"The role of isoprenoids in the protection against UV-B radiation"

JULIA EMILIANI; PATRICIA LEÓN; MANUEL RODRIGUEZ CONCEPCIÓN; PAULA CASATI

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2014

Isoprenoids are a group of biologically active molecules present in all living organisms, and some of them have general functions in growth and development. There are two unrelated routes for the synthesis of isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP), which are the precursors for the biosynthesis of all types of isoprenoids in plants: the acetate/mevalonate (MVA) pathway occurs in the cytoplasm while the MEP pathway (named for the first committed molecule in the pathway, 2Cmethyl-D-erythritol 4-phosphate), occurs in the plastids.. In order to analyze the role of isoprenoids in protecting plants against UV-B radiation, different Arabidospis thaliana transgenic lines with increased or decreased levels of enzymes of the MEP pathway, which catalyze the first and the penultimate steps in the biosynthesis of IPP, were UV-B-irradiated, and we evaluated DNA damage accumulation by dot blot assays. Physiological parameters were also assessed immediately after the UV-B treatment, such as the maximum efficiency of photosystem II, chlorophyll and flavonoid content. Together, our data demonstrate a protective role of isoprenoids against UV-B.