Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and season...Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and seasonal dynamics is much less known in the coast ecosystem with intensive anthropic disturbance.In this study,year-round changes of protist community composition and diversity in the coastal water of Yantai,a city along the northern Yellow Sea in China,were investigated using HTS for the V4 region of 18S rDNA.The interactions among protist groups were also analyzed using the co-occurrence network.Data analyses showed that Alveolata,Chlorophyta,and Stramenopiles are the most dominant phytoplanktonic protists in the investigated coastal area.The community composition displayed strong seasonal variation.The abundant families Dino-Group-I-Clade-1 and Ulotrichales_X had higher proportions in spring and summer,while Bathycoccaceae exhibited higher ratios in autumn and winter.Alpha diversities(Shannon and Simpson)were the highest in autumn and the lowest in spring(ANOVA test,P<0.05).Nutrients(SiO42−,PO43−),total organic carbon(TOC),and pH seemed to drive the variation of alpha diversity,while temperature,PO43−and TON were the most significant factors influencing the whole protist community.Co-variance network analyses reveal frequent co-occurrence events among ciliates,chlorophytes and dinoflagellate,suggesting biotic interactions have been induced by predation,parasitism and mixotrophy.展开更多
Coastal and estuarine protists are frequently exposed to salinity undulation.While the tolerance and stress responses of microalgae to salinity have been extensively studied,there have been scarce studies on the physi...Coastal and estuarine protists are frequently exposed to salinity undulation.While the tolerance and stress responses of microalgae to salinity have been extensively studied,there have been scarce studies on the physiological response of heterotrophic protists to salinity stressing.In this study,we investigated the physiological response of the heterotrophic ciliate Gastrostyla setifera to a salinity of 3,via a transcriptomic approach.The first transcriptome of genus Gastrostyla was obtained utilizing a group of manually isolated ciliate individuals(cells)and RNA-seq technique.The completeness of the transcriptome was verified.Differentially expressed gene(DEG)analysis was performed among the transcriptomes of G.setifera acclimated in saline water(salinity 3)and those cultured in fresh water.The results demonstrated a significant alternation in gene transcription,in which the ciliate exhibits a transcripttomic acclimation in responding salinity stressing.The up-regulated DEGs were enriched in the pathways of cytoskeleton proteins,membrane trafficking,protein kinases and protein phosphatases.These may represent enhanced functions of ion transport,stress response and cell protections.Pathways involved in energy metabolism and biosynthesis were markedly down-regulated,reflecting decreased cell activity.Particularly,we detected significantly down-regulated genes involved in several pathways of amino acid catabolism,which may lead to accumulation of amino acids in the ciliate cell.Amino acid could act as compatible solutes in the cytoplasm to maintain the osmotic balance in saline water.Overall,this work is an initial exploration to the molecular basis of the heterotrophic protist responding to salinity stressing.The result sheds light on the mechanisms of enhancement of cell protection,reduction of cell activity,and osmotic pressure regulation in ciliates acclimated to salinity.展开更多
Mariculture exerts a direct influence on planktonic eukaryotic microorganisms protists.Previous studies have focused on phytoplankton,while the heterotrophic and parasitic protistan groups are unknown.Currently,in Mup...Mariculture exerts a direct influence on planktonic eukaryotic microorganisms protists.Previous studies have focused on phytoplankton,while the heterotrophic and parasitic protistan groups are unknown.Currently,in Muping Marine Ranch(MR)which is along the littoral zone of northern Yellow Sea of China,environmental DNA methods were employed to investigate the diversity and seasonal dynamics of near shore planktonic protists in response to mariculture.Through an integrated analysis of functional groups and a comparison to adjacent sea areas,we found a dominance of harmful algae blooms(HAB)species nearshore MR,and a significant reduction in the diversity of planktonic protists including photosynthetic,heterotrophic and parasitic groups.High nutrient and low salinity were suggested to drive the dominance of HAB species nearshore MR,which in return might inhibit predators,saprophytes and algal parasites.Our investigations revealed an Olisthodiscus luteus outbreak in spring,as well as significant seasonal variations in the planktonic protist community,which might be caused by the changes of temperature.The offshore hypoxia reduced the abundance of phytoplankton but increased mixotrophs and animal parasites of the protistan community nearshore MR.This study highlights the influence of mariculture on the overall community function of planktonic protists,and is helpful to assess the mariculture's impact on water health.展开更多
基金the National Natural Science Foundation of China(Nos.31672251,31772413)the Youth Innovation Promotion Association,CAS(No.2019216)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050303)the Key Research Project of Frontier Science,CAS(No.QYZDBSSW-DQC013-1).
文摘Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and seasonal dynamics is much less known in the coast ecosystem with intensive anthropic disturbance.In this study,year-round changes of protist community composition and diversity in the coastal water of Yantai,a city along the northern Yellow Sea in China,were investigated using HTS for the V4 region of 18S rDNA.The interactions among protist groups were also analyzed using the co-occurrence network.Data analyses showed that Alveolata,Chlorophyta,and Stramenopiles are the most dominant phytoplanktonic protists in the investigated coastal area.The community composition displayed strong seasonal variation.The abundant families Dino-Group-I-Clade-1 and Ulotrichales_X had higher proportions in spring and summer,while Bathycoccaceae exhibited higher ratios in autumn and winter.Alpha diversities(Shannon and Simpson)were the highest in autumn and the lowest in spring(ANOVA test,P<0.05).Nutrients(SiO42−,PO43−),total organic carbon(TOC),and pH seemed to drive the variation of alpha diversity,while temperature,PO43−and TON were the most significant factors influencing the whole protist community.Co-variance network analyses reveal frequent co-occurrence events among ciliates,chlorophytes and dinoflagellate,suggesting biotic interactions have been induced by predation,parasitism and mixotrophy.
基金supported by the National Natural Science Foundation of China(Nos.32370488,42176163,31970398 and 31672251)the Youth Innovation Promotion Association of CAS(Nos.2019216 and 2022211).
文摘Coastal and estuarine protists are frequently exposed to salinity undulation.While the tolerance and stress responses of microalgae to salinity have been extensively studied,there have been scarce studies on the physiological response of heterotrophic protists to salinity stressing.In this study,we investigated the physiological response of the heterotrophic ciliate Gastrostyla setifera to a salinity of 3,via a transcriptomic approach.The first transcriptome of genus Gastrostyla was obtained utilizing a group of manually isolated ciliate individuals(cells)and RNA-seq technique.The completeness of the transcriptome was verified.Differentially expressed gene(DEG)analysis was performed among the transcriptomes of G.setifera acclimated in saline water(salinity 3)and those cultured in fresh water.The results demonstrated a significant alternation in gene transcription,in which the ciliate exhibits a transcripttomic acclimation in responding salinity stressing.The up-regulated DEGs were enriched in the pathways of cytoskeleton proteins,membrane trafficking,protein kinases and protein phosphatases.These may represent enhanced functions of ion transport,stress response and cell protections.Pathways involved in energy metabolism and biosynthesis were markedly down-regulated,reflecting decreased cell activity.Particularly,we detected significantly down-regulated genes involved in several pathways of amino acid catabolism,which may lead to accumulation of amino acids in the ciliate cell.Amino acid could act as compatible solutes in the cytoplasm to maintain the osmotic balance in saline water.Overall,this work is an initial exploration to the molecular basis of the heterotrophic protist responding to salinity stressing.The result sheds light on the mechanisms of enhancement of cell protection,reduction of cell activity,and osmotic pressure regulation in ciliates acclimated to salinity.
基金supported by the National Natural Science Foundation of China(Nos.42176163,31970398,and 32370488)the Youth Innovation Promotion Association,CAS(Nos.2019216 and 2022211)。
文摘Mariculture exerts a direct influence on planktonic eukaryotic microorganisms protists.Previous studies have focused on phytoplankton,while the heterotrophic and parasitic protistan groups are unknown.Currently,in Muping Marine Ranch(MR)which is along the littoral zone of northern Yellow Sea of China,environmental DNA methods were employed to investigate the diversity and seasonal dynamics of near shore planktonic protists in response to mariculture.Through an integrated analysis of functional groups and a comparison to adjacent sea areas,we found a dominance of harmful algae blooms(HAB)species nearshore MR,and a significant reduction in the diversity of planktonic protists including photosynthetic,heterotrophic and parasitic groups.High nutrient and low salinity were suggested to drive the dominance of HAB species nearshore MR,which in return might inhibit predators,saprophytes and algal parasites.Our investigations revealed an Olisthodiscus luteus outbreak in spring,as well as significant seasonal variations in the planktonic protist community,which might be caused by the changes of temperature.The offshore hypoxia reduced the abundance of phytoplankton but increased mixotrophs and animal parasites of the protistan community nearshore MR.This study highlights the influence of mariculture on the overall community function of planktonic protists,and is helpful to assess the mariculture's impact on water health.
