ATIVIDADE DE ENZIMAS RELACIONADAS À PATOGÊNESE EM PLANTAS DE CAPIM AMARGOSO INOCULADO COM Pratylenchus brachyurus

Abstract

The damage caused by the presence of Digitaria insularis (sourgrass) in the field is not only attributed to competition from water, light and nutrients. It can act as a host for nematodes, being a source of inoculum in the area, enabling the attack of nematodes on cultivated plants, making its control difficult. Little is known about the interaction between bitter grass and nematodes. The objective of this study was to evaluate the defense responses of bitter grass inoculated with Pratylenchus brachyurus. Fifty days after inoculation, the nematodes were extracted following the method of Coolen and D’Herde (1972) and the calculation of the reproduction factor (FR) was performed. In order to detect defense responses, plants were collected at 1, 3, 9 and 17 days after inoculation (DAI). Total protein extraction was performed and the activity of four specific enzymes evaluated. D. Insularis is susceptible to P. brachyurus with a FR of 2.44. The plant showed activities of Phenylalanine ammonia lyase, Lipoxygenase and β-1,3-glucanase and Chitinase in the presence of P. Brachyurus.