Proteomic analysis provides new insights into the adaptive response of a dinoflagellate Prorocentrum donghaiense to changing ambient nitrogen

Abstract

Nitrogen (N) is the major nutrient limiting phytoplankton growth and productivity over large ocean areas. Dinoflagellates are important primary producers and major causative agents of harmful algal blooms in the ocean. However, very little is known about their adaptive response to changing ambient N. Here, we compared the protein profiles of a marine dinoflagellate Prorocentrum donghaiense grown in inorganic N-replete, N-deplete and N-resupplied conditions using 2-D fluorescence differential gel electrophoresis. The results showed that cell density, chlorophyll a and particulate organic N contents presented low levels in N-deplete cells, while particulate organic carbon content and glutamine synthetase (GS) activity maintained high levels. Comparison of the protein profiles of N-replete, N-deplete and N-resupplied cells indicated that proteins involved in photosynthesis, carbon fixation, protein and lipid synthesis were down-regulated, while proteins participating in N reallocation and transport activity were up-regulated in N-deplete cells. High expressions of GS and 60 kDa chaperonin as well as high GS activity in N-deplete cells indicated their central role in N stress adaptation. Overall, in contrast with other photosynthetic eukaryotic algae, P. donghaiense possessed a specific ability to regulate intracellular carbon and N metabolism in response to extreme ambient N deficiency.

Comparative Transcriptomic Analysis Reveals Novel Insights into the Adaptive Response of Skeletonema costatum to Changing Ambient Phosphorus

“…In our study, expressions of ribulose-bisphosphate carboxylase (RuBisco) large subunit genes increased in P-deficient cells and decreased in P-resupplied-4 h cells (Supplementary Table S6 ). RuBisco catalyzes the first step of the Calvin cycle of photosynthesis and the oxidation of ribulose bisphosphate in the first step of photorespiration ( Miziorko and Lorimer, 1983 ; Zhang Y.J. et al, 2015 ).…”

“…Transcripts of LHC I, LHC II, P680, and P700 were up-regulated significantly in P-deficient cells, and down-regulated in P-resupplied cells (Supplementary Table S6 ). The LHC plays an important role in absorbing light and transferring energy to the center of the photosystem ( Hiller et al, 1993 , 1995 ; Boldt et al, 2012 ; Zhang Y.J. et al, 2015 ).…”

“…As the key player in the marine ecosystem, diatoms play important roles in regulating biogeochemical cycles of biogenic elements, i.e., carbon, silica, nitrogen, and P ( Obata et al, 2013 ; White and Dyhrman, 2013 ). Moreover, many diatom species are also major causative agents of algal blooms in the ocean ( Shatwell et al, 2014 ; Ou et al, 2015 ; Zhang Y.J. et al, 2015 ).…”

Algicidal Activity of Novel Marine Bacterium Paracoccus sp. Strain Y42 against a Harmful Algal-Bloom-Causing Dinoflagellate, Prorocentrum donghaiense

“…Prorocentrum donghaiense is a major cause of HABs in the Yangtze River estuary and the adjacent East China Sea and is responsible for frequent large-scale HABs and serious damage to marine ecosystems and mariculture, resulting in enormous economic losses over the past 2 decades (23,24). Considerable efforts have been devoted to the investigation of environmental conditions that regulate the occurrence and maintenance of P. donghaiense blooms and the cellular responses of this dinoflagellate to different conditions, such as N/P repletion, N/P depletion, different N/P substrates, acidification, and eutrophication (25)(26)(27)(28)(29). Although many algicidal bacteria have been identified and exploited in the control of Microcystis aeruginosa (5,7,14,17,30), Alexandrium tamarense (9,12,18,19), Phaeocystis globosa (8,11,16,(31)(32)(33), and Skeletonema costatum (34)(35)(36)(37), few studies have reported bacteria with algicidal effects against P. donghaiense.…”

Cell Cycle-Dependent Expression Dynamics of G1/S Specific Cyclin, Cellulose Synthase and Cellulase in the Dinoflagellate Prorocentrum donghaiense

“…The blooms of P. donghaiense can extend 10,000 km 2 and last for 1 month in some year (Zhou and Yu, 2007), and pose serious impact on costal marine ecosystem. The bloom of this species is result of a complex ecological and oceanographic process, which is affected by various environmental factors, such as nutrient availability (Ou et al, 2010; Zhang et al, 2015), temperature and salinity (Xu et al, 2010). However, the regulation of population growth and biomass accumulation of this species is still poorly understood.…”