2 results for Ambrose, M

  • Broad spectrum antimicrobial activity of functionalized polyanilines

    Gizdavic Nikolaidis, Marija; Bennett, JR; Swift, Simon; Easteal, AJ; Ambrose, M (2011-07-24)

    Journal article
    The University of Auckland Library

    The antimicrobial properties of conductive functionalized polyanilines (fPANI) were investigated by exploring their interaction with bacterial cells. In sharp contrast to polyaniline (PANI), lower concentrations of fPANI were needed to strongly inhibit the growth of wild-type Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, as well as several antibiotic-resistant clinical pathogens. To gain an insight into how fPANI have an impact on cellular physiology we used a whole genome expression study in the model E. coli MG1655 strain exposed to a representative fPANI. The expression levels of 218 (???5.1%) genes changed significantly. Moreover, we found that certain oxidative damage-responsive genes were strongly induced, while genes potentially involved in energy metabolism and transport and in forming bacterial cell walls and stress-resistant cellular communities (biofilms) were repressed. Taken together, our results appear to indicate that the antimicrobial effects of fPANI, in part at least, might stem from their ability to target the operations of multiple and diverse cellular processes, and suggest that fPANI could be useful ingredients for biomaterials used in the development of food packaging and medical devices

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  • NODULE ROOT and COCHLEATA maintain nodule development and are legume orthologs of Arabidopsis BLADE-ON-PETIOLE genes

    Couzigou, JM; Zhukov, V; Mondy, S; Abu el Heba, G; Cosson, V; Ellis, THN; Ambrose, M; Wen, J; Tadege, M; Tikhonovich, I; Mysore, KS; Putterill, Joanna; Hofer, J; Borisov, AY; Ratet, P (2012-11)

    Journal article
    The University of Auckland Library

    During their symbiotic interaction with rhizobia, legume plants develop symbiosis-specific organs on their roots, called nodules, that house nitrogen-fixing bacteria. The molecular mechanisms governing the identity and maintenance of these organs are unknown. Using Medicago truncatula nodule root (noot) mutants and pea (Pisum sativum) cochleata (coch) mutants, which are characterized by the abnormal development of roots from the nodule, we identified the NOOT and COCH genes as being necessary for the robust maintenance of nodule identity throughout the nodule developmental program. NOOT and COCH are Arabidopsis thaliana BLADE-ON-PETIOLE orthologs, and we have shown that their functions in leaf and flower development are conserved in M. truncatula and pea. The identification of these two genes defines a clade in the BTB/POZ-ankyrin domain proteins that shares conserved functions in eudicot organ development and suggests that NOOT and COCH were recruited to repress root identity in the legume symbiotic organ.

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