Search

Prosopis strombulifera (Lam.) Benth. is a halophytic shrub found in highly saline soils in Argentina, with high tolerance against NaCl but strong growth inhibition by Na2SO4. In the present study, the differences in the physiological responses caused by these salts and an iso-osmotic combination thereof on photosynthesis, mineral composition and metabolism were analyzed. Na2SO4 treated plants were the most affected by salinity, showing a significant decrease in several photosynthetic parameters. Proline and cysteine accumulated significantly in the plants in response to salt stress. These results show by the first time that the SO42− anion is triggering damage in the photosynthetic apparatus and consequently affecting the photosynthetic process, which may explain the strong growth inhibition in these plants at high salinity. Moreover, the SO42− anion provoke challenges in the incorporation of nutrients, decreasing the levels of K, Ca, P and Mg, and inducing a strong antioxidant activity in P. strombulifera. Fil: Reginato, Mariana Andrea. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Botánica. Laboratorio de Fisiología Vegetal; Argentina Fil: Turcios, Ariel E.. Leibniz Universitat Hannover; Alemania Fil: Luna, Maria Virginia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Botánica. Laboratorio de Fisiología Vegetal; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; Argentina Fil: Papenbrock, Jutta. Leibniz Universitat Hannover; Alemania

Knowledge about Solanaceae species naturally adapted to salinity is scarce, despite the fact that a considerable number of Solanaceae has been reported growing in saline environments. Lycium humile Phil. inhabits extreme saline soils in the Altiplano-Puna region (Central Andes, South America) and represents a promising experimental model to study salt tolerance in Solanaceae plants. Seeds, leaves and roots were collected from a saline environment (Salar del Diablo, Argentina). Seeds were scarified and 30 days after germination salt treatments were applied by adding NaCl salt pulses (up to 750 or 1000 mM). Different growth parameters were evaluated, and leaf spectral reflectance, endogenous phytohormone levels, antioxidant capacity, proline and elemental content, and morpho-anatomical characteristics in L. humile under salinity were analyzed both in controlled and natural conditions. The multiple salt tolerance mechanisms found in this species are mainly the accumulation of the phytohormone abscisic acid, the increase of the antioxidant capacity and proline content, together with the development of a large leaf water-storage parenchyma that allows Na+ accumulation and an efficient osmotic adjustment. Lycium humile is probably one of the most salt-tolerant Solanaceae species in the world, and, in controlled conditions, can effectively grow at high NaCl concentrations (at least, up to 750 mM NaCl) but also, in the absence of salts in the medium. Therefore, we propose that natural distribution of L. humile is more related to water availability, as a limiting factor of growth in Altiplano-Puna saline habitats, than to high salt concentrations in the soils.

Mangroves are able to withstand a number of stress factors, such as high salt concentrations, tidal flooding, strong wind, solar radiation and heat. Their ability to grow under these circumstances is based on morphological and physiological adaptations, among them the high abundance of plant secondary metabolites. We are interested to investigate and exploit their medicinal and biotechnological potential for new bioactive compounds, without collecting material in the countries of origin and in a sustainable way. Therefore, a simple identification system based on molecular marker analysis, and a sustainable greenhouse propagation protocol for the continuous supply of fresh plant material, were established. DNA barcoding of the internal transcribed spacer (ITS) including ITS1, the 5.8S rRNA region and ITS2 as a molecular marker was applied for several mangrove species. The obtained data and GenBank sequences were used for species identification. Three mangrove species are cultivated in our greenhouse and propagated in different ways: Avicennia species produced many propagules in the greenhouse, however, further propagation by cuttings was not successful. Laguncularia racemosa was propagated by cuttings in a fog house whereas Bruguiera cylindrica was difficult to cultivate and propagation was not successful. Finally, the concentration of secondary phenolic compounds, including flavonoids, and the content of major elements were compared among naturally and greenhouse-grown mangroves indicating comparable amounts and composition.

Plant scientists usually record several indicators in their abiotic factor experiments. The common statistical management involves univariate analyses. Such analyses generally create a split picture of the effects of experimental treatments since each indicator is addressed independently. The Euclidean distance combined with the information of the control treatment could have potential as an integrating indicator. The Euclidean distance has demonstrated its usefulness in many scientific fields but, as far as we know, it has not yet been employed for plant experimental analyses. To exemplify the use of the Euclidean distance in this field, we performed an experiment focused on the effects of mannitol on sugarcane micropropagation in temporary immersion bioreactors. Five mannitol concentrations were compared: 0, 50, 100, 150 and 200 mM. As dependent variables we recorded shoot multiplication rate, fresh weight, and levels of aldehydes, chlorophylls, carotenoids and phenolics. The statistical protocol which we then carried out integrated all dependent variables to easily identify the mannitol concentration that produced the most remarkable integral effect. Results provided by the Euclidean distance demonstrate a gradually increasing distance from the control in function of increasing mannitol concentrations. 200 mM mannitol caused the most significant alteration of sugarcane biochemistry and physiology under the experimental conditions described here. This treatment showed the longest statistically significant Euclidean distance to the control treatment (2.38). In contrast, 50 and 100 mM mannitol showed the lowest Euclidean distances (0.61 and 0.84, respectively) and thus poor integrated effects of mannitol. The analysis shown here indicates that the use of the Euclidean distance can contribute to establishing a more integrated evaluation of the contrasting mannitol treatments.

Water deficit negatively affects crop development and productivity. With decreasing rainfall and shortage of arable land, there is a demand for alternative drought-tolerant species for use on non-arable land. The tree species Balanites aegyptiaca is considered as drought tolerant and a potential source of many secondary metabolites. The oil-containing seeds may also be used as biofuel. Genetic diversity was investigated amongst the B. aegyptiaca collected from different geographical regions using amplified fragment length polymorphism (AFLP) and the relationship among geographical distribution and genetic diversity was determined. Plants were grown from seedlings collected at 12 locations from 11 provenances. AFLP produced 510 bands of which 477 (93.5%) were polymorphic. Cluster and principal component analyses indicated that individual samples of B. aegyptiaca were distributed in 3 main clades and that the provenance El-Kharga represented a single clade. Several key morpho-physiological responses to water stress were examined to evaluate drought stress tolerance and to compare respective stress responses among different provenances under greenhouse conditions. Severe drought stress decreased biomass parameters in all genotypes. However, B. aegyptiaca provenances also differed in their adaptive responses to water shortage. By appropriate grouping of 2 or 3 response factors, the effects of water deficit on the various provenances could readily be distinguished. Provenance El-Kharga showed the smallest amount of biomass reduction under severe drought stress and retained the highest leaf water content. Key words: Amplified fragment length polymorphism (AFLP), Balanites aegyptiaca, biometrical growth parameters, drought tolerance, stomatal conductance.

The tropical seagrass Enhalus acoroides is considered as a potential bioindicator for heavy metals. To date, studies on the accumulation of heavy metals in each specific seagrass organ have been limited. In this study, surface sediment and E. acoroides samples collected at six distinct beds from the coast of Khanh Hoa province, Vietnam, were evaluated for their heavy metal concentrations (Cd, Cu, Pb and Zn) to determine which organs of E. acoroides could be used as bioindicators for heavy metals. The metal concentrations in both the sediment and the seagrass organs were measured using inductively coupled plasma mass spectrometry (ICP-MS). Bio-concentration factor ( BCF ) and Metal pollution index ( MPI ) were determined on the seagrass organs, and Pearson's correlation and ANOVA were used for statistical analysis. The results showed that the highest BCF values of Cd and Zn were found in leaves, the highest BCF value of Cu was found in the rhizomes and the highest BCF value of Pb was found in the roots. Generally, MPI was lower in the sediment than in seagrass organs at the same locations. For Cd, Pearson's correlation showed that a significant positive correlation was only observed between sediment and leaves with respect to BCF . A significant positive correlation of BCF for Cu was observed between sediment and rhizome while significant positive correlations of BCF for Cu, Pb and Zn were observed between sediment and roots. Based on the results, it can be concluded that E. acoroides leaves should be used as a bioindicator for Cd and Zn, rhizomes for Cu, and roots for the three metals Cu, Pb and Zn.

Seagrasses beds are vulnerable ecosystems. Human-induced disturbances, including heavy metal pollution, cause losses in seagrass beds. Assessment of the heavy metal concentration in seagrass meadows is an urgent need in order to protect and sustain these ecosystems. The concentration of eight trace metals in the surface sediment was observed from six seagrass beds at Khanh Hoa's coast, Vietnam. Three pollution indices and statistical analysis were used to evaluate the levels of contamination with these elements. This report on heavy metals within seagrass beds in Vietnam shows that, based on enrichment factors, only one location revealed moderately severe enrichment of Cu. Geo-accumulation indices fall in the uncontaminated class at all locations whereas for the ecological risk factor, values of Cu at My Giang and of Pb at Thuy Trieu were in a moderate risk class. Hence, two of eight locations may be exposed to high Cu and Pb.

Adapting biological processes to an endogenous rhythm enables plants to cope with the daily changes in light and temperature in a more predictable way enhancing growth and fitness. A number of biological processes such as metabolic pathways as well as the immunity in plants are under diurnal or circadian control. In this study a possible circadian regulation of key enzymes in the sulfur assimilation and the corresponding metabolites was investigated in the agriculturally important crop plant oilseed rape (Brassica napus). Leaves of a commercially available cultivar were harvested in the course of a day under diurnal and under free-running conditions with constant light. Analyses in this study were focused on sulfur-containing metabolites and expression analysis of enzymes involved in sulfur assimilation. Expression analysis showed that the transcript levels of the sulfate transporters Sultr3;1 and Sultr4;2 as well as APR2 and APR3 oscillated diurnally. Results revealed a periodic rhythm of sulfur-containing metabolites such as glutathione, sulfate and certain glucosinolates in the course of a day which were only partly maintained under constant light. Therefore, we conclude that a diurnal rhythm and not the circadian clock regulates sulfur metabolism in plants.

The biodegradation of the antibiotic sulfamethazine (SMT) by using different crude extracts of halophytes was investigated. For this purpose, crude water extracts of the halophytes Chenopod...

Along with coral reefs and mangroves, seagrass meadows are being threatened globally Southeast Asia is considered within the area of seagrasses’ cradle of diversity. However, information on the current status of seagrass beds from Southern Viet Nam is limited due to lack of reliable data about seagrass species occurring in the Southeast Asian region. One factor is the difficulty of unambiguous species identification. For example, the leaf morphological characteristics of Halophila ovalis and closely related species are overlapping which leads to misidentifications. In this study, the latest satellite Landsat 8 OLI and SENTINEL-2B image analyses were applied to determine the distribution of seagrass beds in Southern Viet Nam. Detailed morphological and genetic marker analyses were used to determine and update the species composition. The present study together with literature reviews indicate that the total area of seagrass beds from Southern Viet Nam are 10,832.1 ha. 2562 ha (or 19.1%) of seagrass coverage has been lost. The seagrass beds at Phu Quoc Island are the largest with 7579 ha. The occurrence of Halophila major is updated for almost all off-shore islands and open-water areas.

Taxonomic challenges of seagrasses were met by using 18S ribosomal subunit of ribosomal deoxyribonucleic acid (18S rDNA) sequence data of 14 seagrass species from India and two temperate species from Germany. The phylogenetic trees presented are based on the 18S rDNA sequence analysis of 41 nucleotide sequences including sequences obtained in the present study as well as previously published sequences of freshwater and saltmarsh plants, and seagrasses for identifying the evolutionary lineage. The 18S rDNA data indicates independent origin of temperate and tropical seagrasses with the genus Halophila as the intermediate group for both the regions. Based on the complex morphological structures the Halophila group represents the basal form among seagrasses whereas Enhalus is considered to be the most recently originated seagrass species. In that context, the marine Hydrocharitaceae group of Enhalus, Thalassia and Halophila has been proposed to be separated into two groups such as Enhalus/Thalassia and Halophila subfamilies. Hence, the present systematic studies warrant a revised taxonomy for seagrasses, which better reflects the phylogenetic results obtained from molecular and conventional data.

The halophyte species Sea Aster (Tripolium pannonicum) was grown with different concentrations of artificial seawater. In a second experiment, T. pannonicum was cultivated with a nutrient solution containing different concentrations of NaCl. This halophyte biomass was used to determine the biogas production potential. According to the findings, it is possible to produce high yields of methane using biomass from halophytes cultivated in the presence of salt. Biogas and methane yield are influenced by the salt content of the plant tissue, however, high concentrations of salt in the anaerobic reactors itself inhibit the biogas and methane production. The highest methane yield is obtained using plant substrates grown at 22.5 g L−1 sea-salt with a value of 313 cm3 g−1 of VS. When treating T. pannonicum with different concentrations of NaCl, biogas and methane yields are highest when using plant substrates grown at 30 g L−1 to produce values of 554 cm3 g−1 of VS and 447 cm3 g−1 of VS, respectively. Other research was carried out to study the effect of sodium on the biogas and methane yields using substrate from T. pannonicum cultured under non-saline conditions and adding different amounts of NaCl to the anaerobic reactors. Adding NaCl to the reactors decreases the biogas and methane production but using a salt-adapted inoculum increases the biogas yield in comparison to the non-adapted inoculum.

Salt marsh ecosystems are extremely impacted by human activities whilst also acting as sinks of contaminants such as heavy metals. Halophytic plant species can survive and thrive in estuarine and coastal areas with higher salt conditions that are generally not favourable to most plants. Halophyte distribution and abundance clearly relate to anthropogenic pressure levels and thus the impact of heavy metals needs to be rapidly assessed and monitored in a fast-developing world. To assess and manage this impact the search for suitable and efficient biomarkers is of great importance, aiming to produce a clear picture of environmental quality. The present work aimed to evaluate the application of optical tools, like non-invasive chlorophyll a pulse amplitude modulated (PAM) fluorometry, in four halophytic species (Halimione portulacoides, Sarcocornia fruticosa, Spartina maritima and Spartina patens), from three salt marshes of the Tagus estuary with different degrees of contamination, to investigate biomarkers for inclusion in a Multivariate Photochemical Pressure Index (Multi-PPI) destined for ecological quality assessment. The application of this index allowed to distinguish between less (Alcochete) and more (Rosario and Seixal) heavy metal contaminated salt marshes. This was observed particularly for S. maritima, in which Multi-PPI was lower for the higher contaminated sites, albeit this pattern was similarly observed in S. patens and S. fruticosa. On the other hand, the Multi-PPI index for H. portulacoides, a phytoextractor species, increased with the contamination gradient along the three salt marshes, and therefore this strategy should be considered when applying this index. Therefore, since these species are well represented in the Mediterranean, the use of optical tools to generate an easy fast index will have a great impact on the future of transitional ecosystem pollution impact assessments as well as in ecotoxicology research.

Balanites aegyptiaca (Balanitaceae) is a drought-tolerant but salt-sensitive tree species distributed in the tropical and arid lands in Africa and Asia. The tree contains many secondary metabolites and a high percentage of oil in the kernels that can be used for biodiesel production. This study aimed to establish an in vitro propagation system of two B. aegyptiaca provenances (El-Kharga and Wadi El-Alaqi) from nodal and cotyledon explants. The explants were placed on Murashige and Skoog medium supplemented with different concentrations of 6-benzyladenine (BA) and thidiazuron (TDZ) for shoot induction. BA was significantly more effective in shoot induction from nodal explants and treatment with BA also resulted in higher regeneration rates of about 40–60 % of adventitious shoots on cotyledon explants, whereas on TDZ-containing medium slightly higher shoot numbers per explant but a negative effect on shoot length were recorded. Rooting was achieved in 40–60 % of the shoots on medium containing between 1.2 and 4.8 µM indole-3-butyric acid. Three different Agrobacterium tumefaciens strains (EHA105, GV3101, and LBA4404) harboring the plasmid pCAMBIA2301 containing the nptII marker and gus reporter genes were used to establish a transformation system in B. aegyptiaca. Strain GV3101 resulted in the highest survival rates and highest number of explants positive in the GUS assay. This selected A. tumefaciens strain was used to introduce pBinAR containing the sequence encoding ERD10 (early responsive to dehydration 10) to produce salt-tolerant B. aegyptiaca plants. The presence of the ERD10 and the nptII gene were detected by PCR in transformed B. aegyptiaca plants.

Genetic modifications of pineapple provide the potential to increase fungal resistance without the use of pesticides. Previously, we developed a procedure for pineapple callus transformation, introducing the antifungal chitinase and AP24 genes, and the herbicide-tolerance conferring bar gene as a selectable marker. The three recombinant genes were under the control of the constitutively expressing promoters OCS-35S CaMV-rice actin I, 35S CaMV, and maize Ubi1, respectively. The objective of this study was to analyze whether these genetic modifications caused unintentional side effects on growth-related properties under field conditions. We analyzed the third vegetative generation of a transgenic pineapple clone, approximately 7 years after the genetic modification occurred. Plant height and diameter, chlorophyll and phenolic contents, fruit mass and D leaf (middle-age) mass, water content, succulence, sap pH, transpiration, CO2 assimilation, and water use efficiency were recorded and compared to a micro-propagated cultivar. A macro-propagated variant was also cultivated at the field site in order to distinguish unintended effects of the propagation method from that of the genetic modification. While all parameters analyzed in this study were highly similar to each other for the three cultivars, statistically analyses revealed significant deviations of the genetically modified variant for the succulence index being higher at in the morning and evening, carbon dioxide assimilation being lower at noon and, at night, the water use efficiency was lower. The minor deviations were all within the range which can be expected between common cultivars grown together.

The effects of opening the Suez Canal as a connection between the Red Sea and the Mediterranean Sea were reported for a number of marine species. However, the evolutionary origin of the seagrasses in the Red Sea and the linking population genetics of seagrasses between the Arabian Sea, the Gulf of Aden, the Red Sea and the Mediterranean Sea have not yet been investigated in detail. The invasion of Halophila stipulacea Asch. from the Red Sea into the Mediterranean Sea after the opening of the Suez Canal was already recorded. We hypothesize that Halophila ovalis populations in the Red Sea developed through long-term historical processes such as vicariant evolutionary diversification. Seagrass samples were collected along the Egyptian coastline of the Red Sea and analysed by the molecular marker ITS. The sequences were compared with published ITS sequences from seagrasses collected in the whole area of interest. In this study, we reveal the linking population genetics, phylogeography and phylogenetics of two dominant seagrass species, Halophila stipulacea and Halophila ovalis, among species collected in the Red Sea and worldwide. The results indicate that the Red Sea Halophila ovalis populations do not group to Halophila ovalis worldwide, and Halophila major, Halophila ovalis collected worldwide and Halophila ovalis collected at the Red Sea are sister clades. Hence, vicariant evolutionary diversification for Halophila ovalis may occur in the Red Sea.

Euphorbia tirucalli, a member of Euphorbiaceae, is a drought and salt-tolerant species. It is distributed in subtropical and semi-arid parts of Africa and was brought to Asia and North America. The plant has succulent stems performing CAM metabolism and small non-succulent leaves performing C3 metabolism. Different genotypes of E. tirucalli showed different tolerance to drought stress, especially Morocco and Senegal genotypes. This difference has tempted us to investigate the difference in antioxidant stress mechanisms in stems as compared to leaves. Plants from both genotypes have been subjected to drought (10% Volumetric Water Content, VWC) for 8 weeks and the leaves and stems were investigated for their reactive oxygen species (ROS) and antioxidants levels. Shoots of Morocco genotype retained water more efficiently under drought compared to Senegal shoots. Although H2O2 accumulated in stems under drought compared to leaves, however, the stems have elevated levels of various non-enzymatic and enzymatic antioxidants. Stems of Morocco increased their levels of H2O2 more under drought compared to Senegal stems, and Morocco stems showed a higher increase in their non-enzymatic and enzymatic antioxidants under drought. Morocco stems are distinguished by increased ascorbate peroxidase (APX) and peroxidase (POX) activities, while in Senegal stems catalase (CAT) activity specifically increased under drought. Levels of H2O2 in leaves were higher as compared to stems even under control conditions; however, leaves did not show increased antioxidant enzymes levels under drought stress. This tendency to accumulate H2O2 could be used by E. tirucalli as strategy to kill and get rid of leaves under drought to reduce transpirational water loss. These differences in antioxidant systems of Morocco and Senegal genotypes could, at least partly, explain their differences in drought tolerance and may reflect evolutionary adaptations to different local native climates.

C2 photosynthesis operates by shuttling photorespiratory glycine (C2) from mesophyll (M) to bundle sheath (BS) cells, followed by decarboxylation and release of CO2 around RubisCO. C2 plants are characterized by low apparent photorespiration and enhanced refixation of photorespiratory CO2 and the C2 pathway is thought to represent an intermediate step for the evolution from C3 to C4 photosynthesis. Restriction of glycine decarboxylation to the BS cells is considered to be a prerequisite for C2 photosynthesis. In the C3 plant species Arabidopsis thaliana, a cis-element required for expression of the P-subunit of glycine decarboxylase (GDC—P) in M cells (termed the M-box) was previously identified in the promoter of A. thaliana glycine decarboxylase P-subunit 1 (AtGldp1). Consequently, the loss of this element restricted Gldp1 expression to the BS cells. To investigate conservation, Gldp promoter sequences from another C3 and two additional C2 Moricandia species were isolated by genome walking. In comparison to AtGldp1, the M-box was conserved in the promoter of C3 Moricandia moricandioides, but was not found in the promoters of M. nitens, M. suffruticosa, and M. arvensis, indicating the loss of the M-box from several C2 Moricandia species. The AtGldp1 M-box was further analyzed in detail using promoter::GUS fusions. Results show that interaction between two promoter regions containing predicted CAAT and GATA elements are required for expression of the GUS reporter in M cells and these elements including their spacing are conserved in the promoters of different members of the Brassicaceae.

In the search of new compounds with biofilm-inhibiting properties, mangroves with their richness of secondary metabolites can be a valuable resource. Crude methanolic leaf extracts from the mangrove Laguncularia racemosa enriched in phenolic substances cause a reduction in initial cell adhesion of Candida glabrata and Candida albicans, but not on Escherichia coli. LC/MS-guided fractionation of the phenolic compounds resulted in 19 fractions, of which ten were analyzed for their bioactivity against cell adhesion. Effects on cell adhesion and planktonic growth of Escherichia coli, Candida glabrata and Candida albicans were measured in 96-well microtiter plates in the presence of 0.2 mg ml-1 of the isolated fractions. Two fractions caused a reduction of cell adhesion of Candida albicans. These fractions containing bioactive compounds were analyzed by LC/MS and NMR spectroscopy. Casuarinin and digalloyl-hexahydroxydiphenoyl-glucose were identified in the active fractions, in addition to three signals of ellagitannins. These results indicate a specific mode of action of hydrolysable tannins against cell adhesion of Candida albicans, which needs to be further analyzed.

The influence of salinity on the biosynthesis of secondary metabolites with a focus on single glucosinolates (GSLs) was investigated in Lepidium latifolium L., which is a plant species rich in antioxidants. Mature plants were subjected to 0, 15, 22.5, and 35 Practical Salinity Units (PSU) for 1–4 weeks. While phenols, flavonoids, and the oxygen radical absorbance capacity (ORAC) increased with increasing salinity, the ascorbate concentration did not follow a specific pattern. The concentration of single GSLs was influenced by salinity in different ways: While the concentration of aliphatic GSLs like glucoiberin and sinigrin increased, the concentration of aromatic GSLs such as glucobrassicin decreased under salinity stress. Salinity increased the total GSL concentration significantly with sinigrin being the major contributing GSL. The exact molecular role of the different GSLs in abiotic stress defense needs further analysis.

Phytochelatins (PCs), the heavy metal-binding peptides of plants, play a main function in heavy metal detoxification. In this study, Enhalus acoroides samples collected at six distinct seagrass beds from the coast of Khanh Hoa province, Viet Nam, were evaluated for their PCs. The contents of different PCs in each organ including leaf, rhizome, and root were determined by using HPLC analysis. Significant differences of PC2 contents among specific organs and their relation were tested by ANOVA, Tukey test, and Pearson's correlation. The results showed that higher PC2, appearance of PC3 and a strong correlation between PC2 and Pb concentration were found in the root organ collected from a Pb contaminated area. We conclude that high Pb in the sediment induce high PC2 and PC3 production in the root. This first report on in situ detection of PCs of seagrass encourages future investigation on the ability to use seagrass for phytoremediation and as a bioindicator of heavy metals based on PC contents.

This project analyses the uptake and biodegradation of the antimicrobial sulfadimidine (SDI) from the culture medium and up to the anaerobic digestion. Tripolium pannonicum was grown under hydroponic conditions with different concentrations of SDI (0, 5 and 10mg·L(-1)) and the fresh biomass, containing different amounts of SDI taken up, was used as substrate for biogas production. SDI was analyzed by liquid chromatography coupled to positive ion electrospray mass spectrometry (ESI LC-MS). Based on the findings, T. pannonicum is able to uptake SDI. The more SDI is in the culture medium, the higher the SDI content in the plant tissue. According to this study, it is possible to produce high yields of biogas using biomass of T. pannonicum containing SDI and at the same time biodegradation of SDI is carried out. The highest specific biogas yield is obtained using shoots as substrate of the plants cultivated at 5mg·L(-1) SDI.

Complex processes on all levels, transcripts, proteins, and metabolites, are involved in drought stress tolerance, but in a different way from species to species. Recent evidences lead to the assumption that sulfur not only acts like other macronutrients, such as nitrate and phosphate, but that an increasing demand for sulfate during metabolic adaptation reactions to drought stress reflects specific roles of sulfur-containing compounds. The biosynthesis of osmolytes and osmoprotectants, such as choline-O-sulfate and polyamines, is increased, the levels of the main antioxidant, the tripeptide glutathione, and its precursor cysteine are elevated, and 3′-phosphoadenosine 5′-phosphate (PAP), produced in secondary sulfur assimilation as a byproduct in sulfation reactions from 3′-phosphoadenosine 5′-phosphosulfate (PAPS), was recently suggested to act in retrograde signaling in drought. Data available on the protection against abiotic stress is summarized and discussed, in particular, the compartment-specific importance of glutathione in connection with the subcellular accumulation of ROS during drought stress. There is evidence that a significant co-regulation of sulfur metabolism and the biosynthesis of the drought hormone abscisic acid (ABA) operates to ensure sufficient cysteine availability for aldehyde oxidase maturation. In addition, the role of glucosinolates (Gls) in drought stress will be delineated, as the drought-induced accumulation of aliphatic Gl is related to ABA formation whereas indole and aromatic Gl decreased during drought stress, suggesting that these Gls are not involved in the plants’ response to drought.

In India 14 seagrass species can be found with monospecific genera (Enhalus, ThalassiaandSyringodium),Cymodoceawith two species andHalophilaandHalodulerepresented by more than two taxonomically complex species. Considering this, the present study was made to understand the level and pattern of genetic variability among these species collected from Tamilnadu coast, India. Random amplified polymorphic DNA (RAPD) analysis was used to evaluate the level of polymorphism existing between the species. Out of the 12 primers tested, 10 primers amplified 415 DNA fragments with an average of 41.5 fragments per primer. Of the total 415 amplified fragments only 123 (29.7%) were monomorphic and the remaining 292 (70.3%) were polymorphic for Indian seagrass species. Among the 10 primers used four are identified as the key primers capable of distinguishing all the Indian seagrasses with a high degree of polymorphism and bringing representative polymorphic alleles in all the tested seagrasses. From the present investigation, this study shows that the RAPD marker technique can be used not only as a tool to analyse genetic diversity but also to resolve the taxonomic uncertainties existing in the Indian seagrasses. The efficiency of these primers in bringing out the genetic polymorphism or homogeneity among different populations of theHalophilaandHalodulecomplex still has to be tested before recommending these primers as an identification tool for Indian seagrasses.

Many publications describe cryopreservation techniques but only a few studies have focused on the biochemical and physiological changes occurring in plants regenerated from seeds exposed to liquid nitrogen. This paper aims at describing the effect of common bean seed cryostorage on mineral nutrition of young plantlets. The following elements were measured on leaves of 10-day-old plantlets from non-cryopreserved and cryopreserved seeds: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Se, Sr and Zn. At 10 days after sowing, both treatments (control and cryopreserved seeds) showed 100% seed germination without any visual phenotypic difference. However, contents of several elements in the leaves were different. Exposure of seeds to liquid nitrogen decreased Cu, Cd and Na uptake and increased absorption of B and Al. Further studies are required to understand the mechanisms underlying the relationship between seed exposure to liquid nitrogen and mineral nutrition during the early stages of plantlet growth. DAAD Leibniz University of Hannover University of Ciego de Avila, Cuba

This project analyses the biogas potential of the halophyte Chenopodium quinoa Willd. In a first approach C. quinoa was grown with different concentrations of NaCl (0, 10 and 20 ppt NaCl) and the crop residues were used as substrate for biogas production. In a second approach, C. quinoa was grown with 0, 10, 20 and 30 ppt NaCl under hydroponic conditions and the fresh biomass was used as substrate. The more NaCl is in the culture medium, the higher the sodium, potassium, crude ash and hemicellulose content in the plant tissue whereas the calcium, sulfur, nitrogen and carbon content in the biomass decrease. According to this study, it is possible to produce high yields of methane using biomass of C. quinoa. The highest specific methane yields were obtained using the substrate from the plants cultivated at 10 and 20 ppt NaCl in both experiments.

The importance of green technologies is steadily growing. Salt-tolerant plants have been proposed as energy crops for cultivation on saline lands. Halophytes such as Salicornia europaea, Tripolium pannonicum, Crithmum maritimum and Chenopodium quinoa, among many other species, can be cultivated in saline lands, in coastal areas or for treating saline wastewater, and the biomass might be used for biogas production as an integrated process of biorefining. However, halophytes have different salt tolerance mechanisms, including compartmentalization of salt in the vacuole, leading to an increase of sodium in the plant tissues. The sodium content of halophytes may have an adverse effect on the anaerobic digestion process, which needs adjustments to achieve stable and efficient conversion of the halophytes into biogas. This review gives an overview of the specificities of halophytes that needs to be accounted for using their biomass as feedstocks for biogas plants in order to expand renewable energy production. First, the different physiological mechanisms of halophytes to grow under saline conditions are described, which lead to the characteristic composition of the halophyte biomass, which may influence the biogas production. Next, possible mechanisms to avoid negative effects on the anaerobic digestion process are described, with an overview of full-scale applications. Taking all these aspects into account, halophyte plants have a great potential for biogas and methane production with yields similar to those produced by other energy crops and the simultaneous benefit of utilization of saline soils.