Event Title

Effects of acidic pH on sexual reproduction in the giant kelp Macrocystis pyrifera

Mentor 1

Filipe Alberto

Location

Union Wisconsin Room

Start Date

5-4-2019 1:30 PM

End Date

5-4-2019 3:30 PM

Description

As atmospheric CO2 concentrations increase due to anthropogenic sources, ocean acidification (OA) rates are predicted to increase. As more CO2 enters the ocean ecosystem, bicarbonate (HCO3-) and CO2 concentrations increase while carbonate (CO32-) concentrations decrease. Seaweeds like the giant kelp, Macrocystis pyrifera, an ecosystem engineer, can utilize both bicarbonate and carbon dioxide as a carbon source. However, they must convert bicarbonate into metabolically useful CO2 using CO2-concentrating mechanisms (CCMs). CO2 uptake therefore requires less energy than bicarbonate uptake, and it has been shown that seaweeds increase their CO2 uptake in lower pH conditions. The MARINER project’s goal is to create a sustainable off-shore seaweed aquaculture program aimed at biofuel production. In the Alberto lab our goal pertains to the genomic selection of gametophyte lines to seed such aquaculture systems by characterizing the association between genes and phenotype traits of interest. The performance of microscopic sexual phases (gametophytes) is an important aspect for assessing how both a farm and natural populations would fare in a more acidic ocean. We hypothesize that M. pyrifera will use less energy on CCMs in low pH conditions and therefore will have increased reproductive performance. We will test this by applying control (7.8), worst-case OA scenario (7.2), and extreme (6.5) pH conditions to three genetic populations gametophytes. Gametophyte sexual performance will be evaluated by tracking the amount of time taken to produce egg cells and sporophytes, and the proportion of egg cells and sporophytes in each sample. Preliminary results indicate a strong ability for M. pyrifera metabolism to buffer pH conditions. Gametophyte health was also not affected in a low pH (6.6) trial.

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Apr 5th, 1:30 PM Apr 5th, 3:30 PM

Effects of acidic pH on sexual reproduction in the giant kelp Macrocystis pyrifera

Union Wisconsin Room

As atmospheric CO2 concentrations increase due to anthropogenic sources, ocean acidification (OA) rates are predicted to increase. As more CO2 enters the ocean ecosystem, bicarbonate (HCO3-) and CO2 concentrations increase while carbonate (CO32-) concentrations decrease. Seaweeds like the giant kelp, Macrocystis pyrifera, an ecosystem engineer, can utilize both bicarbonate and carbon dioxide as a carbon source. However, they must convert bicarbonate into metabolically useful CO2 using CO2-concentrating mechanisms (CCMs). CO2 uptake therefore requires less energy than bicarbonate uptake, and it has been shown that seaweeds increase their CO2 uptake in lower pH conditions. The MARINER project’s goal is to create a sustainable off-shore seaweed aquaculture program aimed at biofuel production. In the Alberto lab our goal pertains to the genomic selection of gametophyte lines to seed such aquaculture systems by characterizing the association between genes and phenotype traits of interest. The performance of microscopic sexual phases (gametophytes) is an important aspect for assessing how both a farm and natural populations would fare in a more acidic ocean. We hypothesize that M. pyrifera will use less energy on CCMs in low pH conditions and therefore will have increased reproductive performance. We will test this by applying control (7.8), worst-case OA scenario (7.2), and extreme (6.5) pH conditions to three genetic populations gametophytes. Gametophyte sexual performance will be evaluated by tracking the amount of time taken to produce egg cells and sporophytes, and the proportion of egg cells and sporophytes in each sample. Preliminary results indicate a strong ability for M. pyrifera metabolism to buffer pH conditions. Gametophyte health was also not affected in a low pH (6.6) trial.