The effects of carbon sources (sucrose, glucose, fructose and mannitol) and auxins [indolebutyric acid (IBA) and α-naphthaleneacetic acid (NAA)] on in vitro propagation of banana (Musa spp. AAA) were studied. Over all carbon sources tested, sucrose induced highest frequency of shoot proliferation. Optimal shoot proliferation rates were achieved on the Murashige and Skoog (MS) medium supplemented with sucrose and glucose combination (1:1) at the concentration of 30 g dm^-3. Similarly, higher frequency of root induction was obtained at IBA and NAA combination (1:1; concentration of 2 mg dm^-3) than at other concentrations of IBA or NAA alone or their combinations.

Oxidative injury and antioxidant responses were investigated in two banana genotypes (Musa AAA 'Berangan' and Musa AA 'Mas') subjected to 40 % PEG-induced water stress. PEG treatment resulted in oxidative injury, as expressed in increased lipid peroxidation and reduced membrane stability index, in both cultivars; however, greater oxidative injury was detected in 'Mas'. Under PEG treatment, catalase activity and glutathione reductase activity were enhanced in both cultivars, but were higher in 'Mas'. Ascorbate peroxidase activity was enhanced in 'Berangan' under water stress, but was unaffected in 'Mas'. Meanwhile, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in 'Berangan'. Higher ascorbate peroxidase and superoxide dismutase activities were associated with greater protection against water stress-induced oxidative injury.

Random amplified polymorphic DNA (RAPD) markers were used to assess the genetic diversity of 14 individuals belonging to 7 populations of Coscinium fenestratum (Gaertn.) Colebr. (Menispermaceae). 18 decamer primers used for the analysis generated 99 scorable bands of which 79 were found to be polymorphic. Coefficient of similarity ranged from 0.6604 to 0.9809. Variation within population was slightly higher than between populations. Similarity between individuals within and between populations was found. Dendrogram was obtained by using unwieghed pair-group method analysis (UPGMA). Distinct accession also exhibited higher percentage of medicinally active compound.

Leaf explants of Phalaenopsis amabilis var. formosa formed clusters of somatic embryos directly from epidermal cells without an intervening callus within 20 - 30 d when cultured on 1/2-strength modified Murashige and Skoog medium supplemented with 0.1, 1 and 3 mg dm^-3 TDZ. Repetitive production of embryos involved secondary embryogenesis could be obtained by culturing segments of embryogenic masses on TDZ-containing media. Plantlet conversion from embryos was successfully achieved on regulator-free growth medium.

A rapid and efficient in vitro plant regeneration method was developed for Aristolochia indica. Multiple shoot formation was induced from shoot tip and nodal explants on Murashige and Skoog (MS) medium with 1 - 6 mg dm^-3 2-isopentenyl-adenine (2-iP) or 1 - 4 mg dm^-3 6-benzyladenine (BA). Maximum number of shoots were induced with 5 mg dm^-3 2-iP alone (about 12 - 14 shoots). Shoot differentiation occurred directly from the leaf bases as well as from the internodes when cultured on 1 - 4 mg dm^-3 BA and 0.8 - 2 mg dm^-3 α-naphthaleneacetic acid (NAA) containing medium. Regeneration from the callus occurred when the calli initiated on MS medium containing 0.6 - 4 mg dm^-3 NAA in combination with 0.8 - 3 mg dm^-3 BA were transferred to 1 - 6 mg dm^-3 BA alone containing medium. Elongated shoots were separated and rooted in MS medium containing 1 mg dm^-3 indole-3-butyric acid. These were then transferred to soil after gradual acclimatization.

The aim of this work was to estimate genetic variability for in vitro culture response of recombinant inbred lines (RILs) of the genus Lycopersicon. The callus percentage (C), the regeneration percentage (R) and the productivity rate (PR) were evaluated 45 d after culture initiation in a set of 16 elite tomato RILs and their parents. The narrow sense heritability (h²) values were 0.38 ± 0.04 for C, 0.46 ± 0.04 for R, and 0.28 ± 0.03 for R, while the genetic correlation (r _g ) values were -0.96 ± 0.07 between C and R, 0.81 ± 0.14 between PR and R, and -0.79 ± 0.16 between PR and C. Three AFLP markers associated to the in vitro traits were identified.

This review summarizes the recent progress made towards the development of transgenic plants with improved tolerance to water stress and salinity. Of the various strategies employed, emphasis has been given to the genes engineered for the biosynthesis of osmoprotectants and osmolytes. This review also briefly discusses the importance of the use of specific stress inducible promoters and the future prospects of transgenic plants with improved agronomic traits.

The effects of osmotic dehydration on the photochemical activity, gene transcription, and protein content of photosystem 2 (PS 2) in leaves of two wheat (Triticum aestivum L.) cultivars Miannnong No. 4 and No. 5 were studied. Roots of both cultivars were submerged into polyethylene glycol (PEG) solutions with an osmotic potential of -0.5 MPa for 0, 24, 48, and 72 h. Relative water content (RWC) decreased markedly after 48 and 72 h. Simultaneously, marked increase in electrolyte leakage, decrease in contents of chlorophylls (Chl) a and b, and inhibition in PS 2 activity were observed. Northern hybridization indicated that progressive water stress remarkably reduced contents of the chloroplast gene psbA and psbD and nuclear gene cab transcripts. Urea-SDS-PAGE and Western blotting analysis showed that the contents of major PS 2 proteins, including the D1 and D2 proteins in the PS 2 reaction centre (RC) and the light-harvesting Chl a/b-protein complex (LHC 2) in periphery, declined with increasing water stress. Miannong No. 5 had less destroyed plasma membranes and higher RWC, Chl contents, and PS 2 activity during water stress than Miannong No. 4, which suggested its better drought resistance. The significant difference in steady state contents of LHC 2 proteins of two cultivars can be mainly attributed to the marked difference in transcript level of cab gene, which indicated that LHC 2 proteins protect PS 2 RC.

Multiple shoots were induced by culturing nodal explants excised from 1-month-old aseptic seedlings of red pepper (Capsicum annuum L. cv. Pusa Jwala) on Murashige and Skoog (MS) medium supplemented with (0.1-10 μM) thidiazuron (TDZ). The rate of multiple shoot induction per explant was maximum (14.4 ± 0.06) on MS medium supplemented with 1.0 μM TDZ. Regenerated shoots were elongated well on growth regulator free MS medium. Adventitious roots were induced two weeks after transfer of elongated shoots to MS medium supplemented with auxins (IAA, IBA or NAA) in different concentrations. Optimum root formation frequency was obtained in medium containing 1.0 μM IBA. Ex-vitro rooting was also achieved by pulse treatment with 300 μM IBA for 10 min. Rooted shoots were transplanted in plastic pots containing garden soil (with 90 % survival rate), where they grew well and attained maturity. Regenerated plants were phenotypically and cytologically normal.

Proline accumulation in two different bean (Phaseolus vulgaris L.) cultivars, one drought-sensitive (Canario 60) and one drought-resistant (Pinto Villa) was investigated. Both tolerated salt concentrations up to 150 mM NaCl, but the sensitive Canario 60 did not survive at 400 mM NaCl. In response to salt stress, both cvs. accumulated proline in all the analyzed tissues, the lowest contents were detected in roots. Pinto Villa accumulated higher proline concentrations than Canario 60 only at 400 mM NaCl. The addition of polyamines or ornithine increased proline content in plant tissues without stress, while they decreased it under salt stress.

Kalanchoë pinnata mitochondria readily oxidized succinate, malate, NADH, and NADPH at high rates and coupling. The highest respiration rates usually were observed in the presence of succinate. The high rate of malate oxidation was observed at pH 6.8 with thiamine pyrophosphate where both malic enzyme (ME) and pyruvate dehydrogenase were activated. In CAM phase III of K. pinnata mitochondria, both ME and malate dehydrogenase (MDH) simultaneously contributed to metabolism of malate. However, ME played a main function: malate was oxidized via ME to produce pyruvate and CO₂ rather than via MDH to produce oxalacetate (OAA). Cooperative oxidation of two or three substrates was accompanied with the dramatic increase in the total respiration rates. Our results showed that the alternative (Alt) pathway was more active in malate oxidation at pH 6.8 with CoA and NAD⁺ where ME operated and was stimulated, indicating that both ME and Alt pathway were related to malate decarboxylation during the light. In K. pinnata mitochondria, NADH and NADPH oxidations were more sensitive with KCN than that with succinate and malate oxidations, suggesting that these oxidations were engaged to cytochrome pathway rather than to Alt pathway and these capacities would be desirable to supply enough energy for cytosol pyruvate orthophosphate dikinase activity.

Plants of two cytotypes (2n=2x=20, and 2n=3x=30) of pinto peanut (Arachis pintoi Krapov. & W.C. Gregory) were regenerated through somatic embryogenesis. Embryogenic calli were induced from shoot tips or immature leaves dissected from in vitro growing plants. In the case of the diploid peanut the best somatic embryogenesis was achieved when shoot tips were cultured on Murashige and Skoog (MS) medium supplemented with 10 mg dm^-3 Picloram (PIC) and 0.1 mg dm^-3 6-benzylaminopurine (BAP) or when explants from immature leaves were cultured on MS + 10 mg dm^-3 PIC + 0.01 mg dm^-3 BAP. In the case of triploid peanut the highest number of somatic embryos was obtained when shoot tips were cultured on MS + 10 mg dm^-3 PIC + 0.01 mg dm^-3 BAP or when immature leaves were cultured on MS + 20 mg dm^-3 PIC + 0.01 mg dm^-3 BAP. Somatic embryos were converted into plants by culture on MS + 0.01 mg dm^-3 naphthaleneacetic acid + 0.01 mg dm^-3 BAP. Plants were successfully transferred to pots in greenhouse.

Growth parameters and cadmium accumulation were investigated in alfalfa seedlings treated with 10 μM salicylic acid (SA) at the beginning of seed imbibition. Shoot and root growths were accelerated by SA treatment and suppressed by Cd both in presence and absence of SA. Cd accumulation was stimulated by SA in alfalfa seedlings in dependence of the treatment duration. K, Mg, Ca and Fe contents in roots are decreased in the presence of Cd alone, while SA induces a decrease of Mg, Ca and Fe. Shoot K, Mg and Ca concentrations are increased by Cd only in the absence of SA, while SA induces also an increase of these concentrations, but only in the absence of Cd. High negative correlation of Cd concentration with K and Ca concentrations in root indicates a competition for the same carrier not regulated by SA. Positive correlation between Cd and Mg concentrations in shoots, which is decreased by SA pre-treatment, together with the increase of positive correlation between Cd and Fe concentrations in shoots under the influence of SA, indicates a possible mechanism of SA action through maintenance of ionic homeostasis.

The changes in activities of soluble and cell wall-bound peroxidases and lignin contents in juglone-stressed soybean (Glycine max) seedlings and their relationships with root growth were investigated. Soybean seedlings (3-d-old) were cultivated in nutrient solution supplemented with 0.5 to 25 μM juglone for 24 h. Length and dry mass of roots decreased after 5 to 25 μM juglone treatments. Low juglone concentrations (≤ 1 μM) increased soluble peroxidase activity, while high concentrations (≥ 10 μM) inhibited activities of soluble and cell wall-bound peroxidases. Juglone (≤ 1 μM) did not affect lignin content but highly increased lignification after 5 to 25 μM treatments. Results indicate that lignification may be an important step in root growth reduction of juglone-stressed soybean.

Exposure of pea plants to high irradiance (HI) for 60 min caused a reversible photoinhibition as shown by changes in variable to maximum fluorescence ratio (F_v/F_m). A significant decline in F_m was observed in leaves from both pea cultivars subjected to HI, the decrease being higher in JI281 than in JI399 plants. The values recovered during the post-stress period in both cultivars. In both cultivars, minimal fluorescence (F₀) increased under HI, but in cultivar JI399 F₀ recovered to initial value during the post-stress period. The expression of antioxidant enzyme genes was higher in JI399 than in JI281, both in control and stressed plants. In JI281, after 60 min of HI, an induction of the transcripts of CAT, chlMDHAR, cytAPX and cytCu,Zn-SOD was observed, whereas there was a slight increase in PHGPX, stAPX and chlCu,Zn-SOD mRNAs. After 24 h of the recovery period, the induction of some transcripts was not maintained (CAT, cytAPX and cytCu,Zn-SOD), whereas the induction of others was maintained (PHGPX and chlCu,ZnSOD) or even increased (cytGR, stAPX and chlMDHAR). In JI399, CAT and cytAPX were increased strongly after 60 min of HI, and slight increases were observed in cytGR, chlGR and chlMDHAR. In the post-stress period the expression of stAPX, cytGR and chlMDHAR was even slightly higher than after 60 min of HI, however, expression of CAT, cytAPX, cytCu,ZnSOD, chlCu,ZnSOD and chlGR decreased.

We analyzed low molecular mass phenolics, lignin content and both soluble and cell wall bound peroxidase activity in the needles of three Picea omorika (Pancic) Purkyne lines grown in the generative seed orchard. The highest values of the total phenol content as well as of catechine, caffeic acid, coniferyl alcohol, isoferulic acid and lignin concentration were detected in B5 line ("semidichotomy" line). The soluble guaiacol peroxidase activity was the highest in A3 line (line "borealis"). The highest activity of cell wall bound peroxidases was measured in B5 line, and it was in correlation with lignin content.

Ageing of plant organs is accompanied by an increased production of free radicals what results in membrane lipid peroxidation. Non-polar aldehydes originating from this process interact with the cellular material to form the fluorescent end-products, lipofuscin-like pigments (LFP). Their formation was studied both qualitatively and quantitatively in ageing of bean cotyledons. The concentration of lipofuscin-like pigments increased 9-fold in 14-d-old (senescent) cotyledons in relation to 8-d-old (young) cotyledons. HPLC fractionation patterns indicate changes in their composition during ageing. The LFP increase in old cotyledons was accompanied by elevated levels of non-polar aldehydes that increased during ageing to 167 %. The composition of aldehydes was studied by mass spectrometry. The most abundant fraction in both young and old cotyledon was represented by C12 aldehydes, which comprised both saturated and unsaturated species. We have observed differences in abundances of individual aldehydes between the young and the old cotyledons that might explain the differences in the composition of lipofuscin-like pigments. These results support the involvement of free radicals in plant ageing; however, it is suggested that plant aldehydic products of lipid peroxidation differ from those found in animals.

In this study, a relationship between lipid peroxidation, the antioxidant defense system and salt stress in salt-sensitive cultivated tomato (Lycopersicon esculentum) and its salt-tolerant wild relative (L. pennellii) was established. Superoxide dismutase (SOD) activities were significantly higher in the leaves of L. pennellii than those of L. esculentum after 12 and 84 d. POX activity showed a gradual increase in both cultivars under 70 mM NaCl. POX activity in L. pennellii significantly increased after 6 and 84 d whereas showed no remarkable change in leaves of L. esculentum under 140 mM NaCl. A higher salinity tolerance of L. pennellii was also correlated with a lower lipid peroxidation, which might be due to a higher content of antioxidant enzymes studied.

Direct somatic embryogenesis from ray floret explants of five chrysanthemum cultivars has been obtained within 12 - 15 d on Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA). Scanning electron microscopic observation also confirmed the direct origin of somatic embryos from explants. Somatic embryos developed asynchronously on the adaxial surface of explants. Among the five cultivars tested, Birbal Sahani was best responding (40 % explants responded on 4 mg dm^-3 2,4-D and 2 mg dm^-3 BA supplemented medium). Precocious germination of somatic embryos was noticed on the same medium. The best sucrose concentration in the medium was found to be 60 g dm^-3 where 70 % explants responded while 55 % embryogenic response was obtained on medium supplemented with 400 mg dm^-3 inositol. Plants developed from somatic embryos were transferred to soil and produced true-to-type flowers.

This study assessed the effects of salinity and drought upon leaf construction (CC) and maintenance (MC) costs in Avicennia germinans growing under contrasting soil salinities in the field. Additionally, an analysis of leaf chemical composition was carried out to determine the underlying reasons for possible variation in CC. With the increase of external salinity, leaf osmotic potential (ψ_s) declined and a significant negative correlation was found between both variables. Changes in average CC were about 15 % when ψ_s changed by 85 %. Despite this, leaf ash-free heat of combustion per unit of leaf dry mass remained relatively constant at 21.3 ± 0.9 kJ g^-1 in all conditions. The estimated maximum and minimum CC for the synthesis of protein present in leaves increased significantly with total leaf CC. Conversely, the estimated CC for lipid synthesis shows a tendency to decrease with total leaf CC. Under conditions of high salinity, ash content increased by 78 % compared to that of leaves collected at low salinity. It is concluded that undergoing changes in proteins and lipids (expensive) and ash (cheap) explain the changes in CC under contrasting salinities. Additionally, the average MC remained almost constant at moderate salinity and declined by 6 % under hyper-saline conditions. Thus, differences in CC and MC with salinity are explained in part by changes in the chemical composition of different compound fractions.

1, 5, or 10 mM arginine and 25, 50, or 100 μM cysteine were added in the Murashige and Skoog medium. By increasing arginine concentration the number of shoots per explant increased. Inclusion of 50 μM cysteine in the medium resulted in maximum number of shoots but it was not significantly different in comparison to 10 mM arginine. The chlorophyll content was significantly increased in explants treated with 10 mM arginine in comparison to the control, 1 mM arginine and 25 μM cysteine. By increasing arginine and cysteine concentrations of the medium, N, K, and Ca contents of explants increased but no significant changes in P, Mg, Fe, Mn, Zn, and B contents were observed.

Two pigeonpea [Cajanus cajan (L.) Millsp.] genotypes, a salt tolerant Manak and a salt sensitive ICPL 88039 were subjected to stress treatment of 3 mM boron, 60 mM NaCl and boron + NaCl at the seedling stage. Radicle and plumule proteins were analyzed by SDS-PAGE. Boron treatment increased 28.3 kDa proteins in plumule and 38.3 and 51.9 kDa proteins in radicle of Manak, however, there was no specific protein in ICPL 88039 either in plumule or in radicle. In NaCl treatment 95.6 kDa proteins appeared in plumule and 67.5 kDa proteins in radicle of Manak. Conversely content of some proteins decreased by boron treatment alone or in combination with NaCl although they were present in the controls. Thus, 54.3 kDa protein disappeared in ICPL 88039 plumule, 68.4 kDa in Manak radicle and 28.1 kDa in ICPL 88039 radicle.

Competition is a major density-dependent factor structuring plant populations and communities in both natural and agricultural systems. Seedlings of the model plant species Arabidopsis thaliana cv. Columbia, and the Columbia-derived stomatal mutants sdd1 and tmm1, were grown under controlled conditions at increasing densities of 1, 10, 20, and 50 plants per pot. We demonstrate significant effects of time (days after planting), density, genotype, density and genotype, and the three-way interaction with time upon several fitness components (plant height, silique number, leaf biomass and flowering stalk biomass) in Columbia and these mutants.

Optimization of primer screening for evaluation of genetic relationship in 34 cultivars of rose through random amplified polymorphic DNA (RAPD) markers was investigated. Four series of decamer primers were used for screening and optimization of RAPD analysis between which A and N series performed good amplification of fragments as compared with other series. The primers OPN-07 and OPN-15 produced maximum number of DNA fragments in Rosa hybrida cv. Anuraag. Some primer either did not produce amplification or produced very poor amplification. Further, ten selected primers were used for genetic analysis of 34 rose cultivars. The primer OPN-15 amplified 21 fragments in all cultivars tested. A total of 162 distinct DNA fragments (bands) ranging from 100 to 3400 base pairs were amplified by using 10 selected random primers. The cluster analysis indicated that these rose cultivars formed nine clusters.

A new full-length cDNA encoding 3-hydroxy-3-methylglutaryl-CoA synthase (designated as TmHMGS, GenBank Accession No. AY644708), which catalyses the condensation of acetyl CoA and acetoacetyl CoA to form 3-hydroxy-3-methylglutaryl-CoA as an early step in the taxol biosynthetic pathway, was isolated from young leaves of Taxus × media by rapid amplification of cDNA ends (RACE) for the first time. The full-length cDNA of TmHMGS contained a 1431 bp open reading frame (ORF) encoding a deduced protein of 476 amino acid residues. The deduced protein had an isoelectric point of 5.23 and a calculated molecular mass of about 53 kDa. Amino acid sequence comparison analysis showed that TmHMGS had high similarity with a number of HMGSs ranging from Schizosaccharomyces pombe to humans, with much higher identity with other HMGSs from plants than those from yeast and humans. Phylogenic analysis showed that TmHMGS had closest relationship with HMGS from Pinus sylvestris. Tissue expression pattern analysis showed that TmHMGS expressed in needles and stems at similar level, but no expression could be detected in roots. Expression of TmHMGS was all induced by under different elicitors such as silver nitrate, ammonium ceric sulphate and methyl jasmonate, revealed that TmHMGS was an elicitor-responsive gene.

Changes in the conformation of spinach thylakoid membranes were monitored in 5-doxyl stearic acid (SAL)-treated thylakoid membranes in the presence of various anions (Cl^-, Br^-, I^-, NO₂^-, SO₄^2-, PO₄^3-). The presence of anions made the thylakoid membrane more fluid. The extent of change in membrane fluidity differed with different anion and was reversible.

Agrobacterium rhizogenes A4M70GUS-mediated transformation of Savoy cabbage (Brassica oleracea L. var. sabauda) and two local lines of cabbage (B. oleracea L. var. capitata) was obtained using hypocotyl and cotyledon explants. The percentage of explants which formed roots was very high in all genotypes: 92.3 % in Savoy Gg-1, 64.4 % in cabbage P₂₂I₅, and 87.2 % in P₃₄I₅. Spontaneous shoot regeneration of excised root cultures grown on the hormone-free medium occurred in all three genotypes. In cabbage lines P₂₂I₅ and P₃₄I₅ shoot regeneration was higher (9.3 and 2.6 % respectively) than in Savoy cabbage Gg-1 (1.3 %). Transgenic nature of hairy root-derived plants was evaluated by GUS histological test and PCR analysis. All the tested cabbage shoots were GUS positive whilst in a Savoy cabbage GUS expression was registered only in 55 % of tested clones. PCR analysis demonstrated the presence of the GUS gene in regenerated shoot clones and in T₁ progeny.