The innards of the cell: studies of water dipolar relaxation using ACDAN and PRODAN fluorescent probes

CABADAS, MANUEL; OTAIZA GONZÁLEZ SN; ROBERT G; MALACRIDA LEONEL; LASCANO HR

Porto Alegre

Congreso; XVIII Brazilian Congress of Plant Physiology; 2022

Water is the major and principal component of all living cells. In plant cells, it is known to account for approximately 90% of their total weight. The role assigned to water in living systems has changed over time. Many of the properties of water change drastically when measured in living systems compared to in vitro solutions. In our experiments, we have used the fluorophores ACDAN and PRODAN (2 of the 3 members of the DAN probes series) to measure changes in the dipolar relaxation of water in root cells (elongation zone, meristematic zone and root cap) and leaves cells (stomata) of Arabidopsis thaliana. These molecules, widely characterized in biomimetic systems, respond to changes in the polarity of the environment.What is observed are changes in the degree of intracellular water dipolar relaxation between different tissues, and between different subcellular structures, evidence that supports the existence of heterogeneities in the degree of intracellular water dipolar relaxation in plant cells. In addition, we observed a dose-dependent effect on the degree of intracellular water dipolar relaxation under oxidative stress conditions, being able to identify lethal and sublethal doses of ROS.These results are interpreted considering an alternative view of cellular physiology: The Association-Induction Hypothesis (AIH). This theory is a theoretical framework that emphasizes the structure of intracellular water in the maintenance of the living state in cells.