RESUMO
A new in vitro experimental system was developed to study the morphogenesis of discrete regions of a single extraradical mycelium of the arbuscular mycorrhizal (AM) fungus Glomus intraradices, growing simultaneously in six different agar-based media. The media were (i) unamended water agar (WA), (ii) WA+PO(4)(3-) (PO(4)(3-)), (iii) WA+NO(3)(-) (NO(3)(-)), (iv) WA+NH(4)(+) (NH(4)(+)), (v) WA+NH(4)(+)+MES (NH(4)(+)+MES) and (vi) minimal medium (M, complete nutrients). Each medium was amended with the pH indicator bromocresol purple. The extraradical mycelium of the fungus showed between-treatment differences in morphogenesis, architecture, formation of branched absorbing structures (BAS) and sporulation. Extraradical hyphae that developed in WA or PO(4)(3-) compartments exhibited an economic development pattern, in which runner hyphae radially extended the external colony. Extraradical hyphal growth in the NO(3)(-) compartments was characterized by increased formation of runner hyphae, BAS and spores and an alkalinization of the medium. In the two NH(4)(+)-amended media (NH(4)(+), NH(4)(+)+MES), sporulation was suppressed and considerable morphological changes were noted. These results show the plasticity of G. intraradices that lets it efficiently exploit an heterogeneous substrate.
Assuntos
Fixação de Fratura/veterinária , Fraturas Ósseas/veterinária , Medicina Veterinária/métodos , Analgesia/veterinária , Animais , Antibacterianos/administração & dosagem , Fixação de Fratura/instrumentação , Fixação de Fratura/métodos , Consolidação da Fratura , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/cirurgia , Fraturas Ósseas/terapia , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/veterináriaRESUMO
Reduction of acetophenone by Daucus carota hairy root cultures afforded (S)-phenylethanol in high yield (96%) and excellent enantiomeric excess (ee>or=98%). Aromatic ketones, keto esters, and a simple aliphatic ketone were reduced with good stereoselectivity (ee=62-98%) and moderate to high chemical yields (25-90%).
Assuntos
Daucus carota/metabolismo , Cetonas/metabolismo , Raízes de Plantas/metabolismo , Acetofenonas/química , Acetofenonas/metabolismo , Biotransformação , Cetonas/química , Estrutura Molecular , Álcool Feniletílico/química , Álcool Feniletílico/metabolismo , Estereoisomerismo , Técnicas de Cultura de TecidosRESUMO
To elucidate the effect of cold storage on spore dormancy in the arbuscular mycorrhizal (AM) fungus Glomus intraradices, spores were cold stratified at 4 degrees C, for either 0, 3, 7, 14, 90 or 120 days, prior to germination tests at 25 degrees C. The results showed that cold stratification longer than 14 days significantly increased spore germination. Moreover, the longer cold storage periods clearly reduced spore mortality from 90% to 50% and considerably altered the hyphal growth pattern. Long polarized hyphae were only observed after cold stratification periods longer than 14 days, involving consequences for root infectivity. The results clearly show that environmental factors, e.g., coldness, can affect the physiology of AM fungal spores.