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Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34.

Červený J, Sinetova MA, Zavřel T, Los DA - Life (Basel) (2015)

Bottom Line: PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses.We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C.In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Adaptation Biotechnologies, Global Change Research Centre, Academy of Sciences of the Czech Republic, Drásov 470, CZ-66424 Drásov, Czech Republic. cerveny.j@czechglobe.cz.

ABSTRACT
Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34) is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

No MeSH data available.


Related in: MedlinePlus

Respiration and gross photosynthesis activities of Synechocystis WT (a) and ΔHik34 mutant (b) measured as oxygen consumption and evolution, respectively. Dashed lines mark the time of heat shock. The results represent typical values of 4 independent experiments for both WT and ΔHik34 mutant.
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life-05-00676-f002: Respiration and gross photosynthesis activities of Synechocystis WT (a) and ΔHik34 mutant (b) measured as oxygen consumption and evolution, respectively. Dashed lines mark the time of heat shock. The results represent typical values of 4 independent experiments for both WT and ΔHik34 mutant.

Mentions: Cultures were grown and monitored in flat-panel photobioreactors, which ensured precise control of cultivation conditions and allowed automatic measurements of selected physiological parameters within a time range of minutes. Using photobioreactors, we were able to monitor heat stress effects on growth rate, pigment content as well as activity of photosynthesis and respiration in Synechocystis wild-type and ∆Hik34 mutant cells (Figure 1 and Figure 2). We assessed the culture growth by measuring changes in OD720 and by measuring the difference in optical densities Δ680 = OD680 − OD720. It is shown that OD720 is approximation of biomass concentration, and Δ680 is proportional to the chlorophyll concentration [1,32].


Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34.

Červený J, Sinetova MA, Zavřel T, Los DA - Life (Basel) (2015)

Respiration and gross photosynthesis activities of Synechocystis WT (a) and ΔHik34 mutant (b) measured as oxygen consumption and evolution, respectively. Dashed lines mark the time of heat shock. The results represent typical values of 4 independent experiments for both WT and ΔHik34 mutant.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390874&req=5

life-05-00676-f002: Respiration and gross photosynthesis activities of Synechocystis WT (a) and ΔHik34 mutant (b) measured as oxygen consumption and evolution, respectively. Dashed lines mark the time of heat shock. The results represent typical values of 4 independent experiments for both WT and ΔHik34 mutant.
Mentions: Cultures were grown and monitored in flat-panel photobioreactors, which ensured precise control of cultivation conditions and allowed automatic measurements of selected physiological parameters within a time range of minutes. Using photobioreactors, we were able to monitor heat stress effects on growth rate, pigment content as well as activity of photosynthesis and respiration in Synechocystis wild-type and ∆Hik34 mutant cells (Figure 1 and Figure 2). We assessed the culture growth by measuring changes in OD720 and by measuring the difference in optical densities Δ680 = OD680 − OD720. It is shown that OD720 is approximation of biomass concentration, and Δ680 is proportional to the chlorophyll concentration [1,32].

Bottom Line: PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses.We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C.In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

View Article: PubMed Central - PubMed

Affiliation: Department of Adaptation Biotechnologies, Global Change Research Centre, Academy of Sciences of the Czech Republic, Drásov 470, CZ-66424 Drásov, Czech Republic. cerveny.j@czechglobe.cz.

ABSTRACT
Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34) is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

No MeSH data available.


Related in: MedlinePlus