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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 photosynthesis related genes psbA (A), psbD (B), and rbcL (C) in A. tamarense. 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 7: Effect of the bacterial culture on the transcription of photosynthesis related genes psbA (A), psbD (B), and rbcL (C) in A. tamarense. 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: The effects of the two concentrations (1.0 and 2.0%) of the bacterial culture on transcription of the photosynthesis-related genes, psbA and psbD (which encode the core proteins of PS II) and the carbon dioxide fixation related gene rbcL are shown in Figure 7. Within 6 h of treatment, the relative transcriptional abundances of gene psbA were obviously inhibited (p < 0.01) in the 2.0% concentration and, at the same time, in the 1.0% concentration had a higher up-regulation value (p < 0.05) compared to the control (Figure 7A). However, within the 24 h exposure, the relative transcriptional abundances of this gene showed an opposite result after 6 h of treatment. The gene expression of psbA showed down-regulation in the 1.0% and up-regulation in the 2.0% concentration compared to the control. psbD exhibited a somewhat similar response to the bacterial culture as psbA did (Figure 7B). Within 6 h exposure, the gene expression showed an obvious up-regulation in the 1.0% treatment in contrast with the control, and the relative transcriptional abundances were significantly decreased in the 2.0% concentration. Within 24 h of treatment, the relative expressions of psbD were 0.51 (p < 0.05) and 0.45 (p < 0.05)-fold those of the control at the 1.0 and 2.0% concentrations. Different from the relative transcriptional abundances of gene psbA and psbD, the transcription of rbcL was inhibited in all treatment groups in both the 6 h and 24 h exposure (Figure 7C). The 1.0 and 2.0% treatment groups showed obvious inhibitory effects (p < 0.01) on the transcription of rbcL after 6 h of treatment. The transcription of rbcL in the 1.0 and 2.0% treatment groups was only 0.29− (p < 0.01) and 0.24-fold (p < 0.01) compared to the control within the 24 h exposure.


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 photosynthesis related genes psbA (A), psbD (B), and rbcL (C) in A. tamarense. 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

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

Figure 7: Effect of the bacterial culture on the transcription of photosynthesis related genes psbA (A), psbD (B), and rbcL (C) in A. tamarense. 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: The effects of the two concentrations (1.0 and 2.0%) of the bacterial culture on transcription of the photosynthesis-related genes, psbA and psbD (which encode the core proteins of PS II) and the carbon dioxide fixation related gene rbcL are shown in Figure 7. Within 6 h of treatment, the relative transcriptional abundances of gene psbA were obviously inhibited (p < 0.01) in the 2.0% concentration and, at the same time, in the 1.0% concentration had a higher up-regulation value (p < 0.05) compared to the control (Figure 7A). However, within the 24 h exposure, the relative transcriptional abundances of this gene showed an opposite result after 6 h of treatment. The gene expression of psbA showed down-regulation in the 1.0% and up-regulation in the 2.0% concentration compared to the control. psbD exhibited a somewhat similar response to the bacterial culture as psbA did (Figure 7B). Within 6 h exposure, the gene expression showed an obvious up-regulation in the 1.0% treatment in contrast with the control, and the relative transcriptional abundances were significantly decreased in the 2.0% concentration. Within 24 h of treatment, the relative expressions of psbD were 0.51 (p < 0.05) and 0.45 (p < 0.05)-fold those of the control at the 1.0 and 2.0% concentrations. Different from the relative transcriptional abundances of gene psbA and psbD, the transcription of rbcL was inhibited in all treatment groups in both the 6 h and 24 h exposure (Figure 7C). The 1.0 and 2.0% treatment groups showed obvious inhibitory effects (p < 0.01) on the transcription of rbcL after 6 h of treatment. The transcription of rbcL in the 1.0 and 2.0% treatment groups was only 0.29− (p < 0.01) and 0.24-fold (p < 0.01) compared to the control within the 24 h exposure.

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