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Physiological outperformance at the morphologically-transformed edge of the cyanobacteriosponge Terpios hoshinota (Suberitidae: Hadromerida) when confronting opponent corals.

Wang JT, Hsu CM, Kuo CY, Meng PJ, Kao SJ, Chen CA - PLoS ONE (2015)

Bottom Line: In this study, we compared the indicators of photosynthetic capability and nitrogen status of a sponge-cyanobacteria association at proximal, middle, and distal portions of opponent corals.Terpios tissues in contact with corals displayed significant increases in photosynthetic oxygen production (ca. 61%), the δ13C value (ca. 4%), free proteinogenic amino acid content (ca. 85%), and Gln/Glu ratio (ca. 115%) compared to middle and distal parts of the sponge.The inconsistent results between photosynthetic oxygen production and Fv/Fm values indicated that maximum quantum yields might not be a suitable indicator to represent the photosynthetic function of the Terpios-cyanobacteria association.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biotechnology, Tajen University, Pingtung, Taiwan.

ABSTRACT
Terpios hoshinota, an encrusting cyanosponge, is known as a strong substrate competitor of reef-building corals that kills encountered coral by overgrowth. Terpios outbreaks cause significant declines in living coral cover in Indo-Pacific coral reefs, with the damage usually lasting for decades. Recent studies show that there are morphological transformations at a sponge's growth front when confronting corals. Whether these morphological transformations at coral contacts are involved with physiological outperformance (e.g., higher metabolic activity or nutritional status) over other portions of Terpios remains equivocal. In this study, we compared the indicators of photosynthetic capability and nitrogen status of a sponge-cyanobacteria association at proximal, middle, and distal portions of opponent corals. Terpios tissues in contact with corals displayed significant increases in photosynthetic oxygen production (ca. 61%), the δ13C value (ca. 4%), free proteinogenic amino acid content (ca. 85%), and Gln/Glu ratio (ca. 115%) compared to middle and distal parts of the sponge. In contrast, the maximum quantum yield (Fv/Fm), which is the indicator usually used to represent the integrity of photosystem II, of cyanobacteria photosynthesis was low (0.256~0.319) and showed an inverse trend of higher values in the distal portion of the sponge that might be due to high and variable levels of cyanobacterial phycocyanin. The inconsistent results between photosynthetic oxygen production and Fv/Fm values indicated that maximum quantum yields might not be a suitable indicator to represent the photosynthetic function of the Terpios-cyanobacteria association. Our data conclusively suggest that Terpios hoshinota competes with opponent corals not only by the morphological transformation of the sponge-cyanobacteria association but also by physiological outperformance in accumulating resources for the battle.

No MeSH data available.


Related in: MedlinePlus

Changes in δ15N (A) and δ13C (B) values of isolated symbiotic cyanobacteria from Terpios hoshinota at the growth front where it contacts the coral, mid-body, and non-contact front.Data are means ± S.E. (n = 8). Bars with the same letter are not significantly different at P = 0.05 (Tukey’s honest significant difference test).
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pone.0131509.g004: Changes in δ15N (A) and δ13C (B) values of isolated symbiotic cyanobacteria from Terpios hoshinota at the growth front where it contacts the coral, mid-body, and non-contact front.Data are means ± S.E. (n = 8). Bars with the same letter are not significantly different at P = 0.05 (Tukey’s honest significant difference test).

Mentions: Physiological differences in the three Terpios body locations were detected during photosynthetic oxygen production and dark respiration. The photosynthesis-irradiance (P-I) curve of the sponge CF was determined before examining photosynthetic performance. Terpios reached its maximum photosynthetic rate at an irradiance of > 400 μmol photons m-2s-1 and no photoinhibition occurred below 1,000 μmol photons m-2s-1 (Fig 2). The data obtained at irradiances >1,000 were not used in this study because they caused respiration chamber temperatures to rise. The variables shown in Fig 2 fitted well into a non-photoinhibition equation model (P = Pmax (I)/ KI + (I); r2 = 0.910). With this equation, the calculated Pmax (maximum photosynthetic rate) was 36 ± 3 pmol O2 min-1 cm-2, and KI (half saturation constant) was 93 ± 28 μmol photons m-2s-1. When comparing photosynthetic performance between Terpios from the CF, MB, and NCF (n = 17 for each parts) at an irradiance of 400 μmol photons m-2s-1, sponges displayed significantly higher photosynthetic rates in the CF samples (33 ± 3 pmol min-1 cm-2) than in MB (20 ± 2 pmol min-1 cm-2) and NCF samples (21 ± 2 pmol min-1 cm-2) (F(2,48) = 6.538, P < 0.01) (Fig 3A). Measured from the same Terpios sample, the three different sampled parts had comparable dark respiration rates (Fig 4B), which were 21 ± 2 pmol min-1 cm-2 for CF and MB and 21 ± 1 pmol min-1 cm-2 for NCF (F(2,48) = 0.023, P > 0.05).


Physiological outperformance at the morphologically-transformed edge of the cyanobacteriosponge Terpios hoshinota (Suberitidae: Hadromerida) when confronting opponent corals.

Wang JT, Hsu CM, Kuo CY, Meng PJ, Kao SJ, Chen CA - PLoS ONE (2015)

Changes in δ15N (A) and δ13C (B) values of isolated symbiotic cyanobacteria from Terpios hoshinota at the growth front where it contacts the coral, mid-body, and non-contact front.Data are means ± S.E. (n = 8). Bars with the same letter are not significantly different at P = 0.05 (Tukey’s honest significant difference test).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481517&req=5

pone.0131509.g004: Changes in δ15N (A) and δ13C (B) values of isolated symbiotic cyanobacteria from Terpios hoshinota at the growth front where it contacts the coral, mid-body, and non-contact front.Data are means ± S.E. (n = 8). Bars with the same letter are not significantly different at P = 0.05 (Tukey’s honest significant difference test).
Mentions: Physiological differences in the three Terpios body locations were detected during photosynthetic oxygen production and dark respiration. The photosynthesis-irradiance (P-I) curve of the sponge CF was determined before examining photosynthetic performance. Terpios reached its maximum photosynthetic rate at an irradiance of > 400 μmol photons m-2s-1 and no photoinhibition occurred below 1,000 μmol photons m-2s-1 (Fig 2). The data obtained at irradiances >1,000 were not used in this study because they caused respiration chamber temperatures to rise. The variables shown in Fig 2 fitted well into a non-photoinhibition equation model (P = Pmax (I)/ KI + (I); r2 = 0.910). With this equation, the calculated Pmax (maximum photosynthetic rate) was 36 ± 3 pmol O2 min-1 cm-2, and KI (half saturation constant) was 93 ± 28 μmol photons m-2s-1. When comparing photosynthetic performance between Terpios from the CF, MB, and NCF (n = 17 for each parts) at an irradiance of 400 μmol photons m-2s-1, sponges displayed significantly higher photosynthetic rates in the CF samples (33 ± 3 pmol min-1 cm-2) than in MB (20 ± 2 pmol min-1 cm-2) and NCF samples (21 ± 2 pmol min-1 cm-2) (F(2,48) = 6.538, P < 0.01) (Fig 3A). Measured from the same Terpios sample, the three different sampled parts had comparable dark respiration rates (Fig 4B), which were 21 ± 2 pmol min-1 cm-2 for CF and MB and 21 ± 1 pmol min-1 cm-2 for NCF (F(2,48) = 0.023, P > 0.05).

Bottom Line: In this study, we compared the indicators of photosynthetic capability and nitrogen status of a sponge-cyanobacteria association at proximal, middle, and distal portions of opponent corals.Terpios tissues in contact with corals displayed significant increases in photosynthetic oxygen production (ca. 61%), the δ13C value (ca. 4%), free proteinogenic amino acid content (ca. 85%), and Gln/Glu ratio (ca. 115%) compared to middle and distal parts of the sponge.The inconsistent results between photosynthetic oxygen production and Fv/Fm values indicated that maximum quantum yields might not be a suitable indicator to represent the photosynthetic function of the Terpios-cyanobacteria association.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biotechnology, Tajen University, Pingtung, Taiwan.

ABSTRACT
Terpios hoshinota, an encrusting cyanosponge, is known as a strong substrate competitor of reef-building corals that kills encountered coral by overgrowth. Terpios outbreaks cause significant declines in living coral cover in Indo-Pacific coral reefs, with the damage usually lasting for decades. Recent studies show that there are morphological transformations at a sponge's growth front when confronting corals. Whether these morphological transformations at coral contacts are involved with physiological outperformance (e.g., higher metabolic activity or nutritional status) over other portions of Terpios remains equivocal. In this study, we compared the indicators of photosynthetic capability and nitrogen status of a sponge-cyanobacteria association at proximal, middle, and distal portions of opponent corals. Terpios tissues in contact with corals displayed significant increases in photosynthetic oxygen production (ca. 61%), the δ13C value (ca. 4%), free proteinogenic amino acid content (ca. 85%), and Gln/Glu ratio (ca. 115%) compared to middle and distal parts of the sponge. In contrast, the maximum quantum yield (Fv/Fm), which is the indicator usually used to represent the integrity of photosystem II, of cyanobacteria photosynthesis was low (0.256~0.319) and showed an inverse trend of higher values in the distal portion of the sponge that might be due to high and variable levels of cyanobacterial phycocyanin. The inconsistent results between photosynthetic oxygen production and Fv/Fm values indicated that maximum quantum yields might not be a suitable indicator to represent the photosynthetic function of the Terpios-cyanobacteria association. Our data conclusively suggest that Terpios hoshinota competes with opponent corals not only by the morphological transformation of the sponge-cyanobacteria association but also by physiological outperformance in accumulating resources for the battle.

No MeSH data available.


Related in: MedlinePlus