588 research outputs found

    Discovery of the first pectin methylesterase gene in a plant-parasitic nematode

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    The root lesion nematode (RLN) Pratylenchus penetrans is considered one of the most damaging plant-parasitic nematode (PPN) species worldwide affecting important agronomic and horticultural crops (e.g. potato, corn). The successful invasion of roots by RLNs is related to their ability to overcome the barrier imposed by the plant cell wall. Like other PPNs, RLNs are equipped with a protrusible stylet that mechanically disrupts the cell wall and through which cell wall-degrading enzymes are secreted to facilitate penetration and migration of the nematode through host roots. Herein, we identified and characterized a pectin methylesterase gene for P. penetrans. Sequence analysis confirm the eukaryotic gene structure of Pp-pme. Expression of the Pp-pme gene was localized in the esophageal glands of P. penetrans as determined by in situ hybridization. The possible function and activity of the gene were assessed by transient expression of Pp-pme in plants of Nicotiana benthamiana plants via a Potato Virus X-based vector. PMEs have been so far described for plants, fungus, bacteria, and to a restrict number of insects. To our knowledge, this is the first report a PME within the phylum Nematoda

    Microcallus growth from maize protoplasts

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    Maize ( Zea mays L. ) protoplasts obtained from Type I and Type II calli from several genotypes were shown to be capable of synthesizing cell walls and forming small clusters of cells. The medium used also supported cluster formation from protoplasts obtained from root tips. The effects of various additions to the medium (such as casein hydrolysate, coconut water, amino acids, sugars, phytohormones, nitrate, calcium, and dimethylsulfoxide as well as pH variations on cellcluster formation were determined. The method of culture (protoplasts plated in agarose or supported in alginate beads in liquid medium) as well as several components of the medium were found to be critical for microcallus formation. Protoplasts obtained from embryogenic Type I callus and cultured in the medium of C. Nitsch and J.P. Nitsch (1967, Planta 72 , 355–370) modified by various additions (NN 67-mod medium) were affected most by various sugars, casein hydrolysate, coconut water, and a combination of the auxins napthalene-1-acetic acid (2 mg/l) and 2,4-dichlorophenoxyacetic acid (0.1 mg/l), and the cytokinin N 6 -benzylaminopurine (0.5 mg/l). Cluster size in the agarose culture system was from 0.1 to 0.5 mm diameter and in the alginate culture system, up to 2.0 mm diameter.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47472/1/425_2004_Article_BF00395067.pd

    Japanese version of the family dermatology life quality index: translation and validation

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    Skin conditions affect the quality of life (QoL) of patients and their family. To assess family members' QoL, a questionnaire uniquely designed for family members is necessary. We translated the Family Dermatology Life Quality Index (FDLQI), originally created and validated by Basra et al., into Japanese, and evaluated its reliability and validity. For psychometric evaluations, 150 dermatology patients and their family members were included. The Japanese version of the FDLQI showed high test–retest reliability (intraclass correlation coefficient = 0.95) and internal consistency reliability (Cronbach's alpha = 0.86). FDLQI scores significantly correlated with DLQI scores (r = 0.58, P < 0.01, Spearman's rho) and global question (GQ) which measured the patient's skin condition on a visual analog scale (r = 0.36, P < 0.01). Family members of patients with inflammatory skin diseases showed higher FDLQI scores than those with isolated lesions, but the difference was not statistically significant (P = 0.062, Mann–Whitney U-test). Responsiveness to change was demonstrated in a group in which the patient's skin condition was assessed as improved (n = 37, r = 0.46, P < 0.01) but not in that in which it became worse. The difference of the change between the two groups was statistically significant (P < 0.01). Additionally, the change in FDLQI scores and GQ were significantly correlated (r = 0.40, P < 0.01). Exploratory factor analysis suggested essential unidimensionality of the instrument. We showed acceptable validity and responsiveness of this Japanese version of FDLQI. Further clinical epidemiological studies are required to confirm this

    The 1501 Ma Kuonamka Large Igneous Province of northern Siberia: U-Pb geochronology, geochemistry, and links with coeval magmatism on other crustal blocks

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    © 2015.A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dikes and sills in the formerly attached Sao Francisco craton (SFC)-Congo craton to yield a short-duration event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (6 new herein) from dolerite dikes and sills across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age uncertainty of the ID-TIMS ages. Geochemical data indicate a tholeiitic basalt composition with low MgO (4-7 wt%) within-plate character based on trace element classification diagrams and source between E-MORB and OIB with only minor contamination from crust or metasomatized lithospheric mantle. Two subgroups are distinguished: Group 1 has gently sloping LREE ((La/Sm)PM = 1.9) and HREE ((Gd/Yb)PM = 1.8) patterns, slightly negative Sr and moderate TiO2 (2.2 wt%), and Group 2 has steeper LREE ((La/Sm)PM = 2.3) and HREE ((Gd/Yb)PM = 2.3), strong negative Sr anomaly, is higher in TiO2 (2.7 wt%), and is transitional from tholeiitic to weakly alkaline in composition. The slight differences in REE slopes are consistent with Group 2 on average melting at deeper levels. Proposed reconstructions of the Kuonamka LIP with 1500 Ma magmatism of the SFC-Congo craton are supported by a geochemical comparison. Specifically, the chemistry of the Chapada Diamantina and Curaga dikes of the SFC can be linked to that of Groups 1 and 2, respectively, of the Kuonamka LIP and are consistent with a common mantle source between EMORB and OIB and subsequent differentiation history. However, the coeval Humpata sills and dikes of the Angola block of the Congo craton represent a different magma batch
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