a decrease of DIC but a constant alkalinity in
the cultures aerated with air or CO 2-free air, suggesting that bicarbonate utilization was concomitant with an efflux of OH −. Both alkalinity and pH were maintained rather constant in air-grown culture of low-calcifying strain of E. huxleyi, suggesting that diffusive entry of CO 2 could meet the requirement of DIC for its photosynthesis and growth. High-calcifying strain of E. huxleyi, however, showed a pattern of decrease of alkalinity and DIC but an almost constant pH, indicating that bicarbonate was the
major form of inorganic carbon utilised by this organism and bicarbonate uptake is unlikely to be accompanied by an efflux
of OH −.
The final pH values reached by N. oculata, P. tricornutum and P. purpureum in a closed system were 10.75, 10.60 and 9.85 respectively, showing that bicarbonate utilisation is concomitant with an efflux
of OH −. While the final pH of 8.4 in high-calcifying E. huxleyi suggests that bicarbonate utilization was not accompanied by an efflux of OH −.
Contribution No. 3557 from the Institue of Oceanology, Chinese Academy of Sciences.
This work was supported by NERC grant GRE3/7853 U. K. and partly supported by Bio-Engineering Center, SSTC 96-C01-05-01. 相似文献
11.
Fe^2＋ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe^2＋ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentrations of Fe^2＋. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1-102.1μg/L, 10-100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentrations, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually. 相似文献
12.
Porphyra haitanensis and P. yezoensis are two main Porphyra species cultured in China. Their life histories are slightly different. So far we have not observed that P. haitanensis naturally produces monospores developing into thalli. P. yezoensis produces monospores which directly germinate into young thalli used in cultivation (Zeng, et al., 1985). Some somatic cells
in P. yezoensis develop in vitro into monospore-like cells which later grow into young thalli (Lu, 1983). Studies on whether or not somatic
cells in P. haitanensis can produce in vitro monospore-like cells that later grow into young thalli is important for understanding its life history
and for culturing new varieties. 相似文献
13.
Pyropia yezoensis, belongs to the genus of Porphyra before 2011, inhabit on intertidal zone rocks where irradiation changes dramatically, implying that the seaweed has gained certain mechanisms to survive a harsh environment. Based on the photosynthetic parameters with or without the inhibitors determined by a Dual-PAM-100 apparatus, we investigated the photosynthetic performance and the changes in electron flow that occurred during the algae were stressed with different light intensities previously. When the irradiation saturation was approaching, the CEF around PS I became crucial since the addition of inhibitors usually led to an increase in non-photochemical quenching. The inhibitor experiments showed that there were at least three different CEF pathways in Py. yezoensis and these pathways compensated each other. In addition to maintaining a proper ratio of ATP/NAD(P)H to support efficient photosynthesis, the potential roles of CEF might also include the regulation of different photoprotective mechanisms in Py. yezoensis. Under the regulation of CEF, chlororespiration is thought to transport electrons from the reduced plastoquinone (PQ) pool to oxygen in order to mitigate the reduction in the electron transfer chain. When irradiation was up to the high-grade stress conditions, the relative value of CEF began to decrease, which implied that the NADP + pool or PQ + pool was very small and that the electrons were transferred from reduced PS I to oxygen. The scavenging enzymes might be activated and the water-water cycle probably became an effective means of removing the active oxygen produced by the irradiation stressed Py. yezoensis. We believe that the different mechanisms could make up the photoprotective network to allow Py. yezoensis for survival in a highly variable light stress habitat, which may enlighten scientists in future studies on irradiance stress in other algae species. 相似文献
15.
A genetic transformation model for the seaweedLaminaria japonica mainly includes the following aspects:
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1.
The method to introduce foreign genes into the kelp,L. japonica
Biolistic bombardment has been proved to be an effective method to bombard foreign DNA through cell walls into intact cells of both sporophytes and gametophytes. The expression ofcat andlacZ was detected in regenerated sporophytes, which suggests that this method could induce random integration of foreign genes.
Promoters to drive gene expression
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2.
The CaMV35S promoter was first used by us to induce the expression of GUS gene in brown algae. But results of further studies suggested that CaMV35S could be a tissue-specific promoter. Our use of SV40 promoter resulted in both transient and stable expression oflacZ andcat in sporophytes or gametophytes. No GUS or LacZ background was found in either sporophytes or gametophytes.The regeneration route of transgenic kelp
The regeneration efficiency of explants is still very low. By using female gametophytes as gene hosts and parthenogenesis as regeneration route, CAT activity and LacZ activity were detected in regenerated sporophytes of parthenogenetic kelp. li]4.|The way to select transgenic kelp
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1.
Results of sensitivity tests showed that kelp was only sensitive to chloramphenicol and hygromycin among many antibiotics. The regenerated sporophytes by parthenogenesis were more sensitive to hygromycin than to chloramphenicol. Resistant kelp was created by transforming female gametophytes with pSV40-CAT and stimulating parthenogenesis followed by selection in medium with lethal concentration of chloramphenicol.
Safety consideration of transgenic kelp
L. japonica was originally introduced from Japan. In China it is a cultured population. The possibility of its negative impact on natural populations is very low. 2) The vectors and target genes used for transformation should be restricted in order to avoid any negative impacts on human health and environment. 3) Specially devised containers (3.6 L, made of 200 μm membrane) were used to ensure that the kelp cannot escape or be eaten by marine animals. 4) To avoid the release of spores, it is very necessary to harvest the kelp at suitable age before the sporangium forms.
相似文献
16.
Lytic Characteristics and Identification of Two Alga-lysing Bacterial StrainsBeaulieu, S. E., M. R. Sengco, and D. M. Anderson, 2005. Using clay to control harmful algal blooms: deposition and resuspension of clay/algal flocs. Harmful Algae . (4): 123-138… 相似文献
17.
Laboratory culture experiments showed that <100μ mol/L nitrate, amonium or mixture of amino acids promote the growth of the
red tide organism Prorocentrum micans Ehrenb, but that >100μmol/L of ammonium, or mixture of glycine and glutamate was harmful to growth, and that orthophosphate
was P. micans’ main phosphorous source in the ocean. Presence of 80μ mol/L EDTA, 0.5 to 1 μmol/L Fe 3+, 1.0 to 20.0 μ mol/L Mn 2+ 0.1 to 0.4 μmol/L Co 2+ in the culture medium could improve the growth of P. micans. Vitamin B 1 promoted growth, but vitamin B 12 and biotin did not. The estimated minimum cell quotas ( q
o) for nitrogen and phosphorus being 0.74 pmole/cell and 0.045 pmole/cell show that phosphorus (more than nitrogen) limits
the growth of P. micans in the study area.
This project was supported by the Natural Science Foundation of Zhejiang Province. 相似文献
19.
The structure gene for ferredoxin,petFI, fromAnabaena siamensis has been amplified by polymerase chain reaction(PCR) and cloned into cloning vector pGEM-3zf(+). The nucleotide sequence ofpetFI has been determined with silver staining sequencing method. There is 96.8% homology between coding region ofpetFI fromA. siamensis and that ofpetFI fromA. sp. 7120. Amino acid sequences of seven strains of blue-green algae are compared. 相似文献
20.
Free-living conchocelis of Porphyra yezoensis Ueda (Bangiales, Rhodophyta) were treated with 60Co-γ rays of different doses (ranging from 100 Gy to 1000 Gy) to induce mutation. Most of the conchocelis maintained the capability
of penetrating into shells, growing and forming colonies in shells, but their vitality was seriously impaired by the irradiation
of γ-rays. A few conchocelis pigments were mutagenized directly into different color pigment mutants whose progeny-conchospores
and foliose thalli had the same colors. However, some irradiated conchocelis did not show the change in color at the conchocelis
stage. The pigment mutation could be observed only after the conchospores of these conchocelis had germinated into young foliose
thalli. Irradiation of low dose (100 Gy) promoted the growth of thallus and many with altered morphology were observed. Conchospores
of the irradiated conchocelis attached to the culture nets were cultured in the sea, and growth of these progenies was observed
and measured. 相似文献
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