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Scheibe, R; Beck, E: Drought, Desiccation and Oxidative Stress, Ecological Studies, Springer Berlin, Heidelberg, New York, In: Lüttge U., Beck E., Bartels D. (eds) Plant desiccation tolerance.(215), 209-231 (2011), doi:10.1007/978-3-642-19106-0_11
Abstract:
Reactive oxygen species (ROS) are noxious but inevitable by-products of aerobic metabolism. Singlet oxygen 1O2, the oxygen radical anion O 2 − , the extremely toxic hydroxyl radical OH•, and finally H2O2 originate in photosynthesis, but O 2 − and H2O2 can also arise in the mitochondrial electron transport, and H2O2 is a normal intermediate in photorespiration and a product of several plasma membranes or apoplastic oxidases. All aerobic organisms, in particular plants, have a great variety of antioxidative and detoxifying compounds and enzymes to keep the level of ROS in all cellular compartments low. Under stress, the production of ROS is enhanced and organisms must counteract oxidative stress by enhancing their antioxidative potential. The elevated level of ROS, especially of H2O2, can be sensed and start MAP-kinase signaling cascades or can activate or inactivate signal transmitting elements such as protein kinases and phosphatases. Redox regulation of thiol–disulfide interchanges plays a major role in ROS signaling. Interaction of osmotic and ROS signals result in mutual modulations of the respective signaling networks. Such interactions are shown for drought-induced gene activation and for the regulation of stomata closure. Thus, ROS play a dual role in plants, as noxious reactants involved in uncontrolled or programmed cell death, but also as signals stimulating adaptation to abiotic stress, in particular from desiccation and drought. Representing one of the major challenges for plant life, tolerance of, or resistance to oxidative stress under drought is a promising aim for genetic engineering of crop plants.

Letzte Änderung 06.07.2020