The influence of hydrogen peroxide on the content of prohibitines Phb3 and Phb4 in the leaves of Arabidopsis thaliana

According to modern ideas, plant mitochondria regulate the expression of nuclear genes and actas signaling organelles providing the tolerance of plants to external stressors. Highlyconservative membrane proteins prohibitines (Phb) responsible for membrane-peptideinteractions in organelles of animals, plants and microorganisms accumulate in mitochondriaand modulate the state of their membranes, participating in the regulation of mitochondrial-mediated signaling. The tuning of the content of the Phb is poorly investigated for today day.Most of biotic and abiotic stresses are associated with production of reactive oxygen species(ROS) which can play as signaling role as well as cause damage. Hydrogen peroxide is one ofthe forms of ROS. The goal of this research was to study the effect of different doses ofhydrogen peroxide on the Phb3 and Phb4 content in Arabidopsis plants. In the leaves ofArabidopsis thaliana heat shock (HS, 42°C, 3 h) caused the increasing of the content of Phbafter 24 h from the stop of the influence and the increasing of superoxide radical contentimmediately after HS. So the increasing of the content of Phb and ROS as a result of HS occurssimultaneously. Next we investigated the influence of oxidative stress on Phb content. It wasshown at first that H2O2 decreases the content of Phb in dose-depend manner at the startinghours of the action (2 to 40 mM H2O2 during 1 to 2 h were used). At the continuation of theinfluence till 24 h the content of Phb returns to the control value. Herewith the suppressing effectis demonstrated by non-stress doses of H2O2 (2 to 10 mM). The stress dose of H2O2 (40 mM at24 h) doesn’t effect on the content of Phb, but causes the increasing of the content of Hsp 17.7and wilting of the leaves which indicates the stressed condition of the plants. The resultsreceived speak in favor that at the protein level the increasing of Phb3 and Phb4 content is notactivated by ROS-mediated system even during the development of the oxidative stress.