Molecular characterization and expression analysis of the Na<Superscript>+</Superscript>/H<Superscript>+</Superscript> exchanger gene family in <Emphasis Type="Italic">Medicago truncatula</Emphasis>

One important mechanism plants use to cope with salinity is keeping the cytosolic Na⁺ concentration low by sequestering Na⁺ in vacuoles, a process facilitated by Na⁺/H⁺ exchangers (NHX). There are eight NHX genes (NHX1 through NHX8) identified and characterized in Arabidopsis thaliana. Bioinformatics analyses of the known Arabidopsis genes enabled us to identify six Medicago truncatula NHX genes (MtNHX1, MtNHX2, MtNHX3, MtNHX4, MtNHX6, and MtNHX7). Twelve transmembrane domains and an amiloride binding site were conserved in five out of six MtNHX proteins. Phylogenetic analysis involving A. thaliana, Glycine max, Phaseolus vulgaris, and M. truncatula revealed that each individual MtNHX class (class I: MtNHX1 through 4; class II: MtNHX6; class III: MtNHX7) falls under a separate clade. In a salinity-stress experiment, M. truncatula exhibited ~?20% reduction in biomass. In the salinity treatment, sodium contents increased by 178 and 75% in leaves and roots, respectively, and Cl^? contents increased by 152 and 162%, respectively. Na⁺ exclusion may be responsible for the relatively smaller increase in Na⁺ concentration in roots under salt stress as compared to Cl^?. Decline in tissue K⁺ concentration under salinity was not surprising as some antiporters play an important role in transporting both Na⁺ and K ⁺ . MtNHX1, MtNHX6, and MtNHX7 display high expression in roots and leaves. MtNHX3, MtNHX6, and MtNHX7 were induced in roots under salinity stress. Expression analysis results indicate that sequestering Na⁺ into vacuoles may not be the principal component trait of the salt tolerance mechanism in M. truncatula and other component traits may be pivotal.     

Fungi of certain stored vegetable seeds in relation to pre- and post-emergence effects

A number of fungi were found associated with stored cauliflower, common bean, and pea seeds, but onlyHelminthosporium sp. on cauliflower,Fusarium sp. on common bean, andAlternaria sp. on pea were proved pathogenic. Artificial inoculation tests withHelminthosporium sp.,Fusarium sp., andAlternaria sp. resulted in 30, 16.6, and 26.6 % pre-emergence injuries to cauliflower, common bean, and pea respectively. Also, these fungi were responsible for considerable post-emergence mortality of seedlings.

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Zusammenfassung Eine Anzahl von Pilzen sind mit dem Samen von Karfiol, Bohnen und Erbsen vergesellschaftet gefunden worden.Helminthosporium sp. nur an Karfiol,Fusarium sp. nur an Bohnen undAlternaria sp. nur an Erbsen haben sich als pathogen erwiesen. Küristliche Einimpfung mitHelminthosporium sp.,Fusarium sp., undAlternaria sp. gab positive Resultate in 30, 16.6, und 26.6 % bezw. in Karfiol, Bohnen und Erbsen. Diese Pilzen waren auch für das Absterben junger Pflanzen verantwortlich.

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Portion of a thesis submitted by the senior author to the Agra University, Agra, India, in partial fulfilment of the requirements for the degree of M.Sc. (Ag.).     

Partial trisomy for the short arm of chromosome 2 due to familial balanced translocation

Summary A partial trisomy for the short arm of chromosome 2 (p21pter) was observed in a severely retarded infant with facial, skeletal, genital, renal, and CNS anomalies. The phenotypically normal mother and older brother had a balanced translocation between the short arm of chromosome 2 and the long arm of chromosome 14: 46,XX-XY,t(2;14)(p21;q32).     

Effect of manganese on zinc-65 absorption by rice seedlings and its translocation within the plants

Summary Effect of manganese on absorption and translocation of zinc by rice seedlings was studied in a nutrient solution using radioactive zinc (Zn⁶⁵). With increase in manganese application, zinc uptake decreased in roots, but increased in shoots with an application upto 10 M manganese. Reduction in zinc absorption was more at low rates of zinc application. However, translocation of zinc from roots to shoots increased with manganese application upto 20 M but the increase was more pronounced with an application of 2M zinc only.     

Changes in extractable organic phosphorus in soil in the presence and absence of plants

Summary The effect of cropping on soil organic phosphorus was investigated in laboratory and greenhouse work with six soils. Successively lower contents of extractable organic phosphorus were found in samples that had been (a) airdried initially and stored in that condition, (b) incubated in a moist condition but without a crop, and (c) planted to four successive crops, the roots of the crops being removed before analysis of the soil. These differences were statistically significant. Samples of rhizosphere soil taken after the fourth crop did not yield significantly different amounts of extractable organic phosphorus than did bulk samples of cropped soil taken at the same time. Extractable organic and inorganic phosphorus in the soils were not significantly affected by drying the soil before each crop.Journal Paper No. J-5916 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 1183.Former Rockefeller Fellow and Professor, respectively. The senior author is now Associate Professor, Department of Soils, Punjab Agricultural University, Ludhiana, Punjab.     

Identification of inducible proteins in the phenanthrene degrader <Emphasis Type="Italic">Sphingobium chungbukense</Emphasis> DJ77 by 2-dimentional electrophoresis and liquid chromatography/tandem mass spectrometry

Sphingomonas chungbukensis DJ77 is a novel aromatic hydrocarbon-degrading bacterium capable of growing on phenanthrene as its sole source of carbon and energy. In this study, the protein expression profiles of S. chungbukensis DJ77 grown in the presence of phenanthrene were investigated by using two-dimensional gel electrophoresis (2-DE). Among 1000 protein spots visualized by 2-DE, the four proteins (i.e. 4-oxalocrotonate decarboxylase, 2-hydroxy-6-oxo-phenylhexa-2,4-dienoate hydrolase, glutathione S-transferase, and 2,3-dihydroxybiphenyl 1,2-dioxygenase) showing the significant upregulation by phenanthrene were identified by reversed-phase liquid chromatography–tandem mass spectrometry. Evidently, these proteins were involved in the metabolism of aromatic hydrocarbons. This can explain why S. chungbukensis DJ77 shows a significantly higher rate of phenanthrene consumption during the degradation process. The present analysis of proteomic responses and the detailed analysis results will be quite helpful to better understand the global physiology of S. chungbukensis DJ77, as proteome databases for various aromatic hydrocarbon-degrading strains have already been established.     

Metal chelates with biological activity. Part 4. Solution properties of iron(III)-histidinehydroxamic acid

Reactions of carbon monoxide with iron(II) diethyldithiocarbamate and iron(II) ethylxanthate were followed using solution IR spectroscopy. In DMF and CH₃CN solutions, the only Fe—dithiocarbamate—carbon monoxide complex observed was cis-[Fe(CO)₂(dedtc)₂]. This complex formed rapidly and appeared to be very stable, resisting displacement of the coordinated CO molecules by other ligands. Fe(exa)₂ showed very little coordination of CO in DMF solution, but in CH₃CN solution formed the complex cis-[Fe(CO)₂(exa)₂] rapidly via the monocarbonyl intermediate [Fe(CO)(exa)₂CH₃CN]. In CHCl₃ solution, in the presence of CO and added bases, a series of complexes, [Fe(CO)(exa)₂L], where L = pyridine, pyrrolidine, diethylamine and triphenylphosphine, was formed. However, with the exception of [Fe(CO)(exa)₂(ø₃P)], these monocarbonyl complexes were unstable with respect to disproportionation to cis-[Fe(CO)₂(exa)₂] and [Fe(exa)₂L₂]. No mixed-ligand monocarbonyl complexes were observed with Fe(dedtc)₂.     

Genomic analysis of Indian strains of Salmonella enterica subsp. enterica serovar Typhi indicates novel genetic repertoire for pathogenicity and adaptations

Molecular Biology Reports - In the era of emerging antibiotic resistance, Salmonella enterica subsp. enterica serovar Typhi the causative agent of typhoid, is a threat for healthcare systems in...