Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chloro...Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.展开更多
应用双向电泳结合液相色谱-质谱联用(LC-MS)分析,筛选得到干旱胁迫下白菜型冬油菜与光合作用相关差异蛋白质RuBisCo小亚基。根据已发表白菜型油菜(Brassicarapa)RuBisCo亚基rbcL和rbcS保守序列设计引物,采用RT-PCR扩增陇油7号的cDNA,获...应用双向电泳结合液相色谱-质谱联用(LC-MS)分析,筛选得到干旱胁迫下白菜型冬油菜与光合作用相关差异蛋白质RuBisCo小亚基。根据已发表白菜型油菜(Brassicarapa)RuBisCo亚基rbcL和rbcS保守序列设计引物,采用RT-PCR扩增陇油7号的cDNA,获得rbcL和rbcS基因开放阅读框,长度分别为1095 bp和549 bp,编码364和181个氨基酸的蛋白质。生物信息学分析结果显示, rbcL与大白菜(Brassica rapa subsp. chinensis)的蛋白质同源性达到99%以上,其保守序列属于RuBisCoLarge超家族,该蛋白质理论相对分子量及等电点分别为40.29kDa和6.70,不稳定指数(instabilityindex,II>40为不稳定蛋白质)为41.67,属于不稳定蛋白;脂融指数(aliphaticindex)为83.63,平均亲水性值(grand average of hydropathicity)为-0.232,属于亲水性蛋白质;二级结构包括38.74%α-螺旋(alpha helix)、10.99%延伸链(extendedstrand)及50.27%自由卷曲(randomcoil);三级结构具有5个不同的活性口袋。rbcS与甘蓝(Brassicaoleracea)蛋白质同源性达到99%,其保守序列具有rbcS超家族和RuBisCo Small Like超家族,理论相对分子量为20.32 kDa,理论等电点为8.23,不稳定指数为33.66,属于稳定蛋白质;脂融指数为74.86,平均亲水性值为-0.142,属于亲水性蛋白质;二级结构包括16.02%α-螺旋、28.73%的延伸链及55.25%自由卷曲;三级结构具有4个不同的活性口袋。实时荧光定量和半定量分析显示,干旱胁迫下,白菜型冬油菜叶片rbcL和rbcS基因表达量下调是光合作用下降的原因。并且,冬油菜叶片Pn下降与RuBPCase表达抑制和活性降低有关,非气孔限制是Pn下降的主要因素。展开更多
基金Supported by the National Key Research and Development Program of China(No.2019YFD0901401)the National Natural Science Foundation of China(Nos.42176206,81900630)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2021MD071)the“One Hundred Talents”Project of Guangxi(No.6020303891251)the Outstanding Youth Project of Yunnan Provincial Department of Science and Technology(No.2019F1019)。
文摘Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic Pacific.The WSG is characterized by high nutrient and low chlorophyll.We carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton better.Microscopic method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to north.Dinoflagellates and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,respectively.Major chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and Cryptophyta.At the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all samples.Ochrophyta and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,respectively.Further,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and salinity.The proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to nutrients.This work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observation and rbc L gene sequences,which highlight the necessity of combining the microscopic and molecular methods to reveal the diversity of phytoplankton in marine environment.
文摘应用双向电泳结合液相色谱-质谱联用(LC-MS)分析,筛选得到干旱胁迫下白菜型冬油菜与光合作用相关差异蛋白质RuBisCo小亚基。根据已发表白菜型油菜(Brassicarapa)RuBisCo亚基rbcL和rbcS保守序列设计引物,采用RT-PCR扩增陇油7号的cDNA,获得rbcL和rbcS基因开放阅读框,长度分别为1095 bp和549 bp,编码364和181个氨基酸的蛋白质。生物信息学分析结果显示, rbcL与大白菜(Brassica rapa subsp. chinensis)的蛋白质同源性达到99%以上,其保守序列属于RuBisCoLarge超家族,该蛋白质理论相对分子量及等电点分别为40.29kDa和6.70,不稳定指数(instabilityindex,II>40为不稳定蛋白质)为41.67,属于不稳定蛋白;脂融指数(aliphaticindex)为83.63,平均亲水性值(grand average of hydropathicity)为-0.232,属于亲水性蛋白质;二级结构包括38.74%α-螺旋(alpha helix)、10.99%延伸链(extendedstrand)及50.27%自由卷曲(randomcoil);三级结构具有5个不同的活性口袋。rbcS与甘蓝(Brassicaoleracea)蛋白质同源性达到99%,其保守序列具有rbcS超家族和RuBisCo Small Like超家族,理论相对分子量为20.32 kDa,理论等电点为8.23,不稳定指数为33.66,属于稳定蛋白质;脂融指数为74.86,平均亲水性值为-0.142,属于亲水性蛋白质;二级结构包括16.02%α-螺旋、28.73%的延伸链及55.25%自由卷曲;三级结构具有4个不同的活性口袋。实时荧光定量和半定量分析显示,干旱胁迫下,白菜型冬油菜叶片rbcL和rbcS基因表达量下调是光合作用下降的原因。并且,冬油菜叶片Pn下降与RuBPCase表达抑制和活性降低有关,非气孔限制是Pn下降的主要因素。
