An in vivo system involving co-expression of cyanobacterial flavodoxin and ferredoxin-NADP(+) reductase confers increased tolerance to oxidative stress in plants

Mariana Giró; Romina D Ceccoli; Hugo O Poli; Néstor Carrillo; Anabella F Lodeyro

doi:10.1016/j.fob.2011.10.004

An in vivo system involving co-expression of cyanobacterial flavodoxin and ferredoxin-NADP(+) reductase confers increased tolerance to oxidative stress in plants

FEBS Open Bio. 2011 Nov 11:1:7-13. doi: 10.1016/j.fob.2011.10.004. Print 2011 Dec.

Authors

Mariana Giró¹, Romina D Ceccoli, Hugo O Poli, Néstor Carrillo, Anabella F Lodeyro

Affiliation

¹ Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.

Abstract

Oxidative stress in plants causes ferredoxin down-regulation and NADP(+) shortage, over-reduction of the photosynthetic electron transport chain, electron leakage to oxygen and generation of reactive oxygen species (ROS). Expression of cyanobacterial flavodoxin in tobacco chloroplasts compensates for ferredoxin decline and restores electron delivery to productive routes, resulting in enhanced stress tolerance. We have designed an in vivo system to optimize flavodoxin reduction and NADP(+) regeneration under stress using a version of cyanobacterial ferredoxin-NADP(+) reductase without the thylakoid-binding domain. Co-expression of the two soluble flavoproteins in the chloroplast stroma resulted in lines displaying maximal tolerance to redox-cycling oxidants, lower damage and decreased ROS accumulation. The results underscore the importance of chloroplast redox homeostasis in plants exposed to adverse conditions, and provide a tool to improve crop tolerance toward environmental hardships.

Keywords: Cytb6f, cytochrome b6f; Electron transport; FNR, Ferredoxin–NADP+ reductase; Fd, ferredoxin; Ferredoxin; Ferredoxin–NADP+ reductase; Flavodoxin; Fld, flavodoxin; MV, methyl viologen; NPQ, non-photochemical quenching; Oxidative stress; PC, plastocyanin; PETC, photosynthetic electron transport chain; PQ, plastoquinone; PS, photosystem; Photosynthesis; ROS, reactive oxygen species; TP, transit peptide; sFNR, soluble cyanobacterial FNR.