PHYSIOLOGICAL CHANGES IN PLANTS UNDER EXTREME CLIMATIC EVENTS: IMPACTS ON BRAZILIAN AGRICULTURE

Abstract

Global agriculture faces increasing challenges due to the rising frequency of extreme climate events, such as heat waves and severe droughts, which compromise productivity and food security. This study aimed to review and describe the main physiological changes in plants exposed to extreme climate events, providing a theoretical basis for the development of anticipatory adaptation strategies in agriculture. Physiological changes in plants under climate change are marked by a complex interaction between increased carbon dioxide (CO₂) levels and extreme temperature and drought events. Although elevated CO₂ may initially stimulate photosynthesis and growth, these benefits are often offset by heat stress, which damages the photosynthetic machinery, inactivates the enzyme Rubisco, and destabilizes cellular membranes. Under conditions of water deficit and salinity, plants activate stomatal closure mediated by abscisic acid (ABA) to reduce transpiration, which simultaneously restricts carbon uptake and compromises nutrient absorption and biomass production. In addition, oxidative stress resulting from the production of reactive oxygen species (ROS) degrades proteins and pigments, while plants attempt to mitigate these damages through osmotic adjustments and molecular responses.