Влияние вирусной инфекции на функционирование и лизис черноморских микроводорослей Tetraselmis viridis (Chlorophyta) и Phaeodactylum tricornutum (Bacillariophyta)

Author(s):  
Л. В. Стельмах ◽  
О. А. Степанова
Author(s):  
O.A. Stepanova ◽  
◽  
P.V. Gaisky ◽  
S.A. Sholar ◽  
◽  
...  

The change in sensitivity to viral infection of cultures of three species of Black Sea microalgae (Tetraselmis viridis, Dunaliella viridis and Phaeodactylum tricornutum) after exposure to a constant unidirectional magnetic field with a magnetic induction of 600 G is experimentally studied. The studies were carried out with using a developed laboratory installation. With the duration of the experiments 24 h and 48 h, it was recorded that being in a magnetic field resulted in an increase in the resistance to viral lysis in microalgae T. viridis, its decrease in P. tricornutum and no changes in D. viridis. We assume that the revealed changes in the sensitivity of microalgae to viral infection after exposure to a magnetic field are due to their species characteristics and selectivity.


Author(s):  
O.A. Stepanova ◽  

Virus monitoring is a widespread control of their background circulation. Since 2002, the monitoring of algal viruses that infect microalgae Tetraselmis viridis and Phaeodactylum tricornutum has been carried out in the bays of Sevastopol differing in ecological conditions. The purpose of this work is to analyze and assess the results of this long-term (2002–2020) monitoring. The results obtained with taking into account the exactingness or resistance to environmental conditions of hosts of algal viruses that infect microalgae T. viridis and P. tricornutum were the basis for the following conclusions regarding the ecological well-being of the studied bays of Sevastopol: – relatively favorable ecological conditions in 2007–2008, 2017–2018 and in 2020. (maximum frequency of isolation PtV, and/or minimum TvV, and / or maximum difference in frequency of isolation between PtV and TvV); – unfavorable ecological conditions in 2002–2003, 2006 and 2015 (maximum frequency of isolation TvV, and/or minimum PtV, and/or maximum difference in frequency of isolation between TvV and PtV). Analysis of the monitoring results of algal viruses of T. viridis and P. tricornutum in 2015–2020 revealed that the studied relatively ecologically safe bays are characterized by the maximum number of all isolates of algal viruses (both TvV and PtV) and the numerical predominance of strains of algal virus of P. tricornutum, which is demanding to environmental conditions. At the same time, the minimum amount of all viral isolates was recorded in the ecologically unfavorable bay. The results of a long-term monitoring of algal viruses of T. viridis and P. tricornutum have established the possibility of using the monitoring of marine viruses, in particular of algal viruses of microalgae which are indicative of the ecological situation, as a component of complex ecological monitoring as ecological indicator.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kaidian Zhang ◽  
Zhi Zhou ◽  
Jiashun Li ◽  
Jingtian Wang ◽  
Liying Yu ◽  
...  

AbstractPhosphorus (P) is an essential nutrient for marine phytoplankton. Maintaining intracellular P homeostasis against environmental P variability is critical for phytoplankton, but how they achieve this is poorly understood. Here we identify a SPX gene and investigate its role in Phaeodactylum tricornutum. SPX knockout led to significant increases in the expression of phosphate transporters, alkaline phosphatases (the P acquisition machinery) and phospholipid hydrolases (a mechanism to reduce P demand). These demonstrate that SPX is a negative regulator of both P uptake and P-stress responses. Furthermore, we show that SPX regulation of P uptake and metabolism involves a phosphate starvation response regulator (PHR) as an intermediate. Additionally, we find the SPX related genes exist and operate across the phytoplankton phylogenetic spectrum and in the global oceans, indicating its universal importance in marine phytoplankton. This study lays a foundation for better understanding phytoplankton adaptation to P variability in the future changing oceans.


2021 ◽  
Author(s):  
Richard Smith ◽  
Juliette Jouhet ◽  
Chiara Gandini ◽  
Vladimir Nekrasov ◽  
Eric Marechal ◽  
...  

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