TY - JOUR

T1 - Leaf Age-Dependent Photosystem II Photochemistry and Oxidative Stress Responses to Drought Stress in Arabidopsis thaliana Are Modulated by Flavonoid Accumulation

AU - Sperdouli, Ilektra

AU - Moustaka, Julietta

AU - Ouzounidou, Georgia

AU - Moustakas, Michael

PY - 2021

Y1 - 2021

N2 - We investigated flavonoid accumulation and lipid peroxidation in young leaves (YL) and mature leaves (ML) of Arabidopsis thaliana plants, whose watering stopped 24 h before sampling, characterized as onset of drought stress (OnDS), six days before sampling, characterized as mild drought stress (MiDS), and ten days before sampling, characterized as moderate drought stress (MoDS). The response to drought stress (DS) of photosystem II (PSII) photochemistry, in both leaf types, was evaluated by estimating the allocation of absorbed light to photochemistry (phi(PSII)), to heat dissipation by regulated non-photochemical energy loss (phi(NPQ)) and to non-regulated energy dissipated in PSII (phi(NO)). Young leaves were better protected at MoDS than ML leaves, by having higher concentration of flavonoids that promote acclimation of YL PSII photochemistry to MoDS, showing lower lipid peroxidation and excitation pressure (1 - q(p)). Young leaves at MoDS possessed lower 1 - q(p) values and lower excess excitation energy (EXC), not only compared to MoDS ML, but even to MiDS YL. They also possessed a higher capacity to maintain low phi(NO), suggesting a lower singlet oxygen (O-1(2)) generation. Our results highlight that leaves of different developmental stage may display different responses to DS, due to differential accumulation of metabolites, and imply that PSII photochemistry in Arabidopsis thaliana may not show a dose dependent DS response.

AB - We investigated flavonoid accumulation and lipid peroxidation in young leaves (YL) and mature leaves (ML) of Arabidopsis thaliana plants, whose watering stopped 24 h before sampling, characterized as onset of drought stress (OnDS), six days before sampling, characterized as mild drought stress (MiDS), and ten days before sampling, characterized as moderate drought stress (MoDS). The response to drought stress (DS) of photosystem II (PSII) photochemistry, in both leaf types, was evaluated by estimating the allocation of absorbed light to photochemistry (phi(PSII)), to heat dissipation by regulated non-photochemical energy loss (phi(NPQ)) and to non-regulated energy dissipated in PSII (phi(NO)). Young leaves were better protected at MoDS than ML leaves, by having higher concentration of flavonoids that promote acclimation of YL PSII photochemistry to MoDS, showing lower lipid peroxidation and excitation pressure (1 - q(p)). Young leaves at MoDS possessed lower 1 - q(p) values and lower excess excitation energy (EXC), not only compared to MoDS ML, but even to MiDS YL. They also possessed a higher capacity to maintain low phi(NO), suggesting a lower singlet oxygen (O-1(2)) generation. Our results highlight that leaves of different developmental stage may display different responses to DS, due to differential accumulation of metabolites, and imply that PSII photochemistry in Arabidopsis thaliana may not show a dose dependent DS response.

KW - acclimation

KW - non-photochemical quenching (NPQ)

KW - mild drought stress

KW - moderate drought stress

KW - young leaves

KW - mature leaves

KW - lipid peroxidation

KW - singlet oxygen (O-1(2))

KW - reactive oxygen species (ROS)

KW - SINGLET OXYGEN PRODUCTION

KW - CHLOROPHYLL-A FLUORESCENCE

KW - ABSORBED LIGHT

KW - ABIOTIC STRESS

KW - PHOTOSYNTHETIC PERFORMANCE

KW - PHOTOPROTECTIVE MECHANISM

KW - PHOTOOXIDATIVE STRESS

KW - THYLAKOID MEMBRANES

KW - LIPID-PEROXIDATION

KW - WATER-STRESS

U2 - 10.3390/molecules26144157

DO - 10.3390/molecules26144157

M3 - Journal article

C2 - 34299433

VL - 26

JO - Molecules (Print Archive Edition)

JF - Molecules (Print Archive Edition)

SN - 1431-5157

IS - 14

M1 - 4157

ER -