Template-Type: ReDIF-Article 1.0 Author-Name: A. Parvaiz Author-Workplace-Name: Biochemistry Laboratory CRDT, Indian Institute of Technology, New Delhi, India Author-Name: S. Satyawati Author-Workplace-Name: Biochemistry Laboratory CRDT, Indian Institute of Technology, New Delhi, India Title: Salt stress and phyto-biochemical responses of plants - a review Abstract: The ability of plants to tolerate salts is determined by multiple biochemical pathways that facilitate retention and/or acquisition of water, protect chloroplast functions and maintain ion homeostasis. Essential pathways include those that lead to synthesis of osmotically active metabolites, specific proteins and certain free radical enzymes to control ion and water flux and support scavenging of oxygen radicals. No well-defined indicators are available to facilitate the improvement in salinity tolerance of agricultural crops through breeding. If the crop shows distinctive indicators of salt tolerance at the whole plant, tissue or cellular level, selection is the most convenient and practical method. There is therefore a need to determine the underlying biochemical mechanisms of salinity tolerance so as to provide plant breeders with appropriate indicators. In this review, the possibility of using these biochemical characteristics as selection criteria for salt tolerance is discussed. Keywords: salt stress, proline, chlorophyll, sugar, protein, antioxidant Journal: Plant, Soil and Environment Pages: 89-99 Volume: 54 Issue: 3 Year: 2008 DOI: 10.17221/2774-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/2774-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-200803-0001.txt Handle: RePEc:caa:jnlpse:v:54:y:2008:i:3:id:2774-PSE Template-Type: ReDIF-Article 1.0 Author-Name: B. Kotková Author-Workplace-Name: Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: J. Balík Author-Workplace-Name: Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: J. Černý Author-Workplace-Name: Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: M. Kulhánek Author-Workplace-Name: Czech University of Life Sciences in Prague, Prague, Czech Republic Author-Name: M. Bazalová Author-Workplace-Name: Czech University of Life Sciences in Prague, Prague, Czech Republic Title: Crop influence on mobile sulphur content and arylsulphatase activity in the plant rhizosphere Abstract: The changes of mobile sulphur (S) contents were investigated in the plant rhizosphere using precise model experiments with rhizoboxes. The tested plants were winter wheat (Triticum aestivum L.), winter rape (Brassica napus L.) and white lupine (Lupinus albus L.). In this experiment, a Cambisol from a precise field experiment treated with sewage sludge or manure was used. Total extractable S concentration and mineral S (S-SO2-4) concentration in the water extract were higher in the plant rhizosphere (< 6 mm from the root) compared to the so-called bulk soil (> 6 mm). The contents of total extractable S0 decreased in order: lupine (5-35 mg/kg) > rape (4-18 mg/kg) > wheat (1.5-3 mg/kg). The same order was observed for mineral S- SO2-4where the contents in soil extracts were 1-10 mg/kg, 2-7 mg/kg, and 0.5-3 mg/kg, respectively. The highest total extractable S and mineral S (S- SO2-4) contents were found in the treatments fertilized with organic fertilizers. In the case of rape and wheat the arylsulphatase (ARS) activity was higher in the rhizosphere compared to the bulk soil; the opposite was recorded for lupine. It was acknowledged that the ARS activity was higher in the treatments fertilized with organic fertilizers (manure or sewage sludge) with all three tested plants. The highest determined ARS activity was found after wheat cultivation, the lowest after the lupine cultivation. The organic sulphur content followed an opposite tendency (lupine > rape > wheat). Keywords: sewage sludge, manure, rape, wheat, lupine, rhizosphere, sulphur, arylsulphatase Journal: Plant, Soil and Environment Pages: 100-107 Volume: 54 Issue: 3 Year: 2008 DOI: 10.17221/2776-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/2776-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-200803-0002.txt Handle: RePEc:caa:jnlpse:v:54:y:2008:i:3:id:2776-PSE Template-Type: ReDIF-Article 1.0 Author-Name: M. Jursík Author-Workplace-Name: Department of Agroecology and Biometeorology, Czech University of Life Sciences, Prague, Czech Republic Author-Name: J. Holec Author-Workplace-Name: Department of Agroecology and Biometeorology, Czech University of Life Sciences, Prague, Czech Republic Author-Name: J. Soukup Author-Workplace-Name: Department of Agroecology and Biometeorology, Czech University of Life Sciences, Prague, Czech Republic Author-Name: V. Venclová Author-Workplace-Name: Department of Agroecology and Biometeorology, Czech University of Life Sciences, Prague, Czech Republic Title: Competitive relationships between sugar beet and weeds in dependence on time of weed control Abstract: Small plot trials were carried out in years 2001-2003 with sugar beet. In the treatment without weed control, dry weight of sugar beet top and LAI of sugar beet were very low (approx. 50 g/m2 and 0.5 m2/m2, respectively). Yield loss of sugar beet was 80-93%. Dominant weeds were Chenopodium album, Fumaria officinalis and Galium aparine. In the treatments where weeds were removed (by hand) until 4 leaf stage of sugar beet, dry weight of sugar beet top and LAI of sugar beet at first increased normally, but were markedly decreased from the half of the vegetation period. Yield loss of sugar beet was 54-28%. Dominant weed in this treatment was Amaranthus retroflexus. The development of sugar beet top dry weight and LAI of sugar beet was practically identical in the treatments where weeds were removed until 8-10 leaf stage of the crop and in those where weeds were removed during the whole vegetation period (500-900 g/m2, or 4-7 m2/m2, respectively). No yield loss of sugar beet was recorded. Dry weight of weeds did not exceed 30 g/m2 and LAI 0.1 m2/m2. A. retroflexus and Mercurialis annua were the most frequent weeds in this treatment. Keywords: sugar beet, weed competition, yield loss, annual weeds, seed production, reproductive ability, time of emergence, competition Journal: Plant, Soil and Environment Pages: 108-116 Volume: 54 Issue: 3 Year: 2008 DOI: 10.17221/2687-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/2687-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-200803-0003.txt Handle: RePEc:caa:jnlpse:v:54:y:2008:i:3:id:2687-PSE Template-Type: ReDIF-Article 1.0 Author-Name: S. Gao Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Author-Name: R. Yan Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Author-Name: M. Cao Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Author-Name: W. Yang Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Author-Name: S. Wang Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Author-Name: F. Chen Author-Workplace-Name: Sichuan Key Laboratory of Resource Biology and Biopharmaceutical Engineering, Key Laboratory of Bio-resources and Eco-environment, Ministry of Education, College of Life Sciences, Sichuan University, Sichuan, P.R. China Title: Effects of copper on growth, antioxidant enzymes and phenylalanine ammonia-lyase activities in Jatropha curcas L. seedling Abstract: The effects of different concentrations of copper (0-800 μmol) on growth, protein contents, peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL) in Jatropha curcas L. seedlings were assessed by means of pot experiments. Results suggested that increased copper concentrations lead to decreased shoot elongation and seedling biomass. Protein content in the leaves and roots reached their highest levels at the copper concentrations of 400 μmol, while the highest protein content in the stem was observed at 800 μmol copper. POD activity in leaves and stems was unaffected at low copper concentrations, but showed a considerable variation at high copper concentrations. In roots, the highest POD activity was observed at 200 μmol copper. Under copper stress, SOD activity in leaves increased concomitantly with increasing copper up to 400 μmol, and SOD activity in stems and roots showed a slight increase. Catalase activity significantly elevated in leaves and roots but showed no significant changes in stems of the seedlings exposed to copper. A gradual increase of PAL activity in leaves and roots at the copper concentration of 400 and 200 μmol was observed, while PAL activity remained unchanged in stems. Keywords: toxic element, ROS-scavenging enzymes, defensive mechanism of plant, abioti Journal: Plant, Soil and Environment Pages: 117-122 Volume: 54 Issue: 3 Year: 2008 DOI: 10.17221/2688-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/2688-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-200803-0004.txt Handle: RePEc:caa:jnlpse:v:54:y:2008:i:3:id:2688-PSE Template-Type: ReDIF-Article 1.0 Author-Name: M.N.A. Hasaneen Author-Workplace-Name: Department of Botany, Faculty of Science, University of Mansoura, Mansoura, Egypt Author-Name: M.E. Younis Author-Workplace-Name: Department of Botany, Faculty of Science, University of Mansoura, Mansoura, Egypt Author-Name: D.M.A. El-Bialy Author-Workplace-Name: Department of Botany, Faculty of Science, University of Mansoura, Mansoura, Egypt Title: Plant growth, metabolism and adaptation in relation to stress conditions: Further studies supporting nullification of harmful effects of salinity in lettuce plants by urea treatment Abstract: Foliar application of urea to lettuce plants induced pronounced changes in the total amount and in the relative composition of the nitrogen pool. As compared with untreated lettuce plants, urease (UR), nitrate reductase (NR), asparaginase (AS) and glutamine synthetase (GS) activities were, in general, increased with an increase in the concentration of urea. On the other hand, salinization of lettuce plants with NaCl induced a significant decrease in the activities of UR, NR, AS and GS, at vegetative and adult growth stages. In general, treatment of lettuce plants with increasing concentrations of urea fertilizer in combination with each of the levels of salinity resulted in significant increases in all enzyme activities. Treatment with increasing concentrations of urea fertilizer induced significant decreases both in glycine and proline contents below control levels. On the other hand, salinization of lettuce plants with NaCl induced significant pronounced increases in the contents of the two amino acids. Further increments in glycine and proline contents were observed in differently salinized lettuce plants foliary sprayed with increasing concentrations of urea at vegetative and adult growth stages. Salinity solely enhanced the occurrence of novel proteins that were detected neither in the water control nor in the urea-treated plants. Protein banding patterns of lettuce plants treated with urea either alone or in combination with NaCl showed different de novo protein bands with different molecular weights, induced by urea and/or NaCl at vegetative and adult growth stages. Keywords: Lactuca sativa L., NaCl, urea, nitrogen content, amino acids, nitrogen enzymes, protein patterns Journal: Plant, Soil and Environment Pages: 123-131 Volume: 54 Issue: 3 Year: 2008 DOI: 10.17221/2775-PSE File-URL: http://pse.agriculturejournals.cz/doi/10.17221/2775-PSE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pse-200803-0005.txt Handle: RePEc:caa:jnlpse:v:54:y:2008:i:3:id:2775-PSE