This review provides an overview about recent developments and current knowledge about monitoring, generation and the functional role of reactive oxygen species (ROS) - H2O2, HO2, HO, OH(-), (1)O2 and O2(-) - in both oxidative degradation and signal transduction in photosynthetic organisms including microscopic techniques for ROS detection and controlled generation. Reaction schemes elucidating formation, decay and signaling of ROS in cyanobacteria as well as from chloroplasts to the nuclear genome in eukaryotes during exposure of oxygen-evolving photosynthetic organisms to oxidative stress are discussed that target the rapidly growing field of regulatory effects of ROS on nuclear gene expression.

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The review is devoted to modern trends in the chemistry of nitrogen-, oxygen-and sulfur-containing monocyclic, polynuclear and benzo(hetero)annulated heterocyclic compounds. Methods for the synthesis and chemical reactivity of furazan, furoxan, thiazole, thiadiazole, dithiazole, thiophene, glycoluril, imidazotriazine, diaziridine and other heterocycles are discussed. Characteristic features of reactions depending on the structure of the starting compounds, intermediates and reaction medium (organic solvents, ionic liquids) and mechanistic aspects of the most interesting transformations are considered. Data on the biological activities and prospects for practical applications of the indicated heterocyclic systems are presented. The bibliography includes 383 references.

Kuznetsov, V. V. and Shevyakova, N. I. 1997. Stress responses of tobacco cells to high temperature and salinity. Proline accumulation and phosphorylation of polypeptides. -Physiol. Plant. 100: 320-326.Stress responses to high temperatures (35^8°C) and salinity (170-340 mM NaCl) and thermotolerance were investigated for the salt-sensitive wild type and the salt-tolerant NfEj-l strain of Nicotiana sylvestris L. using suspension-cultured cells. Under saline conditions, NjEs-l strain cells accumulated proline, polyamine (putrescine and spermidine) and betaine in contrast to wild-type cells. The simultaneous treatment of salt-tolerant cells with high temperature (40°C) and NaCl (170 or 340 mM) resulted in a transient overproduction of proline accompanied by an increase in their thermotolerance. At the high temperature, the synthesis of polypeptides and the accumulation of heat shock protein HSP70 mRNA were not affected by salinity. The higher thermotolerance of the NaCl-tolerant cells could not be related to osmoprotecting sugar-starch interconversions but could rather be associated with selective phosphorylation of several polypeptides (23)(24) 27,(31)(32) 47 kDa) pdor to the accumulation of proline. The possible role of polyamines and polypeptide phosphorylation in this respect is discussed.