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Microorganisms plays an important role in the growth of Pyropia haitanensis. To understand the structural and functional diversity of the microorganism community of P. haitanensis(PH40), the associated metabolic pathway network in cluster of orthologous groups(COG) and Kyoto Encyclopedia of Genes and Genomes(KEGG), and carbohydrate-active enzymes(CAZymes) were explored in metagenomic analysis. DNA extraction from gametophytes of P. haitanensis was performed first, followed by library construction, sequencing, preprocessing of sequencing data, taxonomy assignment, gene prediction, and functional annotation. The results show that the predominant microorganisms of P. haitanensis were bacteria(98.98%), and the phylum with the highest abundance was Proteobacteria(54.64%), followed by Bacteroidetes(37.92%). Erythrobacter(3.98%) and Hyunsoonleella jejuensis(1.56%) were the genera and species with the highest abundance of bacteria, respectively. The COG annotation demonstrated that genes associated with microbial metabolism was the predominant category. The results of metabolic pathway annotation show that the ABC transport system and two-component system were the main pathways in the microbial community. Plant growth hormone biosynthesis pathway and multi-vitamin biosynthesis functional units(modules) were the other important pathways. The CAZyme annotation revealed that the starch might be an important carbon source for microorganisms. Glycosyl transferase family 2(GT2) and glycosyl transferase family 3(GT3) were the highly abundant families in glucoside transferase superfamily. Six metagenome-assembled genomes containing enzymes involved in the biosynthesis of cobalamin(vitamin B 12) and indole-3-acetic acid were obtained by binning method. They were confirmed to belong to Rhodobacterales and Rhizobiales, respectively. Our findings provide comprehensive insights into the microorganism community of Pyropia.  相似文献   

3.
Pyropia haitanensis poly saccharide(LP) have been found for having many excellent functions such as anti-aging.Using Caenorhabditis elegans models,we evaluated the anti-aging activity of LP by observing the lifespan,reproduction,pharyngeal pumping,stress response,quantitative fluorescence of poly glutamic acid,and nuclear localization of DAP-16 of worms.The results reveal that LP could extend the adult lifespan of wild-type and polyQ nematodes,indicating a connection of its anti-aging benefit with the toxicity-suppressing effect The number of polyglutamic acid aggregates in high concentration groups decreased by 24.39%(P0.05) to the control.The high-dose group strongly induced DAP-16 nuclear translocation over intermediate and cytosolic localizations compared with the control(P0.001).Therefore,we believe that LP could extend the lifespan and reduce the protein aggregation in C.elegans through nuclear DAF-16::GFP expression.  相似文献   

4.
Members of the Dna J family are proteins that play a pivotal role in various cellular processes, such as protein folding, protein transport and cellular responses to stress. In the present study, we identified and characterized the full-length Dna J c DNA sequence from expressed sequence tags of Pyropia yezoensis( Py Dna J) via rapid identification of c DNA ends. This c DNA encoded a protein of 429 amino acids, which shared high sequence similarity with other identified Dna J proteins, such as a heat shock protein 40/Dna J from Pyropia haitanensis. The relative m RNA expression level of Py Dna J was investigated using real-time PCR to determine its specific expression during the algal life cycle and during desiccation. The relative m RNA expression level in sporophytes was higher than that in gametophytes and significantly increased during the whole desiccation process. These results indicate that Py Dna J is an authentic member of the Dna J family in plants and red algae and might play a pivotal role in mitigating damage to P. yezoensis during desiccation.  相似文献   

5.
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 CO 2 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 signifi cantly 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 CO 2 concentration during moderate dehydration,which might be caused by the enhancement of cyclic electron fl ow.These results suggested that P.yezoensis can directly utilize CO 2 in ambient air during moderate dehydration.  相似文献   

6.
Volatile organic compounds in marine algae have been reported to comprise characteristic flavor of algae and play an important role in their growth, development and defensive response. Yet their biogeneration remain largely unknown. Here we studied the composition of volatile compouds in Pyropia yezoensis and their variations in response to methyl jasmonate(MeJA) and diethyldithiocarbamic acid(DIECA) treatment using gas chromatography-mass spectrometry(GC-MS). A total of 44 compounds belonging to the following chemical classes(n) were identified, including aldehydes(11), alcohols(8), acids and esters(6), alkanes(5), ketones(5), alkenes(3), and S-or N-containing miscellaneous compounds(6). External treatment with plant hormone MeJA increased the content of 1-dodecanol, 4-heptenal, and 2-propenoic acid-2-methyl dodecylester, but decreased the content of phytol, 3-heptadecene, 2-pentadecanone, and isophytol. When pretreated with DIECA, an inhibitor of the octadecanoid pathway leading to the biosynthesis of endogeneous jasmonates and some secondary metabolites, phytol and isophytol were increased, while 4-heptenal, 1-dodecanol, and 2-propenoic acid-2-methyl dodecylester were decreased, both of which were negatively correlated with their variations under MeJA treatment. Collectively, these results suggest that MeJA does affect the volatile composition of P. yezoensis, and the octadecanoid pathway together with endogenous jasmonate pathway may be involved in the biosynthesis of volatile compounds, thereby providing some preliminary envision on the composition and biogeneration of volatile compounds in P. yezoensis.  相似文献   

7.
To explore ef fective physiological indexes to distinguish the resistant lines and susceptible lines of Pyt hium porphyrae,the causal agent of red rot disease of Pyropia yezoensis,and establish the disease-resistance breeding strategy,we obtained and analyzed the candidate resistant and susceptible lines by population selection.Gametophytes of the candidate lines were cultured in seawater containing Pyt.porphyrae zoospores.Antioxidase activities,including superoxide dismutase(SOD),peroxidase(POD) and polyphenol oxidase(PPO),were measured and compared between the two lines before and after infection.In the resistant lines,SOD and POD activities increased and then decreased,but PPO activity rose with the prolongation of the infection time.The phenylalanine ammonia lyase(PAL) activities also increased and then decreased after infection,but it had significantly different expression in the two lines without pathogen attack.The synthesis rates of β-1,3-glucanase,and cell-wall degrading enzyme were different from each other between the two lines after infection of P yt.porphyrae.Comparison in the contents of malondialdehyde(MDA) and reactive oxygen species(ROS) in the two lines showed that,the two contents varied synchronously in response to the pathogen attack.Changes of these enzymes activities or contents demonstrated that Pyr.yezoensis could resist against the pathogen of P yt.porphyrae with the antioxidant defense capacity.In addition,β-1.3-glucanase content showed extremely significant dif ference between the two lines,and the PAL had consistent expression dif ference.Therefore,phenylalanine ammonia lyase(PAL) and β-1,3-glucanase can be considered as an ef fective index to distinguish susceptible line and resistant line,with which the workload of the resistant breeding could be reduced in the future.  相似文献   

8.
Qiu  Liping  Mao  Yunxiang  Tang  Lei  Tang  Xianghai  Mo  Zhaolan 《中国海洋湖沼学报》2019,37(3):1102-1112
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   

9.
Pyropia haitanensis has prominent stress-resistance characteristics and is endemic to China. Studies into the stress responses in these algae could provide valuable information on the stress-response mechanisms in the intertidal R hodophyta. Here, the ef fects of salinity and light intensity on the quantum yield of photosystem II in P y. haitanensis were investigated using pulse-amplitude-modulation fluorometry. Total RNA and genomic DNA of the samples under dif ferent stress conditions were isolated. By normalizing to the genomic DNA quantity, the RNA content in each sample was evaluated. The c DNA was synthesized and the expression levels of seven potential internal control genes were evaluated using q RT-PCR method. Then, we used ge Norm, a common statistical algorithm, to analyze the q RT-PCR data of seven reference genes. Potential genes that may constantly be expressed under dif ferent conditions were selected, and these genes showed stable expression levels in samples under a salinity treatment, while t ubulin, glyceraldehyde-3-phosphate dehydrogenase and actin showed stability in samples stressed by strong light. Based on the results of the pulse amplitude-modulation fluorometry, an absolute quantification was performed to obtain gene copy numbers in certain stress-treated samples. The stably expressed genes as determined by the absolute quantification in certain samples conformed to the results of the ge Norm screening. Based on the results of the software analysis and absolute quantification, we proposed that e longation factor 3 and 18 S ribosomal RNA could be used as internal control genes when the P y. haitanensis blades were subjected to salinity stress, and that α-tubulin and 18 S ribosomal RNA could be used as the internal control genes when the stress was from strong light. In general, our findings provide a convenient reference for the selection of internal control genes when designing experiments related to stress responses in Py. haitanensis.  相似文献   

10.
Pyropia haitanensis(T.J.Chang et B.F.Zheng) N.Kikuchi et M.Miyata( Porphyra haitanensis) is an economically important genus that is cultured widely in China.P.haitanensis is cultured on a larger scale than Pyropia yezoensis,making up an important part of the total production of cultivated Pyropia in China.However,the majority of molecular mechanisms underlying the physiological processes of P.haitanensis remain unknown.P.haitanensis could utilize inorganic carbon and the sporophytes of P.haitanensis might possess a PCK-type C 4-like carbon-fixation pathway.To identify micro RNAs and their probable roles in sporophyte and gametophyte development,we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P.haitanensis.Five micro RNAs were identified that shared no sequence homology with known micro RNAs.Our results indicated that P.haitanensis might posses a complex s RNA processing system in which the novel micro RNAs act as important regulators of the development of different generations of P.haitanensis.  相似文献   

11.
Pyropia yezoensis is an important macroalga because of its extensive global distribution and economic importance. Color is an important trait in the thalli of P. yezoensis, it is also an effective marker to identify the hybridization in genetic breeding. In this study, a high-density genetic linkage map was constructed based on high-throughput single nucleotide polymorphism(SNP) markers, and used for analyzing the quantitative trait loci(QTLs) of red color trait in the thalli of P. yezoensis. The conchospore undergoes meiosis to develop into an ordered tetrad, and each cell has a haploid phenotype and can grow into a single individual. Based on this theory, F1 haploid population was used as the mapping population. The map included 531 SNP markers, 394.57 cM long on average distance of 0.74 cM. Collinear analysis of the genetic linkage map and the physical map indicated that the coverage between the two maps was 79.42%. Furthermore, QTL mapping identified six QTLs for the chromosomal regions associated with the red color trait of the thalli. The value of phenotypic variance explained(PVE) by an individual QTL ranged from 4.71%–63.11%. And QTL qRed-1-1, with a PVE of 63.11%, was considered the major QTL. Thus, these data may provide a platform for gene and QTL fine mapping, and marker-assisted breeding in P. yezoensis in the future.  相似文献   

12.
Pyropia haitanensis,a commercially important species,was cultured at two CO2 concentrations(390×10- 6 and 700×10-6(parts per million)) and at low and high nutrient levels,to explore the effect of elevated CO2 on the species under nutrient enrichment. Results show that in CO2-enriched thalli,relative growth rate(RGR) was enhanced under nutrient enrichment. Elevated CO2 decreased phycobiliprotein(PB) contents,but increased the contents of soluble carbohydrates. Nutrient enrichment increased the contents of chlorophyll a(Chl a) and PB,while soluble carbohydrate content decreased. CO2 enrichment enhanced the relative maximum electronic transport rate and light saturation point. In nutrient-enriched thalli the activity of nitrate reductase(NRA) increased under elevated CO2. An instantaneous pH change in seawater(from 8.1 to 9.6) resulted in reduction of NRA,and the thalli grown under both elevated CO2 and nutrient enrichment exhibited less pronounced reduction than in algae grown at the ambient CO2. The thermal optima of NRA under elevated CO2 and/or nutrient enrichment shifted to a lower temperature(10–15°C) compared to that in ambient conditions(20°C). We propose that accelerated photosynthesis could result in growth increment. Nassimilation remained high in acidified seawater and refl ected increased temperature sensitivity in response to elevated CO2 and eutrophication.  相似文献   

13.
Yang  Huichao  Yan  Yongwei  Li  Jie  Tang  Lei  Mao  Yunxiang  Mo  Zhaolan 《中国海洋湖沼学报》2020,38(1):168-176
Pseudoalteromonas marina is one of the potential pathogens that cause green spot disease(GSD) in Pyropia yezoensis. To prevent GSD from development and spread, an ef fective method to detect the pathogen at early GSD infection stages need to be established. In this research, PCR methods were established targeting the dnaA gene(encoding chromosome replication initiator protein) and the dnaN gene(encoding β sliding clamp of DNA polymerase Ⅲ protein) to detect P. marina with three primer pairs pws-dnaA 2(Forward, 5′-ACCGCATTAACGAACTACTCGTG-3′; Reverse, 5′-TGCCATTACCTACAGCATGG-3′), pcs-dnaN 2(Forward, 5′-CTTACAACGTTATCAGCGGC-3′; Reverse, 5′-GTTGAGTATTAAGTGATTGAGTAAGC-3′) or pws-dnaN 3(Forward, 5′-ACTTACAACGTTATCAGCGGC-3′; Reverse, 5′-ACTGCTGTTTGAGTCTGCTAAC-3′). Three PCR methods corresponding to the three primer pairs su ? ciently distinguished P. marina from 22 bacterial species, thus resulting in detection limits of 4 to 4×10 2 CFU cells or 2.37×10 1 to 2.37×10 3 fg of P. marina DNA per PCR reaction. In an arti?cial infection experiment of P. yezoensis infected with P. marina, all established PCRs successfully detected P. marina at early GSD infection stages. The results show that the established PCRs are speci?c and sensitive, and are potential for applications in early diagnosis of GSD in Pyropia.  相似文献   

14.
Pyropia yezoensis, belongs to the genus of P orphyra 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 fl ow that occurred during the algae were stressed with dif ferent 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 dif ferent 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 effi cient photosynthesis, the potential roles of CEF might also include the regulation of dif ferent 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 ef fective means of removing the active oxygen produced by the irradiation stressed Py. yezoensis. We believe that the dif ferent 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.
The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitocho ndria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria) inheritance in P yezoensis,the wild type RZ(maternal strain) was cro ssed with the red mutant HT(paternal strain) and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT) were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP) loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.  相似文献   

16.
Members of the DnaJ family are proteins that play a pivotal role in various cellular processes, such as protein folding, protein transport and cellular responses to stress. In the present study, we identified and characterized the full-length DnaJ cDNA sequence from expressed sequence tags of Pyropia yezoensis (PyDnaJ) via rapid identification of cDNA ends. This cDNA encoded a protein of 429 amino acids, which shared high sequence similarity with other identified DnaJ proteins, such as a heat shock protein 40/DnaJ from Pyropia haitanensis. The relative mRNA expression level of PyDnaJ was investigated using real-time PCR to determine its specific expression during the algal life cycle and during desiccation. The relative mRNA expression level in sporophytes was higher than that in gametophytes and significantly increased during the whole desiccation process. These results indicate that PyDnaJ is an authentic member of the DnaJ family in plants and red algae and might play a pivotal role in mitigating damage to P. yezoensis during desiccation.  相似文献   

17.
Volatile organic compounds in marine algae have been reported to comprise characteristic flavor of algae and play an important role in their growth, development and defensive response. Yet their biogeneration remain largely unknown. Here we studied the composition of volatile compouds in Pyropia yezoensis and their variations in response to methyl jasmonate (MeJA) and diethyldithiocarbamic acid (DIECA) treatment using gas chromatography-mass spectrometry (GC-MS). A total of 44 compounds belonging to the following chemical classes (n) were identified, including aldehydes (11), alcohols (8), acids and esters (6), alkanes (5), ketones (5), alkenes (3), and S- or N-containing miscellaneous compounds (6). External treatment with plant hormone MeJA increased the content of 1-dodecanol, 4-heptenal, and 2-propenoic acid-2-methyl dodecylester, but decreased the content of phytol, 3-heptadecene, 2-pentadecanone, and isophytol. When pretreated with DIECA, an inhibitor of the octadecanoid pathway leading to the biosynthesis of endogeneous jasmonates and some secondary metabolites, phytol and isophytol were increased, while 4-heptenal, 1-dodecanol, and 2-propenoic acid-2-methyl dodecylester were decreased, both of which were negatively correlated with their variations under MeJA treatment. Collectively, these results suggest that MeJA does affect the volatile composition of P. yezoensis, and the octadecanoid pathway together with endogenous jasmonate pathway may be involved in the biosynthesis of volatile compounds, thereby providing some preliminary envision on the composition and biogeneration of volatile compounds in P. yezoensis.  相似文献   

18.
Pyropia haitanensis (T. J. Chang et B. F. Zheng) N. Kikuchi et M. Miyata (Porphyra haitanensis) is an economically important genus that is cultured widely in China. P. haitanensis is cultured on a larger scale than Pyropia yezoensis, making up an important part of the total production of cultivated Pyropia in China. However, the majority of molecular mechanisms underlying the physiological processes of P. haitanensis remain unknown. P. haitanensis could utilize inorganic carbon and the sporophytes of P. haitanensis might possess a PCK-type C4-like carbon-fixation pathway. To identify microRNAs and their probable roles in sporophyte and gametophyte development, we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P. haitanensis. Five microRNAs were identified that shared no sequence homology with known microRNAs. Our results indicated that P. haitanensis might posses a complex sRNA processing system in which the novel microRNAs act as important regulators of the development of different generations of P. haitanensis.  相似文献   

19.
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   

20.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations.  相似文献   

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