Temperature response of photosynthetic light‐ and carbon‐use characteristics in the red seaweed Gracilariopsis lemaneiformis (Gracilariales, Rhodophyta). Issue 2 (11th March 2014)

• Record Type: Journal Article
• Authors: Zou, Dinghui; Gao, Kunshan; Harley, C.
• Is Part Of: Journal of phycology. Volume 50:Issue 2(2014:Apr.)
• Page Start: 366
• Page End: 375
• Publication Date: 2014-03-11
• Subjects: Algae -- Periodicals; 579.8
• DOI: 10.1111/jpy.12171
• Languages: English
• ISSNs: 0022-3646

Abstract

<abstract abstract-type="main" id="jpy12171-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The red seaweed <italic>Gracilariopsis</italic> is an important crop extensively cultivated in China for high‐quality raw agar. In the cultivation site at Nanao Island, Shantou, China, <italic>G</italic><italic>. lemaneiformis</italic> experiences high variability in environmental conditions like seawater temperature. In this study, <italic>G</italic><italic>. lemaneiformis</italic> was cultured at 12, 19, or 26°C for 3 weeks, to examine its photosynthetic acclimation to changing temperature. Growth rates were highest in <italic>G</italic><italic>. lemaneiformis</italic> thalli grown at 19°C, and were reduced with either decreased or increased temperature. The irradiance‐saturated rate of photosynthesis (P<sub>max</sub>) decreased with decreasing temperature, but increased significantly with prolonged cultivation at lower temperatures, indicating the potential for photosynthesis acclimation to lower temperature. Moreover, P<sub>max</sub> increased with increasing temperature (~30 μmol O<sub>2</sub> · g<sup>−1</sup>FW · h<sup>−1</sup> at 12°C to 70 μmol O<sub>2</sub> · g<sup>−1</sup>FW · h<sup>−1</sup> at 26°C). The irradiance compensation point for photosynthesis (I<sub>c</sub>) decreased significantly with increasing temperature (28 μmol photons · m<sup>−2</sup> · s<sup>−1</sup> at high temperature vs. 38 μmol photons · m<sup>−2</sup> · s<sup>−1</sup> at low temperature). Both the photosynthetic light‐ and carbon‐use efficiencies increased with increasing growth or temperatures (from 12°C to 26°C). The results suggested that the thermal acclimation of photosynthetic performance of <italic>G</italic><italic>. lemaneiformis</italic> would have important ecophysiological implications in sea cultivation for improving photosynthesis at low temperature and maintaining high standing biomass during summer. Ongoing climate change (increasing atmospheric CO<sub>2</sub> and global warming) may enhance biomass production in <italic>G</italic><italic>. lemaneiformis</italic> mariculture through the improved photosynthetic performances in response to increasing temperature.</p> </abstract>