The effects of nitrogen fertilization on the growth, photosynthetic pigment contents, gas exchange, and chlorophyll (Chl) fluorescence parameters in two tall fescue cultivars (Festuca arundinacea cv. Barlexas and Crossfire II) were investigated under heat stress at 38/30 °C (day/night) for two weeks. Shoot growth rate of two tall fescue cultivars declined significantly under heat stress, and N supply can improved the growth rates, especially for the Barlexas. Chl content, leaf net photosynthetic rate, stomatal conductance, water use efficiency, and the maximal efficiency of photosystem 2 photochemistry (F_v/F_m) also decreased less under heat stress by N supply, especially in Crossfire II. Moreover, cultivar variations in photosynthetic performance were associated with their different response to heat stress and nitrogen fertilization, which were evidenced by shoot growth rate and photosynthetic pigment contents.

Pepper (Capsicum annuum L.) plants were sprayed with salicylic acid (SA) and treated with ultraviolet radiation UV-A (320-390 nm), UV-B (312 nm), and UV-C (254 nm) of 6.1, 5.8, and 5.7 W m^-2, respectively. UV significantly reduced contents of chlorophyll (Chl) a and b, and carotenoids (Car). SA treatment moderated Chl and Car reduction in plants treated with UV-B and UV-C. The quantity of antocyanins, flavonoids, rutin, and UV-absorbing compounds in plants that were treated with UV-B, UV-C, and SA were significantly increased. Foliar spray of SA counteracted the UV effects on pepper.

In higher plants, fatty acid hydroperoxides are intermediates in the synthesis of a diverse group of bioactive compounds. We used the reverse-transcriptase polymerase chain reaction to isolate a gene responsible for the oxidization of fatty acids from Petunia hybrida. A P450 cDNA that has not previously been isolated (CYP76A3) contained an open reading frame predicted to encode a polypeptide consisting of 507 amino acid residues. The cyp76A3 cDNA was expressed in Saccharomyces cerevisiae AH22 cells under the control of an alcohol dehydrogenase promoter and terminator. The recombinant yeast microsome containing the CYP76A3 hemoprotein was found to specifically catalyze ω-hydroxylation of myristic acid. A high level of the transcripts of the cyp76A3 gene was found in the leaves and roots of P. hybrida, but not in the stems and flowers.

This paper describes multiple shoot regeneration from leaf and nodal segments of a medicinally important herb Centella asiatica L. on Murashige and Skoog's (MS) medium supplemented with a range of growth regulators. The highest number of multiple shoots was observed on MS augmented with 3.0 mg dm^-3 N⁶-benzylaminopurine (BAP) and 0.05 mg dm^-3 α-naphthaleneacetic acid (NAA). Leaf explant showed maximum percentage of cultures regenerating shoots (81.6 %), with the highest shoot number (8.3 shoots per explant) and the shoot length (2.1 cm) whereas, nodal explant showed less number of shoots with callus formation at the base cut end. Successive shoot cultures were established by repeatedly sub-culturing the original explant on a fresh medium. Rooting of in vitro raised shoots was best induced on half strength MS supplemented with 0.5 mg dm^-3 indole-3-butyric acid (IBA) with highest percentage of shoot regenerating roots (76.8 %) with 3-4 roots per shoot. Plantlets were acclimated in Vermi-compost and eventually established in soil. Contents of chlorophyll, total sugars, reducing sugars and proteins were estimated in leaf tissue from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants, whereas other three components were higher in in vitro plants.

Molecular farming provides a powerful tool for low cost production of recombinant proteins with pharmaceutical value. The use of transgenic plants has been increasingly tested as alternative system for obtaining biologically active human lactoferrin in plants. Precise selection of plant species, transformation techniques and expression cassettes, in addition to conduction of detailed glycosylation and immunogenicity studies, serves as basis of obtaining safe recombinant human lactoferrin in high concentrations for the use of pharmacy. On the other hand, expression of antimicrobial protein lactoferrin in plants is a promising opportunity for crop quality improvement by increasing plant disease resistance.

In this study, bulked segregant analysis (BSA) was used on Larix leptolepis × Larix olgensis hybrids to identify a random amplified polymorphic DNA (RAPD) marker associated with high rooting ability in larch. Two DNA bulks: H (high rooting ability) bulk and L (low rooting ability) bulk were constructed according to the rooting percentages of the stock plants. Among the 328 primers, only S356 could amplify a specific band, named S356₄₄₅, which only existed in the H bulk and was further confirmed following selective genotyping of individual hybrids. Grounded on the border sequences, S356₄₄₅ was converted to a sequence characterized amplified region (SCAR) marker, HRL445, which can be useful in marker-assisted selection (MAS) to screen for larch with high rooting ability. All the results strongly indicated that S356₄₄₅ and HRL445 were closely associated with high rooting ability in larch.

The effects of silicon application before sowing on the drought-induced oxidative stress and antioxidant defense in wheat (Triticum aestivum L.) were investigated. Drought stress was applied by withholding watering till sampling at booting or filling stage. Application of Si increased the water potential of drought-stressed plants at filling stage, whereas it did not at booting stage. The superoxide dismutase (SOD) activity was inhibited and peroxidase (POD) activity was enhanced by drought at booting stage, and no differences were observed due to the Si treatment. At filling stage, however, application of Si increased the SOD activity and decreased the POD activity of drought-stressed plants. The catalase (CAT) activity was slightly increased by drought only in the absence of Si and at booting stage. The activity of glutathione reductase (GR) was not greatly influenced. Application of Si did not change the contents of H₂O₂, total soluble protein and protein carbonyl of drought-stressed plants at booting stage, whereas at filling stage, it decreased the content of H₂O₂ and protein carbonyl and increased the content of total soluble protein. The content of thiobarbituric acid reactive substances (TBARS) and the activities of acid phospholipase (AP) and lipoxygenase (LOX) in drought-stressed plants were also decreased by application of Si at both stages.

Exposure of Lemna minor L. to high temperatures leads to an initial decrease in the ubiquitin (Ub) monomer pool size and the accumulation of high molecular mass Ub-protein conjugates, possibly reflecting an increment in the supply of protein substrates to the Ub/proteasome pathway. Alternative explanations include, for example, changes in the transcription rates of one or more pathway components. To measure the effect of heat shock on the simultaneous rates of transcription of selected genes encoding five Ub pathway components (Ub, E1, E2, β subunit and ATPase subunit of the 26S proteasome), a semi-quantitative RT-PCR method was developed using cDNA normalized against the housekeeping gene encoding the 18S ribosomal RNA. Whilst Ub transcription is abruptly increased, there is a moderate increment in the transcription of E1 and the β subunit, a moderate reduction in the transcription of the ATPase subunit and a marked reduction in the case of E2, indicating a differential transcription pattern of the various components of the Ub/proteasome pathway in L. minor subjected to high temperatures. These observations suggest that the increment in the Ub/proteasome pathway intermediates is due to an augmented supply of substrates derived from the stress-induced damage imposed on the cellular proteins. The initial build up of intermediates occurs not only at the expense of the pre-existing pool of free Ub, but also as a result of the prompt increase in Ub expression.

Embryo-rescue was used to facilitate interspecific hybridization of Cucumis anguria L. and C. zeyheri Sond. Embryos were excised from developing fruits at one week intervals for six weeks after hand pollination. Medium containing coconut water was the most suitable for initial germination, and a medium with ascorbic acid was the best for embryo development and plant recovery. Viable plants were obtained from embryos and these plants showed morphological characteristics different from both parents. The analysis of the leucine aminopeptidase (LAP) locus revealed three hybrid types, H1.1, H1.2 and H2.

A micropropagation protocol through multiple shoot formation was developed for Thlaspi caerulescens L., one of the most important heavy metals hyperaccumulator plants. In vitro seed-derived young seedlings were used for the initiation of multiple shoots on Murashige and Skoog (MS) medium with combinations of benzylaminopurine (BA; 0.5-1.0 mg dm^-3), naphthaleneacetic acid (NAA; 0-0.2 mg dm^-3), gibberellic acid (GA₃; 0-1.0 mg dm^-3) and riboflavin (0-3.0 mg dm^-3). The maximum number of shoots was developed on medium containing 1.0 mg dm^-3 BA and 0.2 mg dm^-3 NAA. GA₃ (0.5 mg dm^-3) in combination with BA significantly increased shoot length. In view of shoot numbers, shoot length and further rooting rate, the best combination was 1.0 mg dm^-3 BA + 0.5 mg dm^-3 GA₃ + 1.0 mg dm^-3 riboflavin. Well-developed shoots (35-50 mm) were successfully rooted at approximately 95 % on MS medium containing 20 g dm^-3 sucrose, 8 g dm^-3 agar and 1.0 mg dm^-3 indolebutyric acid. Almost all in vitro plantlets survived when transferred to pots.

A minimal gene cassette comprised of the ubiquitin (Ubi) promoter + green fluorescent protein (Gfp) gene + Nos terminator DNA sequences, derived from the plasmid vector pPZP201-Gfp was utilized for transformation of creeping bentgrass using particle bombardment. Bentgrass calli bombarded individually with equivalent amounts of the cassette or whole plasmid DNA were compared for Gfp expression and the GFP-positive calli were subsequently regenerated into plants. Percentage of GFP expressing calli and the number of GFP spots/calli were significantly higher in calli that were bombarded with the minimal gene cassette when compared to the whole plasmid. The Gfp expression was stable up to the T₂ generation in minimal gene cassette transformants and there was a lower degree of gene silencing. Southern blot analysis of transgenic plants derived from minimum gene cassette bombardment revealed the presence of single or few copy of the transgene and fairly simple integration patterns. In comparison, whole plasmid transformants had multiple copies and complex integration patterns of the transgene. These results illustrate the advantages of using simple gene cassette for stable plant transformation in bentgrass with possible applications to other plant species.

The water-water cycle which may be helpful for dissipating the excitation pressure over electron transport chain and minimizing the risk of photoinhibition and photodamage was investigated in rice after 10-d P-deficient treatment. Net photosynthetic rate decreased under P-deficiency, thus the absorption of photon energy exceeded the energy required for CO₂ assimilation. A more sensitive response of effective quantum yield of photosystem 2 (Φ_PS2) to O₂ concentration was observed in plants that suffered P starvation, indicating that more electrons were transported to O₂ in the P-deficient leaves. The electron transport rate through photosystem 2 (PS 2) (J_f) was stable, and the fraction of electron transport rate required to sustain CO₂ assimilation and photorespiration (J_g/J_f) was significantly decreased accompanied by an increase in the alternative electron transport (J_a/J_f), indicating that a considerable electron amount had been transported to O₂ during the water-water cycle in the P-deficient leaves. However, the fraction of electron transport to photorespiration (J_o/J_f) was also increased in the P-deficient leaves and it was less sensitive than that of water-water cycle. Therefore, water-water cycle could serve as an efficient electron sink. The higher non-photochemical fluorescence quenching (q_N) in the P-deficient leaves depended on O₂ concentration, suggesting that the water-water cycle might also contribute to non-radiative energy dissipation. Hence, the enhanced activity of the water-water cycle is important for protecting photosynthetic apparatus under P-deficiency in rice.

The effects of salinity on growth, leaf nutrient content, water relations, gas exchange parameters and chlorophyll fluorescence were studied in six-month-old seedlings of citrus (Citrus limonia Osbeck) and rooted cuttings of olive (Olea europaea L. cv. Arbequina). Citrus and olive were grown in a greenhouse and watered with half strength Hoagland's solution plus 0 or 50 mM NaCl for citrus, or plus 0 or 100 mM NaCl for olive. Salinity increased Cl^- and Na⁺ content in leaves and roots in both species and reduced total plant dry mass, net photosynthetic rate and stomatal conductance. Decreased growth and gas exchange was apparently due to a toxic effect of Cl^- and/or Na⁺ and not due to osmotic stress since both species were able to osmotically adjust to maintain pressure potential higher than in non-salinized leaves. Internal CO₂ concentration in the mesophyll was not reduced in either species. Salinity decreased leaf chlorophyll a content only in citrus.

A high efficient four step protocol (callus initiation, regeneration, shoot elongation and rooting) for in vitro propagation of Dracaena sanderiana Sander ex Mast was developed. Callusing was achieved from nodal stem segment explants treated with various concentrations of ethylmethane sulphonate (EMS) on MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D; 1.5 g m^-3). A significant increase in callus induction percentage and biomass production was noticed from lower EMS treated lines (ET₁ and ET₂) comparatively to control and other (ET₃, ET₄ and ET₅) lines. Calli of ET₁ line showed high regeneration potential on MS medium with N ⁶-benzylaminopurine (BAP; 1.75 g m^-3). Length of microshoots, which was reduced by EMS, restored by addition of gibberellic acid (GA₃; 0.4 g m^-3). A marked increase in rooting with increasing EMS concentration was noticed on MS medium fortified with 3-indolebutyric acid (IBA; 1.5 g m^-3).

A cDNA sequence OsMT3 was initially isolated from the subtractive cDNA library of ammonium-fed rice (Oryza sativa L.) leaves, which was further confirmed by Northern blot to be highly ammonium-up-regulated as compared to nitrate. Its full-length cDNA was cloned by RT-PCR, and in silico analysis reveals that the cDNA includes an open reading frame of 186 bp and encodes a rice metallothionein type 3 peptide. Northern blotting analysis showed that OsMT3 gene predominantly expressed in rice leaves, weakly in stems, and barely in buds and roots. The gene transcripts in leaves were significantly induced by polyethylene glycol (PEG), low temperature, NaCl and Cu²⁺, but not by Pb²⁺. Activities of three anti-oxidative enzymes (superoxide dismutase, catalase and peroxidases) and two non-enzymic antioxidants (reduced ascorbate and reduced glutathione) little differed in ammonium-and nitrate-fed rice leaves, indicating that the induced OsMT3 expression was not mediated by ammonium-elicited oxidative signals.

In the reproductive organs of maize (Zea mays L.), the changes in transcription that occur during meiosis at early stage of water deficit were characterized. We used oligo microarray analysis, which included 57452 transcripts representing more than 30 000 genes, and combined this with reverse Northern blot analysis. After 1 d stress, 1 809 transcripts were differentially expressed (by 2-fold or greater) with 34 % of them being upregulated in the tassels, while in the ears 861 transcripts were differentially expressed with 41 % being upregulated. Of these, 33 transcripts were upregulated in both organs, including those involved in protective functions, reactive oxygen species detoxification, nitrogen metabolism and gibberellin metabolism. In contrast, the transcripts involved in polyamine and sugar metabolism were downregulated.

In this work the volatiles emitted from in vitro shoot-cultures and micropropagated plants of Lavandula viridis L'Hér. were characterized and compared with those obtained from the field-grown mother-plant, using headspace solid phase micro-extraction following by capillary gas chromatography coupled to mass spectrometry (HS-SPME-GC/MS). The headspace composition consisted mainly in oxygenated monoterpenes (66.7-79.2 %), where the major constituents emitted by the mature field-grown mother-plant, in vitro shoot-cultures and micropropagated plants were 1,8-cineole (74.0, 51.9 and 57.8 %) and camphor (2.9, 15.3 and 8.7 %), respectively. The headspace of in vitro shoot-cultures and micropropagated plants showed greater amount of α-pinene, camphene, β-pinene, β-selinene and selina-3,7(11)-diene, when compared with the field-grown mother-plant.

An efficient protocol for micropropagation of Harpagophytum procumbens DC., an endangered African medicinal plant, was developed. Maximum shoot multiplication without callus was obtained from nodal explants cultured on Murashige and Skoog (MS) basal salts plus Gamborg's (B₅) vitamins supplemented with 0.1 mg dm^-3 indole-3-acetic acid and 5.0 mg dm^-3 kinetin. The shoots were subsequently subcultured every 3 weeks on the same medium. Detached axillary shoots were transferred to MS basal salts plus B₅ vitamins supplemented with various concentrations of α-naphthalene-acetic acid or indole-3-butyric acid (IBA), ranging from 0.5 to 2.5 mg dm^-3 and 100 % rooting and optimal subsequent acclimatization was achieved on 1.0 mg dm^-3 IBA. After 4 weeks of culture, the rooted shoots (>5 cm) were planted in pots containing peat, vermiculite and bark (2:1:1), covered with plastic domes and maintained at 25 °C for 2 weeks before being transferred to a glasshouse. Plant survival was about 40 %.

Glutamine synthetase (GS) showed highest expression and activity in bud (youngest topmost leaf) of Camellia sinensis, lower in older leaves, while lowest activity in stem and roots. GS expression and activity was increased by ammonium and nitrate and also by cadmium and salt stress but decreased by copper, aluminum, drought, cold and heat stress.

Wild-abortive (WA), Honglian (HL) and Baro-II (BT) are three important cytoplasmic male sterility (CMS) types in rice. It is essential to investigate genetic mode and allelism of fertility restorer (Rf) genes and the relationship between Rf and CMS. Fertility of the all test-cross F₁ plants shows that the restorer-maintainer relationship is similar for HL-CMS and BT-CMS, while that is variance for WA-CMS and HL-CMS (or BT-CMS), respectively. Genetic analysis of Rf genes indicates that HL-or BT-CMS are controlled by single dominant Rf gene and WA-CMS is controlled by one or two pairs of dominant Rf genes, which reflects the characters of the gametophytic and sporophytic restoration CMS type. It is concluded that there are at least three Rf loci in different accessions with Rf genes for each CMS type.

Cell wall composition in leaves and regenerating leaf-derived protoplasts was studied in Beta vulgaris L. and Nicotiana tabacum L. Several oligosaccharides that characterize arabinogalactan proteins (AGPs) and pectins were visualized in situ by a series of immunocytochemical reactions. The most conspicuous difference between the two species involved the expression of AGP epitopes that bind LM2 and MAC207 in only sugar beet cells; both epitopes being characterized by the presence of glucuronic acid (GlcA). Moreover, B. vulgaris leaves and protoplast-derived cells showed lower content of pectin side-chains bearing (1→4)-β-D-galactose residues as compared to N. tabacum.

Treatment of tomato seedlings (Lycopersicon esculentum Mill. cv. 63/5 F1) with increasing CdCl₂ concentrations in the culture medium resulted in Cd accumulation more important in roots than in leaves. Biomass production was severely inhibited, even at low Cd concentration. Cd reduced chlorophyll content in leaves and enhanced lipid peroxidation. An increase in antioxidative enzyme (superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase) activities was more pronounced in leaves than in roots, while catalase activity increased only in roots. In addition, changes in isoenzyme composition were observed using the non-denaturing polyacrylamid gel electrophoresis.

Nicotiana is a small and well characterized genus of Solanaceae and in this study we have used polymorphisms in phytochrome A coding sequence (phyA) and promoter to asses the phylogenetic relationships among species representative of all the sections of the genus. Allopolyploid species kept the two copies of the gene derived from each of the progenitors as resulted from the analyses of the coding region and promoter. Moreover, both copies of phyA present in tetraploids are transcribed, indicating that are properly regulated and do not undergo silencing.

Fourteen efficient inter-simple sequence repeat (ISSR) primers were screened and optimized for detecting the genetic diversity in wild populations of Glycyrrhiza uralensis Fisch. By using these primers, 249 polymorphic bands out of a total of 270 (92.2 %) were generated from 70 individuals of 4 wild G. uralensis populations sampled from Inner Mongolia Province of China. Nei's gene diversity (h) and Shannon index (I) calculated from the data matrix of the ISSR phenotypes revealed a high level of genetic diversity with h = 0.268 and I = 0.415 within this plant. Analysis of molecular variation (AMOVA) showed that most of the genetic variation (81 %) occurred within the populations, whereas the variance among populations was only 19 %. The UPGMA tree based on Nei's unbiased genetic diversity illustrated that populations from Bulage and Bayanwusu were genetically close related, while the population from Shanghaimiao was found to be the most diverse from the other three. The high genetic diversity implies that the wild resources of this species could be restored soon if an appropriate and efficient protection strategy was employed. Our results also provided an optimized method for evaluating genetic diversity of G. uralensis using ISSR markers which was useful for further investigation.