The effects of drought and rehydration on tea seedlings were significant. After five days of drought imposition the contents of chlorophylls, carotenoids, ascorbate and glutathione, and activities of guaiacol peroxidase and glutathione reductase decreased. Simultaneously, contents of proline, H₂O₂ and superoxide anion, lipid peroxidation and activities of catalase and superoxide dismutase increased. These parameters recovered to different degrees during subsequent rehydration.

Enzyme changes in non-rooted (treated with Fe-EDTA) and rooted (treated with Fe-EDDHA) stems of rootstock GF-677 (Prunus amygdalus×P. persica) during adventitious root formation in vitro have been recorded. The first roots appeared approximately after 12 d on the rooting medium. By contrast to non-rooted stems, rooted stems showed a maximum of soluble peroxidase activity on the 9^th day, of ionically bound peroxidase to cell wall on the 6^th and 12^th day and of catalase on the 6^th and the 15^th day. A time course study of changes of soluble peroxidases isoenzymes showed that there was a band visible only in the rooted stems and also a new band appeared three days before the emergence of roots.

Thermotolerance of pearl millet (Pennisetum glaucum cv. ICMV-94133) and maize (Zea mays cv. Golden) was assessed at germination and vegetative stage. Final percentage of germinated seeds and rate of germination (number of days to 50 % germination) decreased due to high temperature (45 °C) similarly in the both species. In contrast, at the vegetative stage, high temperature (38/27 °C) caused a significant reduction in shoot dry mass of maize, whereas this attribute remained almost unchanged in pearl millet. Relative growth rate and net assimilation rate (NAR) increased significantly in pearl millet due to high temperature, but in contrast, in maize NAR was slightly reduced. Concentrations of N, P, and K in the shoots of both species increased at high temperature, but N accumulation was more pronounced in pearl millet than in maize. High temperature caused a marked increase in both shoot and root Ca²⁺ concentration in maize, but it did not affect that of pearl millet. S concentration in the shoots of maize decreased significantly due to high temperature, whereas that in pearl millet remained unaffected. Shoot Na⁺ concentration of both species was not significantly affected by high temperature. High temperature caused a significant increase in uptake of N, P, and K⁺ in pearl millet, but the uptake of Ca²⁺, Mg²⁺, Na⁺ and S remained unaffected in this species. In contrast, in maize, a significant increase in uptake of K⁺ and Ca²⁺, and a decrease in uptake of N, S, Mg²⁺, and Na⁺ were found at high temperature. Overall, maize showed lower tolerance to high temperature compared with pearl millet.

Fatty acid content and composition of chloroplast membranes, ethylene production associated with thylakoid lipids degradation as well as photosynthetic electron transport involving photosystems 1 and 2 were used to determine the effects of increasing Cd concentrations in the growth medium [0, 14, 28, and 42 mg (Cd) kg^-1(sand)] on the photosynthetic performance of barley plants (H. vulgare L., cv. CE9704). High concentrations of Cd triggered serious disturbances of the chloroplast membranes. Ethylene production increased whereas a drop of 18:3 fatty acid content occurred, indicating that Cd mediates lipid peroxidation in the thylakoids. The enhanced ethylene production could be used as an early indicator of Cd-induced membrane degradation, yet at very high concentration (42 mg kg^-1) Cd decreased ethylene production.

Following 16, 40 and 64 h exposure to 0.33 M NaCl given after 8 h water imbibition, lentil seeds showed a gradual decrease of germination upon their transfer to water. These salt related changes were accompanied by modifications in the protein patterns of embryo axes as revealed by two-dimensional electrophoresis separation and by the computer image analysis of protein spots. In comparison with 8 h water imbibed seeds, prominent proteins comprised between the 5.1 - 7.6 pH isoelectric point in the first dimension and 75 - 50 kDa molecular mass in the second dimension showed a significant increase in their abundance as salt exposure increased. On transfer to water to complete germination, the content of many of these proteins decreased at 24h in 2 - 3 cm length embryo axes in comparison with the corresponding embryo axes of seeds continuously imbibed in water for 24 h. Some groups of proteins ranging between 15.5 - 17.3 kDa, already present after 8 h water imbibition, were not detectable after 24 h but were expressed in seeds exposed to NaCl and transferred to water for 24 h. Up- and down-regulated proteins in lentil embryo axes, imbibed under non-lethal salt stress conditions, have been tentatively identified by comparison with the protein map of germinating seeds of the model plant Arabidopsis.

In vitro root culture of yellow wort (Blackstonia perfoliata (L.) Huds.) was initiated on Murashige and Skoog (MS) medium. In the presence of benzylaminopurine (BAP) numerous adventitious buds formed, which developed into shoots. Presence of indole-3-butyric acid (IBA) in media significantly decreased number of buds, but increased development of lateral roots. On hormone-free medium shoots successfully rooted and developed flowers and viable seeds that formed another generation. Shoot cultures of B. perfoliata inoculated with suspension of Agrobacterium rhizogenes strain A4M70GUS developed hairy roots at 3 weeks and they were cultured on hormone-free MS medium. Spontaneous shoot regeneration occurred in 3 clones.

Changes in the proteins, chlorophyll, virus content and activity of key enzymes of viral RNA biosynthesis were investigated in the light- and dark-green regions of tobacco leaves systemically infected with tobacco mosaic virus. The protein content was increased to 118 % in the dark-green islands in contrast to 60 % in the light-green regions when compared with the control healthy leaves. The comparative analysis of soluble proteins from healthy and light- or dark-green regions of leaves by means of SDS-PAGE revealed that the main soluble proteins are equal in pattern but differ in quantity. The contents of chlorophylls did not differ from healthy tissues in the dark-green islands but were considerably lower in the light-green regions. The content of virus in light-green tissues was about 10 times higher than in the dark-green islands. The activities of key enzymes of oxidative pentosephosphate cycle -- glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase -- did not differ from healthy tissues in the dark-green islands but were considerably higher in the light-green tissues when compared with healthy control. Similar relationships were observed for ribonuclease, phosphomonoesterase and phosphodiesterase activities. The biosynthesis of viral RNA in the dark-green islands is probably restricted by the steady (or reduced) activities of key enzymes of these metabolic pathways.

A highly reproducible system for efficient somatic embryogenesis was developed to regenerate plantlets from cotton (Gossypium hirsutum L.) cultivars (Nazilli M-503 and Nazilli 143). Shoot apices, hypocotyls and nodes of 10-d-old seedlings were used as explants. High frequency (100 %) embryogenic calli was initiated from all tested explants on Murashige and Skoog (1962) (MS) media supplemented with 1 g dm^-3 polyvinylpyrrolidone (PVP), 1 mg dm^-3 6-benzylaminopurine (BAP), 0.5 mg dm^-3 kinetin for Nazilli M-503 and 1 g dm^-3 PVP, 2 mg dm^-3 BAP, 0.5 mg dm^-3 kinetin for Nazilli-143. Globular stage somatic embryos were produced 4 months after transfer to hormone-free MS medium supplemented with 1 g dm^-3 PVP. Subsequent subculture of globular embryos every 3 weeks on hormone-free MS medium led to the development of torpedo and cotyledonary stage embryos with the frequency of 75 and 83.2 % from hypocotyl explants of Nazilli M-503 and Nazilli-143, respectively. Afterwards, mature somatic embryos were isolated and cultured on hormone-free MS medium for germination and development into plantlets. The highest germination frequency (42.9 %) for Nazilli M-503 somatic embryos were obtained on hormone-free MS medium after 5 months with hypocotyl explants, whereas germination frequencies of Nazilli-143 embryos from hypocotyl, node and apex explants varied between 22 - 30 %.

Two-days-old in vitro grown protonemata of Funaria hygrometrica Hedw. were treated with a mixture PbCl₂ (4 μM Pb²⁺) and CaCl₂ (16 μM Ca²⁺) (Ca+Pb) for 48 h. The results were compared with the control: distilled water (H₂O) and the solution of PbCl₂ (4 μM Pb²⁺) (Pb). Protonemata treated with Ca+Pb were longer and contained more cells than those treated with Pb. Moreover, a lower number of cells showed apical cell deformations typical for lead toxicity: swollen tips and wall thickenings at the apex. If deformations were present they were not as extended as in Pb. In comparison with the control, however, protonemata treated with Ca+Pb were shorter, contained a lower number of cells and some apical cells in this material were altered. It can be concluded that the presence of calcium partially neutralised toxic effects of lead in Funaria hygrometrica protonemata cells.

Two cultivars of tomato (Lycopersicon esculentum Mill.), Selection-7 (shelf life 7-8 d) and ARTH-3 (shelf life 14-15 d) were analyzed for oxidative stress and the antioxidant enzyme system at different stages of fruit ripening. The results presented here suggest that during the early stages of fruit ripening, efficient antioxidant system protects the tomato fruits against the damaging effect of progressive oxidative stress. At later stages, however, oxidative damage occurs due to decreased activities of the ROS scavenging enzymes.

Hydroponics were used to study the impact of acidity on growth, nutritive properties and metabolic changes in kikuyu grass (Pennisetum clandestinum Hochst). Four treatments (pH 6.0, 5.0, 4.0, and 3.0) were compared for effects on biomass, leaf and root length, crude protein, amino acid content and key enzymes of sugar metabolism. Reduction in biomass, root and leaf length, amino acid contents, glucose-6-phosphate dehydrogenase (G6PDH) and pyruvate kinase (PK) content was observed only at pH 3.0, in association with increased leaf proline content. Kikuyu grass is able to grow normally under mild acidity (down to at least pH 4.0).

DNA was isolated from 14 cultivars of Vigna radiata (L.) Wilczek and subjected to RAPD analysis using 14 random decamer primers. These cultivars revealed polymorphism with respect to RAPD markers and were subjected to hierarchical cluster analysis. A dendrogram was prepared based on these data. Analysis of banding patterns confirmed that two strongly aromatic cultivars IC1, IC4, were closely linked. But another aromatic cultivar, B1, formed a separate cluster. The high yielding cultivars were closely related to B1. The phylogenetic tree constructed by the neighbour joining method showed that RAPD results were correlated with morphological characters like plant height, leaf and seed size, seed colour, etc.

The distribution of amino acids in distinct tissues of Canavalia ensiformes was determined during the life cycle of the plant. Glycine was shown to be the main amino acid in mature seeds, while the nonprotein amino acid canavanine exhibited a high concentration in 7-d-old seedlings. Canavanine was lower in the seeds when compared to other tissues analyzed. This does not support the nitrogen-storage function of canavanine, however, it suggests that it is involved in the translocation of amines during the early stages of the development.

We have assayed different combinations of nutrient media and growth regulators to induce callus and plant regeneration from explants of root, shoot and leaf, complete seed, and isolated mature embryo of barley (Hordeum vulgare L. cv. Hassan). The best results were obtained with mature embryo in J25-8 medium supplemented with 2.0 mg dm^-3 2,4-dichlorophenoxyacetic acid where about 75 % developed friable calli. Some 80 - 85 % of these calli regenerated barley plants in the same J25-8 medium supplemented with 1.0 mg dm^-3 indole-3-butyric acid and 0.1 mg dm^-3 kinetin.

Mitochondria were purified from tomato leaves by a differential centrifugation method and a Percoll density-gradient method. A comparative study on the ascorbate-glutathione cycle activity revealed that there was no difference in the specific activity of the antioxidative enzymes and ascorbate and glutathione concentrations between mitochondria prepared by these two methods. However, the contents of dehydroascorbic acid and oxidised glutathione in Percoll-separated organelles were 260 and 210 %, respectively, of those found in mitochondria purified by the differential centrifugation method.

The culture vessels with multiplying shoots of Achras zapota L. on Schenk and Hildebrandt (SH) medium containing 8.88 μM 6-benzylaminopurine (BAP) with or without sucrose were kept under varied CO₂ concentrations ranging from 0.6 to 40.0 g m^-3 using different concentrations of sodium bicarbonate (NaHCO₃), sodium carbonate (Na₂CO₃), potassium bicarbonate (KHCO₃), and potassium carbonate (K₂CO₃) in small acrylic chambers. Complete absence of carbon source caused death of shoots within 20 d. Under elevated concentrations of CO₂ (10.0 and 40.0 g m^-3) the shoots grew photoautotrophically on sucrose-free medium. The growth of cultures was better at 40.0 g (CO₂) m^-3 than on 3.0 % sucrose under ambient air of growth room. However, the best response was obtained at 10.0 g (CO₂) m^-3 and 3.0 % sucrose where maximum number of shoots, shoot length, fresh and dry mass, total number of leaves and leaf area was observed.

The role of random amplified polymorphic DNA (RAPD) markers in detecting intra-clonal genetic variability in vegetatively propagated UPASI-9 clone of tea (Camellia sinensis) was studied. Twenty five decamer primers were used, of which three did not amplify, three gave single bands and the rest of nineteen primers generated upto twelve bands (an average of 6.3 bands per primer). Twenty one primers exhibiting amplified products gave monomorphic banding patterns. Only one primer (OPE-17) gave a unique extra band of similar size in four plants.

The use of two Agrobacterium tumefaciens strains for transformation of Triticum aestivum L. cv. Vesna was studied. Immature embryos, isolated 15 d after pollination, were co-cultivated with the super-binary LBA4404/pTOK233 and the binary AGL1/pDM805 vectors. While the transient GUS-intron expression was high (69.9 and 80.0 %), the number of plants regenerated on selective media containing hygromycin or phosphinotricin did not exceed 0.4 and 0.13 %, respectively. Nevertheless, the regenerated plants were fertile and produced seeds. The T₀ plants, as well as the T₁ seedlings, displayed the activity in the β-glucuronidase histochemical assay and a positive signal in PCR analysis for the presence of uidA gene sequences in their genomes. The data suggest that the transformation of wheat cv. Vesna with both Agrobacterium strains is feasible.

Multiple shoots were induced from the cotyledonary nodes derived from seedling of Sesbania rostrata on Nitsch (1969; N) medium supplemented with various concentrations of benzyladenine (BA). 1 mg dm^-3 BA proved to be the best, eliciting 5.8 ± 1.0 shoots per explant in 100 % cultures. The elongation of shoots was best at 2.0 mg dm^-3 BA. The shoot proliferation capacity increased to 7.5 shoots per explant following transfer of explants to the fresh shoot multiplication medium (MS + 1.0 mg dm^-3 BA), after an initial incubation of 30 d. To further enhance number of shoots per explant an alternative strategy of cultivation of mother explant on fresh shoot multiplication medium after excision of shoots was adopted. Following the repeated harvesting of shoots an average of 33 shoots per explant could be obtained. The in vitro regenerated shoots produced roots when transferred to half-strength MS medium supplemented with 3 % sucrose and 1 mg dm^-3 IBA. The developed plantlets were planted in the soil and transferred to the field after an acclimatization period of 3 - 4 months. These plants produced flowers and fruits in the field and exhibited the development of prominent and more organized stem nodules as compared to the in vivo raised plants of the same age.

Utilizing either Agrobacterium-mediated transformation or particle bombardment we obtained transgenic soybean [Glycine max (L.) Merr.] plants expressing the chitinase gene (chi) and the barley ribosome-inactivating protein gene (rip). Six regenerated plants were grown to maturity and set seed. The identification of transgenic soybean plants that co-integrated the two anti-fungal protein genes was determined by polymerase chain reaction (PCR) and Southern blot analysis. Protein detection from the soybean leaves demonstrated the expression of the chitinase (CHI) and the ribosome-inactivating protein (RIP) in the six R₀ transformants. Soybean cotyledonary nodes were transformed using the bivalent plant expression vector pBRC containing chi and rip both driven by the CaMV 35S double promoter. Following vacuum (0.06 MPa) infiltration treatment of the tissue for 5 min, Agrobacterium was co-cultivated with the cotyledonary nodes for 3 d on MSB medium (MS salts and B₅ vitamins) (pH 5.2), the transformation frequency reached a maximum of 1.33 %. The chi and rip genes were present in all the transgenic plants. Co-bombardment of immature cotyledons with plasmids pBchE (encoding chi) and pARIP (encoding rip) resulted in a maximum transformation frequency of 0.52 % with a 50 % co-integration rate. Our results demonstrate efficient co-transformation of multiple genes in soybean.

The work is concerned with the effect of low concentrations (10^-7 mol dm^-3) of sodium naphthenate on total content of Cd and its particular forms in the intercellular space and inside cells, as well as on some physiological and biochemical parameters of young soybean plants grown in the presence of 1 mmol dm^-3 solution of cadmium chloride. Presence of naphthenate reduced in average by 40 % content total and intracellular Cd in root, stem and leaves and alleviated the harmful effect of Cd on activity of nitrate reductase and content of photosynthetic pigments.

A study was conducted to generate fingerprints of thirty-two Indian potato cultivars using capillary electrophoresis based semi-automated simple sequence repeat analysis. Five fluorescent-tagged primer pairs (STPOACUTR, LEGAST1, STPOAC58, STM0030 and STM0031) used in this study yielded 43 alleles at 16 different loci, showing multi-loci resolving character. The estimated similarity between the cultivars was in the range of 0.72 to 0.98 indicating narrow genetic relationship. None of the primer set alone could differentiate all 32 cultivars included in this study. However, two primer sets STM-0031 and STPOAC58 amplifying 12 and 9 polymorphic alleles, respectively, could together distinguish all of them. The results indicated usefulness of semi-automated capillary electrophoresis in quick and reproducible SSR genotyping of potato cultivars.

Electrophoretic analyses of non-reduced and reduced seed storage proteins from Solanaceae and Cucurbitaceae species and cultivars were performed. High molecular disulfide bonded complexes between intermediary subunits of 11S globulins previously detected in Capsicum annuum cultivars, were found in Solanum melongena cultivars as well. The data obtained might be used for further elucidation of peculiarities of the 11S globulins in dicotyledonous plants.

The redox system and H⁺-transport activities in the plasma membranes from two ecotypes of reed (Phragmites communis Trin.), named swamp reed (SR) and dune reed (DR) according to their habitats, were investigated. Compared to the SR, the DR possessed the very high rates of NADH oxidation and Fe(CN)₆^3- and EDTA-Fe³⁺ reduction when NADH was taken as the electron donor. As NADPH was an electron donor, the rate of NADPH oxidation was also significantly higher in the DR than that in the SR. In addition, the H⁺-transport activity in the plasma membranes was also significantly higher in the DR than in the SR.

The growth and the content of endogenous cytokinins (CKs) of current-year-old shoots from juniper plants (Juniperus communis L.) growing over and off ore site were compared. The juniper shoots from ore site (M plants) had higher metal content and exhibited delayed growth. Less bases and nucleosides of Z- and iP- type CK and more iP-conjugates were present in the M shoots. These changes were probably due to inhibited CK export from the roots and/or altered CK metabolism forming less biologically active CKs.

Changes in antioxidant systems in sunflower (Helianthus annuus L.) inbred lines were studied in relation to different concentrations (0, 2, 3 and 4 mM) of oxalic acid. A great variability of the total superoxide dismutase (SOD) activity was observed in different genotypes after application of oxalic acid. Genotypes showing no change in SOD activity, as well as those with decreased and increased activities, have been found. The highest guaiacol peroxidase (GPX) activity was recorded in the leaves of Ha-26A genotype where the activity of SOD was low. In genotypes with increased GPX activity the malonyldialdehyde content was low. The increase in reduced glutathione content occured in almost all of the genotypes studied with the increase in oxalate concentration. Some genotypes such as PR-ST-3B, showed distinctive and combined activity of several antioxidant systems. Also, obtained results for the content of total phenols support the idea of using soluble phenols as molecular markers and confirm the hypothesis of the defensive role of these compounds in plants.

A rapid and efficient procedure is outlined for in vitro clonal propagation of an elite cultivar of jewel orchid (Anoectochilus formosanus). Multiple shoot proliferation was induced in shoot tip explants on Hyponex (H3) media supplemented with 1 mg dm^-3 benzyladenine or 1 - 2 mg dm^-3 thidiazuron (TDZ). Addition of activated charcoal (1 g dm^-3) to the TDZ containing medium promoted multiple shoot formation (11.1 shoots per explant). However, the regenerated shoots had slow growth rate and failed to elongate. This problem was overcome by transferring the shoot clumps to a hormone free H3 medium supplemented with 2 % sucrose and 0.5 g dm^-3 activated charcoal. Rooting was induced in 100 % of the regenerated shoots in the same media. The plantlets were acclimatized and established in greenhouse.