The Short-Term Effects of Carbon Dioxide on the Cellular Respiration of Ipomoea Batatas (Sweet Potato)

Abstract:

People rely on plants for everything from nutrition to clothing, therefore, it is important for climate research to consider the effect of CO2 pollution on plants. Specifically, it is important to study how the respiration of plants is affected by increased CO2 levels. The plants used in this experiment were Ipomoea batatas (sweet potato) slips, because, as a drought and heat resistant crop, this plant has the potential to become a crucial food crop in a world where climate change is a reality. The hypothesis tested in this experiment is that an environment high in CO2 decreases cellular respiration in Ipomoea batatas. To prevent CO2 absorption due to photosynthesis, the Ipomoea batatas slips were placed in a dark chamber during the experiment. The slips used were also unpotted to prevent CO2 emissions from soil. The experimental setup consisted of placing each of four Ipomoea batatas slips inside an airtight plastic container 15x8x8 cm. The container’s o-ring seal was maintained by a clamp. A CO2 sensor was placed through a hole in the container fitted with a grommet. The container was placed inside an insulated bag, to control for light and temperature. Data from the sensor were transferred through a wireless connection to a computer, running Vernier software for data acquisition and analysis. The respiration of the slip was recorded for 40 minutes immediately after placing the slip into the airtight container as a control. The container had the same carbon dioxide concentration as the atmosphere around it (~800 ppm) After obtaining the control data, the level of CO2 in the container was increased in successive steps. The respiration of the slip was recorded for 40 minutes at each CO2 level. CO2 was released from a bicycle tire pump cartridge and allowed to sink into the open container. The container was sealed when the desired CO2 level was reached. The data from this experiment show that plant respiration slows in an environment of elevated CO2. This finding has important implications for society, because the nutritional value of plant based food and the structural integrity of plant based materials may change with the chemical composition of plants adapting to slower metabolisms.