Photosynthetic activity and proteomic analysis highlights the utilization of atmospheric CO2by Ulva prolifera (Chlorophyta) for rapid growth.
Free-floating Ulva prolifera is one of the causative species of green tides. When green tides occur, massive mats of floating U. prolifera thalli accumulate rapidly in surface waters with daily growth rates as high as 56%. The upper thalli of the mats experience environmental changes such as the change in carbon source, high salinity, and desiccation. In this study, the photosynthetic performances of PSI and PSII in U. prolifera thalli exposed to different atmospheric carbon dioxide (CO2) levels were measured. Changes in photosynthesis within salinity treatments and dehydration under different CO2concentrations were also analyzed. The results showed that PSII activity was enhanced as CO2increased, suggesting that CO2assimilation was enhanced and U. prolifera thalli can utilize CO2in the atmosphere directly, even when under moderate stress. In addition, changes in the proteome of U. prolifera in response to salt stress were investigated. Stress-tolerance proteins appeared to have an important role in the response to salinity stress, whereas the abundance of proteins related to metabolism showed no significant change under low salinity treatments. These findings may be one of the main reasons for the extremely high growth rate of free-floating U. prolifera when green tides occur.
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Li
L
Huan
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Wenhui
W
Gu
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Shan
S
Gao
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Guangce
G
Wang
D020418:Algal Proteins / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D003890:Desiccation; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D020543:Proteome / Q000187:drug effects / Q000378:metabolism*; D054712:Salinity; D012965:Sodium Chloride / Q000494:pharmacology; D044445:Ulva / Q000378:metabolism*
D020418:Algal Proteins; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D020543:Proteome; D002245:Carbon Dioxide; D012965:Sodium Chloride

CO
2
; green tide; photosynthesis; proteome; salt stress