Partial structural studies of four Acacia gum exudates of the series phyllodineae

Methylation and hydrolysis studies have shown that gum specimens from Acacia difformis, A. mabellae, A. retinodes and A. rubida, which belong to Bentham's Series I (Phyllodineae), subseries 6F (Uninerves Racemosae), are similar structurally to those from A. podalyriifolia and A. pycnantha. This is further evidence that A. cyanophylla, which was placed next to A. pycnantha by Bentham, is atypical of the Series I Acacias.     

Synthesis and characterization of Guar gum based biopolymeric hydrogels as carrier materials for controlled delivery of methotrexate to treat colon cancer

Guar Gum has been evaluated for its importance in food and pharmaceutical industry. A blended biopolymeric hydrogel was prepared by solution casting technique using guar gum (GG), chitosan (CS), polyvinyl alcohol (PVA), chemically crosslinked with tetra orthosilicate (TEOS) and impregnated with methotrexate (MTX) to assess its drug carrying capacity against colon cancer (HCT-116). The surface morphology, chemical bonding, hydrophilicity and water absorbing capacity were analyzed by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), contact angle measurements and swelling properties in variable conditions. Furthermore, degradation, drug release kinetics, hemocompatibility, and cytotoxicity of MTX-loaded hydrogel was tested. The release of MTX from GG/CS/PVA biopolymeric blend occurred in sustained manner. Results displayed that in 7 h 25 min duration 96% of the drug was released in phosphate buffer saline (PBS) at pH 7.4. These blends were non-hemolytic, and antiproliferative against HCT-116. Furthermore, the MTT assay has revealed that MTX-loaded hydrogel had prominently decreased the cell viability (with IC50 11.7 µg/ml) as compared to free MTX (with IC50 21.57 µg/ml). Hence, these results suggest that guar gum based hydrogels are potential biomaterials for colon cancer treatment.     

Complexation of Lead by Bermuda Grass Root Exudates in Aqueous Media

Exudates produced from Bermuda grass roots were collected in deionized water from sterilized Bermuda grass sod at 3-day intervals over a period of 15 days. Exudates were analyzed for total organic carbon, and characterized via Fourier Transform Infrared Spectroscopy. Exudate samples were adjusted to pH values of 4.5, 6.5, and 7.5, amended with lead and quantified for soluble and complexed lead via Inductively Coupled Plasma—Optical Emission Spectrometry. Data obtained from total organic carbon measurements indicated compositional changes in Bermuda grass root exudates as organic carbon concentrations increased over time. Analysis of the infrared spectroscopy data indicated that carboxylic acids and amine functional groups were present in root exudates. Also, the ability of root-exuded compounds to solubilize lead in aqueous media was demonstrated as exudate samples dissolved an average of 60% more lead than deionized water. At pH values 4.5 and 7.5, lead complexation by Bermuda grass root exudates increased with decreasing molecular weight size fractions, while an opposite trend was observed at pH 6.5. Results from this study demonstrated the ability of Bermuda grass root exudates to complex lead in aqueous media.     

Achillea millefolium antagonism to Pratylenchus brachyurus

Pratylenchus brachyurus is a phytonematode species mostly damaging crops. It is mainly controlled by agrochemicals which are harmful to the environment and public health. Such outcomes encourage the development of research on products and/or processes to control this phytonematode and to contribute to the sustainability of agricultural systems. Thus, the aim of the current study was to assess host suitability of Achillea millefolium to P. brachyurus, as well as the nematicidal potential of its essential oil and root exudates. We conducted two experiments with two different plant species—Glycine max (soya bean) and Achillea millefolium (yarrow)—based on a 2 × 3 factorial arrangement to assess host suitability. Plants were assessed 5, 10 and 15 days after inoculation through the fuchsine acid staining technique. Based on the results, A. millefolium was an unfavourable host to this phytonematode. Therefore, it can be recommended for crop rotation and/or succession systems in small areas. We tested the nematicidal activity of the essential oil and exudates of A. millefolium at concentrations of 0, 25, 50, 100, 200, 300, 400 and 500 µg/ml in a BOD incubator at 26°C for 48 hr. The essential oil showed increasing linear regression, that is the higher was the concentration, the higher was the mortality rate. Exudates showed a quadratic behaviour (p ≤ .05), leading to 60.83% nematode mortality. Therefore, the essential oil and root exudates of A. millefolium have the potential to control P. brachyurus. The essential oil showed antagonistic properties likely because of the presence of germacrene D (39.55%), (E,E)‐α‐farnesene (25.70%) and chamazulene (8.91%).     

Cereal root exudates contain highly structurally complex polysaccharides with soil‐binding properties

Rhizosheaths function in plant?soil interactions, and are proposed to form due to a mix of soil particle entanglement in root hairs and the action of adhesive root exudates. The soil‐binding factors released into rhizospheres to form rhizosheaths have not been characterised. Analysis of the high‐molecular‐weight (HMW) root exudates of both wheat and maize plants indicate the presence of complex, highly branched polysaccharide components with a wide range of galactosyl, glucosyl and mannosyl linkages that do not directly reflect cereal root cell wall polysaccharide structures. Periodate oxidation indicates that it is the carbohydrate components of the HMW exudates that have soil‐binding properties. The root exudates contain xyloglucan (LM25), heteroxylan (LM11/LM27) and arabinogalactan‐protein (LM2) epitopes, and sandwich‐ELISA evidence indicates that, in wheat particularly, these can be interlinked in multi‐polysaccharide complexes. Using wheat as a model, exudate‐binding monoclonal antibodies have enabled the tracking of polysaccharide release along root axes of young seedlings, and their presence at root hair surfaces and in rhizosheaths. The observations indicate that specific root exudate polysaccharides, distinct from cell wall polysaccharides, are adhesive factors secreted by root axes, and that they contribute to the formation and stabilisation of cereal rhizosheaths.     

Novel strategy for biodegradation of 4-nitrophenol by the immobilized cells of Pseudomonas sp. YPS3 with Acacia gum

The mass organic compound 4-nitrophenol with low molecular is involved in many chemicals processes and most common organic pollutants. 4-Nitrophenol (4-NP) existing in soils and water bodies, thereby causing severe environmental impact and health risk. Even low concentrations are harmful to health and potential mutagenic and carcinogenic. Though the existing methods of biodegradation though effective, their popularity is hindered due to high cost. Hence, in the present study a less expensive method involving the use of Pseudomonas sp. with gum arabic (PAA) was tested. The biodegradation of 4-NP was thoroughly investigated by progressive characterization methods. The promising Pseudomonas sp. YPS 3 was identified with biochemical and molecular identification process. The average particle sizes of stable crystalline PAA was 8–20 nm. The experiments were conducted with optimized parameters viz., pH (7.0), concentration (30 ppm), temperature (37 °C) and time (6 h). The study was tested as adsorbent particle size on 4-NP concurrent adsorption-biodegradation. In addition, these Pseudomonas sp. YPS3 and its PAA are used as an eco-friendly for removal of toxic organic 4-NP pollutant from the ecosystems.     

Scope for genetic manipulation of mineral acquisition in chickpea

Nutrient acquisition in chickpea needs to be efficient, because it is mainly grown as a post-rainy season, rainfed crop, and generally on soils inferior in physical characteristics and poor in fertility. Nutrient deficiencies have been reported to cause yield losses of varying magnitude in chickpea, e.g., 22–50% due to iron (Fe), around 10% due to sub-optimal nodulation and hence nitrogen (N) deficiency, 29–45% due to phosphorus (P), up to 100% due to boron (B), and 16-30% due to sulphur (S). Yield losses due to salinity are equally large but are difficult to estimate because of its heterogeneous occurrence. In chickpea, genotypic differences in morpho-physiological (including root size) and functional (exudates) root traits, and in nodulation capacity for increased nitrogen fixation have been identified. Genotypic differences in response to application of Fe, B and zinc (Zn) have also been found among chickpea genotypes. A drought tolerant chickpea genotype ICC 4958, which has a relatively large root system, acquired more P than other genotypes during the vegetative period in a pot experiment at ICRISAT. The recent thrust on identifying QTLs for root size should facilitate progress in incorporating useful root traits through marker assisted selection in desirable agronomic backgrounds. Selection for nodulation capacity in released cultivars has resulted in high nodulating chickpea genotypes that produced 10% higher yield than the control varieties. Information on targeted crop improvement for higher nutrient-use efficiency for P, S, Zn, B and Fe is not readily available. Methods to screen for tolerance to salinity are available, but sufficiently high levels of tolerance have not yet been found in germplasm or wild relatives of chickpea to warrant breeding for salinity tolerance. Use of alternative approaches, such as mutation to generate genetic diversity or introgression of alien genes from other crops (transgenic) are thus required, and these remain long-term objectives.     

Vertical clingers and gougers: Rapid acquisition of adult limb proportions facilitates feeding behaviours in young Javan slow lorises (Nycticebus javanicus)

Animals of all ages need to access essential food resources, either on their own or with the assistance of conspecifics. Rapid physical and behavioural development is one strategy to help young animals reach adulthood. Specialized gum-feeding mammals exploit a food type that is relatively difficult to access and digest and must possess the appropriate adaptions to access large vertical substrates, i.e. tree trunks. Unlike other gum feeding mammals, the Javan slow loris (Nycticebus javanicus) lacks physical structures, such as keeled nails or claws, which animals commonly use to secure themselves to large vertical substrates. To understand how slow lorises of all ages exploit gum, we examined their vertical gouging posture, locomotor behaviour, habitat use during feeding, and their morphometric measures across three age classes (adult, sub-adult, juvenile). Using data collected in Cipaganti, Java, Indonesia between April 2012 and April 2016, we found that individuals of N. javanicus rely on their hand, foot, and limb morphology to maintain vertical gouging postures, in place of claws or keeled nails. Locomotor behaviour, position in tree, and tree DBH showed no significant difference across age classes while feeding. Juveniles were indistinguishable from adults and sub-adults in regards to limb proportion indices, lower leg length, hand span and foot span. Some morphometric measures scaled isometrically e.g. arm length, but those highlighted during prolonged vertical postures scaled allometrically e.g. leg, hand, and foot measures. These findings suggest that the rapid behavioural and physical development of key features may act as an ontogenetic adaptation to facilitate access to a stable food resource at a young age. The Javan slow loris exemplifies the complex relationship that exists between an animal’s diet and the specializations that facilitate access to these food resources.