Fahimeh Shahinnia
IPK, Germany
Title: Improvement of biomass and stress tolerance in crop plants using cyanobacteria flavodi-iron proteins (FDPs)
Biography
Biography: Fahimeh Shahinnia
Abstract
Environmental stresses and nutrient limitation are among the major causes for crop losses worldwide. Engineering strategies aimed at improving growth and stress tolerance have mostly focused on overexpression of plant-endogenous genes belonging to molecular networks for stress perception or stress responses. A new alternative approach has recently been applied with considerable success to model plants. It is based on the replacement of stress-sensitive plant targets such as ferredoxin by stress-resistant cyanobacterial flavodoxin. The expression of cyanobacterial flavodoxin in chloroplasts in transgenic tobacco plants led to tolerance to various stresses including drought and iron starvation, thus representing a biotechnological application for the generation of crops tolerant to multiple stresses. In the present study, we have tested additional cyanobacterial proteins, flavodi-iron proteins (FDPs), for further investigation of this approach. FDPs are widely distributed among bacteria, archaea and cyanobacteria and show various properties such as dioxygen-scavenging reductase and nitric oxide-scavenging reductase activity indicating a response to oxidative stress superior to that of flavodoxin. In Cyanobacteria, FDPs are encoded by four different genes Flv1, Flv2, Flv3 and Flv4 and function in tandem. Further, FDPs are a sub-class of redox-active proteins containing Fe in a form that does not occur in higher plant proteins. We have introduced the Flv genes in the genome of the plant species Arabidopsis, tobacco and barley to identify the underlying molecular and biochemical mechanisms for their protective action against oxidative stress and to identify the environmental and nutrient conditions, under which Flv-mediated stress tolerance allows for biomass and yield enhancement.