Impact of Elevated Atmospheric and Intercellular CO₂ on Plant Defense Mechanisms

This review explores the complex relationship between carbon dioxide (CO₂) levels and secondary metabolites in leaves, emphasizing their role in plant defense mechanisms. The synthesis of different research that has been done ranges from the influence of CO₂ on photosynthesis, metabolic pathways, and the synthesis of secondary metabolites, crucial in protecting plants against environmental stressors, especially pathogens. The paper highlights the significance of various factors such as light intensity, water supply, and temperature in regulating stomatal conductance and subsequent CO₂ assimilation. Additionally, it discusses the diverse secondary metabolites found in plants, including phenolic compounds, terpenoids, and tannins, and their antioxidant properties. The review suggests that elevated CO₂ levels may enhance plant defense responses by influencing the production of secondary metabolites. The paper also explores the complex interplay between CO₂ levels, metabolic activity, and defense mechanisms, providing valuable insights into how plants dynamically adjust their metabolism to cope with environmental challenges, highlighting the interaction of adaptation and physiology in plants, offering a holistic understanding of the biochemical and physiological processes involved in plant defense.