CONICET | Buscador de Institutos y Recursos Humanos

Environmental stresses and nutrient limitation are the major causes for crop losses worldwide. Engineering strategies aimed at improving stress tolerance have mostly focused on overexpression of plant-endogenous genes belonging to molecular networks for stress perception or stress responses. Based on the stress responses observed in cyanobacteria an alternative biotechnological approach has been undertaken. The iron-containing ferredoxin is astress-sensitive target in the chloroplast redox balance. To overcome stress-induced inhibition of ferredoxin-dependent pathways, expression in tobacco chloroplasts of an isofunctional protein, a cyanobacterial flavodoxin, which is Fe-free and absent in plants, was used as ferredoxin complementation strategy. Transgenic lines displayed tolerance to a wide range of stress conditions, such as drought, chilling, oxidants, heat or iron starvation. We applied the above-mentioned strategy also to the crop plant species potato to develop transgenic lines with enhanced tolerance against adverse environmental conditions. Soil-grown wild-type and transgenic potato plants were exposed to drought stress and a combined analysis of transcript and metabolite profiles was performed. This combined approach allowed us to identify novel target genes in drought stress and to characterize the role of a flavodoxin-mediated redox balance in the drought stress response of potato.In addition, we are currently testing further cyanobacterial proteins, flavodi-iron proteins (Flv), for similar and additional effects. Flvs show characteristics indicating a response to oxidative stress superior to that of flavodoxin. Flvs have been expressed in the model plants Arabidopsis and tobacco for the identification of mechanisms involved in the protective action against oxidative stress or other environmental and nutrient stresses.