Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarp...Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.展开更多
The transcriptomes of three different parts of the fertile tetrasporophyte of Gracilariopsis lemaneiformis,including tip(T),middle(M),and subjacent(S)parts,with a gradual tetrasporangium maturity were analyzed and com...The transcriptomes of three different parts of the fertile tetrasporophyte of Gracilariopsis lemaneiformis,including tip(T),middle(M),and subjacent(S)parts,with a gradual tetrasporangium maturity were analyzed and compared to identify the genes involved in the process of tetrasporogenesis.The number of differentially expressed genes(DEGs)for the Gple-S versus Gple-T comparison was 10296,and the numbers of DEGs for the Gple-S versus Gple-M and Gple-T versus Gple-M comparisons were 7435 and 1337,respectively.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were performed,and the results showed the enrichment of 132 KEGG pathways(corrected P<0.05).A total of 58 DEGs related to meiosis were screened and blasted against 18 meiosis-related genes(dmc1,mlh1,mnd1,msh4,msh2,msh6,mre11,pds5,pms1,rad21,rad50,rad51,smc1,smc2,smc4,smc5,smc6,and spo11),including four meiosis-specific genes.The transcriptome comparison indicated that in the T part,the meiosis,ribosome,and RNA transport-related genes were mostly up-regulated compared with those in the other two groups.In the M part,the genes related to ribosomes and the endoplasmic reticulum were also up-regulated compared with those in the lower part.Finally,in the S part,the genes associated with photosynthesis were mostly up-regulated,which might be helpful to the recovery from spore formation and release.展开更多
Sulfur is an essential macronutrient for the growth of all photosynthetic organisms and plays important roles in different metabolic pathways.However,sulfur metabolism and its related research on macroalgae with impor...Sulfur is an essential macronutrient for the growth of all photosynthetic organisms and plays important roles in different metabolic pathways.However,sulfur metabolism and its related research on macroalgae with important ecological value is rather limited.In this study,marine ecological valued macroalga Gracilariopsis lemaneiformis was used to study the general physiological responses and transcriptome profiling under the sulfate deficiency.The relative growth rate of algae under sulfate deficiency was statistically significantly lower than that of control after 6 days.However,no significant differences were observed in the pigments content and Fv/Fm value,indicating that the photosynthesis was not obviously affected under the sulfate deficiency.Furthermore,the significantly increased soluble protein and carbohydrate contents,and indistinctively differentially expressed sulfate transporter/permease(ST)and ATP sulfurylase(ATPS)genes suggesting that G.lemaneiformis cells did not use sulfur from internal protein and carbohydrate pools but utilize stored sulfur from vacuole to satisfy their nutritional requirements during the sulfate deficiency.Transcriptome data showed that most annotated differentially expressed genes(DEGs)were down-regulated under the sulfate deficiency,including a large proportion of genes involved in the pathway of sulfur metabolism.Therefore,it was concluded that the pathway of sulfur metabolism was suppressed under the sulfate deficiency in G.lemaneiformis.The results and analysis in this study provide a comprehensive understanding for the physiological and molecular response of G.lemaneiformis to sulfate deficiency.展开更多
Flow cytometry(FCM) technique has been widely applied to estimating the genome size of various higher plants. However, there is few report about its application in algae. In this study, an optimized procedure of FCM w...Flow cytometry(FCM) technique has been widely applied to estimating the genome size of various higher plants. However, there is few report about its application in algae. In this study, an optimized procedure of FCM was exploited to estimate the genome size of two eukaryotic algae. For analyzing Alexandrium catenella, an important red tide species, the whole cell instead of isolated nucleus was studied, and chicken erythrocytes were used as an internal reference. The genome size of A. catenella was estimated to be 56.48 ± 4.14 Gb(1C), approximately nineteen times larger than that of human genome. For analyzing Gracilariopsis lemaneiformis, an important economical red alga, the purified nucleus was employed, and Arabidopsis thaliana and Chondrus crispus were used as internal references, respectively. The genome size of Gp. lemaneiformis was 97.35 ± 2.58 Mb(1C) and 112.73 ± 14.00 Mb(1C), respectively, depending on the different internal references. The results of this research will promote the related studies on the genomics and evolution of these two species.展开更多
Gracilariopsis lemaneiformis is an economically-valued species and widely cultured in China at present.After being acclimated to diff erent growth temperatures(15,20,25,and 30°C)for 7 days,the relative growth rat...Gracilariopsis lemaneiformis is an economically-valued species and widely cultured in China at present.After being acclimated to diff erent growth temperatures(15,20,25,and 30°C)for 7 days,the relative growth rate(RGR),nitrate reductase activity,soluble protein content and chlorophyll a fl uorescence of G.lemaneiformis were examined.Results show that RGR was markedly aff ected by temperature especially at 20°C at which G.lemaneiformis exhibited the highest eff ective quantum yield of PSII[Y(II)]and lightsaturated electron transport rate(ETR max),but the lowest non-photochemical quenching.Irrespective of growth temperature,the nitrate reductase activity increased with the incubation temperature from 15 to 30°C.In addition,the greatest nitrate reductase activity was found in the thalli grown at 20°C.The value of temperature coeffi cient Q10 of alga cultured in 15°C was the greatest among those of other temperatures tested.Results indicate that the optimum temperature for nitrate reductase synthesis was relatively lower than that for nitrate reductase activity,and the relationship among growth,photosynthesis,and nitrate reductase activity showed that the optimum temperature for activity of nitrate reductase in vivo assay should be the same to the optimal growth temperature.展开更多
Three Gracilariopsis lemaneiformis strains,including wild type and high-temperature-resistant cultivars 981 and 2007,were studied with the changes in their photosynthetic pigment contents and related gene transcriptio...Three Gracilariopsis lemaneiformis strains,including wild type and high-temperature-resistant cultivars 981 and 2007,were studied with the changes in their photosynthetic pigment contents and related gene transcription levels under different light intensities(10,60,100,and 200μmolm^(−2)s^(−1)).The three G.lemaneiformis strains had the following photosynthetic pigments with high-to-low contents:phycoerythrin(PE),phycocyanin(PC),allophycocyanin(APC),and chlorophyll a(Chl a).Among the three strains,cultivar 981 had the highest PE content,followed by cultivar 2007.The PC and APC contents were similar among the three strains,but they were higher in cultivars 981 and 2007 than in the wild type.The Chl a contents in the three G.lemaneiformis strains were equal.A low light intensity(10μmolm^(−2)s^(−1))promoted photosynthetic pigment accumulation in G.lemaneiformis and improved the relative PE gene transcription(peA and peB)in a short period(≤6 d).A high light intensity decreased the PE content.PebA and PebB,which catalyzed phycoerythrobilin synthesis,showed no compensatory upregulation at a low light intensity among the strains except for the wild type.At a high light intensity,transcription levels of pebA and pebB in the three strains were upregulated.This study provided an experimental basis for elucidating the photosynthesis of G.lemaneiformis.As key genes of algal growth,photo-synthesis-related genes served as useful gene markers for screening elite varieties with good traits in breeding.Cultivar 2007 was superior to cultivar 981 in terms of maintaining high pigment levels in a wide range of light intensities,which is the most suitable for aquaculture.展开更多
This paper reports the first successful isolation of protoplasts from G racilariopsis bailiniae and their callus formation. The base solution type, concentration of isolating enzymes, concentration of sorbitol, incuba...This paper reports the first successful isolation of protoplasts from G racilariopsis bailiniae and their callus formation. The base solution type, concentration of isolating enzymes, concentration of sorbitol, incubation time, temperature and pH of the enzyme solution were tested to optimize the protoplast yield. The optimized isolation conditions were: 40% base solution 3(deionized water containing 25 mmol/L MESTris and 25 mmol/L CaCl 2 ·2 H 2 O) and 60% crude Marinomonas sp. YS-70 agarase solution, containing 2% w/v cellulase, 1% w/v macerozyme R-10 and 0.4 mol/L sorbitol, with incubation for 4 h at 28°C and pH 6.5. The highest yield of viable protoplasts, which was obtained in these conditions, was(1.75±0.25)×10 6 cells/g fresh weight. Cell wall regeneration of most protoplasts from G. bailiniae was complete within 60 h and the first division of cells happened after ≥3 days. Two division types were observed in the first division of protoplasts from G. bailiniae— asymmetric division and symmetric division. After the first division, the cells underwent a series of divisions to form callus cell masses.展开更多
Reproductive apparatus of Gracilaria/Gracilariopsis lemaneiformis collected from Qingdao city were studied with a light and a transmission electron microscope. The special superficial arrangement of spermatangium for ...Reproductive apparatus of Gracilaria/Gracilariopsis lemaneiformis collected from Qingdao city were studied with a light and a transmission electron microscope. The special superficial arrangement of spermatangium for this species was clearly observed, and the ultrastructure of spermatangial devel-opment revealed the similar cytodynamic pattern followed by all the Gracilariaceae members devel-oped from spermatangial mother cells to spermatangium. The female reproductive apparatus before fertilization was also observed and trichogyne was found protruding above the cortex, contrary to the earlier reports. Tetrasporangium was formed by an outer cortical cell and the tetraspores became spherical and expended after being released.展开更多
Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-c...Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-cies which are important resources for the production of special proteins, phycobilisomes, special carbo-hydrates, and agar in China. In this study, de novo transcriptome sequencing on these four species using the next generation sequencing technology was performed for the first time. Functional annotations on assembled sequencing reads showed that the transcriptomic profiles were quite different between G. lema-neiformis and other three Gracilaria species. Comparative analysis of differential gene expression related to carbohydrate and phycobiliprotein metabolisms also showed that the expression profiles of these essential genes were different in four species. The genes encoding allophycocyanin, phycocyanin and phycoerythrin were further examined in four species and their deduced amino acid sequences were used for phylogenetic analysis to confirm that G. lemaneiformis had close relationship to genus Gracilaria, as well as that within genus Gracilaria, G. chouae had closer relationship to G. vermiculophylla rather than to G. blodgettii. The de novo transcriptome study on four species provided a valuable genomic resource for further understanding and analysis on biological and evolutionary study among marine algae.展开更多
This study reports the morphological, anatomical and agar content difference among various species of Gracilaria. The cortex was found 1-2 layered in G. edulis and G. eucheumatoides whereas 5-6 layered in G. foliifera...This study reports the morphological, anatomical and agar content difference among various species of Gracilaria. The cortex was found 1-2 layered in G. edulis and G. eucheumatoides whereas 5-6 layered in G. foliifera and G. crassa. The medulla was 6-8 layered in G. edulis, 10-11 layered in G. foliifera, 14-15 layered in G. eucheumatoides and 8-10 layered in G. crassa. Similarly, distinct variations were observed in the structure of cystocarp of these taxa. The outer pericarp was 6-8 layered in G. verrucosa (attached type), 8-9 in Graciriopsis megaspora, 12-13 layered cells in G. edulis, 9-11 layered in G. foliifera, 12-15 layered in G. eucheumatoides and 11-14 layered in G. crassa. The tubular nutritive filaments were radiating type in G. edulis whereas these were penetrating and radiating type in G. foliifera. In G. crassa, the same was produced from a small swollen short base and in G. verrucosa (attached type) it was long. Further, in G. eucheumatoides and Gracilariopsis megaspore, nutritive filaments were not observed. Among various species of Gracilariales studied in this work, agar from Gracilaria verrucosa (floating type or sterile type) showed highest yield with gel strength 260 gm/cm2 and viscosity 10 milipass. Based on the agar quality,展开更多
基金Supported by the National Key R&D Program of China(No.2018YFD0901502)the Ningbo Key R&D Science and Technology Program(Nos.2019B10009,2021Z114)the Natural Science Foundation of Zhejiang Province(Nos.LY19C190003,LQ20C190002)。
文摘Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.
基金This research was supported by the Key Program of Science and Technology Innovation in Ningbo(No.2019B10009)the National Natural Science Foundation of China(No.41476111).
文摘The transcriptomes of three different parts of the fertile tetrasporophyte of Gracilariopsis lemaneiformis,including tip(T),middle(M),and subjacent(S)parts,with a gradual tetrasporangium maturity were analyzed and compared to identify the genes involved in the process of tetrasporogenesis.The number of differentially expressed genes(DEGs)for the Gple-S versus Gple-T comparison was 10296,and the numbers of DEGs for the Gple-S versus Gple-M and Gple-T versus Gple-M comparisons were 7435 and 1337,respectively.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were performed,and the results showed the enrichment of 132 KEGG pathways(corrected P<0.05).A total of 58 DEGs related to meiosis were screened and blasted against 18 meiosis-related genes(dmc1,mlh1,mnd1,msh4,msh2,msh6,mre11,pds5,pms1,rad21,rad50,rad51,smc1,smc2,smc4,smc5,smc6,and spo11),including four meiosis-specific genes.The transcriptome comparison indicated that in the T part,the meiosis,ribosome,and RNA transport-related genes were mostly up-regulated compared with those in the other two groups.In the M part,the genes related to ribosomes and the endoplasmic reticulum were also up-regulated compared with those in the lower part.Finally,in the S part,the genes associated with photosynthesis were mostly up-regulated,which might be helpful to the recovery from spore formation and release.
基金supported by Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.GML2019ZD0606)National Natural Science Foundation of China(Grant No.41976125)+3 种基金Special Fund for Science and Technology of Guangdong Province(Grant No.STKJ2021193)Natural Science Foundation of Guangdong Province(Grant No.2022A1515012141)Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515110001)Innovation Project of Guangdong University(Grant No.2018KCXTD012).
文摘Sulfur is an essential macronutrient for the growth of all photosynthetic organisms and plays important roles in different metabolic pathways.However,sulfur metabolism and its related research on macroalgae with important ecological value is rather limited.In this study,marine ecological valued macroalga Gracilariopsis lemaneiformis was used to study the general physiological responses and transcriptome profiling under the sulfate deficiency.The relative growth rate of algae under sulfate deficiency was statistically significantly lower than that of control after 6 days.However,no significant differences were observed in the pigments content and Fv/Fm value,indicating that the photosynthesis was not obviously affected under the sulfate deficiency.Furthermore,the significantly increased soluble protein and carbohydrate contents,and indistinctively differentially expressed sulfate transporter/permease(ST)and ATP sulfurylase(ATPS)genes suggesting that G.lemaneiformis cells did not use sulfur from internal protein and carbohydrate pools but utilize stored sulfur from vacuole to satisfy their nutritional requirements during the sulfate deficiency.Transcriptome data showed that most annotated differentially expressed genes(DEGs)were down-regulated under the sulfate deficiency,including a large proportion of genes involved in the pathway of sulfur metabolism.Therefore,it was concluded that the pathway of sulfur metabolism was suppressed under the sulfate deficiency in G.lemaneiformis.The results and analysis in this study provide a comprehensive understanding for the physiological and molecular response of G.lemaneiformis to sulfate deficiency.
基金supported by the National Natural Science Foundation of China (Nos.41176098 and 31372529)
文摘Flow cytometry(FCM) technique has been widely applied to estimating the genome size of various higher plants. However, there is few report about its application in algae. In this study, an optimized procedure of FCM was exploited to estimate the genome size of two eukaryotic algae. For analyzing Alexandrium catenella, an important red tide species, the whole cell instead of isolated nucleus was studied, and chicken erythrocytes were used as an internal reference. The genome size of A. catenella was estimated to be 56.48 ± 4.14 Gb(1C), approximately nineteen times larger than that of human genome. For analyzing Gracilariopsis lemaneiformis, an important economical red alga, the purified nucleus was employed, and Arabidopsis thaliana and Chondrus crispus were used as internal references, respectively. The genome size of Gp. lemaneiformis was 97.35 ± 2.58 Mb(1C) and 112.73 ± 14.00 Mb(1C), respectively, depending on the different internal references. The results of this research will promote the related studies on the genomics and evolution of these two species.
基金Supported by the National Key R&D Program of China(No.2017YFC0506200)the Shandong Province Science Foundation for Youths(No.ZR201807120023)+3 种基金the Key Research and Development Program of Yantai(No.2018ZHGY082)the China Agriculture Research System(No.CARS-50)the Financial Fund of the Ministry of Agriculture and Rural Aff airs,China(No.NFZX2018)the Project of Guangdong Province Education Department(No.2017KCXTD014)。
文摘Gracilariopsis lemaneiformis is an economically-valued species and widely cultured in China at present.After being acclimated to diff erent growth temperatures(15,20,25,and 30°C)for 7 days,the relative growth rate(RGR),nitrate reductase activity,soluble protein content and chlorophyll a fl uorescence of G.lemaneiformis were examined.Results show that RGR was markedly aff ected by temperature especially at 20°C at which G.lemaneiformis exhibited the highest eff ective quantum yield of PSII[Y(II)]and lightsaturated electron transport rate(ETR max),but the lowest non-photochemical quenching.Irrespective of growth temperature,the nitrate reductase activity increased with the incubation temperature from 15 to 30°C.In addition,the greatest nitrate reductase activity was found in the thalli grown at 20°C.The value of temperature coeffi cient Q10 of alga cultured in 15°C was the greatest among those of other temperatures tested.Results indicate that the optimum temperature for nitrate reductase synthesis was relatively lower than that for nitrate reductase activity,and the relationship among growth,photosynthesis,and nitrate reductase activity showed that the optimum temperature for activity of nitrate reductase in vivo assay should be the same to the optimal growth temperature.
基金This research was supported by the National Natural Sci-ence Foundation of China(No.31872555)the China Agri-culture Research System(No.CARS-50)the Key Pro-gram of Science and Technology Innovation Ningbo(No.2019B10009).
文摘Three Gracilariopsis lemaneiformis strains,including wild type and high-temperature-resistant cultivars 981 and 2007,were studied with the changes in their photosynthetic pigment contents and related gene transcription levels under different light intensities(10,60,100,and 200μmolm^(−2)s^(−1)).The three G.lemaneiformis strains had the following photosynthetic pigments with high-to-low contents:phycoerythrin(PE),phycocyanin(PC),allophycocyanin(APC),and chlorophyll a(Chl a).Among the three strains,cultivar 981 had the highest PE content,followed by cultivar 2007.The PC and APC contents were similar among the three strains,but they were higher in cultivars 981 and 2007 than in the wild type.The Chl a contents in the three G.lemaneiformis strains were equal.A low light intensity(10μmolm^(−2)s^(−1))promoted photosynthetic pigment accumulation in G.lemaneiformis and improved the relative PE gene transcription(peA and peB)in a short period(≤6 d).A high light intensity decreased the PE content.PebA and PebB,which catalyzed phycoerythrobilin synthesis,showed no compensatory upregulation at a low light intensity among the strains except for the wild type.At a high light intensity,transcription levels of pebA and pebB in the three strains were upregulated.This study provided an experimental basis for elucidating the photosynthesis of G.lemaneiformis.As key genes of algal growth,photo-synthesis-related genes served as useful gene markers for screening elite varieties with good traits in breeding.Cultivar 2007 was superior to cultivar 981 in terms of maintaining high pigment levels in a wide range of light intensities,which is the most suitable for aquaculture.
基金Supported by the China Agriculture Research System(No.CARS-50)the Science and Technology Program of Guangdong Province of China(Nos.2016A020222023,2015B090903081)the Project of Guangdong Province Education Department(No.2017KCXTD014)
文摘This paper reports the first successful isolation of protoplasts from G racilariopsis bailiniae and their callus formation. The base solution type, concentration of isolating enzymes, concentration of sorbitol, incubation time, temperature and pH of the enzyme solution were tested to optimize the protoplast yield. The optimized isolation conditions were: 40% base solution 3(deionized water containing 25 mmol/L MESTris and 25 mmol/L CaCl 2 ·2 H 2 O) and 60% crude Marinomonas sp. YS-70 agarase solution, containing 2% w/v cellulase, 1% w/v macerozyme R-10 and 0.4 mol/L sorbitol, with incubation for 4 h at 28°C and pH 6.5. The highest yield of viable protoplasts, which was obtained in these conditions, was(1.75±0.25)×10 6 cells/g fresh weight. Cell wall regeneration of most protoplasts from G. bailiniae was complete within 60 h and the first division of cells happened after ≥3 days. Two division types were observed in the first division of protoplasts from G. bailiniae— asymmetric division and symmetric division. After the first division, the cells underwent a series of divisions to form callus cell masses.
基金Supported by the National Natural Sciences Foundation of China (Grant No. 40606034)the National High-Tech Research and Development Program of China (Grant No. 2006AA10A413)
文摘Reproductive apparatus of Gracilaria/Gracilariopsis lemaneiformis collected from Qingdao city were studied with a light and a transmission electron microscope. The special superficial arrangement of spermatangium for this species was clearly observed, and the ultrastructure of spermatangial devel-opment revealed the similar cytodynamic pattern followed by all the Gracilariaceae members devel-oped from spermatangial mother cells to spermatangium. The female reproductive apparatus before fertilization was also observed and trichogyne was found protruding above the cortex, contrary to the earlier reports. Tetrasporangium was formed by an outer cortical cell and the tetraspores became spherical and expended after being released.
基金The National Natural Science Foundation of China under contract Nos 31140070,31271397 and 41206116the algal transcrip-tome sequencing was supported by 1KP Project(www.onekp.com)
文摘Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-cies which are important resources for the production of special proteins, phycobilisomes, special carbo-hydrates, and agar in China. In this study, de novo transcriptome sequencing on these four species using the next generation sequencing technology was performed for the first time. Functional annotations on assembled sequencing reads showed that the transcriptomic profiles were quite different between G. lema-neiformis and other three Gracilaria species. Comparative analysis of differential gene expression related to carbohydrate and phycobiliprotein metabolisms also showed that the expression profiles of these essential genes were different in four species. The genes encoding allophycocyanin, phycocyanin and phycoerythrin were further examined in four species and their deduced amino acid sequences were used for phylogenetic analysis to confirm that G. lemaneiformis had close relationship to genus Gracilaria, as well as that within genus Gracilaria, G. chouae had closer relationship to G. vermiculophylla rather than to G. blodgettii. The de novo transcriptome study on four species provided a valuable genomic resource for further understanding and analysis on biological and evolutionary study among marine algae.
文摘This study reports the morphological, anatomical and agar content difference among various species of Gracilaria. The cortex was found 1-2 layered in G. edulis and G. eucheumatoides whereas 5-6 layered in G. foliifera and G. crassa. The medulla was 6-8 layered in G. edulis, 10-11 layered in G. foliifera, 14-15 layered in G. eucheumatoides and 8-10 layered in G. crassa. Similarly, distinct variations were observed in the structure of cystocarp of these taxa. The outer pericarp was 6-8 layered in G. verrucosa (attached type), 8-9 in Graciriopsis megaspora, 12-13 layered cells in G. edulis, 9-11 layered in G. foliifera, 12-15 layered in G. eucheumatoides and 11-14 layered in G. crassa. The tubular nutritive filaments were radiating type in G. edulis whereas these were penetrating and radiating type in G. foliifera. In G. crassa, the same was produced from a small swollen short base and in G. verrucosa (attached type) it was long. Further, in G. eucheumatoides and Gracilariopsis megaspore, nutritive filaments were not observed. Among various species of Gracilariales studied in this work, agar from Gracilaria verrucosa (floating type or sterile type) showed highest yield with gel strength 260 gm/cm2 and viscosity 10 milipass. Based on the agar quality,