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The death mechanism of the harmful algal bloom species Alexandrium tamarense induced by algicidal bacterium Deinococcus sp. Y35.

Li Y, Zhu H, Lei X, Zhang H, Cai G, Chen Z, Fu L, Xu H, Zheng T - Front Microbiol (2015)

Bottom Line: Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment.Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited.More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University Xiamen, China ; College of Life Sciences, Henan Normal University Xinxiang, China.

ABSTRACT
Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment. The algicidal bacterium Deinococcus sp. Y35 which can induce growth inhibition on A. tamarense was used to investigate the functional mechanism. The growth status, reactive oxygen species (ROS) content, photosynthetic system and the nuclear system of algal cells were determined under algicidal activity. A culture of strain Y35 not only induced overproduction of ROS in algal cells within only 0.5 h of treatment, also decrease the total protein content as well as the response of the antioxidant enzyme. Meanwhile, lipid peroxidation was induced and cell membrane integrity was lost. Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited. At the same time, photosynthesis-related gene expression showed down-regulation. More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed. The potential functional mechanism of the algicidal bacterium on A. tamarense was investigated and provided a novel viewpoint which could be used in HABs control.

No MeSH data available.


Related in: MedlinePlus

Effect of the bacterial culture on the transcription of the PCNA gene (A) and the destruction of nuclear structure (B–G) in A. tamarense. (B), control cells; (C–E), 12 h treatment time; (F,G), 24 h treatment time. Red fluorescence is algal chloroplast fluorescence, which represents the strength of algal vitality; blue fluorescence represents the nuclear area. Scale bar = 20 μm. All error bars indicate the SE of the three biological replicates. *Represents a statistically significant difference of p < 0.05 when compared to the control; **represents a statistically significant difference of p < 0.01.
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Figure 8: Effect of the bacterial culture on the transcription of the PCNA gene (A) and the destruction of nuclear structure (B–G) in A. tamarense. (B), control cells; (C–E), 12 h treatment time; (F,G), 24 h treatment time. Red fluorescence is algal chloroplast fluorescence, which represents the strength of algal vitality; blue fluorescence represents the nuclear area. Scale bar = 20 μm. All error bars indicate the SE of the three biological replicates. *Represents a statistically significant difference of p < 0.05 when compared to the control; **represents a statistically significant difference of p < 0.01.

Mentions: Within 6 h of treatment, there were no inhibitory effects of the bacterial culture on the gene expressions of the proliferating cell nuclear antigen related gene (PCNA): the gene expression showed up-regulation in both the 1.0 (p < 0.01) and 2.0% (p < 0.05) treatment groups compared to the control (Figure 8A). However, the inhibitory effect on gene expressions showed up in the 24 h exposure in both the 1.0 and 2.0% concentrations. The relative transcriptional abundances of gene PCNA were significantly decreased (p < 0.01) in the 1.0 and 2.0% treatment groups within the 24 h treatment time, and were only 0.47 (p < 0.01) and 0.07-fold (p < 0.01) those of the control.


The death mechanism of the harmful algal bloom species Alexandrium tamarense induced by algicidal bacterium Deinococcus sp. Y35.

Li Y, Zhu H, Lei X, Zhang H, Cai G, Chen Z, Fu L, Xu H, Zheng T - Front Microbiol (2015)

Effect of the bacterial culture on the transcription of the PCNA gene (A) and the destruction of nuclear structure (B–G) in A. tamarense. (B), control cells; (C–E), 12 h treatment time; (F,G), 24 h treatment time. Red fluorescence is algal chloroplast fluorescence, which represents the strength of algal vitality; blue fluorescence represents the nuclear area. Scale bar = 20 μm. All error bars indicate the SE of the three biological replicates. *Represents a statistically significant difference of p < 0.05 when compared to the control; **represents a statistically significant difference of p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585090&req=5

Figure 8: Effect of the bacterial culture on the transcription of the PCNA gene (A) and the destruction of nuclear structure (B–G) in A. tamarense. (B), control cells; (C–E), 12 h treatment time; (F,G), 24 h treatment time. Red fluorescence is algal chloroplast fluorescence, which represents the strength of algal vitality; blue fluorescence represents the nuclear area. Scale bar = 20 μm. All error bars indicate the SE of the three biological replicates. *Represents a statistically significant difference of p < 0.05 when compared to the control; **represents a statistically significant difference of p < 0.01.
Mentions: Within 6 h of treatment, there were no inhibitory effects of the bacterial culture on the gene expressions of the proliferating cell nuclear antigen related gene (PCNA): the gene expression showed up-regulation in both the 1.0 (p < 0.01) and 2.0% (p < 0.05) treatment groups compared to the control (Figure 8A). However, the inhibitory effect on gene expressions showed up in the 24 h exposure in both the 1.0 and 2.0% concentrations. The relative transcriptional abundances of gene PCNA were significantly decreased (p < 0.01) in the 1.0 and 2.0% treatment groups within the 24 h treatment time, and were only 0.47 (p < 0.01) and 0.07-fold (p < 0.01) those of the control.

Bottom Line: Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment.Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited.More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University Xiamen, China ; College of Life Sciences, Henan Normal University Xinxiang, China.

ABSTRACT
Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment. The algicidal bacterium Deinococcus sp. Y35 which can induce growth inhibition on A. tamarense was used to investigate the functional mechanism. The growth status, reactive oxygen species (ROS) content, photosynthetic system and the nuclear system of algal cells were determined under algicidal activity. A culture of strain Y35 not only induced overproduction of ROS in algal cells within only 0.5 h of treatment, also decrease the total protein content as well as the response of the antioxidant enzyme. Meanwhile, lipid peroxidation was induced and cell membrane integrity was lost. Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited. At the same time, photosynthesis-related gene expression showed down-regulation. More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed. The potential functional mechanism of the algicidal bacterium on A. tamarense was investigated and provided a novel viewpoint which could be used in HABs control.

No MeSH data available.


Related in: MedlinePlus