Thermal decomposition of methyl α-d-glycopyranosides

Thermal analysis, coupled with chemical studies, indicates that methyl α-d-glycopyranosides undergo thermal decomposition in two overlapping stages. At lower temperatures, the major reaction is loss of the methoxyl group as methanol, and intra- or inter-molecular condensation of the glycosyl portion of the molecule. At higher temperatures, the predominant reaction is fragmentation of the transglycosylation products. Both reactions were found to be dependent on the configuration of the starting methyl α-d-glycopyranoside.     

Macromolecular naloxone: a novel long-acting polymer-bound drug.

A widely applicable, prolonged-action drug delivery system has been developed using naloxone, a pure narcotic antagonist, as a model. The drug is attached to an inert, water soluble polymer by reversible covalent bonds, whose slow cleavage releases active drug. Naloxone, attached to a hydrazine-substituted polysaccharide by a hydrazone bond, antagonizes morphine analgesia more than 25 times longer than free naloxone.     

Relationship of in vitro and in planta screening: improving the selection process for biological control agents against Fusarium root rot in row crops

Fusarium root rot in row crops is typically managed by cultural practices and fungicide seed treatments. Biological control using microbial agents is another option but needs further development for improved disease management. Screening to identify biocontrol agents are crucial. However, relationships among the steps and how to improve the screening process are unresolved questions. Strains of Burkholderia (4), Bacillus (5) and Trichoderma (26) were studied in vitro against six Fusarium pathogens. All the bacteria and five selected Trichoderma strains were tested in planta in the greenhouse against diseases of Fusarium graminearum and Fusarium oxysporum. Burkholderia ambifaria C628, Bacillus simplex R180, and all Trichoderma isolates showed high reduction in disease levels in corn, soybean and wheat, ranging from 16 to 63%. Responses of the biocontrol agents during in vitro and in planta screening did not always correlate. In vitro and in planta tests should be considered independently in selecting biocontrol candidates.     

Are estrogen receptors cytoplasmic or nuclear? Some immunocytochemical and biochemical studies

The subcellular localization of estradiol receptor (ER) has been examined using various experimental approaches. Immunocytochemical studies using the monoclonal antibody JS 34/32, raised against calf uterine cytosolic ER, yielded only equivocal results. In general, cells and tissues pretreated with estradiol showed positive immunostaining in the nuclei whereas those not exposed to the steroid did not show any staining. Nuclear translocation of ER was examined in intact MCF-7 cells using compounds which are known to influence receptor activation. When MCF-7 cells were exposed to molybdate (20 mM), nuclear translocation was completely inhibited while dithiothreitol (20 mM), dibutyryl cAMP (1 microM) and dibutyryl cGMP (1 microM) increased the translocation 2-3-fold. Phenol red, at the range of concentrations generally used in tissue culture media, also increased translocation. The physiological validity of such translocation was examined using cellular progesterone receptor (PR) synthesis as a specific parameter. When MCF-7 cells were grown in media containing phenol red for 48 h, the PR synthesis increased significantly. We further examined whether cytoskeletal proteins are involved in the translocation of ER. Colchicine, an inhibitor of microtubule assembly, inhibited translocation of ER in MCF-7 cells at 1-10 microM. PR synthesis was also inhibited by colchicine in a dose-dependent manner. It may be concluded from these and other published data that ER may not be located at all times in a single subcellular compartment but may rather exist in a dynamic equilibrium between the plasma membrane, cytoplasm and nucleus.     

CRISPR/Cas9 mediated targeted mutagenesis of LIGULELESS-1 in sorghum provides a rapidly scorable phenotype by altering leaf inclination angle

Sorghum (Sorghum bicolor L. Moench) is one of the world's most cultivated cereal crops. Biotechnology approaches have great potential to complement traditional crop improvement. Earlier studies in rice and maize revealed that LIGULELESS-1 (LG1) is responsible for formation of the ligule and auricle, which determine the leaf inclination angle. However, generation and analysis of lg1 mutants in sorghum has so far not been described. Here, we describe CRISPR/Cas9 mediated targeted mutagenesis of LG1 in sorghum and phenotypic changes in mono- and bi-allelic lg1 mutants. Genome editing reagents were co-delivered to sorghum (var. Tx430) with the nptII selectable marker via particle bombardment of immature embryos followed by regeneration of transgenic plants. Sanger sequencing confirmed a single nucleotide insertion in the sgRNA LG1 target site. Monoallelic edited plantlets displayed more upright leaves in tissue culture and after transfer to soil when compared to wild type. T1 progeny plants with biallelic lg1 mutation lacked ligules entirely and displayed a more severe reduction in leaf inclination angle than monoallelic mutants. Transgene-free lg1 mutants devoid of the genome editing vector were also recovered in the segregating T1 generation. Targeted mutagenesis of LG1 provides a rapidly scorable phenotype in tissue culture and will facilitate optimization of genome editing protocols. Altering leaf inclination angle also has the potential to elevate yield in high-density plantings.