A 2.6 kb intron separates the signal peptide coding sequence of an anther-specific protein from the rest of the gene in sunflower

Summary Metabolism of sulfonylurea herbicides by Streptomyces griseolus ATCC 11796 is carried out via two cytochromes P-450, P-450_SU1 and P-450_SU2. Mutants of S. griseolus, selected by their reduced ability to metabolize a fluorescent sulfonylurea, do not synthesize cytochrome P-450_SU1 when grown in the presence of sulfonylureas. Genetic evidence indicated that this phenotype was the result of a deletion of > 15 kb of DNA, including the structural genes for cytochrome P-450_SU1 and an associated ferredoxin Fd-1 (suaC and suaB, respectively). In the absence of this monooxygenase system, the mutants described here respond to the presence of sulfonylureas or phenobarbital in the growth medium with the expression of only the suhC,B gene products (cytochrome P-450_SU2 and Fd-2), previously observed only as minor components in wild-type cells treated with sulfonylurea. These strains have enabled an analysis of sulfonylurea metabolism mediated by cytochrome P-450_SU2 in the absence of P-450_SU1, yielding an in vivo delineation of the roles of the two different cytochrome P-450 systems in herbicide metabolism by S. griseolus.     

Antibacterial activity of disodium succinoyl glycyrrhetinate,a derivative of glycyrrhetinic acid against Streptococcus mutans

Streptococcus mutans is a cariogenic bacterium that localizes in the oral cavity. Glycyrrhetinic acid (GRA) is a major component of licorice extract. GRA and several derivatives, including disodium succinoyl glycyrrhetinate (GR‐SU), are known to have anti‐inflammatory effects in humans. In this study, the antimicrobial effect of GRA and its derivatives against the S. mutans UA159 strain were investigated. Minimum inhibitory concentrations (MICs) of GRA and GR‐SU showed antibacterial activity against the S. mutans strain, whereas other tested derivatives did not. Because GR‐SU is more soluble than GRA, GR‐SU was used for further experiments. The antibacterial activity of GR‐SU against 100 S. mutans strains was evaluated and it was found that all strains are susceptible to GR‐SU, with MIC values below 256 µg/mL. A cell viability assay showed that GR‐SU has a bacteriostatic effect on S. mutans cells. As to growth kinetics, sub‐MICs of GR‐SU inhibited growth. The effect of GR‐SU on S. mutans virulence was then investigated. GR‐SU at sub‐MICs suppresses biofilm formation. Additionally, GR‐SU greatly suppresses the pH drop caused by the addition of glucose and glucose‐induced expression of the genes responsible for acid production (ldh and pykF) and tolerance (aguD and atpD). Additionally, expression of enolase, which is responsible for the carbohydrate phosphotransferase system, was not increased in the presence of GR‐SU, indicating that GR‐SU suppresses incorporation of sugars into S. mutans. In conclusion, GR‐SU has antibacterial activity against S. mutans and also decreases S. mutans virulence.     

Production of vitamins by Azospirillum brasilense in chemically-defined media

The production of vitamins by Azospirillum brasilense was studied in chemically-defined media amended with malate, gluconate and fructose. The liberation of vitamins was significantly affected by the presence of different carbon sources and the age of the culture. Thiamine, niacin and pantothenic acid were produced in large amounts. Thiamine and riboflavin were produced only in culture containing malate or fructose. Biotin was not detected in the supernatants of the culture media.     

Autophagy contributes to sulfonylurea herbicide tolerance via GCN2-independent regulation of amino acid homeostasis

Sulfonylurea (SU) herbicides inhibit branched-chain amino acid (BCAA) biosynthesis by targeting acetolactate synthase. Plants have evolved target-site resistance and metabolic tolerance to SU herbicides; the GCN2 (general control non-repressible 2) pathway is also involved in SU tolerance. Here, we report a novel SU tolerance mechanism, autophagy, which we call ‘homeostatic tolerance,’ is involved in amino acid signaling in Arabidopsis. The activation and reversion of autophagy and GCN2 by the SU herbicide tribenuron-methyl (TM) and exogenous BCAA, respectively, confirmed that TM-induced BCAA starvation is responsible for the activation of autophagy and GCN2. Genetic and biochemical analyses revealed a lower proportion of free BCAA and more sensitive phenotypes in atg5, atg7, and gcn2 single mutants than in wild-type seedlings after TM treatment; the lowest proportion of free BCAA and the most sensitive phenotypes were found in atg5 gcn2 and atg7 gcn2 double mutants. Immunoblotting and microscopy revealed that TM-induced activation of autophagy and GCN2 signaling do not depend on the presence of each other, and these 2 pathways may serve as mutually compensatory mechanisms against TM. TM inhibited the TOR (target of rapamycin), and activated autophagy in an estradiol-induced TOR RNAi line, suggesting that TM-induced BCAA starvation activates autophagy, probably via TOR inactivation. Autophagy and GCN2 were also activated, and independently contributed to TM tolerance in plants conferring metabolic tolerance. Together, these data suggest that autophagy is a proteolytic process for amino acid recycling and contributes to GCN2-independent SU tolerance, probably by its ability to replenish fresh BCAA.     

Flocculation of Aspergillus terreus with polyelectrolyte complex and production of itaconic acid with the flocculated mycelia

Mycelia from Aspergillus terreus K 26 were flocculated with a polyelectrolyte complex consisting of potassium poly9vinyl alcohol) sulfate (KPVS) and poly(diallyldimethyl-ammonium chloride) (PDDA) by three different methods: (a) PDDA was added into the broth obtained from precultivation of the hyphal inoculum in the presence of KPVS; (b) use of KPVS and PDDA was reversed from that in method a; (c) after the precultivation in the absence of the polymer, the mycelia were harvested, dispersed in 0.1 M phosphate buffer containing PDDA, then flocculated by addition of KPVS. The three types of the flocculated mycelia were investigated concerning growth and itaconic acid production in shake flask cultures. Viscosity and sedimentation were further examined to characterize the flocculated mycelial broths. A slight inhibition caused by flocculation on growth and acid production was observed at the beginning of repeated cultivation, but this was eliminated when cultivation in the fresh medium was repeated. There was no marked difference in the specific rates of acid production between fre and flocculated cells. Viscosity of the flocculated mycelial system was close to that of the medium, even while maintaining a cell concentration of 2 g/dl. The poor sedimentation of mycelia was favorably imporved with these flocculation methods, especially with methods b and c.     

Detection of,and sampling procedures for,the citrus blackfly in urban southern Florida

The dispersion pattern of the citrus blackfly (CBF)Aleurocanthus woglumi Ashby on urban citrus trees was studied in southern Florida. There was no usable correlation (r²=0.41) between the % of older leaves infested with CBF versus that on the newest mature flush, but there was a strong correlation (r²=0.87) between the % of leaves in the newest mature flush infested with CBF and log_e, where is the number of egg spirals of CBF/leaf on the same leaves. CBF egg spirals are distributed among the flushes in groups rather than singly and the flushes are not over-dispersed. Visual surveys proved superior to sticky traps for the detection of CBF at low densities (<5% leaves infested) on citrus trees in an urban setting. A sampling procedure is described herein based upon visual surveys.     

Reproductive isolation between two populations of Aglaoctenus lagotis,a funnel‐web wolf spider

Aglaoctenus lagotis (Lycosidae: Sosippinae) is a spider that, in contrast to the predominant wandering habit of the family, constructs funnel webs. The species is widely distributed throughout the Neotropics and is credited with high levels of intraspecific variation. Here, we evaluate whether reproductive isolating barriers operate between some populations of A. lagotis. We used heterotypic encounters between individuals from two distant localities: southern Uruguay (SU) and Central Argentina (CA). Additionally, we used spiders from an intermediate locality, western Uruguay (WU), where both forms of the species overlap (SU.WU was used to describe individuals from WU reminiscent of those from SU; and CA.WU was used to describe individuals from WU reminiscent of those from CA). No copulations occurred between SU and CA individuals, whereas a single and atypical copulation occurred between SU.WU and CA.WU individuals. Attacks (only by females on males) were rare. In tests of choice based on silk cues, SU males did not prefer homotypic cues but almost did not court CA females, whereas CA males preferred homotypic cues but usually courted heterotypic females. These findings, with a previously reported temporal asynchrony between populations, suggest the occurrence of reproductive isolation between both spider forms and a speciation process favoured by the wide distribution and plasticity of the species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 646–658.     

Comparative studies of flocculation and deflocculation of Saccharomyces uvarum and Kluyveromyces bulgaricus

Summary Flocculation of Kluyveromyces bulgaricus and Saccharomyces uvarum occurred when these yeasts were grown in a peptone glucose medium enriched with calcium ions. K. bulgaricus and S. uvarum flocculated at the beginning and at the end, respectively, of the exponential growth phase. After growth, both yeasts were washed with an EDTA solution, flocculated again in an acetate buffer, and optimum flocculation was obtained at pH 4.5 in the presence of 3.75 mM Ca⁺⁺. K. bulgaricus flocculation was irreversibly suppressed by incubation at 80° C for 6 min. S. uvarum needed an incubation at 100° C for 20 min to be irreversibly deflocculated. For both yeasts, flocculation stability depended on the presence of sugars. Mannose, mannose 6P and oligosaccharides bearing a mannose in a terminal non-reducing position reversed flocculation of S. uvarum, while galactose, galactose 6P and oligosaccharides bearing a galactose in a terminal nonreducing position reversed flocculation of K. bulgaricus. It is suggested that sugars specifically reverse flocculation because cell-to-cell aggregation of these yeasts is a lectin-carbohydrate-linked mechanism; not any sugar is capable of deflocculating any yeast, but the mechanism is specific.     

Rhizoremediation of residual sulfonylurea herbicides in agricultural soils using Lens culinaris and a commercial supplement

Sulfonylureas (SU) are a popular herbicide used today for controlling weeds. While beneficial for this purpose they present a persistent problem in agricultural treated areas, with this treatment proving detrimental for successive crops. This study assessed the phytoremediative properties of lentils (Lens culinaris) grown in uncontaminated and chlorsulfuron-contaminated soil, with and without the addition of a growth supplement, PulseAider?. The results show that in the presence of lentils the degradation of chlorsulfuron is enhanced and this degradation rate is significantly increased when the PulseAider? supplement was included during seed sowing. The supplement PulseAider? also significantly increased shoot and root biomass, root branching, and nodule number under control conditions. While this was not so for plants grown in contaminated soils, the PulseAider? supplement seemed to alter root branching and morphology. Most Probable Number (MPN) assays showed increased numbers of potential chlorsulfuron-degrading bacteria in soil treated with PulseAider?, although this was found to be significant only in the control soil. Sequencing of the 16S ribosomal gene showed the presence of Pseudomonas fluorescens bacterial species which is a known chlorsulfuron-degrading bacterium. This study is one of the first to address the remediation of residual SU herbicides and offers an economically feasible solution that may have an impact on global food security.     

Conserved domains control heterochromatin localization and silencing properties of SU(VAR)3–7

The Drosophila protein SU(VAR)3–7 is essential for fly viability, chromosome structure, and heterochromatin formation. We report that searches in silico and in vitro for homologues of SU(VAR)3–7 were successful within, but not outside, the Drosophila genus. Protein sequence homology between the distant sibling species Drosophila melanogaster and Drosophila virilis is low, except for the general organization of the protein and three conserved motives: seven widely spaced zinc fingers in the N-terminal half and the BESS and BoxA motives in the C-terminal half of the protein. We have undertaken a fine functional dissection of SU(VAR)3–7 in vivo using transgenes encoding truncations of the protein. BESS mediates interaction of SU(VAR)3–7 with itself, and BoxA is required for specific heterochromatin association. Both are necessary for the silencing properties of SU(VAR)3–7. The seven zinc fingers, widely spaced over the N-terminal half of SU(VAR)3–7, are required for binding to polytene chromosomes. One finger is necessary and sufficient to determine the appropriate chromatin association of the C-terminal half of the protein. Conferring a function to each of the conserved motives allows us to better understand the mode of action of SU(VAR)3–7 in triggering heterochromatin formation and subsequent genomic silencing.     

The SuUR gene influences the distribution of heterochromatic proteins HP1 and SU(VAR)3–9 on nurse cell polytene chromosomes of Drosophila melanogaster

We have investigated the distribution of three heterochromatic proteins [SUppressor of UnderReplication (SUUR), heterochromatin protein 1 (HP1), and SU(VAR)3–9] in chromosomes of nurse cells (NCs) and have compared the data obtained with the distribution of the same proteins in salivary gland (SG) chromosomes. In NC chromosomes, the SU(VAR)3–9 protein was found in pericentric heterochromatin and at 223 sites on euchromatic arms, while in SG chromosomes, it was mainly restricted to the chromocenter. In NC chromosomes, the HP1 and SUUR proteins bind to 331 and 256 sites, respectively, which are almost twice the number of sites in SG chromosomes. The distribution of the HP1 and SU(VAR)3–9 proteins depends on the SuUR gene. A mutation in this gene results in a dramatic decrease in the amount of SU(VAR)3–9 binding sites in autosomes. In the X chromosome, these sites are relocated in comparison to the SuUR ⁺, and their total number only varies slightly. HP1 binding sites are redistributed in chromosomes of SuUR mutants, and their overall number did not change as considerably as SU(VAR)3–9. These data together point to an interaction of these three proteins in Drosophila NC chromosomes.Electronic Supplementary Material Supplementary material is available for this article at.     

Lack of early laboratory postzygotic reproductive isolation between two ecotypes of Littorina saxatilis (Mollusca, Gastropoda) showing strong premating sexual isolation

Two sympatric and divergent adaptive ecotypes of Littorina saxatilis (RB and SU) are known to hybridize showing partial premating isolation in the wild. Previous studies have revealed that morphological intermediate forms (presumably hybrids) present fitness (viability, sexual selection and fecundity) similar to that from pure ecotypes at the mid-shore. However, the absence of postzygotic isolation due to genetic incompatibility cannot be ruled out unless it is measured directly on true F ₁ hybrids. In this study, we overcome this problem and present data on 56 individual crosses including the four possible mating combinations (RB/RB, RB/SU, SU/RB and SU/SU) to compare fertilization and fecundity rates (including young progeny viability) between the four type crosses. Pooled RB female crosses showed apparently larger fertility and fecundity than pooled SU female crosses, probably because of differences in fecundity and laboratory survivorship between ecotypes. However, similar fertilization and fecundity rates were found for both RB and SU females when mated with different male types, supporting the idea that genetic-incompatibility-based postzygotic isolation can be ignored as a major determinant of this polymorphism in nature.     

Pronase-susceptible Floc Forming Bacteria: Relationship between Flocculation and Calcium Ion

Six strains of floc-forming bacteria belonging to Flavobacterium were isolated from activated sludge which were deflocculated by Pronase treatment. The flocculated cells of the strain B, one of the isolates, was deflocculated not only by Pronase, but also by ethylenediaminetetraacetate. Growth was stimulated when Pronase was added in the medium. An adequate amount of calcium ion in the medium was required for flocculation. No flocculation was observed, however, when calcium was added to the cells grown with a low level of calcium. Deflocculation was observed at the late stationary phase and the onset of deflocculation depended on the concentrations of calcium in the medium. The higher concentrations delayed the deflocculation. The floes formed in the presence of calcium over 0.5 nm in the medium became resistant to the Pronase treatment.     

Protein-free culture medium containing polyvinylalcohol, vitamins, and amino acids supports development of eight-cell hamster embryos to hatching blastocysts

In vitro development of eight-cell hamster embryos to hatching blastocysts requires the presence of amino acids and a group of water-soluble vitamins in the culture medium. The present studies investigated the effect of type of macromolecule on blastocyst hatching and on the requirement for vitamins. Embryos were cultured for 3 days in the presence of the synthetic macromolecule polyvinylalcohol (PVA) and of different types of bovine serum albumin (BSA), both with and without vitamins. The results showed th at eight-cell embryos develop to hatching blastocysts in the presence of vitamins and amino acids with PVA as the only macromolecule in the medium. The presence of certain types of BSA reduced but did not eliminate the need for vitamins. Glutamine alone was as efficient as a complete amino acid supplement in supporting blastocyst hatching. These results demonstrate for the first time that eight-cell hamster embryos can be cultured to hatching blastocysts in a chemically defined medium.     

Expression of endogenous retrovirus ev/J <Emphasis Type="Italic">gp85</Emphasis> gene and analysis of its immunoreactivity in comparison with exogenous viral protein

The envelope gene gp85 of ev/J, a new family of endogenous avian retroviral sequences identified recently, has the most extensive nucleotide sequence identity ever described with ALV-J avian leukosis virus. This report described expression of ev/J envelope gene gp85 derived from commercial meat-type chicken using the Invitrogen Bac-to-Bac baculovirus expression system. The antigenicity and immunoreactivity of the recombinant endogenous gp85 gene product (SU) were analyzed by indirect immunofluorescence, Western blot, indirect and blocking Enzyme-Linked ImmunoSorbent Assay (ELISA) using JE9 monoclonal antibody (MAb) against the envelope protein of ALV-J (ADOL-4817), positive mouse antiserum against the ev/J gp85 SU and sera from chicken naturally infected with ALV-J. The results showed that the ev/J gp85 SU can bind specifically to JE9 MAb and antiserum from chicken naturally infected with ALV-J, and the binding reactivity between exogenous ALV-J gp85 SU and natural positive chicken serum against exogenous ALV-J can be blocked by positive mouse serum against the ev/J gp85 SU. It is concluded that recombinant endogenous gp85 gene product (SU) has close immunological relatedness to the envelope protein of exogenous ALV-J (ADOL-4817 and IMC₁₀₂₀₀ strain). Foundation items: Natural Science Foundation of China (30460098); China Postdoctoral Science Foundation funded project (2005038585).     

B-group vitamins production by mycorrhizal fungi in response to pH (in vitro studies)

Studies were carried out on B-group vitamins production by mycorrhizal fungi grown in vitro at different pH values. It was found that not all the fungi investigated produced all the B-group vitamins studied. Production of the vitamins varied between species and was influenced by the pH of the medium. Out of seven fungal species studied three did not produce biotin. Suillus bovinus synthesized this vitamin both in the acidic and neutral medium. Thiamin was produced by the fungi in minute amounts mainly in the acidic medium. The greatest amounts of nicotinic acid were produced by Hebeloma crustuliniforme (No 5392). Pantothenic acid was not detected only in the culture of Cenococcum graniforme.     

In vivo analysis of <Emphasis Type="Italic">Drosophila</Emphasis> SU(<Emphasis Type="Italic">Z</Emphasis>)12 function

Polycomb group (PcG) proteins are required to maintain a stable repression of the homeotic genes during Drosophila development. Mutants in the PcG gene Supressor of zeste 12 (Su(z)12) exhibit strong homeotic transformations caused by widespread misexpression of several homeotic genes in embryos and larvae. Su(z)12 has also been suggested to be involved in position effect variegation and in regulation of the white gene expression in combination with zeste. To elucidate whether SU(Z)12 has any such direct functions we investigated the binding pattern to polytene chromosomes and compared the localization to other proteins. We found that SU(Z)12 binds to about 90 specific eukaryotic sites, however, not the white locus. We also find staining at the chromocenter and the nucleolus. The binding along chromosome arms is mostly in interbands and these sites correlate precisely with those of Enhancer-of-zeste and other components of the PRC2 silencing complex. This implies that SU(Z)12 mainly exists in complex with PRC2. Comparisons with other PcG protein-binding patterns reveal extensive overlap. However, SU(Z)12 binding sites and histone 3 trimethylated lysine 27 residues (3meK27 H3) do not correlate that well. Still, we show that Su(z)12 is essential for tri-methylation of the lysine 27 residue of histone H3 in vivo, and that overexpression of SU(Z)12 in somatic clones results in higher levels of histone methylation, indicating that SU(Z)12 is rate limiting for the enzymatic activity of PRC2. In addition, we analyzed the binding pattern of Heterochromatin Protein 1 (HP1) and found that SU(Z)12 and HP1 do not co-localize.     

A high-sucrose diet increases gluconeogenic capacity in isolated periportal and perivenous rat hepatocytes

A high-sucrose (SU) diet increases gluconeogenesis (GNG) in the liver. The present study was conducted to determine the contribution of periportal (PP) and perivenous (PV) cell populations to this SU-induced increase in GNG. Male Sprague-Dawley rats were fed an SU (68% sucrose) or starch (ST, 68% starch) diet for 1 wk, and hepatocytes were isolated from the PP or PV region of the liver acinus. Hepatocytes were incubated for 1 h in the presence of various gluconeogenic substrates, and glucose release into the medium was used to estimate GNG. When incubated in the presence of 5 mM lactate, which enters GNG at the level of pyruvate, glucose release (nmol x h(-1) x mg(-1)) was significantly increased by the SU diet in both PP (84.8 +/- 3.4 vs. 70.4 +/- 2.6) and PV (64.3 +/- 2.5 vs. 38.2 +/- 2.1) cells. Addition of palmitate (0.5 mM) increased glucose release from lactate in PP cells by 11.6 +/- 0.5 and 20.6 +/- 1.5% and in PV cells by 11.0 +/- 4.4 and 51.1 +/- 9.1% in SU and ST, respectively. When cells were incubated with 5 mM dihydroxyacetone (DHA), which enters GNG at the triosephosphate level, glucose release was significantly increased by the SU diet in both cell types. In contrast, glucose release from fructose (0.5 mM) was significantly increased by the SU diet in PV cells only. These changes in glucose release were accompanied by significant increases in the maximal specific activities of glucose-6-phosphatase (G-6-Pase) and phosphoenolpyruvate carboxykinase (PEPCK) in both PP and PV cells. These data suggest that the SU diet influences GNG in both PP and PV cell populations. It appears that SU feeding produces changes in GNG via alterations in at least two critical enzymes, G-6-Pase and PEPCK.     

Genetic Diversity of Plant Growth Promoting Rhizobacteria Isolated from Rhizospheric Soil of Wheat Under Saline Condition

In this study, a total of 130 rhizobacteria was isolated from a saline infested zone of wheat rhizosphere, and screened for plant growth promoting (PGP) traits at higher salt (NaCl) concentrations (2, 4, 6, and 8%). The results revealed that 24 rhizobacterial isolates were tolerant at 8% NaCl. Although all the 24 salt tolerable isolates produced indole-3-acetic acid (IAA), while 10 isolates solubilized phosphorus, eight produced siderophore, and six produced gibberellin. However, only three isolates showed the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Diversity was analyzed through 16S rDNA-RFLP, and of these isolates with three tetra cutter restriction enzymes (HaeIII, AluI, and MspI), the representative cluster groups were identified by 16S rDNA sequencing. Bacillus and Bacillus-derived genera were dominant which showed PGP attributes at 8% NaCl concentration. Out of 24 isolates, nitrogen fixing ability (nif H gene) was detected in the two isolates, SU18 (Arthrobacter sp.) and SU48.     

Thermostable amylolytic enzymes from a cellulolytic fungusMyceliophthora thermophila D14 (ATCC 48 104)

Summary The production of amylolytic enzymes by a thermophilic cellulolytic fungus,Myceliophthora thermophila D14 was investigated by batch cultivation in Czapek-Dox medium at 45° C. Among various nitrogenous compounds used, NaNO₃ and KNO₃ were found to be the best for amylase production. Starch, cellobiose and maltose induced the synthesis of amylase while glucose, fructose, galactose, lactose, arabinose, xylose, sorbitol, mesoinositol and sucrose did not. Calcium ions had the most stimulating effect on enzyme formation amongst many ions investigated. The synthesis of amylolytic enzymes was dependent on growth and occurred predominantly in the mid-stationary phase. The enzyme was active in a broad temperature range (50° C–60° C) and displayed activity optima at 60° C and pH 5.6.