Guest
Warming surface temperatures and increasing frequency and duration of widespread droughts threaten the health of forests. High temperatures and intense droughts can lead to the excessive plant water loss resulting in extensive physical and oxidative damage to sensitive plant components including photosynthetic membranes. However, there is signaling integrated with a mechanism of the phytohormone abscisic acid (ABA), which stimulates stomatal closure leading to a reduction in transpiration and net photosynthesis, alters hydraulic conductivities, and activates defense gene expression including antioxidant systems. While generally assumed to be produced in roots and transported to shoots following drought stress, recent evidence suggests that a large fraction of plant ABA is produced in leaves via the isoprenoid pathway. Thus, through stomatal regulation and stress signaling which alters water and carbon fluxes, we highlight the fact that ABA lies at the heart of the Carbon-Water-ROS Nexus of plant response to high temperatures and drought stress caused by climate change. We discuss potential variations in ABA production and stomatal sensitivity among different plant functional types including isohydric/anisohydric tree species. Finally, we propose a new modeling framework to capture these interactions. We conclude the importance of ABA in diverse tropical ecosystems through increases in the thermotolerance of photosynthesis to drought and heat stress, and the global importance of these mechanisms to carbon and water cycling under climate change scenario. Music theme - Canção foliar da Amazônia. Ramon Barros Baptista – voice, guitar and composition Danielle Colares Lins – violin Cassiano Augusto Ferreira Rodrigues Gatto - guitar Julia de Moura Linhares – percussion Israel Sampaio Filho - composition Filmed at the ZF2: Forest management base of the National Institute of Amazonian Research (INPA), Manaus - Amazonas, Brazil. We wish you have fun and enjoy the video!
