Browsing by Author "Pestana, Margarida"
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- Efeitos de Solanum sisymbriifolium e S. nigrum sobre o nemátode-das-lesões-radiculares, Pratylenchus goodeyi, parasita da bananeiraPublication . Pestana, Margarida; Gouveia, Manuela; Abrantes, IsabelO objectivo deste trabalho foi desenvolver uma estratégia de luta contra o nemátode das-lesões-radiculares, Pratylenchus goo deyi, utilizando Solanum sisymbriifolium e S. nigrum como adubo verde ou biofumi gante. Inicialmente, foram realizados ensaios de patogenicidade, tendo-se verificado que apesar de P. goodeyi se ter reproduzido nas duas plantas, os factores de reprodução fo ram muito baixos (0,001), podendo ser con sideradas como resistentes ou, pelo menos, hospedeiros fracos. A incorporação de qual quer uma das espécies de Solanum no solo, com bananeiras infectadas com P. goodeyi, influenciou o crescimento das bananeiras e a reprodução de P. goodeyi foi superior nas ba naneiras apenas infectadas com o nemátode. Os extractos aquosos de S. sisymbriifolium foram os mais eficazes na mortalidade de P. goodeyi na concentração de 250 mg/ml. De acordo com os resultados obtidos, pode-se concluir que as plantas de S. sisymbriifolium e S. nigrum poderão ser utilizadas como adu bo verde e como biofumigante.
- In vitro evaluation of nematicidal properties of Solanum sisymbriifolium and S. nigrum extracts on Pratylenchus goodeyiPublication . Pestana, Margarida; Rodrigues, Mónica; Teixeira, Lucília; Abrantes, Isabel de O.; Gouveia, Manuela; Cordeiro, NereidaThe root-lesion nematode, Pratylenchus goodeyi, is among the most economically damaging parasites of banana plants. Nematode control can benefit from searching for novel bio-nematicides. The present study was carried out to assess the potential nematicidal properties of two Solanum species (Solanum sisynibriífolíum and S. nigrum) against P. goodeyi, using dichloromethane, acetone, ethanol and either cold or hot water extracts of the plants. Water extracts of both plants at a concentration of 10 mg ml" ' greatly affected nematode movement and also caused mortality. The analysis of sequential extracts at the same experimental concentrations showed that, although water extracts affect nematode mobility and mortality, the acetone extract from S. nigrum was the most efficient, causing 100% mortality after 23 h exposure. The results showed that S. sísymbríífolíum and S. nigrum extracts contain chemical components that induce morphological changes in the body structure of the root-lesion nematode, affect mobihty and cause mortality. The nematostatic and nematicidal potential of the extracts described herein merit further studies to find novel bio-nematicides against the root-lesion nematode.
- Molecular cloning and characterization of cDNA encoding a Translocon-Associated Protein (TRAPδ) from the root-lesion nematode Pratylenchus goodeyiPublication . Pestana, Margarida; Abrantes, Isabel M. de O.; Gouveia, ManuelaThe translocon-associated protein (TRAP) complex comprises four subunits (α, β, γ, δ) and is located in the endoplasmic reticulum membrane at translocation sites. The TRAP complex is required for the efficient translocation of substrates and to correct or eliminate misfolded proteins. In this study, we described the cloning and characterization of a cDNA encoding a TRAP from the phytoparasitic nematode Pratylenchus goodeyi (Pg). The full-length cDNA had an estimated size of 690 bp and encodes a 177 amino acid peptide. The deduced protein after sequence analysis codes for TRAPδ subunit homologous to TRAPδ from other nematodes. The Pg-TRAPδ had a signal peptide indi cating a possible involvement in the transport and binding of other proteins at the endoplasmic reticulum membrane. The increase in relative expression of Pg trapδ, assessed by semi-quantitative PCR, was induced over time in nematodes exposed to a nematostatic/ nematicide extract of Solanum nigrum, suggesting that this gene product might be influenced by response mechanisms to stress in P. goodeyi. This is the first report of the cloning and characterization of trap cDNA from plant endoparasitic nematodes.