The sugarcane subtribe Saccharinae(Andropogoneae,Poaceae)was established in 1846,but its delimitation has long been debated.Moreover,the relationships among the genera of Saccharinae remain unclear,and there is no con...The sugarcane subtribe Saccharinae(Andropogoneae,Poaceae)was established in 1846,but its delimitation has long been debated.Moreover,the relationships among the genera of Saccharinae remain unclear,and there is no consensus on whether Pseudosorghum,a small genus in tropical Asia with only two species,should be included.Here,we performed phylogenomic analyses using whole plastomes(69 of them newly sequenced)from 132 individuals,representing 65 species in 19 related genera.We also built trees with nuclear ribosomal DNA sequences.Our results justify the inclusion of Pseudosorghum,likely also the Eulalia Clade III,in Saccharinae.Furthermore,both morphological and molecular analyses support merging the two Pseudosorghum species.The backbone relationships of the Saccharinae phylogeny were highly supported with four polyphyletic clades of Miscanthus and the inclusion of Narenga and Tripidium rufipilum in Saccharum.Pseudosorghum is moderately supported as sister to the Miscanthus Clade I,while the remaining Tripidium species could be excluded from the subtribe.Saccharinae is estimated to have originated~3.73 million years ago in East Asia,followed by intercontinental dispersals.Our study provides a comprehensive phylogenetic framework for future taxonomic revisions of this economically important subtribe.展开更多
Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for...Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for carbon assimilation. In our study, we cloned the full-length Rubisco gene from S.japonica （SJ-rbc）. It contained an open reading frame for a large subunit gene （SJ-rbcL） of 1 467 bp, a small subunit gene （SJ-rbcS） of 420 bp, and a SJ-rbcL/S intergenie spacer of 269 bp. The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa, 5.81 and 15,84 kDa, 4.71, respectively. After induction with 1 mmol/L isopropyl-β-D- thiogalactopyranoside for 5 h and purification by Ni2＋ affinity chromatography, electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein. Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations： increased expression during the day but suppressed expression at night. This observation implied that Rubisco played a role in normal gametophytic growth and development. In juvenile sporophytes, mRNA levels of SJ-rbcL, carbonic anhydrase, Calvin-Benson- Bassham cycle-related enzyme, and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance. Similarly, expression of these genes was up-regulated under blue light irradiance at 350 umol/（m2.s）. Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements.展开更多
Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight an...Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight and UV irradiation and its blade tip toward dark, and other worse cultivation environmental factors also make S . japonic a face more stresses. In this study, S . japonica transcriptomes corresponding to its four developmental stages were analyzed. In total, 7 800 genes predicted in the genome were transcribed. We found that 1 208 of the 7 800 expressed and 2 697 annotated were virus associating genes. Of 778 diff erentially expressed genes (DEGs), 372 were annotatable and 209 were virus associating. Such portion of virus associating genes indicated that the S . japonica genome contained a large portion of active virus originating genes. It was found that the transcripts abundance associated with sugar biosynthesis was about 2.13 folds of all the expressed, indicating that the biosyntheses of structural and storage sugars were very important cellular processes. The total abundance of genes involved in the biosynthesis of alginate and laminarin were similar among all developmental stages, however, that of genes involved in the biosynthesis of mannitol increased about 2-folds from mushroom and adult stages to mature and aging stages. This trend explained our observation that the content of alginate was almost constant at diff erent development stages, while that of mannitol increased sharply. In addition, we found that a set of defense and cell recurring genes highly expressed and many of them expressed diff erentially among stages. On average, the sum abundance of the transcripts of these genes at four stages were 3.40-and 4.96-folds of all the annotated and all the expressed, respectively. This indicated that S . japonica sporophytes persistently respond possible pathogen and environment stresses. The findings are important for timing S . japonica harvest and amending the current cultivation mode.展开更多
Saccharina is one of the most important cold-water living marine brown algal genera. In this study we ana-lyzed the transcriptome of S. japonica, which belongs to the 1 000 Plants （OneKP） Project, by using a next-ge...Saccharina is one of the most important cold-water living marine brown algal genera. In this study we ana-lyzed the transcriptome of S. japonica, which belongs to the 1 000 Plants （OneKP） Project, by using a next-generation high-throughput DNA sequencing technique. About 5.16 GB of raw data were generated, and 65 536 scaffolds with an average length of 454 bp were assembled with SOAP de novo assembly method. In total, 19 040 unigenes were identified by BLAST;25 734 scaffolds were clustered into 37 Gene ontology functional groups;6 760 scaffolds were classified into 25 COG categories, as well as 2 665 scaffolds that were assigned to 306 KEGG pathways. Majority of the unigenes exhibited more similarities to algae including brown algae and diatom than other cyanobacteria, marine diatom, and plant. Saccharina japonica has the outstanding capability to accumulate halogen such as Br and I via halogenation processes from seawater. We acquired 42 different vanadium-dependent haloperoxidases （vHPO） in S. japonica transcriptome data, including 5 segments of vanadium-dependent iodoperoxidase （vIPO） and 37 segments of vanadium-de-pendent bromoperoxidase （vBPO）. Complicated analyses of identified fulllength S. japonica vBPO1 and S. japonica vBPO2 revealed the importance of vBPO among species of brown algae and the strong relationship between marine algal vBPOs and vIPOs. This study will enhance our understanding of the biological charac-teristics and economic values of S. japonica species.展开更多
Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were ev...Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were evaluated at different levels of pCO2(400 and 800μL L−1)and nutrients(nutrient-enriched and non-enriched seawater).Elevated pCO2 decreased the relative growth rate(RGR),net photosynthetic rate and contents of tissue carbon and tissue nitrogen under non-enriched nutrient conditions,but it had no significant effect on these parameters under nutrient-enriched conditions.The dark respiration rate was positively affected by elevated pCO2 regardless of the nutrient conditions.However,the C:N was unaffected by elevated pCO2 at both nutrient levels.These results implied that ocean acidification could reduce the production and nutrient contents in the tissues of S.japonica,which was associated with nutrient conditions.展开更多
Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in Chi...Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in China,is suffering the harmful golden tide caused by Sargassum horneri.However,it remains unclear whether the detrimental effects of S.horneri on S.japonica cultivation become more severe in future acidified and eutrophic scenario.In this study,we respectively investigated the effects of pCO_(2)(400μatm and 1000μatm)and nutrients(non-enriched and enriched seawater)on the growth,photosynthesis,respiration,chlorophyll contents,and tissue nitrogen of S.japonica and S.horneri.Results indicated that enrichment of nutrients contributed S.horneri to utilize HCO_(3)^(−).The carbon acquisition pathway shifted from HCO_(3)^(−)to CO_(2) in S.japonica,while S.horneri re-mained using HCO_(3)^(−)regulated by nutrient enrichment.S.horneri exhibited better photosynthetic traits than S.japonica,with a higher level of net photosynthetic rate and chlorophyll contents at elevated pCO_(2) and enriched nutrients.Tissue nitrogen also accumulated richly in the thalli of S.horneri under higher pCO_(2) and nutrients.Significant enhancement in growth was only detected in S.horneri under synergistic stress.Together,S.horneri showed competitive dominance in current study.These findings suggest that increasing risk of golden tide in acidified and eutrophic ocean can most likely result in great damage to S.japonica cultivation.展开更多
In the past two decades, many studies have focused on the classification within genus Laminaria, ultimately trying to divide it into two subgroups or genera： Laminaria and Saccharina. A significant debate still surro...In the past two decades, many studies have focused on the classification within genus Laminaria, ultimately trying to divide it into two subgroups or genera： Laminaria and Saccharina. A significant debate still surrounds the question of its division, as the conflicting phylogenetic hypotheses that have resulted from the classification studies are based on different taxon sampling, molecular markers, or analysis methods. It is aimed at elucidate the molecular phylogeny within Laminaria and Saccharina. The nine species of Lami- nariales are sampled from northern Asia and Europe, and 23 new sequences in the nuclear, plastid, and mitochondrial genomes are determined to identify their taxonomic status. The phylogenetic analyses of 71 species are performed, including representatives from six of the seven families of the order Laminariales, based on three separate data sets. An evidence is provided to strongly support a clear split that maintains the two recognized genera, Laminaria and Saccharina, with Laminaria appearing to be the ancestor group. Further, analyses indicate that all taxa in Saccharina and Laminaria did not form a monophyletic lineage, instead Laminariaceae and Lessoniaceae grouped together interlacedly, and Costariaceae appeared as the sister taxon of the Lessoniaceae-Laminariaceae clade. In the phylogenetic analysis, mitochondrial c oxi- dase I （COI） sequences appeared to be the most credible molecular marker which was more befitting than nuclear encoded internal transcribed spacer （ITS） and plastid encoded rbcL for establishment of Laminariales systematics. It is the most comprehensive phylogeny of the order Laminariales, and contributes to an enhanced understanding and estimation of the phylogenetic relationships for the economically important seaweeds, Laminaria and Saccharina.展开更多
Long non-coding RNAs(lncRNAs)regulate a variety of biological processes,including sexual reproduction and differentiation.Saccharina japonica,a commercially important brown alga in China,shows remarkable sexual dimorp...Long non-coding RNAs(lncRNAs)regulate a variety of biological processes,including sexual reproduction and differentiation.Saccharina japonica,a commercially important brown alga in China,shows remarkable sexual dimorphism in haploid gametophytes.The sex of Saccharina japonica gametophytes is determined by UV sexual system.However,no results have been reported on the lncRNAs involved in the sex-related gene regulation of S.japonica.This study identified a number of lncRNAs and assessed their expression levels in male and female gametophytes.Among them,a total of 405 lncRNAs and 211 mRNAs showed differential expressions.Furthermore,the functions of target genes of differentially expressed lncRNAs(DELs)differed from those of differentially expressed genes(DEGs),suggesting that lncRNA may interact with other functional proteins,in addition to DEGs,to involve sex regulation in S.japonica.There were 32 and 90 potential cis-regulatory and trans-regulatory interactions between DELsDEGs,respectively.Five of these lncRNAs(LNC_002974,LNC_021059,LNC_038466,LNC_051584,and LNC_027400)interacted with putative male sex determination region(SDR)genes,suggesting that they act as regulators in gametophytes'sex regulation potentially.Findings from this study contribute to our understanding of the roles of lncRNAs in sex differentiation and lay the foundation for functional studies of candidate lncRNAs in the future.展开更多
Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica ...Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.展开更多
Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plas...Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plastid. Intensive work is in great demand from the perspective of genome colinearity. In this study, 118 sequence-tagged site(STS) markers were screened for phylogenetic analyses, 29 based on genome sequences, while 89 were based on expressed sequence tag(EST) sequences. EST-based STS marker development(29.37%) had an effi ciency twice as high as genome-sequence-based development(9.48%) as a result of high conservation of gene transcripts among the relative species. S. ochotensis, S. religiosa, S. japonica, and L. hyperborea showed great homogeneity in all 118 STS markers. Our result supports the view that the diversifi cation between the genera Saccharina and Laminaria was a more recent event and that Saccharina and Laminaria shared high phylogenetic affi nity. However, when it came to the single nucleotide polymorphism(SNP) level among the 41 SNPs, L. hyperborea owned 29 unique SNPs against 12 within the left three Saccharina species and 12 of the 13 indels were supposedly unique for L. hyperborea, indicated by its high variability. Originating from homologous ancestors, species between the recently diverged genera Laminaria and Saccharina may have taken in enough mutations at the SNP level only, in spite of different evolutionary strategies for better adaptation to the environment. Our study lays a solid foundation from a new perspective, although more accurate phylogenetic analysis is still needed to clarify the evolutionary traces between the genera Saccharina and Laminaria.展开更多
Eldana saccharina (eldana) is the most wide-spread sugarcane borer in South Africa and causes losses estimated at US$90 million. Breeding for resistance started in 1980. The objectives of this study were to examine th...Eldana saccharina (eldana) is the most wide-spread sugarcane borer in South Africa and causes losses estimated at US$90 million. Breeding for resistance started in 1980. The objectives of this study were to examine the potential of evaluating sugarcane families and parents by using data collected from the seedling stage (Stage I) and determine the potential of using logistic regression models in Stage II to enhance breeding for eldana resistance. Data were collected from Stage I trials (BML12 and FML13) at Bruyns Hill and Pongola research stations, respectively, and Stage II (BSL12 and SSL12) at Bruyns Hill and Glenside research stations, respectively. There were significant family effects for BML12 (P = 0.0029) and FML13 (P = 0.0003) indicating families with low eldana dame could be selected. Family variance for BML12 (P = 0.0144) and FML13 (P = 0.0878) were significant indicating large variability. Broad sense heritability of 0.52 (BML12) and 0.51 (FML13) indicated the effectiveness of selecting elite families. The predicted gains were 19.93% (BSL12) and 68.89% (FML13) indicating the value of family selection. The results showed significant female effects (BML12, P = 0.0017;FML13, P = 0.0041) indicating the dominance of maternal effects and suggested additive genetic control. Significant Female x Male interaction effect (FML13, P = 0.0442) suggested existence of non-additive genetic effects. Logistic regression analysis results showed significant (BSL12, P < 0.0001;SSL12, P = 0.0232) suggesting selecting for eldana was effective. Sensitivity analysis validated discriminating ability for eldana damage. Adopting family selection and logistic regression models would enhance breeding for eldana resistance.展开更多
The increased demand for machinery and transport has led to an overwhelming increase in the use of fossil fuels in the last century. Concerning the economic and environmental concern, macroalgae with high fermentable ...The increased demand for machinery and transport has led to an overwhelming increase in the use of fossil fuels in the last century. Concerning the economic and environmental concern, macroalgae with high fermentable polysaccharide content (mainly mannitol, cellulose and laminarin), can serve as an excellent alternative to food crops for bioethanol production, a renewable liquid fuel. In this study, Saccharina latissima, a brown macroalgae readily available on the Norwegian coast was used as the carbohydrate source for the fermentative production of bioethanol. The macroalgae harvested was found to contain 31.31 ± 1.73 g of reducing sugars per 100 g of dry Saccharina latissima upon enzymatic hydrolysis. The subsequent fermentation with Saccharomyces cerevisiae produced an ethanol yield of 0.42 g of ethanol per g of reducing sugar, resulting in a fermentation efficiency of 84% as compared to the theoretical maximum. Using these results, an evaluation of the fermentation process has demonstrated that the brown macroalgae Saccharina latissima could become a viable bioethanol source in the future.展开更多
The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wast...The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wastes, filters with dried marine alga Saccharina bongardiana in combination with zeolite and pumice are recommended. Combined Saccharina-based sorbents remove heavy metal ions more effectively, increasing adsorption capacity by five times compared to mineral （pumice） sorhents. As a result of desorption, a tenfold increase of the solution concentration is reached after the first sorption cycle. Valuable elements （Ni, Co, Cu etc.） can then be extracted from concentrates by any known method. It increases economic efficiency of the mining industry due to recycling of non-ferrous metals. Saccharina-based sorbents can be also utilized for purification of polluted natural waters. It may serve as environmental protection measure and provide for ecological safety of the unique natural environment of Kamchatka and its bioresources.展开更多
Algae of the order Laminariales represent main seaweed resource of Russia,Most important commercial species formerly belonged to Laminaria Lamoroux.However,taxonomic revision of this genus and resurrection of Sacchari...Algae of the order Laminariales represent main seaweed resource of Russia,Most important commercial species formerly belonged to Laminaria Lamoroux.However,taxonomic revision of this genus and resurrection of Saccharina Stackhouse based on genetic studies resulted in transfer of most Laminaria species to Saccharina.At the Russian Pacific coasts Saccharina now includes 10 species,while only three species for sure represent Laminaria:L.longipes Bory de Saint-Vincent,L.solidungula J.Agardh,L.yezoensis Miyabe,their placement within Laminaria is supported by genetic data.All examined Far Eastern species of Saccharina are noticed to possess haptera in the form of rhizoids,whereas members of Laminaria have disk-like holdfasts(L.solidungula,L.yezoensis),or creeping rhizomes(L.longipes).Three unstudied genetically endemics from the Sea of Okhotsk:L.appressirhiza Petrov et Vozzhinskaya,L.inclinatorhiza Petrov et Vozzhinskaya,L.multiplicata Petrov et Suchovejeva,are still left within Laminaria,but they have rhizoids,so most probably belong to Saccharina.This morphological criterion is inapplicable to Atlantic Laminaria since the type species L.digitata(Hudson)Lamouroux has rhizoids.展开更多
Similar to other macroalgae,Saccharina japonica has CO_(2)-concentrating mechanism(CCM)that allows high photosynthesis efficiency and elevates biomass.Phosphoenolpyruvate carboxykinase(PEPCK)in cytoplasm is an essenti...Similar to other macroalgae,Saccharina japonica has CO_(2)-concentrating mechanism(CCM)that allows high photosynthesis efficiency and elevates biomass.Phosphoenolpyruvate carboxykinase(PEPCK)in cytoplasm is an essential component of CCM.However,no reports on cytosolic PEPCK of S.japonica are available.In this study,the full-length cDNA sequence of a PEPCK gene(SjPCK1)predicted to be localized in cytoplasm,was screened from the full-length transcriptome of S.japonica gametophytes and identified by RT-PCR.The complete cDNA sequence of SjPCK1 was 2174 bp in length,which encompassed an open reading frame(ORF)of 1734 bp,a 5′-untranslated region(UTR)of 216 bp and a 3′-UTR of 224 bp.In parallel,the genomic DNA of SjPCK1 was 21294 bp in length,characterized by the presence of 11 introns and 12 exons.It encoded a protein of 577 amino acids with a molecular weight of 63 kD and an isoelectric point of 8.47.Amino acid sequence alignment showed that the functional sites of PEPCK were highly conserved in the selected species.Phylogenetic analysis and sequence characterization showed that SjPCK1 was an ATP-dependent PEPCK.SjPCK1 gene was expressed by using Escherichia coli prokaryotic expression system,and the SjPCK1 protein with His 6 tag(rSjPCK1)was 81.93 kD in molecular weight.Enzyme activity assay results showed that the specific activity of carboxylase and decar-boxylase of rSjPCK1 was 1.91±0.29 U/mg prog and 11.3±1.97 U/mg prog,respectively.These findings provide valuable molecular and biochemical insights for a further analysis of the role of cytosolic PEPCK in the storage of inorganic carbon in S.japonica.展开更多
基金supported by Yunnan Fundamental Research Project(202401BC070001)a research project of the Germplasm Bank of Wild Species,Kunming Institute of Botany,CAS,and the Project of Science and Technology Commission of Shanghai Municipality(23DZ1204601).
文摘The sugarcane subtribe Saccharinae(Andropogoneae,Poaceae)was established in 1846,but its delimitation has long been debated.Moreover,the relationships among the genera of Saccharinae remain unclear,and there is no consensus on whether Pseudosorghum,a small genus in tropical Asia with only two species,should be included.Here,we performed phylogenomic analyses using whole plastomes(69 of them newly sequenced)from 132 individuals,representing 65 species in 19 related genera.We also built trees with nuclear ribosomal DNA sequences.Our results justify the inclusion of Pseudosorghum,likely also the Eulalia Clade III,in Saccharinae.Furthermore,both morphological and molecular analyses support merging the two Pseudosorghum species.The backbone relationships of the Saccharinae phylogeny were highly supported with four polyphyletic clades of Miscanthus and the inclusion of Narenga and Tripidium rufipilum in Saccharum.Pseudosorghum is moderately supported as sister to the Miscanthus Clade I,while the remaining Tripidium species could be excluded from the subtribe.Saccharinae is estimated to have originated~3.73 million years ago in East Asia,followed by intercontinental dispersals.Our study provides a comprehensive phylogenetic framework for future taxonomic revisions of this economically important subtribe.
基金Supported by the Agriculture Science&Technology Achievements Transformation Fund(No.2011GB24910005)the Modern Agricultural-Industry Technology Research Project(No.200903030)+2 种基金the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A406)the Shandong Agriculture Breeding Engineering Biological Resources Innovation of Research Projectthe National"Twelfth Five-Year"Plan for Science&Technology Support(No.2013BAB01B01)
文摘Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/ oxygenase （Rubisco） activity for carbon assimilation. In our study, we cloned the full-length Rubisco gene from S.japonica （SJ-rbc）. It contained an open reading frame for a large subunit gene （SJ-rbcL） of 1 467 bp, a small subunit gene （SJ-rbcS） of 420 bp, and a SJ-rbcL/S intergenie spacer of 269 bp. The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa, 5.81 and 15,84 kDa, 4.71, respectively. After induction with 1 mmol/L isopropyl-β-D- thiogalactopyranoside for 5 h and purification by Ni2＋ affinity chromatography, electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein. Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations： increased expression during the day but suppressed expression at night. This observation implied that Rubisco played a role in normal gametophytic growth and development. In juvenile sporophytes, mRNA levels of SJ-rbcL, carbonic anhydrase, Calvin-Benson- Bassham cycle-related enzyme, and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance. Similarly, expression of these genes was up-regulated under blue light irradiance at 350 umol/（m2.s）. Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements.
基金Supported by the Fundamental Research Funds for the Central Universities(No.201762017)
文摘Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight and UV irradiation and its blade tip toward dark, and other worse cultivation environmental factors also make S . japonic a face more stresses. In this study, S . japonica transcriptomes corresponding to its four developmental stages were analyzed. In total, 7 800 genes predicted in the genome were transcribed. We found that 1 208 of the 7 800 expressed and 2 697 annotated were virus associating genes. Of 778 diff erentially expressed genes (DEGs), 372 were annotatable and 209 were virus associating. Such portion of virus associating genes indicated that the S . japonica genome contained a large portion of active virus originating genes. It was found that the transcripts abundance associated with sugar biosynthesis was about 2.13 folds of all the expressed, indicating that the biosyntheses of structural and storage sugars were very important cellular processes. The total abundance of genes involved in the biosynthesis of alginate and laminarin were similar among all developmental stages, however, that of genes involved in the biosynthesis of mannitol increased about 2-folds from mushroom and adult stages to mature and aging stages. This trend explained our observation that the content of alginate was almost constant at diff erent development stages, while that of mannitol increased sharply. In addition, we found that a set of defense and cell recurring genes highly expressed and many of them expressed diff erentially among stages. On average, the sum abundance of the transcripts of these genes at four stages were 3.40-and 4.96-folds of all the annotated and all the expressed, respectively. This indicated that S . japonica sporophytes persistently respond possible pathogen and environment stresses. The findings are important for timing S . japonica harvest and amending the current cultivation mode.
基金The National Natural Science Foundation of China under contract Nos 41206116,31140070 and 31271397Technology Project of Ocean and Fisheries of Guangdong Province under contract No.A201201E03+1 种基金the Fundamental Research Funds for the Central Universities under contract No.201262003the algal transcriptome sequencing was supported by OneKP Project(www.onekp.com)
文摘Saccharina is one of the most important cold-water living marine brown algal genera. In this study we ana-lyzed the transcriptome of S. japonica, which belongs to the 1 000 Plants （OneKP） Project, by using a next-generation high-throughput DNA sequencing technique. About 5.16 GB of raw data were generated, and 65 536 scaffolds with an average length of 454 bp were assembled with SOAP de novo assembly method. In total, 19 040 unigenes were identified by BLAST;25 734 scaffolds were clustered into 37 Gene ontology functional groups;6 760 scaffolds were classified into 25 COG categories, as well as 2 665 scaffolds that were assigned to 306 KEGG pathways. Majority of the unigenes exhibited more similarities to algae including brown algae and diatom than other cyanobacteria, marine diatom, and plant. Saccharina japonica has the outstanding capability to accumulate halogen such as Br and I via halogenation processes from seawater. We acquired 42 different vanadium-dependent haloperoxidases （vHPO） in S. japonica transcriptome data, including 5 segments of vanadium-dependent iodoperoxidase （vIPO） and 37 segments of vanadium-de-pendent bromoperoxidase （vBPO）. Complicated analyses of identified fulllength S. japonica vBPO1 and S. japonica vBPO2 revealed the importance of vBPO among species of brown algae and the strong relationship between marine algal vBPOs and vIPOs. This study will enhance our understanding of the biological charac-teristics and economic values of S. japonica species.
基金Ocean University of China in 2018 and the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020708).
文摘Environmental changes,such as ocean acidification and eutrophication,have created threats to kelp mariculture.In this study,the growth,photosynthesis,respiration and nutrient composition of Saccharina japonica were evaluated at different levels of pCO2(400 and 800μL L−1)and nutrients(nutrient-enriched and non-enriched seawater).Elevated pCO2 decreased the relative growth rate(RGR),net photosynthetic rate and contents of tissue carbon and tissue nitrogen under non-enriched nutrient conditions,but it had no significant effect on these parameters under nutrient-enriched conditions.The dark respiration rate was positively affected by elevated pCO2 regardless of the nutrient conditions.However,the C:N was unaffected by elevated pCO2 at both nutrient levels.These results implied that ocean acidification could reduce the production and nutrient contents in the tissues of S.japonica,which was associated with nutrient conditions.
基金This work is funded by the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020708).
文摘Ocean acidification and eutrophication are two important environmental stressors.They inevitably impact marine macroalgae,and hence the coastal ecosystem of China.Saccharina japonica,as the main culture species in China,is suffering the harmful golden tide caused by Sargassum horneri.However,it remains unclear whether the detrimental effects of S.horneri on S.japonica cultivation become more severe in future acidified and eutrophic scenario.In this study,we respectively investigated the effects of pCO_(2)(400μatm and 1000μatm)and nutrients(non-enriched and enriched seawater)on the growth,photosynthesis,respiration,chlorophyll contents,and tissue nitrogen of S.japonica and S.horneri.Results indicated that enrichment of nutrients contributed S.horneri to utilize HCO_(3)^(−).The carbon acquisition pathway shifted from HCO_(3)^(−)to CO_(2) in S.japonica,while S.horneri re-mained using HCO_(3)^(−)regulated by nutrient enrichment.S.horneri exhibited better photosynthetic traits than S.japonica,with a higher level of net photosynthetic rate and chlorophyll contents at elevated pCO_(2) and enriched nutrients.Tissue nitrogen also accumulated richly in the thalli of S.horneri under higher pCO_(2) and nutrients.Significant enhancement in growth was only detected in S.horneri under synergistic stress.Together,S.horneri showed competitive dominance in current study.These findings suggest that increasing risk of golden tide in acidified and eutrophic ocean can most likely result in great damage to S.japonica cultivation.
基金The National Natural Science Foundation of China under contract No.41206116the Postdoctoral Science Foundation of China under contract No.2011M501167+1 种基金the National Public Benefit Research Foundation of China under contract No.201105021the Fundamental Research Funds for the Central Universities under contract No.201362040
文摘In the past two decades, many studies have focused on the classification within genus Laminaria, ultimately trying to divide it into two subgroups or genera： Laminaria and Saccharina. A significant debate still surrounds the question of its division, as the conflicting phylogenetic hypotheses that have resulted from the classification studies are based on different taxon sampling, molecular markers, or analysis methods. It is aimed at elucidate the molecular phylogeny within Laminaria and Saccharina. The nine species of Lami- nariales are sampled from northern Asia and Europe, and 23 new sequences in the nuclear, plastid, and mitochondrial genomes are determined to identify their taxonomic status. The phylogenetic analyses of 71 species are performed, including representatives from six of the seven families of the order Laminariales, based on three separate data sets. An evidence is provided to strongly support a clear split that maintains the two recognized genera, Laminaria and Saccharina, with Laminaria appearing to be the ancestor group. Further, analyses indicate that all taxa in Saccharina and Laminaria did not form a monophyletic lineage, instead Laminariaceae and Lessoniaceae grouped together interlacedly, and Costariaceae appeared as the sister taxon of the Lessoniaceae-Laminariaceae clade. In the phylogenetic analysis, mitochondrial c oxi- dase I （COI） sequences appeared to be the most credible molecular marker which was more befitting than nuclear encoded internal transcribed spacer （ITS） and plastid encoded rbcL for establishment of Laminariales systematics. It is the most comprehensive phylogeny of the order Laminariales, and contributes to an enhanced understanding and estimation of the phylogenetic relationships for the economically important seaweeds, Laminaria and Saccharina.
基金supported by the National Natural Science Foundation of China(No.132072962)the Agricultural Industrial Technology System in Shandong Province(No.SDAIT-26)+3 种基金the‘First Class Fishery Discipline’Programme[(2020)3]in Shandong Provincethe Special Talent Programme‘Yishi Yiyi’in Shandong Province,Chinathe National Key R&D Program of China(No.2018YFD0901500)the Shandong Province Agriculture Seed Project(No.2021LZ GC004)。
文摘Long non-coding RNAs(lncRNAs)regulate a variety of biological processes,including sexual reproduction and differentiation.Saccharina japonica,a commercially important brown alga in China,shows remarkable sexual dimorphism in haploid gametophytes.The sex of Saccharina japonica gametophytes is determined by UV sexual system.However,no results have been reported on the lncRNAs involved in the sex-related gene regulation of S.japonica.This study identified a number of lncRNAs and assessed their expression levels in male and female gametophytes.Among them,a total of 405 lncRNAs and 211 mRNAs showed differential expressions.Furthermore,the functions of target genes of differentially expressed lncRNAs(DELs)differed from those of differentially expressed genes(DEGs),suggesting that lncRNA may interact with other functional proteins,in addition to DEGs,to involve sex regulation in S.japonica.There were 32 and 90 potential cis-regulatory and trans-regulatory interactions between DELsDEGs,respectively.Five of these lncRNAs(LNC_002974,LNC_021059,LNC_038466,LNC_051584,and LNC_027400)interacted with putative male sex determination region(SDR)genes,suggesting that they act as regulators in gametophytes'sex regulation potentially.Findings from this study contribute to our understanding of the roles of lncRNAs in sex differentiation and lay the foundation for functional studies of candidate lncRNAs in the future.
基金financially supported by the National Key R&D Program of China(Nos.2018YFD0900305,2018YFD 0901500)the China Agriculture Research System of MOF and MARA,Central Public-interest Scientific Institution Basal Research Fund CAFS(No.2020TD27)the‘Young Talent of Fishery Sciences’project from Laboratory for Marine Fisheries and Aquaculture(No.2018-MFS-T12).
文摘Saccharina japonica gametophytes can survive a long period under unfavorable environmental conditions,while they also delay in growth and/or reproduction.Although the reproduction in delayed gametophyte of S.japonica was known to be strongly influenced by light intensity,light quality,and photoperiod,no previous studies have evaluated their interactive effects on gametogenesis.To evaluate these effects,we used an orthogonal experiment to expose delayed gametophytes of S.japonica to different light intensities,light qualities,and photoperiods for 12 days.The results showed that changes in light intensity rather than light quality and photoperiod significantly affected the relative growth rates of the delayed gametophytes.Blue light had the greatest promotion on reproduction rate.The optimal light conditions in the early vegetative growth phase in gametogenesis induction for the delayed gametophytes were at 60–80μmol photons m^(−2) s^(−1) with daylength of 12 or 16 hours under white or blue light.When the delayed gametophytes were maintained in a constant light condition from delayed state to gametogenesis,the beneficial photoperiods for vegetative growth and reproductive rate were both 16L(16 hours of light):8D(8 hours of dark).However,when the delayed S.japonica gametophytes achieve the optimal growth state during the first 6 days and then they were cultured at different light conditions for the following 6 days,the reproduction rate increased as the daylength decreased and attained a peak value in group of 8L:16D photoperiod,indicating that photoperiod adjustment at the transition period is crucial in the gametogenesis induction process of delayed gametophyte of S.japonica.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A406)the Science and Technology Development Project of Shandong Province,China(No.2006GG3205001)+2 种基金the National Basic Scientific Special Fund of the Ministry of Science and Technology,China(No.2007FY210500)the National Public Benefit Research Foundation of the State Bureau of Oceanography,China(No.200805075)the Research Fund for Basic Sciences of Higher Education by National Ministry of Finance and Education,China(No.201262003)
文摘Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plastid. Intensive work is in great demand from the perspective of genome colinearity. In this study, 118 sequence-tagged site(STS) markers were screened for phylogenetic analyses, 29 based on genome sequences, while 89 were based on expressed sequence tag(EST) sequences. EST-based STS marker development(29.37%) had an effi ciency twice as high as genome-sequence-based development(9.48%) as a result of high conservation of gene transcripts among the relative species. S. ochotensis, S. religiosa, S. japonica, and L. hyperborea showed great homogeneity in all 118 STS markers. Our result supports the view that the diversifi cation between the genera Saccharina and Laminaria was a more recent event and that Saccharina and Laminaria shared high phylogenetic affi nity. However, when it came to the single nucleotide polymorphism(SNP) level among the 41 SNPs, L. hyperborea owned 29 unique SNPs against 12 within the left three Saccharina species and 12 of the 13 indels were supposedly unique for L. hyperborea, indicated by its high variability. Originating from homologous ancestors, species between the recently diverged genera Laminaria and Saccharina may have taken in enough mutations at the SNP level only, in spite of different evolutionary strategies for better adaptation to the environment. Our study lays a solid foundation from a new perspective, although more accurate phylogenetic analysis is still needed to clarify the evolutionary traces between the genera Saccharina and Laminaria.
文摘Eldana saccharina (eldana) is the most wide-spread sugarcane borer in South Africa and causes losses estimated at US$90 million. Breeding for resistance started in 1980. The objectives of this study were to examine the potential of evaluating sugarcane families and parents by using data collected from the seedling stage (Stage I) and determine the potential of using logistic regression models in Stage II to enhance breeding for eldana resistance. Data were collected from Stage I trials (BML12 and FML13) at Bruyns Hill and Pongola research stations, respectively, and Stage II (BSL12 and SSL12) at Bruyns Hill and Glenside research stations, respectively. There were significant family effects for BML12 (P = 0.0029) and FML13 (P = 0.0003) indicating families with low eldana dame could be selected. Family variance for BML12 (P = 0.0144) and FML13 (P = 0.0878) were significant indicating large variability. Broad sense heritability of 0.52 (BML12) and 0.51 (FML13) indicated the effectiveness of selecting elite families. The predicted gains were 19.93% (BSL12) and 68.89% (FML13) indicating the value of family selection. The results showed significant female effects (BML12, P = 0.0017;FML13, P = 0.0041) indicating the dominance of maternal effects and suggested additive genetic control. Significant Female x Male interaction effect (FML13, P = 0.0442) suggested existence of non-additive genetic effects. Logistic regression analysis results showed significant (BSL12, P < 0.0001;SSL12, P = 0.0232) suggesting selecting for eldana was effective. Sensitivity analysis validated discriminating ability for eldana damage. Adopting family selection and logistic regression models would enhance breeding for eldana resistance.
文摘The increased demand for machinery and transport has led to an overwhelming increase in the use of fossil fuels in the last century. Concerning the economic and environmental concern, macroalgae with high fermentable polysaccharide content (mainly mannitol, cellulose and laminarin), can serve as an excellent alternative to food crops for bioethanol production, a renewable liquid fuel. In this study, Saccharina latissima, a brown macroalgae readily available on the Norwegian coast was used as the carbohydrate source for the fermentative production of bioethanol. The macroalgae harvested was found to contain 31.31 ± 1.73 g of reducing sugars per 100 g of dry Saccharina latissima upon enzymatic hydrolysis. The subsequent fermentation with Saccharomyces cerevisiae produced an ethanol yield of 0.42 g of ethanol per g of reducing sugar, resulting in a fermentation efficiency of 84% as compared to the theoretical maximum. Using these results, an evaluation of the fermentation process has demonstrated that the brown macroalgae Saccharina latissima could become a viable bioethanol source in the future.
文摘The development of gold and cobalt-copper-nickel deposits in Kamchatka threatens the loss of biodiversity in spawning rivers and lakes and has negative effects on coastal ecosystems. To reduce pollution by mining wastes, filters with dried marine alga Saccharina bongardiana in combination with zeolite and pumice are recommended. Combined Saccharina-based sorbents remove heavy metal ions more effectively, increasing adsorption capacity by five times compared to mineral （pumice） sorhents. As a result of desorption, a tenfold increase of the solution concentration is reached after the first sorption cycle. Valuable elements （Ni, Co, Cu etc.） can then be extracted from concentrates by any known method. It increases economic efficiency of the mining industry due to recycling of non-ferrous metals. Saccharina-based sorbents can be also utilized for purification of polluted natural waters. It may serve as environmental protection measure and provide for ecological safety of the unique natural environment of Kamchatka and its bioresources.
文摘Algae of the order Laminariales represent main seaweed resource of Russia,Most important commercial species formerly belonged to Laminaria Lamoroux.However,taxonomic revision of this genus and resurrection of Saccharina Stackhouse based on genetic studies resulted in transfer of most Laminaria species to Saccharina.At the Russian Pacific coasts Saccharina now includes 10 species,while only three species for sure represent Laminaria:L.longipes Bory de Saint-Vincent,L.solidungula J.Agardh,L.yezoensis Miyabe,their placement within Laminaria is supported by genetic data.All examined Far Eastern species of Saccharina are noticed to possess haptera in the form of rhizoids,whereas members of Laminaria have disk-like holdfasts(L.solidungula,L.yezoensis),or creeping rhizomes(L.longipes).Three unstudied genetically endemics from the Sea of Okhotsk:L.appressirhiza Petrov et Vozzhinskaya,L.inclinatorhiza Petrov et Vozzhinskaya,L.multiplicata Petrov et Suchovejeva,are still left within Laminaria,but they have rhizoids,so most probably belong to Saccharina.This morphological criterion is inapplicable to Atlantic Laminaria since the type species L.digitata(Hudson)Lamouroux has rhizoids.
基金supported by the National Natural Science Foundation of China(grant No.41376136)the National Key Research and Development Program of China(grant No.2018YFD0901500).
文摘Similar to other macroalgae,Saccharina japonica has CO_(2)-concentrating mechanism(CCM)that allows high photosynthesis efficiency and elevates biomass.Phosphoenolpyruvate carboxykinase(PEPCK)in cytoplasm is an essential component of CCM.However,no reports on cytosolic PEPCK of S.japonica are available.In this study,the full-length cDNA sequence of a PEPCK gene(SjPCK1)predicted to be localized in cytoplasm,was screened from the full-length transcriptome of S.japonica gametophytes and identified by RT-PCR.The complete cDNA sequence of SjPCK1 was 2174 bp in length,which encompassed an open reading frame(ORF)of 1734 bp,a 5′-untranslated region(UTR)of 216 bp and a 3′-UTR of 224 bp.In parallel,the genomic DNA of SjPCK1 was 21294 bp in length,characterized by the presence of 11 introns and 12 exons.It encoded a protein of 577 amino acids with a molecular weight of 63 kD and an isoelectric point of 8.47.Amino acid sequence alignment showed that the functional sites of PEPCK were highly conserved in the selected species.Phylogenetic analysis and sequence characterization showed that SjPCK1 was an ATP-dependent PEPCK.SjPCK1 gene was expressed by using Escherichia coli prokaryotic expression system,and the SjPCK1 protein with His 6 tag(rSjPCK1)was 81.93 kD in molecular weight.Enzyme activity assay results showed that the specific activity of carboxylase and decar-boxylase of rSjPCK1 was 1.91±0.29 U/mg prog and 11.3±1.97 U/mg prog,respectively.These findings provide valuable molecular and biochemical insights for a further analysis of the role of cytosolic PEPCK in the storage of inorganic carbon in S.japonica.
