EXPRESSION OF A CYANOBACTERIAL FLAVODOXIN IN PLASTIDS AFFECTS PLANT DEVELOPMENT AND PRODUCTIVITY

MAYTA MARTÍN; HAJIREZAEI MOHAMMAD-REZA; CARRILLO NÉSTOR; ARCE ROCÍO; ZANOR, MARIA INES; LODEYRO ANABELLA F; ZURBRIGGEN, MATIAS D.; VALLE, ESTELA M.

Córdoba

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

Sociedad Argentina de fisiología Vegetal

Light energy capture through photosynthesis determinesplant productivity with leaves being the main organdriving this process. Therefore, understanding and controllingleaf growth is of prime importance for agriculture.Leaf development proceeds firstly through cellproliferation, followed by cell expansion to achieve itsfinal size. Reactive oxygen species (ROS) play signalingroles in leaf development but their subcellular sourceis not completely clarified. It has been shown that aplastid-targeted flavodoxin (Fld) prevents ROS accumulationin chloroplast of transgenic tobacco lines, actingas an antioxidant specific for these organelles.Tobacco and tomato plants expressing Fld (pfld lines)showed smaller leaves due to a repression of cell expansion.Therefore, total plant biomass was decreasedin transgenic lines. However, fruit yield was unchangedin pfld plants resulting in an increase on the harvestindex. Interestingly, higher expression of proteasomerelatedgenes and proteasome activity was observed inFld-expressing tobacco leaves at different developmentalstages, suggesting a delay in endo-reduplication.Altogether, these results indicate that chloroplast redoxstate might be involved in early leaf development. Moreover,they reveal a novel intervention point to modifyplant architecture in order to obtain higher productivityin crops.