Faster photosynthetic induction in tobacco by expressing cyanobacterial flavodiiron proteins in chloroplasts

GÓMEZ, RODRIGO; CARRILLO, NÉSTOR; MORELLI, MARÍA P.; TULA, SURESH; SHAHINNIA, FAHIMEH; HAJIREZAEI, MOHAMMAD-REZA; LODEYRO, ANABELLA F.

PHOTOSYNTHESIS RESEARCH

SPRINGER

Lugar: Berlin; Año: 2017

0166-8595

Plants grown in the fieldexperience sharp changes in irradiation due to shading effects caused by clouds,other leaves, etc. The excess of absorbed light energy is dissipated by anumber of mechanisms including cyclic electron transport, photorespiration, andMehler-type reactions. This protection is essential for survival but decreases photosyntheticefficiency. All phototrophs except angiosperms harbor flavodiiron proteins(Flvs) which relieve the excess of excitation energy on the photosyntheticelectron transport chain by reducing oxygen directly to water. Introduction ofcyanobacterial Flv1/Flv3 in tobacco chloroplasts resulted in transgenic plantsthat showed similar photosynthetic performance under steady-state illumination,but displayed faster recovery of various photosynthetic parameters, includingelectron transport and non-photochemical quenching during dark?lighttransitions. They also kept the electron transport chain in a more oxidizedstate and enhanced the proton motive force of dark-adapted leaves. The results indicatethat, by acting as electron sinks during light transi-tions, Flvs contribute toincrease photosynthesis protectionand efficiency under changing environmental conditionsas those found by plants in the field.