Reactive oxygen species mediate the relationship between mitochondrial function and delayed luminescence during senescence of strawberry (Fragaria ananassa) fruits

Relationship between photosystem activity and ultraweak luminescence excitation in Cerasus humilis leaves under salt stress

Cerasus humilis (Bge.) Sok (C. humilis) is a wild fruit tree endemic to China. It mainly grows on saline land and often suffers from osmotic stress. Biophotons are ultraweak luminescence (UWL) radiations that are closely related to various biological processes and activities. UWL emission essentially originates from the oxidative stress process of organisms. However, it is unclear whether UWL production is related to the redox state of chloroplasts. Therefore, to understand the UWL emission mechanism in plants, we studied the effect of salt stress on the photosystem (PS) activity and UWL of C. humilis leaves and analyzed the correlation between PS activity and UWL. The results showed that salt stress severely inhibited the PS activity of C. humilis leaves and oxygen-evolving complex, damaged the integrity of the thylakoid membrane, decreased the photochemical efficiency of PSII, and hindered the Q_A-Q_B electron transfer. At the same time, the intensity of UWL also decreased. Further, correlation analyses of PS activity indices and UWL showed that UWL was significantly correlated with main parameters of photosystem activity such as PSII the maximum photochemical efficiency (F_v/F_m) and photosynthetic performance index based on absorbed light energy (PI_ABS), as well as the absorption, capture, and transfer of energy in the unit reaction center and unit leaf section. These results indicated that the PS activity of C. humilis was related to the production of UWL, and the intensity of UWL decreased with the decrease in PS activity.

Role of Reactive Oxygen Species in Aging and Age-Related Diseases: A Review

Research on the role of reactive oxygen species (ROS) in the aging process has advanced significantly over the last two decades. In light of recent findings, ROS takes part in the aging process of cells along with contributing to various physiological signaling pathways. Antioxidants being cells' natural defense mechanism against ROS-mediated alteration, play an imperative role to maintain intracellular ROS homeostasis. Although the complete understanding of the ROS regulated aging process is yet to be fully comprehended, current insights into various sources of cellular ROS and their correlation with the aging process and age-related diseases are portrayed in this review. In addition, results on the effect of antioxidants on ROS homeostasis and the aging process as well as their advances in clinical trials are also discussed in detail. The future perspective in ROS-antioxidant dynamics on antiaging research is also marshaled to provide future directions for ROS-mediated antiaging research fields.