Subprojeto 15 – Using advanced fluorescent microscopic tools to study the signal role of the radical nitric oxide (NO) in pathological and physiological processes in plants, at the cellular level

Participant: Ione Salgado (Institute of Biology, UNICAMP)

In recent years nitric oxide (NO) has been recognized as a key signaling molecule in plant defense responses against pathogens. It has been also implicated in several physiological processes in plants, such as seed germination, root and leaf development, flowering, among others. This pleiotropic action of NO is explained by its physical and chemical properties. NO is a gaseous free radical without charge and with a relatively long half-life when compared to other radicals. As one of the smallest diatomic molecules, it is highly diffusible and able to easily migrate through hydrophobic and hydrophilic compartments of the cell such as membranes and the cytosol. NO is able to interact with transition metals, leading to nitrosyl modifications of target molecules and cause S-nitrosylation of proteins or low molecular weight compounds by reacting with sulfur groups on cysteine residues. NO can also rapidly react with superoxide anion, producing peroxynitrite that, when in excess, may cause the nitration of tyrosines and the oxidation of thiol residues. Several fluorescent probes have been developed in order to follow NO production and the various NO-derived products in the cell. Our group has been used these methodologies to study the signaling role of NO during plant pathogen-interactions and in the processes of flower development and root differentiation. Our contributions, using these methodologies, have had a high impact in the literature, as measured by the number of citations our publications has received. The possibility to use advanced fluorescent microscopic tools, such as laser multiphoton, SHG, FRET and FCS in our investigations, will certainly increase the quality of studies and allow an increase in the impact of our work in the scientific community.