Analysis of Genetic Variation Among Accessions of <Emphasis Type="Italic">Pueraria montana</Emphasis> (Lour.) Merr. var. <Emphasis Type="Italic">lobata</Emphasis> and <Emphasis Type="Italic">Pueraria phaseoloides</Emphasis> (Roxb.) Benth. based on RAPD Markers

Pueraria montana var. lobata and P. phaseoloides originating from tropical Asia and parts of Oceania are ecologically and economically important legumes that are used as green manure, cover crop or forage plants. Conservation and use of plant genetic resources require an understanding of the extent and distribution of genetic diversity in any given region. In this study, genetic variation of five P. montana var. lobata and 16 P. phaseoloides accessions was analysed developing a random amplified polymorphic DNA (RAPD) marker methodology for Pueraria species and thereby creating basic data for follow-up research and the development of conservation strategies. Seeds were collected from native populations in Bac Kan Province, a mountainous region in Northeast Vietnam. P. montana var. lobata presented a high level of variation with 54.3% of the detected markers being polymorphic, whereas P. phaseoloides exhibited an intermediate to high level of variation (45.5%). The P. montana var. lobata accessions clustered in congruence with their eco-geographical origin. For P. phaseoloides no correspondence between sampling sites and genetic differentiation was found. Inter-population differentiation was measured as Jaccard's similarity coefficient (JSC). Mean JSC amounted to 0.35 in P. montana var. lobata and 0.52 in P. phaseoloides. Results are compared to other genetic studies of herbaceous legumes and conservation strategies are suggested.     

Anti- and prooxidative properties of gallic acid in fenton-type systems

The anti- and prooxidative properties of gallic acid in Fenton-type systems containing H(2)O(2) and Fe(III) were examined in pH 3-10 reaction media and at reaction temperatures of 20-50 degrees C. Although it is a free radical scavenger, gallic acid may exhibit prooxidative properties, as it promotes the production of hydroxyl radicals due to iron chelation. The overall effect is prooxidative if the ratio of the concentrations of gallic acid and Fe(III) in the reaction medium is smaller than 2. If the ratio is greater than 2, the overall effect of gallic acid presence is antioxidative due to free radical scavenging properties. The dependence of rates and of apparent activation energies of gallic acid consumption on pH in Fenton-type systems was also examined, and it is concluded that the rate-determining steps in acidic and alkaline media are different, the overall rate of gallic acid consumption being lowest at pH 7.     

Phosphate-Solubilizing Microbes and Biocontrol Agent for Plant Nutrition and Protection: Current Perspective

ABSTRACT

Phosphate-solubilizing microbes (PSM) are widely distributed in the rhizosphere and helps plant to acquire phosphates from soil. The availability of phosphates in soil are governed by several factors among which the proton exchange capacity has been regarded to be the most important factor involved in cation complex formations with soluble phosphates making them unavailable to plants, thereby disturbing the phosphorus cycling events found in arable soils. PSM solubilizes the cation complexes and thereby improves the functioning of phosphorus cycle in soil. In addition to involvement in biogeochemical cycling events, PSM have been also found to have antagonistic potential against several plant phytopathogens. These biocontrol microbes represent the most abundant groups of soil microflora. Among which some nutrient solubilizers have been used for effective biocontrol of important plant diseases. This review article shows contributions of different plant growth promoters used in nutrient and disease management practices in agriculture.

Abbreviations: P (phosphorus), PSM (phosphate-solubilizing microbes), PSB (phosphate-solubilizing bacteria), PSF (phosphate-solubilizing fungi), PGPM (plant growth-promoting microbes), PGPB (plant growth-promoting bacteria), SAR (systemic acquired resistance), ISR (induced systemic resistance), TCP (tri-calcium phosphate), HCN (hydrogen cyanide), IAA (indole-3-acetic acid), ^aPhosphorus [(SSP) single super phosphate, RP (rock phosphate), PM (poultry manure) and FYM (farm yard manure)], PAL (phenylalanine ammonia lyase), ESI-MS (electrospray ionization mass spectrometry), DAPG (2,4-diacetylphloroglucinol) and NMR (¹H nuclear magnetic resonance).     

Actinobacteria-enhanced plant growth, nutrient acquisition, and crop protection: Advances in soil, plant, and microbial multifactorial interactions

Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.     

Dereplication Strategies for Targeted Isolation of New Antitrypanosomal Actinosporins A and B from a Marine Sponge Associated-Actinokineospora sp. EG49

High resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy were employed as complementary metabolomic tools to dereplicate the chemical profile of the new and antitrypanosomally active sponge-associated bacterium Actinokineospora sp. EG49 extract. Principal Component (PCA), hierarchical clustering (HCA), and orthogonal partial least square-discriminant analysis (OPLS-DA) were used to evaluate the HRFTMS and NMR data of crude extracts from four different fermentation approaches. Statistical analysis identified the best culture one-strain-many-compounds (OSMAC) condition and extraction procedure, which was used for the isolation of novel bioactive metabolites. As a result, two new O-glycosylated angucyclines, named actinosporins A (1) and B (2), were isolated from the broth culture of Actinokineospora sp. strain EG49, which was cultivated from the Red Sea sponge Spheciospongia vagabunda. The structures of actinosporins A and B were determined by 1D- and 2D-NMR techniques, as well as high resolution tandem mass spectrometry. Testing for antiparasitic properties showed that actinosporin A exhibited activity against Trypanosoma brucei brucei with an IC₅₀ value of 15 µM; however no activity was detected against Leishmania major and Plasmodium falciparum, therefore suggesting its selectivity against the parasite Trypanosoma brucei brucei; the causative agent of sleeping sickness.     

Interactions of organic and inorganic chromium species with Ca-polygalacturonate

This study investigated the interactions of CrIII and CrVI present as free metal ions or as organic CrIII (Cr-L) with a Ca-polygalacturonate (Ca-PG) network. Ca-PG networks were treated with solutions of chromium (CrIII and CrVI) at different concentrations at three different pH values. The Cr-L complex were obtained by water extraction of hydrolysed leather. The CrVI had almost no interaction with the Ca-PG networks, whereas CrIII as a free metallic ion was strongly retained by the network. The calculated Langmuir adsorption isotherms showed a twofold increase in maximum CrIII adsorption but a decrease in the affinity of the metal with the Ca-PG networks. This would indicate that the different chromium species, i.e. CrIII and its hydrolytic species, interact in a different way with the polygalacturonate chains. In addition, thermal analysis showed that CrIII sorption modified the structure of the network. These modifications were reduced, and thermal stability increased if Ca-PG adsorbed Cr-L or L. Furthermore, the treatment of Ca-PG with hydrolysed leather water extract-reduced CrIII sorption by 94%. The hydrolysed leather fraction immobilized onto the Ca-PG networks probably consisted of peptides and could therefore represent an important source of organic N.     

Wintertime photosynthesis and water uptake in a boreal forest

Warm air in combination with frozen soil is a major cause of wintertime drought damage in evergreen plants in subalpine and boreal environments. We analyzed diurnal tree stem diameter variation (SDV), which reflects soil water uptake, canopy-level water vapor flux (Fw), stand photosynthesis (Ps), photosynthetically active radiation (PAR), soil and air temperatures (Ts and T air, respectively) and soil liquid water content (theta) to determine under what conditions photosynthesis is possible in wintertime and how crucial water uptake from soil is for photosynthesis. Measurements were made under field conditions in a Scots pine forest in southern Finland during winter 2002-2003. We found four wintertime periods when there was measurable Ps and SDV, the latter always starting 2-7 days after photosynthesis and both usually ending on the same day. Stand photosynthesis began when T air reached 3-4 degrees C and ended when T air dropped below -7 degrees C. The trees appeared to rely on stored stem water first and started taking up water from the soil a few days later, when the transpirational demand became strong enough. The more difficult it was to access soil water because of low Ts or low theta, the longer the trees used water stored in their stems. Even partial stem freezing did not prevent photosynthesis or soil water uptake.     

Platelet-bound antibodies detected by a flow cytometric assay in cats with thrombocytopenia

In cats, primary or secondary immune-mediated thrombocytopenia have rarely been described or characterised. The objective of this study was to determine platelet-bound antibodies (PBA) by a flow cytometric assay in both healthy and thrombocytopenic cats. Direct PBA testing was performed in 42 thrombocytopenic cats (platelet counts 6-179 x 10(9)/l, median 56 x 10(9)/l). Of these 42 cats, 19 had positive PBA test results, 17 of which were considered to have secondary immune-mediated thrombocytopenia (sITP). Underlying diseases included fat necroses (four cases), feline infectious peritonitis (three), feline leukaemia virus (two) or feline immunodeficiency virus (two) infections, lymphoma (two), leukaemia (one), hepatitis (one), pyelonephritis (one), or hyperthyroidism (one). In two cats, no underlying disease was found suggesting a primary immune-mediated thrombocytopenia (pITP). The PBA test was negative in 23 cats diagnosed with varying underlying diseases and in 47 healthy control cats with platelet values within the reference range. Only seven of the 42 cats with thrombocytopenia (platelet count 10-57 x 10(9)/l, median 34 x 10(9)/l) had spontaneous bleeding. This study suggests that immune-mediated destruction of platelets might be an important pathological mechanism for feline thrombocytopenia caused by various underlying diseases. In cats, pITP appears to be rarely diagnosed.     

Influence of Low Molecular Weight Glutenins on Viscoelastic Properties of Intact Wheat Kernels and Their Relation to Functional Properties of Wheat Dough

The mechanical and viscoelastic properties of intact wheat kernels of 36 wheat cultivars differing in low molecular weight glutenin subunit (LMW‐GS) composition (loci Glu‐A3, Glu‐B3, and Glu‐D3) were evaluated using load‐compression tests. Comparison among genotypic groups representing Glu‐3 allelic variants showed that groups representing the alleles Glu‐A3 b, c, and d; Glu‐B3 d, g, and h; and Glu‐D3 a, b, and d, had harder kernel texture, higher kernel elastic work and larger gluten strength‐related parameters than those possessing alleles Glu‐A3 e; Glu‐B3 f, i and j (translocation 1B/1R); and Glu‐D3 d. Modulus of elasticity (stress to strain ratio) showed low values (111.9–168.8 MPa) for allelic groups possessing poor elastic properties (Glu‐A3 e; Glu‐B3 f, i, and j; and Glu‐D3 d), and high values (179.8–222.6 MPa) for allelic groups possessing high kernel elastic properties (Glu‐A3 b c, and d; Glu‐B3 d, g, and h; and Glu‐D3 a, b and c). The highest values for gluten strength‐related parameters (SDS‐sedimentation, dough mixing time, and dough strength [W]) corresponded to allelic groups Glu‐A3 d; Glu‐B3 d and g; and Glu‐D3 d, while the lowest corresponded to Glu‐A3 e and Glu‐B3 j. No significant differences were observed among groups with regard to gluten extensibility parameters; however, the highest P/L value (least extensibility) corresponded to Glu‐B3 j, which indicates presence of 1B/1R translocation. Except for the Glu‐B3 j (translocation 1B/1R) allele, which presented more variation within samples, a general relationship between kernel viscoelastic properties and dough viscoelastic properties was observed; samples showing higher elastic work to plastic work ratio (E/P) tended to possess better gluten strength than cultivars with low E/P ratio.