TY - JOUR

T1 - Leaf age-dependent effects of foliar-sprayed CuZn nanoparticles on photosynthetic efficiency and ROS generation in Arabidopsis thaliana

AU - Sperdouli, Ilektra

AU - Moustaka, Julietta

AU - Antonoglou, Orestis

AU - Adamakis, Ioannis Dimosthenis S.

AU - Dendrinou-Samara, Catherine

AU - Moustakas, Michael

PY - 2019/8/1

Y1 - 2019/8/1

N2 - Young and mature leaves of Arabidopsis thaliana were exposed by foliar spray to 30 mg L-1 of CuZn nanoparticles (NPs). The NPs were synthesized by a microwave-assisted polyol process and characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CuZn NPs effects in Arabidopsis leaves were evaluated by chlorophyll fluorescence imaging analysis that revealed spatiotemporal heterogeneity of the quantum efficiency of PSII photochemistry (ϕPSII) and the redox state of the plastoquinone (PQ) pool (qp), measured 30 min, 90 min, 180 min, and 240 min after spraying. Photosystem II (PSII) function in young leaves was observed to be negatively influenced, especially 30 min after spraying, at which point increased H2O2 generation was correlated to the lower oxidized state of the PQ pool. Recovery of young leaves photosynthetic efficiency appeared only after 240 min of NPs spray when also the level of ROS accumulation was similar to control leaves. On the contrary, a beneficial effect on PSII function in mature leaves after 30 min of the CuZn NPs spray was observed, with increased FPSII, an increased electron transport rate (ETR), decreased singlet oxygen (1O2) formation, and H2O2 production at the same level of control leaves.An explanation for this differential response is suggested.

AB - Young and mature leaves of Arabidopsis thaliana were exposed by foliar spray to 30 mg L-1 of CuZn nanoparticles (NPs). The NPs were synthesized by a microwave-assisted polyol process and characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CuZn NPs effects in Arabidopsis leaves were evaluated by chlorophyll fluorescence imaging analysis that revealed spatiotemporal heterogeneity of the quantum efficiency of PSII photochemistry (ϕPSII) and the redox state of the plastoquinone (PQ) pool (qp), measured 30 min, 90 min, 180 min, and 240 min after spraying. Photosystem II (PSII) function in young leaves was observed to be negatively influenced, especially 30 min after spraying, at which point increased H2O2 generation was correlated to the lower oxidized state of the PQ pool. Recovery of young leaves photosynthetic efficiency appeared only after 240 min of NPs spray when also the level of ROS accumulation was similar to control leaves. On the contrary, a beneficial effect on PSII function in mature leaves after 30 min of the CuZn NPs spray was observed, with increased FPSII, an increased electron transport rate (ETR), decreased singlet oxygen (1O2) formation, and H2O2 production at the same level of control leaves.An explanation for this differential response is suggested.

KW - Bimetallic nanoparticles

KW - Hydrogen peroxide

KW - Mature leaves

KW - Non-photochemical quenching

KW - Photoprotective mechanism

KW - Photosynthetic heterogeneity

KW - Plastoquinone pool

KW - Redox state

KW - Spatiotemporal heterogeneity

KW - Young leaves

UR - http://www.scopus.com/inward/record.url?scp=85070614210&partnerID=8YFLogxK

U2 - 10.3390/ma12152498

DO - 10.3390/ma12152498

M3 - Journal article

C2 - 31390827

AN - SCOPUS:85070614210

VL - 12

SP - 1

EP - 17

JO - Materials

JF - Materials

SN - 1996-1944

IS - 15

M1 - 2498

ER -