Diverse responses of sporophytic photochemical efficiency and gametophytic growth for two edible kelps, Saccharina japonica and Undaria pinnatifida, to ocean acidification and warming

Undaria pinnatifida is the commercially second most important brown alga in the world. Its global annual yield has been more than two million tonnes since 2012. It is extensively cultivated in East Asia, mainly consumed as food but also used as feed for aquacultural animals and raw materials for extraction of chemicals applicable in pharmaceutics and cosmetics. Cultivar breeding, which is conducted on the basis of characteristics of the life history, plays a pivotal role in seaweed farming industry. The common basic life history shared by kelps determines that their cultivar breeding strategies are similar. Cultivar breeding and cultivation methods of U. pinnatifida have usually been learned or directly transferred from those of Saccharina japonica. However, recent studies have revealed certain peculiarity in the life history of U. pinnatifida. In this article, we review the studies relevant to cultivar breeding in this alga, including the peculiar component of the life history, and the genetics, transcriptomics and genomics tools available, as well as the main cultivar breeding methods. Then we discuss the prospects of cultivar breeding based on our understanding of this kelp and what we can learn from the model brown alga and land crops.

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Nutrient Enrichment Regulates the Growth and Physiological Responses of Saccharina japonica to Ocean Acidification

Journal of Ocean University of China ◽

10.1007/s11802-020-4359-7 ◽

2020 ◽

Vol 19 (4) ◽

pp. 895-901

Author(s):

Yaoyao Chu ◽

Yan Liu ◽

Jingyu Li ◽

Qiaohan Wang ◽

Qingli Gong

Keyword(s):

Ocean Acidification ◽

Nutrient Enrichment ◽

Physiological Responses ◽

Saccharina Japonica

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Alleviation of solar ultraviolet radiation (UVR)-induced photoinhibition in diatom Chaetoceros curvisetus by ocean acidification

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315414001568 ◽

2014 ◽

Vol 95 (4) ◽

pp. 661-667 ◽

Cited By ~ 9

Author(s):

Heng Chen ◽

Wanchun Guan ◽

Guoquan Zeng ◽

Ping Li ◽

Shaobo Chen

Keyword(s):

Growth Rate ◽

Ultraviolet Radiation ◽

Ocean Acidification ◽

Specific Growth Rate ◽

Cell Density ◽

Specific Growth ◽

Photochemical Efficiency ◽

Solar Ultraviolet Radiation ◽

Chaetoceros Curvisetus ◽

Solar Ultraviolet

The study aimed to unravel the interaction between ocean acidification and solar ultraviolet radiation (UVR) in Chaetoceros curvisetus. Chaetoceros curvisetus cells were acclimated to high CO2 (HC, 1000 ppmv) and low CO2 concentration (control, LC, 380 ppmv) for 14 days. Cell density, specific growth rate and chlorophyll were measured. The acclimated cells were then exposed to PAB (photosynthetically active radiation (PAR) + UV-A + UV-B), PA (PAR + UV-A) or P (PAR) for 60 min. Photochemical efficiency (ΦPSII), relative electron transport rate (rETR) and the recovery of ΦPSII were determined. HC induced higher cell density and specific growth rate compared with LC. However, no difference was found in chlorophyll between HC and LC. Moreover, ΦPSII and rETRs were higher under HC than LC in response to solar UVR. P exposure led to faster recovery of ΦPSII, both under HC and LC, than PA and PAB exposure. It appeared that harmful effects of UVR on C. curvisetus could be counteracted by ocean acidification simulated by high CO2 when the effect of climate change is not beyond the tolerance of cells.

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Effects of elevated pCO2 and nutrient enrichment on the growth, photosynthesis, and biochemical compositions of the brown alga Saccharina japonica (Laminariaceae, Phaeophyta)

PeerJ ◽

10.7717/peerj.8040 ◽

2019 ◽

Vol 7 ◽

pp. e8040 ◽

Cited By ~ 2

Author(s):

Yaoyao Chu ◽

Yan Liu ◽

Jingyu Li ◽

Qingli Gong

Keyword(s):

Ocean Acidification ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Saccharina Japonica ◽

Soluble Proteins ◽

Interactive Effects ◽

Soluble Carbohydrates ◽

Negative Effects ◽

Relative Growth ◽

Biochemical Compositions

Ocean acidification and eutrophication are two major environmental issues affecting kelp mariculture. In this study, the growth, photosynthesis, and biochemical compositions of adult sporophytes of Saccharina japonica were evaluated at different levels of pCO2 (400 and 800 µatm) and nutrients (nutrient-enriched and non-enriched seawater). The relative growth rate (RGR), net photosynthetic rate, and all tested biochemical contents (including chlorophyll (Chl) a, Chl c, soluble carbohydrates, and soluble proteins) were significantly lower at 800 µatm than at 400 µatm pCO2. The RGR and the contents of Chl a and soluble proteins were significantly higher under nutrient-enriched conditions than under non-enriched conditions. Moreover, the negative effects of the elevated pCO2 level on the RGR, net photosynthetic rate, Chl c and the soluble carbohydrates and proteins contents were synergized by the elevated nutrient availability. These results implied that increased pCO2could suppress the growth and biochemical composition of adult sporophytes of S. japonica. The interactive effects of ocean acidification and eutrophication constitute a great threat to the cultivation of S. japonica due to growth inhibition and a reduction in quality.

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