Rapid micropropagation was achieved in Chlorophytum borivilianum Santapau and Fernandes using shoot base as explants. Multiple shoots were induced on Murashige and Skoog's (MS) medium supplemented with 3.0 mg dm^-3 6-benzylaminopurine, 0.1 mg dm^-3 1-naphthaleneacetic acid, 150 mg dm^-3 adenine sulphates and 3 % saccharose. Rooting was readily achieved upon transferring the shoots onto half strength MS medium supplemented with 0.1 mg dm^-3 indolebutyric acid and 2 % saccharose. Micropropagated plantlets were hardened in the greenhouse and successfully established in soil. Random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic stability of the micropropagated plants. Thirty one arbitrary decamers were used to amplify genomic DNA from in vitro and in vivo plant material to assess the genetic stability. All RAPD profile analysis from micropropagated plants was genetically similar to mother plants.

Lipase class 3 is part of the triacylglycerol lipase family involved in lipid degradation, esterification, and transesterification processes in plants. In this study, a lipase class 3 gene and promoter from oil palm (Elaeis guineensis Jacq.) were isolated and characterized by Northern blot, Southern blot, oil palm genome sequence, and transient expression GUS assay. The full-length lipase class 3 (FLL1) deduced polypeptide encoded 483 amino acids and was identical to that deduced from lipase (EgLip1) cDNA (GI: 409994625). It contained the lipase consensus sequence, GxSxG motif, and a putative catalytic triad and had a 3-dimensional protein model similar to that of a lipase from Giberella zeae with a 50 % identity. The Northern blot and reverse transcription polymerase chain reaction (RT-PCR) show that FLL1 was predominantly expressed in the mesocarp and the expression increased as fruits reached maturity. A lower expression was detected in germinated seedlings and especially in roots. The expression of FLL1 was also enhanced in the mesocarp of cold treated fruits. A high oil accumulation in the mesocarp during fruit development makes this tissue a suitable target for a genetic modification, hence the isolation of the FLL1 promoter. The transient expression of the β-glucuronidase (GUS) gene driven by the FLL1 promoter detected the GUS expression in mesocarp slices, especially in vascular bundles. This suggests the potential role of using the promoter as tool to direct the expression of a transgene to the mesocarp of transgenic oil palm.

In the present study, we found that the expression patterns of the vegetative profilins and actin depolymerizing factors (ADFs) were specifically altered under low temperature (17 °C) stress using a real-time PCR. Our results show that also reorganization of the actin cytoskeleton was triggered by a low temperature. Facilitation of microfilament (MF) assembly by phalloidin treatment resulted in an enhanced low temperature stress tolerance, whereas blocking MF assembly with latrunculin B resulted in enhanced low temperature stress sensitivity. Our results show that the specific members of the vegetative profilins and ADFs might participate in regulating the response of plants to a low temperature stress, and the actin cytoskeleton is vital for the tolerance of Arabidopsis seedlings to low temperature stress.

Tomato plants were treated for two weeks with different concentrations of Cr(III) or Cr(VI) compounds to compare their toxic effects. The concentration of total Cr in plant tissues increased linearly with its concentration in the growth medium and Cr accumulated largely in the roots, regardless of the form in which it was supplied to the plant. All measured plant growth parameters were negatively affected by Cr, but Cr(VI) showed much more pronounced toxic effects. Leaf net photosynthetic rate (P_N) was decreased by both Cr forms, and the decrease was also greater for Cr(VI). Cr(III) caused no significant effect on leaf stomatal conductance, whereas Cr(VI) reduced it. Cr(VI) also markedly reduced the variable to maximum chlorophyll a fluorescence ratio, measured in dark-adapted leaves.

A wheat stay-green mutant, named tasg1, was generated using the mutagen ethyl methane sulphonate applied to wheat (Triticum aestivum L.) cv. HS2. A drought stress was imposed by controlling irrigation and sheltering plants from rain. The antioxidant defence was characterized in the flag leaves of the tasg1 and wild-type (WT). Compared with WT, tasg1 had higher reduced ascorbate/oxidized ascorbate ratio, reduced glutathione/oxidized glutathione ratio, and antioxidant enzyme activities during senescence under both normal and drought stress conditions. The DHAR gene expression remained higher in tasg1 than in WT during the drought stress and tasg1 had a higher antioxidant defence competence which may contribute towards the delayed leaf senescence. The different transcriptional responses of some wheat senescence-associated genes to the drought stress between tasg1 and WT were observed. These results suggest that the competent antioxidative capacity might play an important role in the enhanced drought tolerance in tasg1.

A protocol for in vitro multiplication of Capparis decidua (Forsk.) Edgew. has been developed from cultured leaves procured from multiplying axillary shoots on the cultured nodal explants. The highest efficiency of shoot formation was observed on Murashige and Skoog (MS) medium containing 2 mg dm^-3 benzyladenine (BA) and 0.5 mg dm^-3 1-naphthaleneacetic acid. The regenerated shoots were transferred to MS medium containing 3 mg dm^-3 BA for growth and proliferation. Shoots above 2 cm in length were transferred to MS medium supplemented with 1 mg dm-3 indole-3-butyric acid plus 0.5 mg dm^-3 indole-3-acetic acid for root induction. No variation was detected among the micropropagated plants by randomly amplified polymorphic DNA (RAPD) markers.

The ATP binding cassette B/multidrug-resistance/P-glycoprotein (ABCB/MDR/PGP) subfamily is a member of the ABC protein family. Significant progress has been made in the functional characterization of ABCB genes, particularly in Arabidopsis thaliana. This review evaluates recent advances concerning the plant ABCB subfamilies including their evolution and structure, the involvement and regulation of ABCB-mediated auxin transport, and the roles of ABCBs in plant growth and development. Insights into specific functions of members of the ABCB subfamily and their mediation of various regulatory pathways are also presented.

Flow-sorted chromosomes have been used to simplify analyses of complex plant genomes. In bread wheat, majority of studies involve cultivar Chinese Spring, a genotype chosen for sequencing. Telosomic lines developed from this cultivar enable isolation by flow sorting chromosome arms, which represent less than 3.4 % of the genome. However, access to other wheat cultivars is needed to allow mapping and cloning useful genes. In these cultivars, cytogenetic stocks are not readily available and only one chromosome (3B) can be sorted. Remaining chromosomes form composite peaks on flow karyotypes and cannot be sorted. In order to overcome this difficulty, we tested a pragmatic approach in which composite chromosome peaks are dissected to smaller sections. The analysis of chromosome composition in sorted fractions confirmed feasibility of obtaining sub-genomic fractions comprising only a few chromosomes. Usually one of the chromosomes was more abundant and the frequencies of dominant chromosomes in sorted fractions ranged from 16 % (chromosome 7B) to 80 % (chromosome 2B). The enrichment factor, calculated as the relative proportion of chromosomal DNA in the wheat genome to the proportion of chromosomal DNA in a sorted fraction, ranged from 3.2-fold (7B) to 16.4-fold (5D). At least a 5-fold enrichment can be obtained for 17 out of 21 wheat chromosomes. Moreover, we show that 15 out of the 21 chromosomes can be sorted without being contaminated by their homoeologs. These observations provide opportunities for constructing sub-genomic large-insert DNA libraries, optical mapping, and targeted sequencing selected genome regions in various cultivars of wheat. The availability of fractions enriched for chromosomes of interest and free of contaminating homoeologs will increase the efficiency of research projects and reduce their costs as compared to whole genome approaches. The same methodology should be feasible in other plants where single chromosome types cannot be sorted.

We evaluated the combined effects of elevated CO₂ and water availability on photosynthesis in barley. Soil and plant water content decreased with water stress, but less under elevated CO₂ concentration (EC) compared with ambient CO₂ concentration (AC). During water stress, stomatal conductance, carboxylation rate, RuBP regeneration, and the rate of triose phosphate utilisation (TPU) were decreased but less when plants grew under EC. Drought treatments caused only a slight effect on maximum photochemical efficiency (variable to maximum fluorescence ratio, F_v/F_m), whereas the actual quantum yield (Φ_PS2), maximum electron transport rate (J_max) and photochemical quenching (qP) were decreased and the non photochemical quenching (NPQ) was enhanced. Under water deficit, the allocation of electrons to CO₂ assimilation was diminished by 49 % at AC and by 26 % at EC while the allocation to O₂ reduction was increased by 15 % at AC and by 12 % at EC.

In this study, the anthocyanin content and real-time quantitative expression of the anthocyanin biosynthesis-related genes were investigated in leaves, stems, and tubers of purple yam (Dioscorea alata L.). The anthocyanin content, its accumulation, and the expression of genes encoding phenylalanine ammonia lyase (PAL), flavanone-3-hydroxylase (F3H), anthocyanidin synthase (ANS), and UDP-glycose flavonoid glycosyl transferase (UFGT) were studied. The anthocyanin content in the leaves and stems was high at early stages of growth, but it decreased and remained at a similar level from the 35^th day onward. The anthocyanin content in the tubers firstly increased, reached a high peak at the 110^th day of growth, after which decreased. Anthocyanin accumulation rates and the expressions of the anthocyanin biosynthesis genes were high at the early stages of growth in the leaves and stems, but in tubers, two peaks were observed: at days 80 and 140 for the gene expression and at days 125 and 170 for the anthocyanin accumulation rate. Thus, there was coordination between the gene expressions and the anthocyanin accumulation rates in the various organs as well as in the entire plants.

Dramatic accumulation of proline is a common physiological response in plants exposed to various abiotic stresses. Accumulation of proline could be due to de novo synthesis, decreased degradation, lower utilization, or hydrolysis of proteins. Extensive intercellular proline transport occurs between the cytosol, chloroplasts, and mitochondria due to its compartmentalized metabolism. Although all functions of proline in stress tolerance are still a matter of debate, it is suggested that proline contributes to stabilization of sub-cellular structures, scavenging free radicals, and buffering cellular redox potential. It also chelates heavy metals, modulates cellular functions, and even triggers gene expression. Apparently, proline acts as stress-related signal exhibiting cross tolerance to a range of different stresses. Besides these significant roles, its metabolism is found to be coupled to several key pathways such as pentose phosphate, tricarboxylic acid, or urea cycles and contributes to, i.e., purine synthesis and the phenylpropanoid pathway. Although the molecular basis of regulation of proline metabolism is still largely obscure, the genetic engineering of proline content could lead to new opportunities to achieve plant stress tolerance.

The issue of finding plants suitable for phytoremediation of inorganic contaminants can be addressed through the preparation of genetically modified plants with an increased metal accumulation potential. A HisCUP gene, which encodes for a yeast metallothionein fused with a polyhistidine tail (His), was chosen for preparation of two plant vectors. These two plant vectors were constructed and a HisCUP gene expression was subsequently investigated. We firstly prepared a vector pNOV2819/RbcS/HisCUP which enabled selection on a mannose medium and contained the HisCUP gene under an inducible Rubisco promoter. Secondly, we designed a vector pGreen0029/35S/HisCUP which enabled selection of plants on a medium with kanamycin and carried the HisCUP gene under a constitutive CaMV 35S promoter. The transient expression of the HisCUP gene in tobacco plants was confirmed at RNA and protein levels for both constructs. The relative expression of the HisCUP gene was determined by semi-quantitative real-time PCR; a higher expression was detected for the vector pNOV2819/RbcS/HisCUP.

Chloride channels (CLCs) play pivotal roles in plant development and anion transport. However, little research has been conducted about the CLC in fruit-bearing plants. Here we provide an insight into the evolution and expression patterns of CLC gene family members in various tissues of trifoliate orange [Poncirus trifoliata (L.) Raf.] and their responses to several treatments. Genome-wide analysis identified six PtrCLC genes. The predicted proteins had similar numbers of amino acids, but shared a low sequence identity. Phylogenetic analysis revealed that PtrCLC were classified into two separate subgroups, and PtrCLC4 and PtrCLC6 in subgroup II were more closely related to bacterial CLCs. Sequence comparison with EcCLCA from Escherichia coli reveals that PtrCLC showed amino acid divergence in anion selectivity of CLC proteins. Real time qPCR analysis shows that PtrCLC genes, particularly PtrCLC6, preferentially expressed in leaves. Nitrogen deficiency irreversibly inhibited expression of PtrCLC genes except for PtrCLC1. In contrast, NaCl stress profoundly induced expression of PtrCLC genes, particularly PtrCLC2 and PtrCLC4, both of which were also upregulated by ABA treatment. The results presented here provide a solid foundation for a future functional research on citrus CLC genes.

The antioxidative system was studied during the development of pea plants. The reduced glutathione (GSH) content was higher in shoots than in roots, but a greater redox state of glutathione existed in roots compared with shoots, at least after 7 d of growth. The 3-d-old seedlings showed the highest content of oxidised ascorbate (DHA), which correlated with the ascorbate oxidase (AAO) activity. Also, the roots exhibited higher DHA content than shoots, correlated with their higher AAO activity. The activities of antioxidant enzymes were much higher in shoots than in roots. Ascorbate peroxidase (APX) activity decreased during the progression of growth in both shoots and roots, whereas peroxidase (POX) activity strongly increased in roots, reflecting a correlation between POX activity and the enhancement of growth. Catalase activity from shoots reached values nearly 3 or 4-fold higher than in roots. The monodehydroascorbate reductase (MDHAR) activity was higher in young seedlings than in more mature tissues, and in roots a decrease in MDHAR was noticed at the 11^th day. No dehydroascorbate reductase (DHAR) was detected in roots from the pea plants and DHAR values detected in seedlings and in shoots were much lower than those of MDHAR. In shoots, GR decreased with the progression of growth, whereas in roots an increase was seen on the 9^th and 11^th days. Finally, superoxide dismutase (SOD) activity increased in shoots during the progression of growth, but specific SOD activity was higher in roots than in shoots.

Roles of an altered porphyrin biosynthesis and antioxidants in protection against chilling and heat stresses were evaluated in rice (Oryza sativa L.). When exposed to the same exposure time (6 or 30 h), heat-stressed (45 °C) plants exhibited a less oxidative stress as indicated by a lower dehydration, ion leakage, and H₂O₂ production compared to chilling-stressed (4 °C) plants. Malondialdehyde production also increased after a mild chilling stress, whereas it increased only after a long-term heat stress. The content of protoporphyrin IX, Mg-protoporphyrin IX and its methyl ester, and protochlorophyllide drastically declined under both the stresses, particularly under the long-term heat stress. Greater increases in catalase and peroxidase activities in heat-stressed plants indicate more cofactors supplied for hemoproteins compared to those of chilling-stressed and untreated control plants. Intermediates of carotenoid biosynthesis, zeaxanthin and antheraxanthin, also increased under the chilling and heat stresses. In comparison to chilling-stressed plants, heat-stressed plants were more efficient in porphyrin scavenging and antioxidant enzyme responses, which may play crucial roles in plant protection under temperature stress, thereby suffering less from oxidative stress.

The effect of benzothiadiazole (BTH) and arbutin (ARB) on sugar metabolism and plant fitness in cucumber growing hydroponically in media with different doses of NO₃ ^- and urea as nitrogen sources (100 % NO₃ ^-, 75 % NO₃ ^- + 25 % urea, and 50 % NO₃ ^- + 50 % urea) was studied on the 7^th and 14^th day after the treatment. The glucose, sucrose, and chlorophyll (Chl) content, acid and alkaline invertases and lactate dehydrogenase activities, as well as leaf area of the 3^rd and 5^th leaves were determined. Urea changed the plant sugar metabolism in a dose-, time- and leaf-age-dependent manners and influenced a cucumber response to the BTH and ARB treatments. The BTH caused a significant cessation of growth, a decrease in Chl content, a reduction of leaf area, and an enhancement of lactate dehydrogenase and alkaline invertase activities. In the older leaves of the BTH-treated plants, a high accumulation of glucose and sucrose was found. At the lower dose of urea, the metabolic changes were limited. In the ARB-treated plants, the Chl content remained unchanged in all the nitrogen variants. In these plants, decrease in glucose and sucrose content and in both invertase activities was observed mainly in younger leaves of the plants grown on the high dose of urea. The ARB improved the fitness of the cucumber plants grown in the presence of urea.

An efficient plant regeneration protocol was developed from rhizomes of two Curcuma species C. longa and C. amada. Response was highly dependent on the season, with above 69 % of culture developing adventitious shoots during spring. Greatest regeneration and multiplication was observed in modified Murashige and Skoog (MS) medium supplemented with 13.31 μM benzyladenine and 2.68 μM α-naphthalene acetic acid (NAA) in C. longa or 2.46 μM indolebutyric acid in C. amada. Effect of sugars and agar at different concentrations were also studied and 2 % maltose and 0.7 % agar were found optimum for shoot multiplication and regeneration. Most plantlets developed roots simultaneously but others formed roots when subcultured in 1/2 MS medium supplemented with 2.68 μM NAA. Plants were successfully hardened in greenhouse with 80 % survival. The genetic purity of micropropagated plantlets was analyzed using RAPD and protein profiles.

The effects of acclimation to cold (4 °C) and heat (36/38/40 °C) on corresponding freezing and heat tolerances of one-year-old Trigonobalanus doichangensis seedlings were studied. In addition, the effects of abscisic acid (ABA) and salicylic acid (SA) pretreatments on the tolerance of this species to temperature extremes were tested. The results show that the content of soluble sugars increased with the duration of acclimation to cold (4 °C), and the relative electrical conductivity and malondialdehyde content increased significantly after 7 d; however, the content of proline did not vary significantly. After acclimation to cold for 3 and 7 d, the semilethal low temperature (LLT₅₀) was 0.8 and 1.1 °C lower, respectively, compared with that of the control. The maximum quantum yield of photosystem II (measured as variable to maximum fluorescence ratio, F_v/F_m) decreased significantly after freezing treatments (-4 to -8 °C), however, less when the plants were pretreated with 1-100 mg dm^-3 ABA. Acclimation to heat did not increase the semilethal high temperature (LHT₅₀). A low concentration (1 mg dm^-3) of SA increased LHT₅₀, but medium and high concentrations (10 and 100 mg dm^-3) decreased it. F_v/F_m decreased significantly after a heat shock (45-54 °C). The pretreatment with 1-50 mg dm^-3 SA ameliorated a subsequent heat (48 °C) stress.

Using in vitro culture, we determined the effect of photoperiod during growth of Chenopodium rubrum mother plants on vegetative and reproductive development of offspring. Photoperiod during flowering induction of mother plants (the first 6 d after the germination) has the key influence on seed germination and offspring growth, while offspring flowering and seed maturation is determined by photoperiod their mothers experienced during, and shortly after, flowering induction. The mechanism can be through changes in seed protein pattern which we found dependent on photoperiod experienced by mother plants.

The effects of AT3-gene silencing on the expression of genes involved in capsaicinoid biosynthesis was investigated in chili pepper (Capsicum annuum L.) cv. Tampiqueño 74 fruits. Seeds were germinated and seedlings were grown in a greenhouse until they produced fruits. Capsaicinoids (capsaicin and dihydrocapsaicin) content and AT3 gene expression were determined in placenta tissue from fruits at 10, 20, 30, 40, 50, and 60 days post-anthesis (DPA). Capsaicin was more abundant than dihydrocapsaicin and both exhibited a similar accumulation pattern at different developmental stages starting at 20 DPA, reaching maximum values at 30-40 DPA before decreasing. The AT3 gene expression, as measured by quantitative RT-PCR, was positively correlated with capsaicinoid accumulation; AT3 transcripts were detected at 20 DPA, achieved a maximum at 30-40 DPA and then decreased. The Tampiqueño 74 seedlings were infected with Agrobacterium tumefaciens bearing a pTRV2-AT3 construct to induce virus-mediated silencing. Fruits were harvested at 40 DPA, and capsaicinoid content and AT3 gene expression were carried out in placenta tissue. A reduction of 81.1 % in AT3 expression and also in capsaicin (89.6 %) and dihydrocapsaicin (87.7 %) content was recorded in the AT3-gene silenced chili pepper plants. Furthermore, fruits from the AT3-silenced plants compared to the non-infected control plants showed a statistically significant reduction in the expression of genes involved in capsaicinoid biosynthesis [pAmt (89.4 %), BCAT (68.8 %), Kas (90.4 %) and Acl (58.6 %)]. These data indicate that AT3 silencing had a negative effect on the transcription of genes involved mainly in the branched-chain fatty acid pathway of capsaicinoid biosynthesis.

Long-distance electrical signals generated in locally stimulated plants are linked with systemic physiological responses. The propagation of electrical signal through a plant can be measured by multiple electrodes attached to different sites of a plant body. As this signal has to be measured with the sensitivity of tens of microvolts, it can be easily disturbed by power-line hums or external electromagnetic fields. These disturbances can mimic the action potentials generated by a plant. In this work, we present a brief summary of various experimental approaches to the measurement of surface electrical potential (SEP) on a plant and a description of our multi-channel device for the SEP measurement. The main advantages of our measuring system are galvanic separation of the measuring unit, resulting in the elimination of power-line disturbances, and simple and stable contact of Ag/AgCl-peletted electrodes with the plant surface, facilitated by an ordinary gel used in human electrocardiography. These improvements enabled us to detect unperturbed variation (slow) and action (fast) potentials on a plant, as demonstrated by the four-electrode measurement of the electrical signal propagation in a locally wounded tomato plant.

Phospholipase D (PLD) and its product phosphatidic acid are now considered to be one of the key elements of numerous physiological processes in plants including the salicylic acid signalling pathway. The presented study investigates the transcriptional regulation of Brassica napus PLDs following treatments with defense-related stimuli. We cloned eight B. napus genes encoding members of PLDβ, γ, and δ isoforms and performed phylogenetic analysis with its ancestor species Brassica rapa and Brassica oleracea, and with the model plant Arabidopsis thaliana. Transcription of the identified genes was monitored after treatment with benzothiadiazole (BTH), methyl jasmonate (MeJA), bacterial elicitor flg22, wounding, and after infection with fungal pathogens Sclerotinia sclerotiorum and Leptosphaeria maculans. Most of the genes responded specifically to a particular treatment. Remarkably the genes encoding the PLDγ and PLDβ isoforms were up-regulated by stimuli associated with the salicylic acid signalling pathway. The generality of this finding was confirmed by the analysis of public transcriptional data from Arabidopsis thaliana.

Analysis of structural changes of octoploid triticale genomes was conducted in F₂ and F₃ generations. The plants were derived from crosses of five cultivars and breeding lines of hexaploid wheat (Triticum aestivum L.) with one cultivar of rye (Secale cereale L). The study used four marker systems: inter-simple sequence repeat (ISSR), inter-retrotransposon amplified polymorphism (IRAP), retrotransposon-microsatellite amplified polymorphism (REMAP), and a technique named inter-transposon amplified polymorphism (ITAP) developed by the authors. Most frequently, elimination of specific bands was observed, especially of rye bands. Depending on the cross combination, the percentage of eliminated rye bands ranged from 73.6 to 80.6 %. A lower percentage of wheat bands was eliminated, i.e., from 57.6 to 76.48 %, depending on the combination of crosses. The emergence of new types of bands in hybrids absent in the parental forms was the rarest phenomenon (14.5-17.9 %). The results indicate the ongoing process of genome rearrangements at the molecular level in the early generations of plant crosses that also involve repeated nucleotide sequences of DNA.

The aim of this study was to investigate acclimation of micropropagated plants of Rhododendron ponticum subsp. baeticum to different irradiances and recovery after exposure to high irradiance. Plants grown under high (HL) or intermediate (IL) irradiances displayed higher values of maximum electron transport rate (ETR_max) and light saturation coefficient (E_k) than plants grown under low irradiance (LL). The capacity of tolerance to photoinhibition (as assessed by the response of photochemical quenching, q_p) varied as follows: HL > IL > LL. Thermal energy dissipation (q_N) was also affected by growth irradiance, with higher saturating values being observed in HL plants. Light-response curves suggested a gradual replacement of q_p by q_N with increasing irradiance. Following exposure to irradiance higher than 1500 μmol m^-2 s^-1, a prolonged reduction of the maximal photochemical efficiency of PS 2 (F_v/F_m) was observed in LL plants, indicating the occurrence of chronic photoinhibition. In contrary, the decrease in F_v/F_m was quickly reverted in HL plants, pointing to a reversible photoinhibition.

Hydrogen peroxide is an effective abiotic elicitor that can induce secondary metabolite biosynthesis in plants. We show that in cell suspension culture of a salt-tolerant medicinal plant Cistanche salsa, the production of bioactive components phenylethanoid glycosides (PeGs) was increased after an H₂O₂ treatment. To identify genes related to PeGs biosynthesis affected by H₂O₂, we constructed a suppression subtractive hybridization library of H₂O₂ responsive genes using a C. salsa cell line and identified 105 expressed sequence tags (ESTs) and 85 genes. EST library functional annotation and gene ontology analyses showed genes related to various stress responses, biosynthesis of secondary metabolites, and transcriptional regulation. Among them we identified two genes related to the PeGs biosynthesis pathway (4-coumarate coenzyme A ligase and cinnamate 4-hydroxylase), and two WRKY type transcription factors. The expressions of selected genes after the H₂O₂ treatment were analyzed by RT-qPCR. An early increased transcription of PeG biosynthesis pathway genes after the treatment revealed that H₂O₂ induced PeGs biosynthesis via up-regulation of its key genes.

A synthetic chimeric gene SbtCryIII(A) encoding the insecticidal protein btCryIII(A), was transformed into Pinus armandii embryos and embryogenic calli using Agrobacterium tumefaciens. Polymerase chain reaction and genomic DNA Southern blot analysis showed that the SbtCryIII(A) gene was integrated into the genome of transgenic Pinus armandii plants, and Northern blot analysis indicated that the SbtCryIII(A) gene was transcribed.

Based on information from the Arabidopsis model system, a putative transcriptional activator of cuticle formation (TaSHN1) was selected among the expressed sequence tags in wheat (Triticum aestivum L.). RT-PCR indicated the preferential expression of this gene in the basal, but not in the middle parts of wheat leaves. This leaf region is a likely site of cuticle formation in cereals. TaSHN1 was cloned and expressed in Arabidopsis, resulting in shiny leaf surfaces and the overproliferation of cuticular material as observed by electron microscopy. Unlike the Arabidopsis WAX INDUCER/SHINE1 (WIN/SHN1) gene, TaSHN1 triggered disorganized cuticular ultrastructure in the transgenic leaves, with the continuous layers replaced by large electrodense bodies embedded in amorphous lipid material. Toluidine blue staining and dark-adapted water release indicated increased cuticular permeability in TaSHN1-expressing Arabidopsis leaves. The expression of TaSHN1 resulted in a moderate decrease of the total number of stomata per unit leaf area in comparison with the wild type. Drought tolerance of Arabidopsis was unaffected by the transgene. The data indicate that this putative wheat orthologue of WIN/SHN transcription factors (TaSHN1) elicited both overlapping and new, distinctive phenotypes compared to other WIN/SHN-overexpressing plants. TaSHN1 transgenic Arabidopsis lines should provide a rich source of material for further comparative biochemical, physiological, and genetic studies.

Little is known about Ni storage in seeds of hyperaccumulating plants and its possible role in the first stages of plant development. The aim of this study was to determine Ni distribution in seeds and seedlings during germination and to test its role during germination with and without an external Ni supply. Field-harvested seeds from the South African Ni-hyperaccumulator Berkheya coddii Roessler were germinated either in Ni-free deionised water or in ultramafic soil. Sections of seeds and seedlings were analyzed using micro-proton induced X-ray emission (micro-PIXE) in order to localise Ni and other elements. Results show that high amounts of Ni were stored within the seeds. In germinating seeds, Ni was located in different parts: the lower epidermis, margins of cotyledons, and the pericarp in the micropylar area. The Ni and Ca were not mobilised during germination sensu stricto. Emergence of the first leaf seemed to trigger the translocation of Ni and Ca within the seedling. Besides, no effect of Ni supply from soil on its redistribution could be established for the germination stage.

We have applied a simple method for evaluation of gfp gene expression in plants using a CCD camera and computerized processing of images. Transgenic tobacco plants were obtained by Agrobacterium tumefaciens-mediated transfer of plasmid T-DNA bearing a m-gfp5-ER sequence governed by the 35S promoter together with the nptII selectable marker gene. Presence of the gfp gene in plants was confirmed by a polymerase chain reaction method. Mean brightness values measured using image analysis software showed differences between transgenic and control plants and suggest the possibility of rapid selection of transgenic individuals among regenerants and their progenies.

Susceptibility of C. rubrum to Agrobacterium-mediated transformation was demonstrated by inoculating the petioles of in vitro grown plants with A. rhizogenes strain A4M70GUS. Hairy roots were produced in 8 % of explants. They were isolated and maintained on plant growth regulator-free solid or liquid half-strength Murashige and Skoog medium for two years. Hairy root fresh mass increased 30 - 90 folds when grown in liquid medium, which was superior to solid medium, where most of the hairy roots produced calli. When these calli were grown on medium supplemented with 0.5 mg dm-3 thidiazuron, embryo-like structures were obtained. Transgenic status of long-term callus and hairy root cultures was confirmed by histochemical GUS assay, by PCR specific to the uidA, rolA&B and ags genes and by Southern hybridization.