Role of PsTrxo1 in TBY-2 cell death after treatment with 35 mM H2O2.
Annals of Botany

Over-expression of Trxo1 and cell viability under H2O2 stress

Ortiz-Espín et al. treat over-expressing PsTrxo1 tobacco (Nicotiana tabacum) BY-2 cells with H2O2 and find a significant delay in cell death compared to controls, which may in part be due to a decreased content of endogenous H2O2 in the over-expressing cells, in which changes in oxidative parameters and antioxidants are less extended after the oxidative treatment.

Hierarchical clustering and heat map of ER stress-related genes in leaves treated with H2O2, Rot, MV, DCMU and 3-AT (average linkage and Euclidean distance as similarity measure).
Annals of Botany

Organelle-originated ROS and endoplasmic reticulum responses

Ozgur et al. induce the formation of reactive oxygen species (ROS) in chloroplasts, mitochondria and peroxisomes of Arabidopsis thaliana and find that relatively low concentrations of ROS are more effective for induction of the ER stress response, and that mitochondrial and chloroplastic ROS production have different induction mechanisms for the UPR and ER stress responses.

An epipelic algal community on air-exposed soil.
Annals of Botany

Diurnal changes in algal xanthophyll cycle and H2O2 concentration

High light activates the xanthophyll cycle and increases the production of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), but the interrelationships between these parameters is poorly understood. Using a natural freshwater community of algae comprising Euglena species, benthic Navicula diatoms, Chlamydomonas and Chlorella species, Roach et al. demonstrate diurnal variations in H2O2 levels, with a peak at midday. At this point the algae rapidly scavenge H2O2 rather than excreting it