Investigating Increased CO2 concentration on the pH of various plant species

Abstract

The concept of bioremediation is quickly becoming the norm in the resolution of environmental issues. The steady increase in carbon dioxide (CO2) levels, as documented by NASA, inspired scientists to engineer plants to absorb excess CO2 from the atmosphere. Here, we have explored the consequences of the uptake of excess CO2 by select plants. Carbon dioxide dissolves in H2O to produce H2CO3, which dissociates to yield H+ ions. We hypothesized that increased CO2 absorption results in decrease in pH of plant sap. Three plants (Byophyllum pinnatum, Romaine Lettuce and Nevada Lettuce), exposed to increased CO2 concentrations (15%), demonstrated a consistent increase in pH towards alkalinity compared to control plants. Based on the outcome being opposite of what we have hypothesized, our results suggest Byophyllum pinnatum, Romaine lettuce and Nevada lettuce, all have a unique homeostatic system to prevent over-absorption of CO2 in a CO2-rich environment.