Callus induction was obtained on Murashige and Skogg agar medium with 45 μM 2,4-dichlorophenoxyacetic acid under dark at 25°C. Among the four explant types investigated, the best callus induction was obtained from two-week old fronds to which a surgical incision was applied in the basal (meristematic) region. This treatment resulted in 89.11% of fronds producing callus which continued to proliferate for another 24 months. To obtain plant regeneration pieces of calluses were transferred onto Murashige and Skoog agar medium containing 22 μM indole-3-acetic acid and 4.6 μM kinetin and maintained under 16-h photoperiod (irradiance of 30 μmol m^-2 s^-1) at 23°C. Green fronds formed on all callus pieces. The regenerated fronds were later transferred onto Wang medium where they formed roots. The regenerated Lemna minor L. plants obtained through indirect organogenesis did not differ morphologically from individuals forming the stock collection.

Plant regeneration via direct somatic embryogenesis from cotyledons, hypocotyls and leaves in seabuckthorn (Hippophae rhamnoides L.) was achieved. The influences of basal media, carbon sources, plant growth regulators (PGRs) with different concentrations and combinations on embryogenesis capacity of explants were studied. The highest frequency of somatic embryos production and germination was obtained on Schenk and Hildebrandt medium (SH) supplemented with 1.0 mg dm^-3 kinetin and 0.2, 0.5 mg dm^-3 indole-3-acetic acid. Granulated sugar was the optimal carbon source. The embryo-derived plantlets with well-developed roots and shoots were transferred successfully to the greenhouse with a maximum survival rate of 55 %. Histological observation revealed that the somatic embryos were similar to those of zygotic embryos.

In vitro propagation of an anticancerous drug synthesizing plant, Ophiorrhiza prostrata D. Don, was established through indirect somatic embryogenesis. Friable embryogenic calluses were initiated from O. prostrata leaf and internode explants on Murashige and Skoog (MS) media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) either alone or in combination with N⁶-benzyladenine (BA) or kinetin (KIN). Somatic embryos were developed after subculture of the friable calluses onto half strength MS media containing 0.45 or 2.26 µM 2,4-D alone or in combination with BA or KIN. Medium supplemented with 2.26 µM 2,4-D and 2.22 µM BA was optimal, supporting the production of a mean of 5.8 globular embryos. Subculture of globular embryo-bearing calluses on half strength MS medium without growth regulators produced the highest embryo frequency, and the majority of them developing to early torpedo stage. Somatic embryos underwent maturation and converted to plantlets at high frequency (90 %) on half strength MS medium supplemented with 0.44 µM BA. Somatic embryo-derived plantlets with well-developed roots were established in field conditions with a 90 % survival rate.

Potted 2-year-old lemon trees [Citrus limon (L.) Burm. fil, cv. Verna] grafted on sour orange (C. aurantium L.) rootstock were subjected to flooding for 3 d. Control plants were irrigated daily to field capacity. Continuously (sap flow, trunk diameter fluctuations) and discretely (predawn and midday leaf water potential, leaf conductance) measured plant-based water status indicators were compared. The sensitivity of the maximum daily trunk shrinkage signal intensity to flooding and its behaviour during the recovery period demonstrated that this indicator is more feasible than the others for use in automatic irrigation. The responses to flooding of continuously and discretely measured plant-based water status indicators were very similar to those observed in response to drought stress indicating that it necessary to use soil water measurement automatic sensors to detect the cause of the stress. The results underlined the robustness of the compensation heat-pulse technique for estimating instantaneous and daily transpiration rates on flooding stress and recovery.

Changes in growth, physiological and biochemical characteristics under salt stress with or without La³⁺ treatment in Saussurea involucrata Kar. et Kir. were investigated. The results showed that La³⁺ relieved the plant growth inhibition, improved the leaf water potential and water content, increased the soluble protein and the proline contents and decreased malondialdehyde content under salt stress. Further, addition of La³⁺ significantly increased the activities of superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase, decreased the photosynthetic pigment decomposition and increased the ratio of total chlorophyll to carotenoids under salt stress.

An efficient protocol for encapsulation of nodal segments of Vitex negundo L. has been developed for the production of non-embryogenic synthetic seeds. The encapsulations of nodal segments were significantly affected by the concentrations of sodium alginate and calcium chloride. A 3 % Na₂-alginate with 100 mM CaCl₂ has been found to be optimum concentration for the production of uniform synthetic seed. For germination, the synseeds were cultured on Murashige and Skoog (MS) basal medium supplemented with kinetin (KIN) and α-naphthalene acetic acid (NAA) either singly or in various combinations. MS medium containing 2.5 μM KIN in combination with 1.0 μM NAA was found to be the optimum for maximum (92.6 ± 3.71 %) plantlet conversion frequency. Well developed regenerated plantlets were hardened, acclimatized and established in field, where they grew well without any detectable variation.

Wild-type and the handshake (has) mutants in Arabidopsis thaliana were analyzed. Compared to the wild-type, has mutants display a number of morphological alterations, which can largely be traced back to altered meristem function. Analyses of apical meristem of mutant plants showed that mutation affected meristem structure and patterns of STM expression.

Arabidopsis thaliana plants (wild type accessions Col and N1438) were grown in nutrient solution for 34 d with or without 50 mM NaCl. Salt stress inhibited plant growth rate more in Col than in N1438 and a decrease in K⁺, Ca²⁺ and nitrogen contents was observed in both accessions. NaCl diminished accumulation of malate, fumarate and citrate only in Col accession. To measure the effect of NaCl on transcript level of superoxide dismutase (SOD) isoforms and copper chaperone for SOD genes, a semi-quantitative polymerase chain reaction (RT-PCR) method was developed using cDNA normalized against the EF1a gene in parallel with quantitative real time RT-PCR (Q-PCR) technique. Both methods gave the same results. The abundance of transcripts of the three genes coding for Cu/Zn-SOD responded similarly to NaCl in both accessions: CSD1 gene was overexpressed, and CSD2 and CSD3 genes were repressed. However, the genes coding for Fe-SOD (FSD1), Mn-SOD (MSD1) and Cu-chaperone for SOD (CCS) responded to NaCl differently in Col and N1438: the former gene was overexpressed in Col and repressed in N1438, and the opposite behaviour was observed for the latter two genes.

In this study, 16 hairpin RNA (hpRNA) vectors were constructed, each harboring 50 bp viral RNA sequence as the stem. They all targeted the coat protein (CP) gene of Potato virus Y (PVY). Virus resistance assay revealed that hairpin constructs targeting the anterior 200 bp regions of the CP gene were unable to induce virus resistance, while the 12 hpRNA constructs targeting posterior 600 bp regions induced high virus resistance up to 77.78 %. Northern blot analysis revealed that 50 bp-length hpRNA constructs could be transcribed efficiently and processed into siRNAs; however, no correlation between siRNA accumulation and degree of antiviral defense was observed. Results presented here indicated that the middle and 3' end of the CP cDNA was important for hpRNA-mediated PVY resistance, improving the design of pathogen-derived hpRNA expression cassettes for transgenic plant against viruses.

A full-length cDNA clone encoding cytosolic glutamine synthetase (GS1; EC 6.3.1.2) was isolated from melon (Cucumis melo L.) for the first time by RT-PCR and RACE approach. The clone, designated as M-GS1 (accession No. DQ851867), contains 1494 nucleotides with an open reading frame (ORF) of 1068 nucleotides. The deduced 356 amino acid sequence showed high similarity with previously reported GS1s from various plant species. Sequence analysis revealed that the predicted protein contains a GS β-Grasp domain, a GS catalytic domain, and the main conserved motifs characteristic of a plant GS1. The phylogenetic analysis displayed that M-GS1 is related most closely to the GS1 from Datisca glomerata. Southern blot analysis indicated that M-GS1 belongs to a small gene family of 2 or 3 members. M-GS1 was expressed in all plant tissues without evident tissue specificity, but with different patterns when the melon plants were fed in hydroponic culture with different forms and concentration of nitrogen. Ammonium dramatically enhanced the contents of M-GS1 transcripts in all tested tissues, while nitrate stimulated M-GS1 transcription only in the roots and leaves, but not in the stems; glutamate, however, depressed M-GS1 transcripts in the roots, but resulted in no significant change to the levels of M-GS1 transcripts in the stems and leaves. Moreover, the same effects were observed at the GS enzyme activity level. These results indicated that melons respond to changes of N nutrition by regulating M-GS1 expression.

Anther-derived pre-embryogenic masses (PEMs) of callus, established via suspension cultures, were encapsulated to form synthetic seeds suitable for cryopreservation. The synchronised suspension culture proliferation necessitated the optimisation of plant growth regulators for different cultivars. The growth phase and density of the culture were also important as well as the exposure of cells to vitrification solution containing 0.75 M sucrose with 0.1 M CaCl₂ and 2.0 % sodium alginate (pH 5.7). Pre-treatment of the encapsulated cells for 2 d with Nitsch and Nitsch (NN) medium containing 0.75 M sucrose solution followed by dehydration for 4 h in a laminar flow box provided maximum cell viability, which varied from 0 to 40 %. The embryo proliferation from the cryopreserved beads involved warming them and then transfer to NN medium containing glutamine (50 mg dm^-3) and activated charcoal (2.5 %). The maximum number of embryos obtained was 31-53 per bead. Subculture into the same medium induced secondary embryogenesis, which was initiated from the meristematic region, radicle, and root cap. Proliferation and maturation of secondary embryos was faster than of primary embryos. No phenotypic variation or abnormal structures compared to the control were observed in the regenerated plantlets.

Effects of reduced atmospheric pressure on morphogenic potential and antioxidative enzyme activities in regenerated tissues of Saussurea involucrata were evaluated. Leaf explants were cultured at atmospheric pressure 30, 60 or 101 kPa on Murashige and Skoog (MS) medium with several plant growth regulators (PGRs). Oxygen and carbon dioxide partial pressures were maintained at 21 and 0.038 kPa, respectively. At 60 kPa, 12 shoots per explant were recorded, which was 1.5 and 2.1-folds higher than at 101 and 30 kPa, respectively. A shooting frequency of 80 % was observed at 60 and 101 kPa. Rooted plantlets were obtained on MS medium with indoleacetic acid. At 30, 60 and 101 kPa, rooting of shoots was 49, 72 and 85.6 %, respectively. The rooted plantlets were successfully acclimatized to soil. Activities of all of antioxidative enzymes determined in present study were affected by hypobaric conditions.

The effect of aluminum and chromium on two barley genotypes differing in Al tolerance was studied in a hydroponic experiment. Al stress decreased plant growth, biomass production, chlorophyll content and photosynthetic efficiency determined as variable to maximum chlorophyll fluorescence ratio (F_v/F_m), net photosynthetic rate (P_N), intercellular CO₂ concentration (c_i), stomatal conductance (g_s) and transpiration rate (E) less in an Al-tolerant genotype Gebeina than in an Al-sensitive genotype Shang 70-119. Cr stress also caused marked reduction in growth and photosynthetic traits in barley plants. Higher reduction was observed at pH 4.0 as compared to pH 6.5. Combined stress of Cr and Al, caused further reduction in growth and photosynthetic parameters.

LAF1 (Long after far-red radiation 1) is a R2R3 Myb transcription factor and a signal transducer of far-red radiation. To investigate the role of LAF1 in leaf and root development, the leaf growth and vein patterning in laf1 mutants under short day conditions were examined. The length of rosette leaves was reduced and the width of the midvein was increased in laf1 mutants compared to their wild-type (WT) counterparts. In addition, cell size and cell number were both decreased in the laf1 mutant in comparison to the WT plant. A comparative analysis of gene expression showed that the transcript levels of PIN and IAA genes, encoding auxin carrier and response proteins, were decreased in laf1 mutants. LAF1 expression was also shown to be induced by 1-naphthaleneacetic acid. These results suggest that both auxin transport and auxin responses are impaired in laf1 mutants, and that LAF1 is involved in the regulation of leaf and root development mediated by auxin signaling under short day conditions.

An efficient regeneration protocol via somatic embryogenesis was optimized for mung bean [Vigna radiata (L.) Wilczek; cv. Vamban 1]. Primary leaf explants were used for embryogenic callus induction in MMS medium (Murashige and Skoog salts with B5 vitamins) containing 2.0 mg dm^-3 2,4-dichlorophenoxyacetic acid (2,4-D), 150 mg dm^-3 glutamine and 3 % sucrose. Fast growing, highly embryogenic cell suspensions were established from 21-d-old calli in MMS medium supplemented with 0.5 mg dm^-3 2,4-D and 50 mg dm^-3 proline (Pro), and maximum recovery of globular (39.0 %), heart-shaped (26.3 %) and torpedo-stage (21.0 %) somatic embryos were observed in this medium. Mature cotyledonary-stage somatic embryos were cultured for 5 d in half strength B5 liquid medium containing 0.05 mg dm^-3 2,4-D, 20 mg dm^-3 Pro, 5 μM abscisic acid, 1000 mg dm^-3 KNO₃, 50 mg dm^-3 polyethylene glycol (PEG 6000) and 30 g dm^-3 D-mannitol. Mature somatic embryos were germinated after dessication for 3 d and complete development of plantlets accomplished in MMS medium containing 30 g dm^-3 maltose, 0.5 mg dm^-3 benzyladenine and 500 mg dm^-3 KNO₃. Profuse lateral roots, and regeneration frequency (up to 60 %) were observed in half-strength MMS medium containing 0.5 mg dm^-3 indolebutyric acid (IBA). The regenerated plants were grown to fruiting and were morphologically normal and fertile.

The aim of this study was to assess the effect of aluminum on the in vitro activity of acid phosphatases (APases) of four potato clones, Macaca and Dakota Rose (Al-sensitive), and SMIC148-A and Solanum microdontum (Al-tolerant), grown in vitro, in hydroponics or in a greenhouse. The enzyme was assayed in vitro in the presence of 0, 1.85, 3.70, 5.55 and 7.40 mM Al. In plantlets grown in vitro, root APases were inhibited by Al in all clones, while shoot APases were inhibited by Al in S. microdontum and Dakota Rose and increased in Macaca at all Al concentrations. In plantlets grown in hydroponics, root APases increased in Macaca at 1.85 mM Al, whereas decreased at all Al levels in S. microdontum. In greenhouse plantlets, root APases decreased at 7.40 mM Al in S. microdontum and SMIC148-A, and at 3.70, 5.55 and 7.40 mM Al in Dakota Rose. Shoot APases decreased in Macaca and SMIC148-A. Conversely, in Dakota Rose, APases increased at 1.85 and 3.70 mM Al. These results show that the effect of Al toxicity on in vitro APase activity depends not only on Al availability but also on the plant organ, genetic background, and the growth conditions. Therefore, it suggests that acid phosphatases activity assessed in vitro might not be a good parameter to validate the screening for adaptation of potato clones to Al toxicity.

Embryogenic and non-embryogenic calli were induced from the Centella asiatica leaf explants on Murashige and Skoog medium supplemented with kinetin and 2,4-dichlorophenophenoxyacetic acid. The extracellular matrix (ECM) layer was seen on the surface of embryogenic cells but not on the non-embryogenic cells. The ECM formed bridges with net-like material between the embryogenic cells. This network like structure was believed to play an important role in plant morphogenesis and can serve as an early structural marker of embryogenic competence in Centella asiatica calli culture.

Telomere-binding proteins have recently been recognised not only as necessary building blocks of telomere structure, but namely as components which are of central importance to telomere metabolism being involved in regulation of telomere length as well as in protective (capping) function of telomeres. Although the knowledge on plant telomeric DNA-binding proteins lags behind that in human and yeast, recent data show both analogies and plant-specific features in the composition and interactions of telomeric proteins. This review focuses primarily on proteins with known amino acid sequence. These can be classified into following groups: 1) the family of proteins with Myb domain at C-terminus, 2) proteins with Myb domain at N-terminus, both binding double-stranded DNA of telomeric repeats TTTAGGG, 3) the single-stranded DNA-binding proteins, and 4) other proteins that act also in non-telomeric chromatin regions. Proteins with C-terminal Myb domain reported as IBP family were previously found in human, whereas Smh family representing proteins with Myb domain at N-terminus was identified only in plants. Also RRM family of the single-stranded DNA-binding proteins is likely to be plant specific.

The removal of Mg²⁺ is an important step in the chlorophyll degradation pathway and extracts from senescent and presenescent Arabidopsis thaliana leaves were analyzed for Mg-dechelatase activity, using chlorophyllin, an artificial derivative of the natural substrate, chlorophyllide. The optimum temperature and pH for this reaction were determined to be at approximately 50 °C and 7.2, respectively. Mg-dechelatase activity was enhanced by addition of EDTA and inhibited by MgCl₂, HgCl₂ and reduced glutathione, indicating phenomenons such as retroinhibition by reaction products and dependence on the redox state of the mixture. Size exclusion chromatography was performed on Arabidopsis leaf extracts, and Mg-dechelatase activity was found in the fraction corresponding to molecular mass of about 42 kDa, which indicates that the Mg-dechelating compound in Arabidopsis is considerably larger than in other systems. During dark-induced senescence, the activity increased over time until reaching a maximum at day 4, and then decreased. The addition of plant growth regulators indicated that the accumulation of Mg-dechelatase was activated by ethylene and delayed by 6-benzylaminopurine.

Leaves from 14-d-old Capsicum annuum L. cv. Anaheim seedlings were cultured on Murashige and Skoog (MS) medium containing different combinations of indole-3-acetic acid (IAA) and 6-benzyladenine (BA). After 3 months, cultures were transferred to new medium where BA was replaced with 9 μM isopentenyladenine (2iP) to enhance the growth of shoot buds. Developing shoots were elongated and rooted on MS medium enriched with 9 μM indole-3-butyric acid (IBA). All cultures were maintained in 250 cm³ baby jars covered with a clear polypropylene lid with or without microporous polypropylene membrane. Vessel type and plant growth regulators significantly affected callus morphogenic appearance, organogenesis and in vitro plantlet growth. Ventilated vessels supported photomixotrophic culture and improved regeneration and growth of plantlets. Higher plantlet dry mass and content of photosynthetic pigments, and lower stomatal density of plantlets grown in ventilated than in non-ventilated vessels facilitated ex vitro acclimation and growth.

Cucumis sativus L. seedlings were pretreated 1 h with 10 μM paraquat (PQ) and then were subjected to normal (25/18 °C) or elevated (42/38 °C) temperature to investigate whether PQ can protect plants against heat stress. Heat stress inhibited fresh and dry masses of the second leaf, root dry mass and shoot fresh mass. In leaves, the stress disintegrated membranes of 84.97 % chloroplasts and elevated contents of malondialdehyde, superoxide radical and hydrogen peroxide. In contrast, PQ pretreatment altered antioxidant activities in leaves, even after PQ was rinsed off before seedlings were exposed to different temperatures. Under heat stress, PQ pretreatment improved plant growth, decreased percentage of abnormal chloroplasts (53.03 %) and reduced contents of malonaldehyde, superoxide radical and hydrogen peroxide due to increased activities of antioxidant enzymes such as superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase.

The response of Arabidopsis thaliana plants to elevated sulfur dioxide could be related to their endogenous salicylic acid (SA) content and signaling. The wild type (WT, ecotype Columbia) and its mutant snc1 with high SA content, npr1-1 with a blockage in SA signaling, transgenic line nahG with low SA content and double mutant snc1nahG plants were exposed to 0.5 mm³ dm^-3 SO₂ for 3 h d^-1 for 14 d in a growth chamber. Under unstressed conditions, total SA contents in snc1 and npr1-1 were 7- and 2-fold higher than those in WT, respectively, but in nahG SA content was only 28 % of that in WT. The expression of nahG in snc1 plants decreased SA content to the WT level. Increased SA contents were observed in snc1, npr1-1 and WT after 12-h SO₂ exposure, whereas no major changes were detected in nahG and snc1nahG plants. The snc1 plants exhibited higher tolerance to SO₂ exposure than snc1nahG plants and especially nahG and npr1-1 plants according to plant biomass, total chlorophyll content and photosynthetic rate. The SO₂ exposure decreased net photosynthetic rate, maximum photochemical efficiency (F_v/F_m) and actual quantum efficiency of photosystem 2 (Φ_PS2). SO₂-induced oxidative damage in the tested plants was confirmed by increased malondialdehyde (MDA) content and electrolyte leakage. Increases in superoxide dismutase (SOD) and peroxidase (POD) activity, reduced glutathione (GSH) content and a ratio of reduced/oxidized glutathione (GSSG) might be responsible for the decreased contents of H₂O₂ and alleviation of oxidative injury in snc1 plants compared with other lines exposed to SO₂. These observations implied that endogenous SA content and signaling may play an essential role in plant responses to SO₂ stress.

We study apical dominance in Alstroemeria, a plant with an architecture very different from the model species used in research on apical dominance. The standard explant was a rhizome with a tip and two vertically growing shoots from which the larger part had been excised leaving ca. 1 cm stem. The axillary buds that resumed growth were located at this 1-cm stem just above the rhizome. They were released by removal of the rhizome tip and the shoot tips. Replacement of excised tips by lanolin with indole-3-butyric acid (IBA) restored apical dominance. The auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and N-1-napthylphthalamic acid (NPA) reduced apical dominance. 6-Benzylaminopurine (BAP) enhanced axillary bud outgrowth but the highest concentrations (> 9 μM) caused fasciation. Thidiazuron (TDZ) did not show improvement relative to BAP. Even though the architecture of Alstroemeria and the model species are very different, their hormonal mechanisms in apical dominance are for the greater part very similar.

The effects of NaCl on the H₂O₂ content and the activities of catalase (CAT) and superoxide dismutase (SOD) were studied in diverse group of plants, such as a unicellular alga, Chlorella sp., an aquatic macrophyte, Najas graminea, and a mangrove plant, Suaeda maritima, all showing high tolerance to NaCl. Significant accumulation of H₂O₂ was observed in all the tested plants upon their exposure to 255 mM NaCl. The activity of both CAT and SOD increased significantly in response to the NaCl treatment. Growing the plants in presence of 255 mM NaCl also resulted in the synthesis of new isoforms of both CAT and SOD.

To gain a comprehensive understanding of plant response to Cd, physiological and proteomic changes in wheat (Triticum aestivum L.) leaves exposed to a range of Cd concentrations (10, 100 and 200 μM) were investigated. Leaf elongation was decreased, whereas the H₂O₂ and malondialdehyde content increased significantly at higher Cd concentrations. Changes in protein profiles were analyzed by two-dimensional electrophoresis. Twenty-one proteins which showed 1.5-fold change in protein abundance in response to Cd were identified. These proteins can be functionally grouped into three groups: 1) oxidative stress response, 2) photosynthesis and sugar metabolism and 3) protein metabolism and others. These results provide a new insight into our understanding of the molecular basis of heavy metal response in plants.

Metallothioneins are involved in detoxification of heavy metals. A cDNA encoding type 3 metallothionein (PcMT3) was isolated from the salt stressed leaf cDNA library of Porteresia coarctata (Roxb.) Tateoka (wild rice) that grows well in the heavy metal laden estuarine soils. The PcMT3 cDNA (581 bp) encodes a protein of 64 amino acids. PcMT3 is highly homologous (82 %) to OsMT-I-3a of rice, but is unique from other type 3 plant MTs due to the presence of an additional glycine residue in the C-terminal domain. Analysis of the 5' upstream region of PcMT3 showed the presence of cis-acting elements like the CG box and STRE previously reported to be involved in gene expression under heavy metal stress. Southern analysis suggested the presence of more than one copy of PcMT3-like sequences in the P. coarctata genome. Analysis of genomic clone of PcMT3 revealed the presence of two introns. A comparison of the genomic sequence of PcMT3 with closely similar type 3 MTs from rice and mangrove species revealed conservation in the number and position of introns. Transcript profiling for PcMT3 in P. coarctata leaves in the presence of Cd, Cu and Zn showed an increase in transcript accumulation.

The growth and ion content of salt sensitive Lycopersicon esculentum Mill. cv. M82 and salt tolerant L. pennellii Correll accession LA716 were examined under both control and stress conditions (150 mM NaCl). L. esculentum grew more vigorously than L. pennellii under optimal conditions, however, L. pennellii was able to maintain its growth better than cultivated tomato when the plants were exposed to salinity. Sodium content of both L. esculentum and L. pennellii increased as a result of NaCl stress. In addition, both species showed reduced potassium and calcium content due to salinity. The physiological traits were also measured in a population of 52 L. pennellii introgression lines grown under both normal and stress conditions. A total of 311 quantitative trait loci (QTL) were identified for the studied traits: plant height, stem diameter, leaf number, leaf and root fresh and dry mass, and sodium, potassium and calcium contents. Some of the loci (124) were identified under both control and stress conditions while 86 QTL were identified only under non-stress conditions and 101 loci were identified only under NaCl stress.

In this study we identified and characterized a major latex lectin - designated as EtLLH - with antimicrobial activity from the succulent African milk tree Euphorbia trigona. The lectin is highly concentrated in the latex of E. trigona and appears to be composed of at least two subunits with a molecular mass of 32 kDa. EtLLH shares significant similarities to known plant lectins - ricin from Ricinus communis and agglutinin from Viscum album coloratum - which specifically bind D-galactose and N-acetyl-D-glucosamine, the major building blocks of many fungal cell walls. Antimicrobial activity assays revealed an impact of EtLLH on three phytopathogenic filamentous ascomycetes. The germination of the conidiospores and the hyphal growth of Aspergillus niger and Fusarium graminearum were severely inhibited by EtLLH already at concentrations below 0.1 mg cm^-3, while the effect on germination of the melanized conidiospores of Botrytis cinerea was less significant.