RESUMO
In the present work, the surface characteristics of a wild-type strain of Yarrowia lipolytica (IMUFRJ50682) were investigated. Six different methods to characterize cell surfaces--adhesion to polystyrene; hydrophobic interaction chromatography (HIC); microbial adhesion to solvents (MATS) test; zeta potential; microbial adhesion to hydrocarbons (MATH) test; and contact angle measurement (CAM)--were employed to explain the cell surface behaviour of Y. lipolytica (IMUFRJ50682). This Y. lipolytica strain presents significant differences at the cell surface compared with another Y. lipolytica strain (W29) previously reported in the literature. The main difference is related to the higher cell adhesion to non-polar solvents. The proteins present on the cell wall of Y. lipolytica IMUFRJ50682 seem to play an important role in these particular surface characteristics because of the consistent reduction of this yeast hydrophobic character after the action of pronase on its cell wall.
Assuntos
Yarrowia/fisiologia , Alcanos , Adesão Celular/fisiologia , Interações Hidrofóbicas e Hidrofílicas , Poliestirenos , Análise Espectral , Propriedades de SuperfícieAssuntos
Brassica , Contenção de Riscos Biológicos , Plantas Geneticamente Modificadas , Aminobutiratos/farmacologia , Sequência de Bases , Brassica/genética , Brassica/fisiologia , Primers do DNA , Resistência a Medicamentos/genética , Genes de Plantas , Herbicidas/farmacologia , Hibridização Genética/genética , Dados de Sequência Molecular , Pólen , TransgenesRESUMO
A clear influence of ploidy was observed on the frequency of both spontaneous and nitroso-methylurea (NMU) induced, streptomycin-resistant, adventitious shoots developing on leaf explants of Nicotiana tabacum and N. plumbaginifolia. At nearly all NMU levels employed a significantly higher yield of resistant shoots was obtained from haploid compared with diploid leaf strips. At 1 mM NMU the differences were not significant and were absent when a high (1000 mg/l) selective concentration of streptomycin sulphate was used. The influence of ploidy is discussed in relation to the possible effect of plastome copy number on mutagenesis and sorting out of resistant plastids.
Assuntos
Nicotiana/genética , Plantas Tóxicas , Ploidias , Estreptomicina/farmacologia , Cloroplastos , Resistência a Medicamentos/genética , Metilnitrosoureia/farmacologia , Mutação/genética , Nicotiana/efeitos dos fármacos , Nicotiana/crescimento & desenvolvimentoRESUMO
The chloroplast genome encodes a number of proteins, including thylakoid proteins and the large subunit of ribulose biphosphate carboxylase, associated with the structure and function of the chloroplast (1-2). In addition, many components of the chloroplast translational machinery, such as all of the RNAs and some of the ribosomal proteins, are coded by the chloroplast DNA. Although there have been numerous investigations into the genetics of algal chloroplasts, similar studies with higher plants have been hampered by the uniparental (maternal) pattern of transmission of chloroplasts observed in most species, and the shortage of suitable genetic markers (3,4).
