Salt tolerance in <Emphasis Type="Italic">Solanum pennellii</Emphasis>: antioxidant response and related QTL

Background  

Excessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, Solanum pennellii, has also been associated with similar changes in antioxidants. In this work, S. lycopersicum M82, S. pennellii LA716 and a S. pennellii introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions.     

Intestinal barrier function in response to abundant or depleted mucosal glutathione in Salmonella-infected rats

Background  

Glutathione, the main antioxidant of intestinal epithelial cells, is suggested to play an important role in gut barrier function and prevention of inflammation-related oxidative damage as induced by acute bacterial infection. Most studies on intestinal glutathione focus on oxidative stress reduction without considering functional disease outcome. Our aim was to determine whether depletion or maintenance of intestinal glutathione changes susceptibility of rats to Salmonella infection and associated inflammation.     

Interactions between cauliflower and Rhizoctonia anastomosis groups with different levels of aggressiveness

Background  

The soil borne fungus Rhizoctonia is one of the most important plant pathogenic fungi, with a wide host range and worldwide distribution. In cauliflower (Brassica oleracea var. botrytis), several anastomosis groups (AGs) including both multinucleate R. solani and binucleate Rhizoctonia species have been identified showing different levels of aggressiveness. The infection and colonization process of Rhizoctonia during pathogenic interactions is well described. In contrast, insights into processes during interactions with weak aggressive or non-pathogenic isolates are limited. In this study the interaction of cauliflower with seven R. solani AGs and one binucleate Rhizoctonia AG differing in aggressiveness, was compared. Using microscopic and histopathological techniques, the early steps of the infection process, the colonization process and several host responses were studied.     

Specifying functional units and reference flows for comparable alternatives

Goal, Scope, and Background  

Despite documentation of product lifetime, performance, and system dependency issues, requirements for specifying functional units and reference flows in LCA have not been developed. The ISO standards simply note that selection between functions is dependent on the goals and scope of the study, that the functional unit must be clearly defined and measurable, and that the reference flows are the amount of product necessary per functional unit. The goal of this work is to suggest and demonstrate the use a set of requirements for specifying the functional unit and reference flows for comparative LCAs.     

Agaroids from New Zealand members of the Gracilariaceae (Gracilariales,Rhodophyta) — a novel dimethylated agar

Polysaccharide extracts from four New Zealand members of the Gracilariaceae have been characterized by ¹³C-NMR spectroscopy and GLC analysis of alditol acetate derivatives prepared using a new double hydrolysis-reduction procedure. All were based on variously substituted repeating disaccharide units of agarobiose and 20% of its precursor containing l-galactose-6-sulfate. Gracilaria truncata yielded a firm gelling agar with 67% methylation on the 6-position of the d-galactose residues. The other extracts belong to a new class of agar molecules having methylation on both the 6-position of the d-galactose units and the 2-position of the l-sugar units. The Curdiea coriacea polysaccharide displayed this double methylation almost completely ( 96 %); the alkali-modified polymer thus had only two free hydroxy-groups per disaccharide repeat unit, yet still gave a firm gel. The Curdiea flabellata and Melanthalia abscissa extracts had this double methylation pattern but to a lesser extent, and additional xylosyl branch units on up to 18% of the repeating disaccharide units.     

Extraction,purification and characterization of an antioxidant from marine waste using protease and chitinase cocktail

Marine waste is a highly renewable resource for the recovery of several value added metabolites with prospective industrial applications. This study describes the production of enzymes on marine waste and their subsequent use for the extraction of antioxidants from marine waste. Microbispora sp. and Bacillus sp. were grown on colloidal chitin and marine waste for the production of chitinase and protease. Microbispora sp. could produce 10.2 U ml⁻¹ chitinase, whereas Bacillus sp. could produce 38 U ml⁻¹ chitinase and 3.39 U ml⁻¹ protease. The production of antioxidants was optimized using statistical designs and 6.6 units of 35 kDa chitinase from Microbispora sp., 16 units of 25 kDa chitinase from Bacillus sp., 2.3 units of protease, 1.5% marine waste and 36 h incubation gave maximum antioxidant activity. Nearly 5.0 mg of compound with antioxidant activity could be recovered per gram of marine waste. This compound was purified by HPLC and characterized by TLC, FT-IR and proton-NMR as N,N′-diacetylchitobiose. It exhibited 53% superoxide radical scavenging activity, 57% hydroxyl radical scavenging activity and 28% lipid peroxidation inhibition activity. Scale up of the extraction of antioxidant from marine waste and its pharmacological studies can extend its use in medicine.     

Heteromorphic seeds of wheat wild relatives show germination niche differentiation

• Crop wild relatives are fundamental genetic resources for crop improvement. Wheat wild relatives often produce heteromorphic seeds that differ in morphological and physiological traits. Several Aegilops and Triticum species possess, within the same spikelet, a dimorphic seed pair, with one seed being larger than the other. A comprehensive analysis is needed to understand which traits are involved in seed dimorphism and if these aspects of variation in dimorphic pairs are functionally related.
• To this end, dispersal units of Triticum urartu and five Aegilops species were X‐rayed and the different seed morphs weighed. Germination tests were carried out on seeds, both dehulled and left in their dispersal units. Controlled ageing tests were performed to detect differences in seed longevity among seed morphs, and the antioxidant profile was assessed in terms of antioxidant compounds equipment and expression of selected antioxidant genes. We used PCA to group seed morphs sharing similar patterns of germination traits, longevity estimates and antioxidant profile.
• Different seed morphs differed significantly in terms of mass, final germination, germination timing, longevity estimates and antioxidant profile in most of the tested species. Small seeds germinated slower, had lower germination when left in their dispersal units, a higher antioxidant potential and were longer‐lived than large seeds. The antioxidant gene expression varied between morphs, with different patterns across species but not clearly reflecting the phenotypic observations.
• The results highlight different trait trade‐offs in dimorphic seeds of Aegilops and T. urartu, affecting their germination phenology and longevity, thereby resulting in recruitment niche differentiation.

     

The Effect of Bioactive Compounds on In Vitro and In Vivo Antioxidant Activity of Different Berry Juices

Background

Berry fruit is known for its high contents of various bioactive compounds. The latter constitute of anthocyanins, flavonols and flavanols and posses high antioxidative activity. The highly dynamic antioxidant system can be evaluated in vitro and in vivo in several model organisms. These measurements represent a good approximation of the real potential of bioactive compounds in the cells of higher eucarions. The aim of the study was thus to determine in vitro and in vivo antioxidant activity of different berry juices, which reportedly contain high amounts of phenolics.

Methodology/Principal Findings

Five different berry species were collected from several locations in central Slovenia and juice was extracted from each species separately. Juice was assessed for their in vitro and in vivo antioxidant activity. Phenolic profiles of berries were determined with the use of a HPLC/MS system, in vitro antioxidant activity with the DPPH radical scavenging method and in vivo antioxidative activity using Saccharomyces cerevisiae. The highest diversity of individual phenols was detected for bilberry juice. The highest in vitro antioxidant capacity was determined for blackcurrant juice. A decrease in intracellular oxidation compared to control was observed in the following order: blackcurrant < chokeberry = blueberry < bilberry. The results indicate important differences in antioxidant activity of berry juices between in vitro and in vivo studies.

Conclusion/Significance

In addition to the total content of phenolic compounds entering the cells, a key factor determining antioxidative activity of berry juices is also the ratio between the compounds. Where high content levels of anthocyanins and very low content levels of flavonols and hydroxycinnamic acids were measured a lower intracellular oxidation has been detected. Specifically, intracellular oxidation increased with higher consumption of hydroxycinnamic acids and lower consumption of anthocyanins in the cells. Antioxidative activity also increased when the consumption of analyzed phenols was rather low.     

Cloning and characterization of a glucosyltransferase from Crocus sativus stigmas involved in flavonoid glucosylation

Background  

Flavonol glucosides constitute the second group of secondary metabolites that accumulate in Crocus sativus stigmas. To date there are no reports of functionally characterized flavonoid glucosyltransferases in C. sativus, despite the importance of these compounds as antioxidant agents. Moreover, their bitter taste makes them excellent candidates for consideration as potential organoleptic agents of saffron spice, the dry stigmas of C. sativus.     

Selective cytotoxicity of Pancratistatin-related natural <Emphasis Type="Italic">Amaryllidaceae</Emphasis> alkaloids: evaluation of the activity of two new compounds

Background  

Pancratistatin (PST), a compound extracted from an Amaryllidaceae (AMD) family plant, has been shown to specifically induce apoptosis in cancer cells with no/minimal toxic effect on normal cells. A systematic synthetic approach has indicated that the minimum cytotoxic pharmacophore comprises the trans-fused b/c-ring system containing the 2, 3, 4-triol unit in the C-ring. To further explore the structure-activity relationship of this group of compounds we have investigated the anti-cancer efficacy and specificity of two PST-related natural compounds, AMD4 and AMD5. Both of these compounds lack the polyhydroxylated lycorane element of PST instead having a methoxy-substuituted crinane skeleton.     

The content of triterpene saponins and phenolic compounds in American ginseng hairy root extracts and their antioxidant and cytotoxic properties

Panax quinquefolium is a perennial herb of the Araliaceae family native to North America. Its roots have been used in traditional and Chinese medicine. The aim of this study was to determine the phenolic profile of methanolic extracts of P. quinquefolium hairy roots cultivated in flasks and a bioreactor, as well as extracts from the roots of three-year-old field-grown plants. Additionally, the phenol and ginsenoside components of the tested extracts were identified by HPLC, and their antioxidant and cytotoxic properties were evaluated. The antioxidant effect was evaluated by FRAP (ferric reducing antioxidant power), and ABTS ([2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation scavenging tests, and their effect on the viability of the glioblastoma cell (T98G) line was measured using the 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The LC–MS/MS analysis revealed the presence of 16 phenolic compounds identified as phenolic acids (ten compounds) or flavonoids (six compounds). The highest phenol content was observed in the transformed roots of flask-grown P. quinquefolium (1.6 mg g^?1 d.w.), followed by these grown in the bioreactor (1.1 mg g^?1 d.w.). However, the highest ginsenoside content was found in the roots of the naturally-cultivated plants (67.6 mg g^?1 d.w.). The methanolic extracts from hairy root culture of P. quinquefolium appear to have significant antioxidant and cytotoxic potential. Such transformed American ginseng root cultures could represent a potential source of bioactive metabolites for the food or pharmaceutical industry.

     

Potential of marine lactic acid bacteria to ferment Sargassum sp. for enhanced anticoagulant and antioxidant properties

Aim

To evaluate the suitability of marine lactic acid bacteria (LAB) as starter cultures for Sargassum sp. fermentation to enhance its antioxidant and anticoagulation activity.

Methods and Results

LAB isolated from marine source were characterized for their ability to utilize seaweed as a sole carbon source and applied to Sargassum fermentation. Fermentation period was optimized by monitoring the fermented sample at regular interval for a period of 18 days. Results revealed that a fermentation period of 12 days was effective with maximum culture viability and other desirable characteristics such as pH, total titratable acidity, total and reducing sugars. Under optimum fermentation period, the sample fermented with P1‐2CB‐w1 (Enterococcus faecium) exhibited maximum anticoagulation activity and antioxidant activity.

Conclusions

The study reveals a novel well‐defined starter culture from marine origin intended for seaweed fermentation for recovery of bioactive molecules.

Significance and Impact of the study

The study provides information for the enhancement of bioactive molecules in an eco‐friendly manner and also paves a way towards the development of wide range of seaweed functional foods.     

Identification of genes differentially expressed in cauliflower associated with resistance to <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis>

Black rot, caused by Xanthomonas campestris pv. campestris (Pammel) Dowson (Xcc), is one of the most damaging diseases of cauliflower and other crucifers. In order to investigate the molecular resistance mechanisms and to find the genes related to black rot resistance in cauliflower, a suppression subtractive hybridization (SSH) cDNA library was constructed using resistant line C712 and its susceptible near-isogenic line C731 as tester and driver, respectively. A total of 280 clones were obtained from the library by reverse northern blotting. Sequencing analysis and homology searching showed that these clones represent 202 unique sequences. The library included many defense/disease-resistant related genes, such as plant defensin gene PDF1.2, lipid transfer protein, thioredoxin h. Gene expression profiles of 12 genes corresponding to different functional categories were monitored by real-time RT-PCR. The results showed that the expression induction of these genes in the susceptible line C712 in response to Xcc was quicker and more intense, while in C731 the reaction was delayed and limited. Our results imply that these up-regulated genes might be involved in cauliflower responses against Xcc infection. Information obtained from this study could be used to understand the molecular mechanisms of disease response in cauliflower under Xcc stress.     

Fluorescent 3-hydroxy-4-pyridinone hexadentate iron chelators: intracellular distribution and the relevance to antimycobacterial properties

Abstract  

We report the synthesis and characterization of a fluorescent iron chelator (4), shown to be effective in inhibiting the growth of Mycobacterium avium in macrophages, together with the synthesis and characterization of two unsuccessful analogues selected to facilitate identification of the molecular properties responsible for the antimicrobial activity. Partition of the chelators in liposomes was investigated and the compounds were assessed with respect to uptake by macrophages, responsiveness to iron overload/iron deprivation and intracellular distribution by flow cytometry and confocal microscopy. The synthesis of the hexadentate chelators is based on a tetrahedral structure to which three bidentate 3-hydroxy-4-pyridinone chelating units are linked via amide bonds. The structure is synthetically versatile, allowing further addition of functional groups such as fluorophores. Here, we analyse the non-functionalized hexadentate unit (3) and the corresponding rhodamine B (4) and fluorescein (5) labelled chelators. The iron(III) stability constant was determined for 3 and the values log β = 34.4 and pFe³⁺ = 29.8 indicate an affinity for iron of the same order of magnitude as that of mycobacteria siderophores. Fluorescence properties in the presence of liposomes show that 4 strongly interacts with the lipid phase, whereas 5 does not. Such different behaviour may explain their distinct intracellular localization as revealed by confocal microscopy. The flow cytometry and confocal microscopy studies indicate that 4 is readily engulfed by macrophages and targeted to cytosol and vesicles of the endolysosomal continuum, whereas 5 is differentially distributed and only partially colocalizes with 4 after prolonged incubation. Differential distribution of the compounds is likely to account for their different efficacy against mycobacteria.     

Evolution and origin of merlin,the product of the <Emphasis Type="Italic">Neurofibromatosis type 2</Emphasis> (<Emphasis Type="Italic">NF2</Emphasis>) tumor-suppressor gene

Background  

Merlin, the product of the Neurofibromatosis type 2 (NF2) tumor suppressor gene, belongs to the ezrin-radixin-moesin (ERM) subgroup of the protein 4.1 superfamily, which links cell surface glycoproteins to the actin cytoskeleton. While merlin's functional activity has been examined in mammalian and Drosophila models, little is understood about its evolution, diversity, and overall distribution among different taxa.     

Enhancing the production of phenolic compounds during barley germination by using chitooligosaccharides to improve the antioxidant capacity of malt

Objective

To enhance the production of phenolic compounds during barley germination using chitooligosaccharide as an elicitor to improve the antioxidant capacity of malt.

Results

When used as an elicitor for barley germination, chitooligosaccharide with a molecular weight of 3 kDa, added at 10 mg/kg barley kernels during the first steeping cycle, led to the maximum production of phenolic compounds. Compared with the control with no chitooligosaccharide added to the steeping water, the total phenolic content was increased by 54.8%. Increases in the total phenolic content of the barley malt occurred when chitooligosaccharide was applied during the first or both the first and the second steeping cycles. Thus the antioxidant capacity of barley malt was increased significantly by adding chitooligosaccharide during the steeping process.

Conclusion

Applying chitooligosaccharides during the steeping process increased the content of phenolic compounds thus improving the antioxidant capacity of the barley malt.