CONICET | Buscador de Institutos y Recursos Humanos

Since most plants possess resistance mechanisms which can be induced upon pretreatment with a variety of chemical compounds, the use of â-aminobutyric acid (BABA) as a defense inducer without reported toxic effect on the environment was studied. The aim of this work was to analyze the effectiveness of BABA to induce resistance against Phytophthora infestans and Fusarium solani in potato cultivars differing in their level of resistance to late blight. The behaviour of some components of biochemical mechanisms by which BABA increases resistance against P. infestans, as well as the effect of BABA on the activity of a potential pathogenic factor of F. solani, were studied. Plants with four applications of BABA throughout the crop cycle produced tubers more resistant to P. infestans and F. solani than did non treated plants. In addition, the tuber slices coming from treated plants, inoculated with P. infestans, showed an increase in phenol and phytoalexin content. The aspartyl protease StAP1 accumulation was also higher in tubers obtained from treated plants and inoculated with P. infestans. This result was observed only in the more resistant potato cultivar, Pampeana, and at an early time after infection. In potato-F. solani interaction, infected tubers coming from BABA treated plants showed a minor fungal proteolytic activity than infected non treated ones. On the other hand, for both potato cultivars Pampeana and Bintje, the BABA treatment improved the yield of harvested tubers. The number of tubers per plant as well as the total weight of harvested tubers was major for those obtained from treated plants with two early or four applications of BABA. The results show that BABA treatment increases the resistance of potatoes but the degree of increase depends on the level of resistance present in each cultivar.