Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- 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 cDNAs encoding cytosolic malate dehydrogenase and vacuolar (H+)-ATPase in Annona cherimola and their expression during postharvest ripeningPublication . Gouveia, Manuela; Rodrigues, Mónica; Teixeira, Lucília; Cordeiro, NereidaThis study aims to investigate the expression of two cherimoya genes putatively related to fruit ripening. Two full-length cDNAs encoding cytosolic NAD-dependent malate dehydrogenase (AccytMDH) and vacuolar (H+)-ATPase c subunit (AcVHA-c) were isolated from Annona cherimola using the reverse transcriptase polymerase chain reaction (RT- PCR) and rapid amplification of cDNA ends (RACE). The AccytMDH codes for a 332 amino acid polypeptide with a predicted molecular mass of 35.6 kDa. The deduced amino acid sequence for AccytMDH shared high identity with other plant homologous malate dehydrogenase proteins. The AcVHA-c encodes a proteolipid subunit of the V-type proton ATPase with 166 amino acids (16.7 kDa). Comparison of the deduced amino acid sequence from AcVHA-c revealed four transmembrane domains highly conserved among plant counterparts. The expression of AccytMDH and AcVHA-c, assessed by semi-quantitative RT-PCR showed that there is an increase in the accumulation of transcripts during postharvest ripening, although not correlated by a significant upsurge of titratable acidity they might contribute to organic acid accumulation and translocation during postharvest ripening of cherimoya in association with other enzymes and carriers. By using AccytMDH and AcVHA-c as molecular targets new strategies can be exploited to get a clear picture in the ripening of cherimoya.