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

Abstract

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 (ΦPSII), to heat dissipation by regulated non-photochemical energy loss (ΦNPQ) and to non-regulated energy dissipated in PSII (ΦNO). 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 − qp). Young leaves at MoDS possessed lower 1 − qp 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 ΦNO, suggesting a lower singlet oxygen (1O2) 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.

Excess Zinc Supply Reduces Cadmium Uptake and Mitigates Cadmium Toxicity Effects on Chloroplast Structure, Oxidative Stress, and Photosystem II Photochemical Efficiency in Salvia sclarea Plants

“…However, Zn 2+ supplementation to Cd 2+ -containing nutrient solution decreased lipid peroxidation, which remained higher compared with control values (Figure 5a), suggesting an increased ROS production. Under optimal growth conditions, a homeostasis of ROS is maintained [59,60], while an alteration in this homeostasis activates defense responses [3,59,61,62], but an elevated ROS level is harmful to plants [59,61]. However, ROS are considered to be essential signaling molecules that adjust plant development and the defense responses to various biotic and abiotic stresses [50,60,63,64].…”

Root-Associated Entomopathogenic Fungi Modulate Their Host Plant’s Photosystem II Photochemistry and Response to Herbivorous Insects

“…Such a compensatory is rationalized by a higher requirement of the remaining leaf area for a higher fraction of the absorbed light energy for photochemistry to fix larger amounts of carbon [ 44 , 74 ]. The light reactions of photosynthesis feed the energy supply required for the production of compounds used in defense, such as hormones, and other defense-related metabolites [ 26 , 75 ].…”

“…The ability of a plant to maintain its photosynthetic efficiency, even when attacked by antagonists, is crucial for the plant’s defense and compensatory responses [ 24 , 25 ]. Moreover, non-photochemical quenching (NPQ) is considered as the principal photoprotective mechanism in plants that dissipates excess light energy as heat and protects light reaction under biotic and abiotic stress conditions, preventing the formation of reactive oxygen species (ROS) [ 26 , 27 , 28 , 29 ]. NPQ is involved in the mechanism of plant acclimation to biotic or abiotic stress and has been suggested to be a major component of the systemic acquired resistance [ 30 , 31 , 32 ].…”

Responses of Secondary Metabolites and Transcriptomes in Tea Cultivar ‘Zhong Ming 6’ (Camellia Sinensis) under Blue Light and Red Light Journal Name: Plant Growth Regulation

“…It is also a crucial signaling factor to the production of yield Ye et al, 2021). In addition, photosynthetic ability is very essential, as it directly contributes to plant growth and productivity (Sperdouli et al, 2021). However, photosynthetic pathways have been detrimentally affected in light stress than other abiotic oppressions (Nouri et al, 2015).…”