Pollination Ecology and Endemic Trends in Pedicularis bracteosa var. atrosanguinea Pennell & Thompson (Scrophulariaceae) in North America

Abstract Pedicularis bracteosa var. atrosanguinea occurs locally in association with P. racemosa or P. groenlandica in the Olympic Mountains in Washington. Other plant species, e.g., Polygonum bistortoides, Lupinus argenteus var. parviflorus and Valeriana sitchensis compete for space and bumblebee pollinators within the study area. Pollinator sharing, resulting from such competition, may increase the frequency of unvisited flowers of P. bracteosa var. atrosanguinea. P. bracteosa var. atrosanguinea , with blood purple nectariferous flowers, is presumed to lack intense reflections of blue spectral components from its corollas in attracting bumblebees compared to those of P. racemosa and P. groenlandica . Six species of bumblebees ( Bombus ) and cuckoo bees ( Psithyrus ) pollinate P. bracteosa var. atrosanguinea . Of these, Bombus mixtus and B. occidentalis occur in higher frequencies and are the major pollinators of P. bracteosa var. atrosanguinea . Queen and larger worker bumblebees pollinate nototribically as they probe for nectar, while smaller worker bumblebees pollinate sternotribically while scraping pollen from anthers deeply hidden in the dome-shaped galea. Corbicular pollen loads of bumblebees collected in the study area contain Pedicularis pollen alone/in combination of Polygonum, Valeriana, Lupinus, Erigeron and Bidens , or exclusively of Polygonum or Valeriana. P. bracteosa var. atrosanguinea does not suffer seriously from deficient pollination but seedlings resulting from pollinated flowers may be subjected to natural selection pressure exerted by colonial plant species for space. P. bracteosa var. atrosanguinea does not propagate asexually but resumes aerial growth seasonally from the self-same underground root stocks. If seedlings are under continuous selection pressure for lack of space, P. bracteosa var. atrosanguinea is presumed to regenerate primarily by perennial root stocks. This behavior may favor endemism in P. bracteosa var. atrosanguinea .     

Evaluation of Certain Cowpea Genotypes for Partial Resistance to Powdery Mildew (Erysiphe polygoni)

Partial resistance to powdery mildew (Erysiphe polygoni) in twenty one cowpea cultivars was assessed over two to three seasons under field conditions. Mildew incidence was recorded as number of leaflets affected/plant and severity as AUDPC or infection rate using Gompertz transformation. Irrespective of the parameter used to measure mildew resistance or the season, mean response of cvs V-105, V-269, V-276, V-282 and V-385 showed clear slow-mildewing, while RC-48, S-488, TVX-944-02E, V-27, V-36 and V-118 were rated as susceptible. Mildew resistance in some cultivars was negatively correlated with that for the leaf rust (Uromyces vignae). AUDPC was a more robust disease parameter than infection rate and showed a good correlation (r²= 0.79) with incidence.     

Reaction of selenomethionine with o-benzoquinone

A new reaction of selenomethionine with o-benzoquinone is described. This reaction can be used to distinguish between methionine and selenomethionine.     

Glucosiduronidation and esterification of androsterone by human breast tumors invitro

The metabolism of ³H-androsterone was studied in homogenates (fortified with uridine 5'-diphosphoglucuronic acid and andenosine 3'-phosphate 5'-phosphosulfate) of eighteen breast tumors, one muscle underlying the primary breast carcinoma and metastatic axillary lymph nodes from a patient with suspected primary breast cancer. The major metabolites identified were less polar than androsterone. On saponification these lipoidal derivatives afforded androsterone as the only product (3 to 48%). Unmetabolized androsterone and lesser quantities of epiandrosterone, 5α-androstane-3α,17β-diol and 5α-androstane-3,17-dione comprised the free steroid fraction. Androsterone glucosiduronate was isolated (0.17–4.1%) from eight breast tumor homogenates and from the node tissue incubation (17%). There was no apparent correlation between glucuronyltransferase activity and histopathology or estrogen receptor content.     

Gametogenesis,endosperm development,and embryogeny inMicrocarpaea muscosa (Scrophulariaceae,Gratioleae)

InMicrocarpaea muscosa gametogenesis, embryo sac development (Polygonum type), endosperm development (cellular), embryogeny (Onagrad type), and seed structure are described. The different modes of endosperm development withinGratioleae are compared.     

Synthesis, spectroscopic characterization and structural studies of mixed ligand complexes of Sr(II) and Ba(II) with 2-hydroxybenzophenone and salicylaldehyde, hydroxyaromatic ketones or β-diketones: Crystal structure of 2-HOC6H4C(O)C6H5

Reactions of Sr(II) and Ba(II) chlorides with 2-hydroxybenzophenone and salicylaldehyde, hydroxyaromatic ketones or β-diketones in 1:1:1 molar ratios have resulted in the formation of mixed ligand complexes of the type [MLL′(H₂O)₂] (M = Sr(II) or Ba(II); HL = 2-hydroxybenzophenone and HL′ = salicylaldehyde, 2-hydroxyacetophenone, 2-hydroxypropiophenone, pentane-2,4-dione, 1-phenylbutane-1,3-dione or 1,3-diphenylpropane-1,3-dione). These complexes have been characterized by elemental analyses, TLC, IR and ¹H NMR spectroscopy.     

Diversity and polymorphism in AHL-lactonase gene (aiiA) of Bacillus

To explore bacterial diversity for elucidating genetic variability in acylhomoserine lactone (AHL) lactonase structure, we screened 800 bacterial strains. It revealed the presence of a quorum quenching (QQ) AHL-lactonase gene (aiiA) in 42 strains. These 42 strains were identified using rrs (16S rDNA) sequencing as Bacillus strains, predominantly B. cereus. An in silico restriction endonuclease (RE) digestion of 22 AHL lactonase gene (aiiA) sequences (from NCBI database) belonging to 9 different genera, along with 42 aiiA gene sequences from different Bacillus spp. (isolated here) with 14 type II REs, revealed distinct patterns of fragments (nucleotide length and order) with four REs; AluI, DpnII, RsaI, and Tru9I. Our study reflects on the biodiversity of aiiA among Bacillus species. Bacillus sp. strain MBG11 with polymorphism (115Alanine > Valine) may confer increased stability to AHL lactonase, and can be a potential candidate for heterologous expression and mass production. Microbes with ability to produce AHL-lactonases degrade quorum sensing signals such as AHL by opening of the lactone ring. The naturally occurring diversity of QQ molecules provides opportunities to use them for preventing bacterial infections, spoilage of food, and bioremediation.     

Design of EGFR kinase inhibitors: a ligand-based approach and its confirmation with structure-based studies

Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were developed for 100 anilinoquinazolines, inhibiting epidermal growth factor receptor (EGFR) kinase. The studies included molecular field analysis (MFA) and receptor surface analysis (RSA). The cross-validated r2 (r2cv) values are 0.81 and 0.79 for MFA and RSA, respectively. The predictive ability of these models was validated by 28 test set molecules. The results of the best QSAR model were further compared with structure-based investigations using docking studies with the crystal structure of EGFR kinase domain. The results helped to understand the nature of substituents at the 6- and 7-positions, thereby providing new guidelines for the design of novel inhibitors.     

Surface modified dendrimers: synthesis and characterization for cancer targeted drug delivery

Dendrimers represents a highly branched three-dimensional structure that provides a high degree of surface functionality and versatility. PAMAM dendrimers are used as well-defined nanocontainers to conjugate, complex or encapsulate therapeutic drugs or imaging moieties. Star-burst [PAMAM] dendrimers represent a superior carrier platform for drug delivery. The present study was aimed at synthesis of a surface modified dendrimer for cancer targeted drug delivery system. For this 4.0 G PAMAM dendrimer was conjugated with Gallic acid [GA] and characterized through UV, IR, 1H NMR and mass spectroscopy. Cytotoxicity study of dendrimer conjugate was carried out against MCF-7 cell line using MTT assay. The study revealed that the conjugate is active against MCF-7 cell line and might act synergistically with anti-cancer drug and gallic acid-dendrimer conjugate might be a promising nano-platform for cancer targeting and cancer diagnosis.     

An improved Agrobacterium-mediated transformation of recalcitrant indica rice (Oryza sativa L.) cultivars

Agrobacterium-mediated transformation of indica rice varieties has been quite difficult as these are recalcitrant to in vitro responses. In the present study, we established a high-efficiency Agrobacterium tumefaciens-mediated transformation system of rice (Oryza sativa L. ssp. indica) cv. IR-64, Lalat, and IET-4786. Agrobacterium strain EHA-101 harboring binary vector pIG121-Hm, containing a gene encoding for β-glucuronidase (GUS) and hygromycin resistance, was used in the transformation experiments. Manipulation of different concentrations of acetosyringone, days of co-culture period, bacterial suspension of different optical densities (ODs), and the concentrations of l-cysteine in liquid followed by solid co-culture medium was done for establishing the protocol. Among the different co-culture periods, 5 days of co-culture with bacterial cells (OD_600 nm?=?0.5–0.8) promoted the highest frequency of transformation (83.04 %) in medium containing l-cysteine (400 mg l^?1). Putative transformed plants were analyzed for the presence of a transgene through genomic PCR and GUS histochemical analyses. Our results also suggest that different cultural conditions and the addition of l-cysteine in the co-culture medium improve the Agrobacterium-mediated transformation frequencies from an average of 12.82 % to 33.33 % in different indica rice cultivars.