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I: High Temperature Stress. Functional Specialization of Plant Class A and B HSFs E. Czarnecka-Verner, et al. The Arabidopsis TCH Genes: Regulated in Expression by Mechanotransduction? J. Braam. The Regulation of GABA Accumulation by Heat Stress in Arabidopsis R.D. Locy, et al. GABA Increases the Rate of Nitrate Uptake and Utilization in Arabidopsis Roots J.M. Barbosa, et al. II: Low Temperature Stress. MAP Kinases in Plant Signal Transduction: Versatile Tools for Signaling Stress, Cell Cycle, and More C. Jonak, et al. The Second Stage of Plant Acclimation to Low Temperatures: The Forgotten Step in Frost Hardening? A. Kacperskla. Genetic Engineering of Biosynthesis of Glycinebetaine Enhances Tolerance to Various Stress A. Sakamoto, et al. III: Salinity Stress. Salt Tolerance at the Whole-Plant Level A.R. Yeo, et al. Plant Homologues to the Yeast Halotolerance Gene HAL3 A. Espinosa-Ruiz, et al. Novel Determinants of Salinity Tolerance N.K. Singh, et al. Progress and Prospects in Engineering Crops for Osmoprotectant Synthesis B. Rathinasabapathi. IV: Drought Stress. Plant AP2/EREBP and bZIP Transcription Factors: Structure and Function C. Nieva, et al. Role of Arabidopsis MYB Transcription Factors in Osmotic Stress E. Cominelli, et al. Gene Expression During Dehydration in the Resurrection Plant Craterostigma plantagineum J.R. Phillips, D. Bartels. Some Physiological and Molecular Insights into the Mechanisms of Dessication Tolerance in the Resurrection Plant Xerophyta viscosa Baker S.G. Mundree, J.M. Farrant. Targets of Modifying Plant Growth and Development by ABA-mediated Signaling A. Himmelbach, et al. V: Signal Transduction. Positional Cloning of A Plant Salt Tolerance Gene L. Xiong, et al. Regulation of Ion Homeostasis in Plants and Fungi J.M. Pardo, et al. Adh as a Model for Analysis of the Integration of Stress Response Regulation in Plants M. Dolan-O'Keefe, R.J. Ferl. Sense and Sensibility: Inositol Phospholipids as Mediators of Abiotic Stress Responses I. Heilmann, et al. VI: Oxidative and Heavy Metal Stress. Manipulation of Glutathione and Ascorbate Metabolism in Plants G.M. Pastori, C.H. Foyer. Cadmium Toxicity in Leaf Peroxisomes from Pea Plants: Effect on the Activated Oxygen Metabolism-Proteolytic Activity L.A. del Rio. Metal-Chelate Reductases and 'Plant MT's' N.J. Robinson, Sadjuga. Evolutionary Responses to Zinc and Copper Stress in Bladder Campion, Silene vulgaris (Moench.) Garcke H. Schat, et al.

Changes in activity of four enzymes associated with the turnover of hydrogen peroxide were monitored during ripening of several fruits. Glycolate oxidase activity increased during ripening in the pulp of pear (Pyrus communis L. var. Bosc), avocado (Persea americana Mill. var. Fuerte), and tomato (Lycopersicon esculentum Mill. var. Rutgers), declined in pear peel, and was not detectable in avocado peel. The changes in glycolate oxidase activity did not correspond to the changes in chlorophyll levels which occurred during ripening. Xanthine oxidase and peroxidase activity also increased during ripening in pear pulp. These changes in enzyme activity followed similar patterns whether expressed in terms of protein content or fresh weight. Catalase in pear pulp showed a continuous decline in activity per gram fresh weight but a slight increase followed by a decline in activity per milligram protein. Previously observed increases in hydrogen peroxide levels in senescent fruit tissue may be related to these chang...

Treatment of intact potato (Solanum tuberosum L.) tubers with acetaldehyde, ethanol or acetic-acid vapors led to a respiratory upsurge which was further increased when the volatiles were applied in 100% O2. Mitochondria from tubers held in 100% O2 (O2 control) displayed a substrate state, state 3, and state 4 in respiration, whereas in mitochondria from the volatile-treated tubers the respiratory rate of the different states was virtually indistinguishable. This respiratory pattern was companied by the development of a cyanide-resistant respiration since these mitochondria exhibited resistance to CN and sensitivity to CN+salicylhydroxamic acid. Acetaldehyde-treated potatoes showed a time-course development (up to 36 h) of cyanide resistance and concomitant sensitivity to salicylhydroxamic acid, indicating the onset of synthetic processes leading to the observed changes in mitochondrial respiration.

Several peroxidase fractions were separated by disc electrophoresis of extract of apple seed embryos. Three fractions of slowest electrophoretic mobility showed little substrate specificity, did not change during seed development and were not influenced by plant hormones. The appearance of the faster moving peroxidases was stimulated by gibberellin and benzyladenine, inhibited by abscisic acid and coumarin and unaffected by indolylacetic acid. The stimulation of those peroxidases by gibberellin, strong in dormant apple embryos, diminished during seed after-ripening.

Mitochondria from whole potatoes (Solanum tuberosum) ordinarily fail to oxidize respiratory substrates and to consume molecular O(2) in the presence of cyanide. Mitochondrial preparations obtained from tubers previously held for 24 hours in ethylene (10 microliters per liter) in air are only partially inhibited by cyanide. Application of ethylene in 100% O(2) led to an additional increase in the resistance of the mitochondrial respiration to cyanide. The resistance to cyanide was accompanied by a decrease in the respiratory control but no change in oxidative phosphorylation as shown by the measurement of ATP synthesis.The development of resistance to cyanide following the application of ethylene appears to require whole tubers and may represent an inductive process.