DEVELOPMENT OF STRESS TOLERANT TOBACCO PLANTS BY EXPRESSING CYANOBACTERIAL FLAVODIIRON PROTEINS

GÓMEZ, RODRIGO; VICINO, PAULA; LODEYRO, ANABELLA F.; CARRILLO, JULIETA; CARRILLO, NÉSTOR

Córdoba

Congreso; XXXII Reunión Argentina XVI congreso Latinoamericano de Fisiología Vegetal; 2018

Sociedad Argentina de fisiología Vegetal

Flavodiiron proteins (Flvs) constitute a large family ofenzymes distributed among prokaryotes and severalplant lineages, but absent from angiosperms. In thecyanobacterium Synechocystis sp. PCC 6803, Flvs areencoded by four different genes (flv1-4) and form twofunctional heterodimers: Flv1-Flv3 and Flv2-Flv4. Theseenzymes help to avoid oxidative stress under unfavorablegrowth conditions. Flv1-Flv3 acts as a solubleNADPH-reductase which dissipates the excess of reducingpower by consuming NADPH and transferring thehydrides to dioxygen to form water in a single step. Thefunction of Flv2-Flv4 is less known and this dimer canbe found only in cyanobacteria. It has been assigned arole in photoprotection of PSII, but its mechanism isnot yet clearly understood.In order to elucidate its function we generated tobaccoplants expressing the Flv2-Flv4 dimer in chloroplasts.These plants showed better tolerance than wild type toseveral types of stress, e.g. salt, high light and oxidative,indicating that although normally absent, Flvscould play a protective function when expressed inplants, and raising questions on the causes of their disappearancefrom the plant genome.