Desarrollo de plantas de tabaco tolerantes a estrés ambiental mediante la expresión de Flavin-dihierro proteínas cianobacterianas?

CARRILLO J B; LODEYRO A; VICINO P; CARRILLO N; GOMEZ R

Cordoba

Congreso; XXXII Reunión Argentina / XVI Congreso Latinoamericano de FISIOLOGÍA VEGETAL; 2020

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 unfavorable growth conditions. Flv1-Flv3 acts as a solubleNADPH-reductase which dissipatestheexcessof reducing power by consuming NADPH and transferring thehydridesto dioxygen toform water in a singlestep.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 toelucidateitsfunction we generated tobaccoplants expressing the Flv2-Flv4 dimer in chloroplasts.These plantsshowed better tolerancethan wild typetoseveral 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 questionson thecausesof their disappearance from the plant genome.