The effects of light on the fluorescence characteristics and biochemical composition of a marine diatom Tha-lassiosira pseudonana in light and dark cycles were investigated with semi-continuous culture. The results in...The effects of light on the fluorescence characteristics and biochemical composition of a marine diatom Tha-lassiosira pseudonana in light and dark cycles were investigated with semi-continuous culture. The results indicate that, with the increase of growing light intensity, DCMU enhanced fluorescence yield (Fd/Chl), enhanced fluorescence ratio (Fd/F) , cellular carbohydrate content. carbohydrate/chlorophyll a and carbohydrate/protein ratio increased , but the fluorescence yield and cellular chlorophyll a content decreased; The protein content declined with the increase of light intensity in the range of 10- 100 μmol/ (m2·s) and increased at higher than 100 μmol/ (m2·s). Sampling time during the day had great effect on the relationships between growing light intensity and cellular chlorophyll a , carbohydrate content , carbohydrate/chlorophyll a and carbohydrate/protein ratio.展开更多
The effects of nutrients on the fluorescence characteristics and biochemical composition of marine diatom Thalassiosira pseudonana 3H in light and dark cycles were investigated with continuous culture. The results sho...The effects of nutrients on the fluorescence characteristics and biochemical composition of marine diatom Thalassiosira pseudonana 3H in light and dark cycles were investigated with continuous culture. The results show that with the increase of nutrient deficiency, the ratio of enhanced fluorescence to fluorescence (Fd/F), cellular chloropyll-a and protein content of the algae decline, but the fluorescence yield (F/Chl) , DCMU enhanced fluorescence yield (Fd/Chl) , cellular carbohydrate content, carbohydrate/Chl, protein/Chl, carbohydrate/protein increase. The changing amplitude of each parameter is different at different nutrition status, sampling time and different light intensity.展开更多
Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20%of global carbon fixation and 40%of marine primary productivity;thus,they are essential for global carbon biogeochemical cycling and c...Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20%of global carbon fixation and 40%of marine primary productivity;thus,they are essential for global carbon biogeochemical cycling and climate.The availability of ten diatom genome sequences has facilitated evolutionary,biological and ecological research over the past decade;however,a complimentary map of the diatom proteome with direct measurements of proteins and peptides is still lacking.Here,we present a proteome map of the model marine diatom Thalassiosira pseudonana using high-resolution mass spectrometry combined with a proteogenomic strategy.In-depth proteomic profiling of three different growth phases and three nutrient-deficient samples identified 9526 proteins,accounting for~81%of the predicted protein-coding genes.Proteogenomic analysis identified 1235 novel genes,975 revised genes,104 splice variants and 234 single amino acid variants.Furthermore,our quantitative proteomic analysis experimentally demonstrated that a considerable number of novel genes were differentially translated under different nutrient conditions.These findings substantially improve the genome annotation of T.pseudonana and provide insights into new biological functions of diatoms.This relatively comprehensive diatom proteome catalog will complement available diatom genome and transcriptome data to advance biological and ecological research of marine diatoms.展开更多
文章以假微型海链藻(Thalassiosira pseudonana)转录组测序数据为基础,对差异表达的功能基因进行GO(gene ontology)和KEGG(kyoto encyclopedia of genes and genomes)富集分析,以研究低盐胁迫条件对其脂肪酸代谢通路相关功能基因表达的...文章以假微型海链藻(Thalassiosira pseudonana)转录组测序数据为基础,对差异表达的功能基因进行GO(gene ontology)和KEGG(kyoto encyclopedia of genes and genomes)富集分析,以研究低盐胁迫条件对其脂肪酸代谢通路相关功能基因表达的影响。结果发现,不同盐度培养下的假微型海链藻在生长期的第2天与第4天时细胞中与脂肪酸生物合成、脂肪酸延伸的相关基因(如:ACC1、arm)的表达量相对于生长第1天均显著升高,与脂肪酸降解相关基因(如:ACADM、ECI1)的表达量无显著变化;与脂肪酸的生物合成、延长相关基因的表达量在试验组和对照组间存在差异(如:起重要作用的KASⅠ、ACAA2等基因表达量显著增加,但也有少数处于下降或者微变动的状态),与脂肪酸降解过程相关基因的表达量显著上升。展开更多
研究了两种赤潮藻即假微型海链藻(Thalassiosira pseudonanaHasle et Heimdalh)和裸甲藻(Gymnodiniumsp.)在不同氮磷比培养条件下的生长特性和藻间竞争作用,探讨了氮磷含量及其比值对赤潮爆发的影响机理.结果表明,在N/P=16条件下,假微...研究了两种赤潮藻即假微型海链藻(Thalassiosira pseudonanaHasle et Heimdalh)和裸甲藻(Gymnodiniumsp.)在不同氮磷比培养条件下的生长特性和藻间竞争作用,探讨了氮磷含量及其比值对赤潮爆发的影响机理.结果表明,在N/P=16条件下,假微型海链藻的最大比增长率最高、相对生长常数最大、平均倍增时间最短,叶绿素a含量最高,说明该N/P值是假微型海链藻最佳生长营养盐条件.对裸甲藻而言,N/P=6是其最佳生长的营养盐条件.叶绿素a含量受N/P值的影响和藻细胞密度所受的影响趋势基本一致.不同N/P值对藻间竞争作用和群落演替的总体影响不明显,都呈现先硅藻后甲藻的群落演替规律.裸甲藻可能具有利用体内磷来维持生长的特点.展开更多
文摘The effects of light on the fluorescence characteristics and biochemical composition of a marine diatom Tha-lassiosira pseudonana in light and dark cycles were investigated with semi-continuous culture. The results indicate that, with the increase of growing light intensity, DCMU enhanced fluorescence yield (Fd/Chl), enhanced fluorescence ratio (Fd/F) , cellular carbohydrate content. carbohydrate/chlorophyll a and carbohydrate/protein ratio increased , but the fluorescence yield and cellular chlorophyll a content decreased; The protein content declined with the increase of light intensity in the range of 10- 100 μmol/ (m2·s) and increased at higher than 100 μmol/ (m2·s). Sampling time during the day had great effect on the relationships between growing light intensity and cellular chlorophyll a , carbohydrate content , carbohydrate/chlorophyll a and carbohydrate/protein ratio.
文摘The effects of nutrients on the fluorescence characteristics and biochemical composition of marine diatom Thalassiosira pseudonana 3H in light and dark cycles were investigated with continuous culture. The results show that with the increase of nutrient deficiency, the ratio of enhanced fluorescence to fluorescence (Fd/F), cellular chloropyll-a and protein content of the algae decline, but the fluorescence yield (F/Chl) , DCMU enhanced fluorescence yield (Fd/Chl) , cellular carbohydrate content, carbohydrate/Chl, protein/Chl, carbohydrate/protein increase. The changing amplitude of each parameter is different at different nutrition status, sampling time and different light intensity.
基金This work was partially supported by research grants from the National Natural Science Foundation of China(Project No.42030404 and 41425021)the Ministry of Science and Technology of the People's Republic of China(Project No.2015CB954003)D-ZW was also supported by the Ten Thousand Talents Program for leading talents in science and technological innovation.
文摘Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20%of global carbon fixation and 40%of marine primary productivity;thus,they are essential for global carbon biogeochemical cycling and climate.The availability of ten diatom genome sequences has facilitated evolutionary,biological and ecological research over the past decade;however,a complimentary map of the diatom proteome with direct measurements of proteins and peptides is still lacking.Here,we present a proteome map of the model marine diatom Thalassiosira pseudonana using high-resolution mass spectrometry combined with a proteogenomic strategy.In-depth proteomic profiling of three different growth phases and three nutrient-deficient samples identified 9526 proteins,accounting for~81%of the predicted protein-coding genes.Proteogenomic analysis identified 1235 novel genes,975 revised genes,104 splice variants and 234 single amino acid variants.Furthermore,our quantitative proteomic analysis experimentally demonstrated that a considerable number of novel genes were differentially translated under different nutrient conditions.These findings substantially improve the genome annotation of T.pseudonana and provide insights into new biological functions of diatoms.This relatively comprehensive diatom proteome catalog will complement available diatom genome and transcriptome data to advance biological and ecological research of marine diatoms.
文摘文章以假微型海链藻(Thalassiosira pseudonana)转录组测序数据为基础,对差异表达的功能基因进行GO(gene ontology)和KEGG(kyoto encyclopedia of genes and genomes)富集分析,以研究低盐胁迫条件对其脂肪酸代谢通路相关功能基因表达的影响。结果发现,不同盐度培养下的假微型海链藻在生长期的第2天与第4天时细胞中与脂肪酸生物合成、脂肪酸延伸的相关基因(如:ACC1、arm)的表达量相对于生长第1天均显著升高,与脂肪酸降解相关基因(如:ACADM、ECI1)的表达量无显著变化;与脂肪酸的生物合成、延长相关基因的表达量在试验组和对照组间存在差异(如:起重要作用的KASⅠ、ACAA2等基因表达量显著增加,但也有少数处于下降或者微变动的状态),与脂肪酸降解过程相关基因的表达量显著上升。
文摘研究了两种赤潮藻即假微型海链藻(Thalassiosira pseudonanaHasle et Heimdalh)和裸甲藻(Gymnodiniumsp.)在不同氮磷比培养条件下的生长特性和藻间竞争作用,探讨了氮磷含量及其比值对赤潮爆发的影响机理.结果表明,在N/P=16条件下,假微型海链藻的最大比增长率最高、相对生长常数最大、平均倍增时间最短,叶绿素a含量最高,说明该N/P值是假微型海链藻最佳生长营养盐条件.对裸甲藻而言,N/P=6是其最佳生长的营养盐条件.叶绿素a含量受N/P值的影响和藻细胞密度所受的影响趋势基本一致.不同N/P值对藻间竞争作用和群落演替的总体影响不明显,都呈现先硅藻后甲藻的群落演替规律.裸甲藻可能具有利用体内磷来维持生长的特点.
