ABSTRACT
The objective of the present study was to evaluate the protection of passion fruit plants against CABMV by using preparations from Agaricus brasiliensis and Lentinula edodes mushrooms. In experiments carried out in the greenhouse, the fruiting body extracts from some of the isolates of both mushrooms significantly reduced CABMV incidence in passion fruit plants. This protective effect occurred when the plant leaves, pre-treated with extracts, were later inoculated mechanically with the virus. However, the extracts did not protect the plants in experiments involving CABMV transmission by aphid vectors. An inhibitory effect of mushroom extracts on the virus particles was also demonstrated on Chenopodium quinoa, a CABMV local lesion host, by inoculating the plants with a mixture of extracts and virus suspension. Still in C. quinoa, the mushroom extracts from some isolates induced systemic resistance against the virus. These results showed that aqueous extracts from A. brasiliensis and L. edodes fruiting bodies had CABMV infectivity inhibitors, but that was not enough to control the viral disease on passion fruit plants at all, considering they were infected through a vector.
O endurecimento dos frutos do maracujazeiro, causado pelo Cowpea aphid-borne mosaic virus (CABMV), é um dos problemas mais sérios que atingem a cultura. Tentativas de se obter plantas resistentes ao vírus ou estirpes fracas premunizantes não apresentaram sucesso até o momento. O objetivo do presente estudo foi o de avaliar a proteção das plantas de maracujá contra o CABMV, utilizando preparações dos cogumelos Lentinula edodes e Agaricus blazei, através da indução de resistência. Em experimentos conduzidos no interior de casa de vegetação, os extratos de basidiocarpos de ambos os cogumelos reduziram significativamente a incidência da virose em plantas de maracujá que tiveram as folhas pré-tratadas com esses extratos e que foram posteriormente inoculadas mecanicamente com o CABMV. No entanto, os extratos não protegeram as plantas em experimentos envolvendo a transmissão do CABMV pelo afídeo-vetor. O efeito inibidor dos extratos foi confirmado inoculando-se Chenopodium quinoa com uma mistura de extratos e suspensão viral. Ainda em C. quinoa, um hospedeiro de lesão local do CABMV, os extratos de alguns isolados dos cogumelos induziram resistência sistêmica contra o vírus. Os resultados mostram que os extratos aquosos de basidiocarpos de L. edodes e A. blazei contêm substâncias inibidoras da infectividade do CABMV, mas isso não é o suficiente para o controle pleno da virose em plantas de maracujá, considerando que elas são infectadas através de um vetor.
ABSTRACT
A number of low molecular weight cationic peptides, named defensins,were purified from neutrophil granuals. Its in vitro cytotoxicity to HL-60 cell line anddirect viral inactivation were examined. The results showed that when incubated with NP-1 and NP-2(100?g/ml) fot 6 hours, more than 60% of HL-60 cells were killed. WhenHerpes simplex virus type I(HSy-I) and influenza virus B strain Beijing 87-1 wereincubated with NP-1(260?g/ml) at 37?C in water bath for 60 min, a marked reduction(98.2% and 90% ) in virus TCID_50 was observed. The results suggested that neutrophilgranulocyte might be able to synthesize peptides which have the cytotoxic and antiviralacitivities.